RARE DISEASE
Alpha-thalassemia
Alpha-thalassemia
Alpha-thalassemia
Drug discovery
2
drugs
With orphan designations
Overview
Alpha-thalassemia is an inherited hemoglobinopathy caused by reduced or absent alpha-globin synthesis, leading to ineffective erythropoiesis and hemolytic anemia. Severity ranges from asymptomatic carriers (1-2 mutated genes) to life-threatening hemoglobin Bart hydrops fetalis syndrome (4 mutated genes). Intermediate forms like HbH disease (3 mutations) cause chronic anemia, hepatosplenomegaly, and iron overload. Diagnosis combines hematologic indices (microcytosis/hypochromia), hemoglobin electrophoresis, and genetic testing [1][6][16].
Categories: rare genetic diseases, rare hematological diseases, rare transplant-related disorders
Research Papers
336 drug discovery papers about Alpha-thalassemia, with 3 first-in-class and 9 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
336 drug discovery papers about Alpha-thalassemia, with 3 first-in-class and 9 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
small molecules
2026-09-10 | Efficacy and safety of mitapivat in adults with transfusion-dependent α-thalassaemia or β-thalassaemia (ENERGIZE-T): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial.
The absence of disease-modifying therapies for patients with α-thalassaemia and oral disease-modifying therapies for patients with β-thalassaemia has been a substantial unmet need in these patients. We assessed the efficacy and safety of mitapivat, an oral allosteric activator of pyruvate kinase, in adults with transfusion-dependent thalassaemia. ENERGIZE-T is a global, double-blind, randomised, placebo-controlled, phase 3 trial, conducted across 19 countries in North America, Europe, Asia-Pacific, South America, and the Middle East. Patients aged 18 years or older with transfusion-dependent α-thalassaemia or β-thalassaemia were randomly allocated (2:1) with a central interactive response technology system, stratified by geographical region and thalassaemia genotype, to receive 100 mg mitapivat or placebo orally twice a day for 48 weeks. The primary endpoint was transfusion reduction response (TRR), defined as a reduction of at least 50% in transfused red blood cell units with a reduction of at least two units in any consecutive 12-week period until week 48 compared with baseline. Efficacy was analysed in the full analysis set, comprising all randomly allocated patients. Type, severity, and relationship of adverse events and serious adverse events were assessed in patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov (NCT04770779) and is active but not recruiting. Between Nov 30, 2021 and May 2, 2023, 305 patients were screened, of whom 258 were randomly allocated (median age 33·5 years [IQR 27·0-44·0]; 136 [53%] female and 122 [47%] male participants). Of 258 patients allocated, 238 (92%) completed the double-blind treatment period. All patients were required to have a safety follow-up approximately 4 weeks after the final dose of study drug, regardless of completion of the double-blind period or continuation into the open-label extension period. In the full analysis set, TRRs occurred in 52 (30%) of 171 patients in the mitapivat group and 11 (13%) of 87 in the placebo group (adjusted difference 18 percentage points [95% CI 8-27]; two-sided p=0·0003). The safety analysis set comprised 172 patients in the mitapivat group (including one patient allocated to the placebo group who received one dose of mitapivat in error) and 85 in the placebo group. Adverse events were reported in 155 (90%) patients treated with mitapivat and 71 (84%) treated with placebo; the most common events with mitapivat were headache, upper respiratory tract infection, initial insomnia, diarrhoea, and fatigue. Serious adverse events were reported in 19 (11%) patients treated with mitapivat and 13 (15%) treated with placebo. Ten (6%) patients who received mitapivat and one (1%) who received placebo discontinued study treatment due to adverse events. No deaths were reported. Mitapivat significantly reduced the transfusion burden and was generally well tolerated, showing a favourable benefit-risk profile. These findings support mitapivat as the first oral disease-modifying therapy for adults with transfusion-dependent α-thalassaemia or β-thalassaemia, providing a new treatment option to reduce transfusion burden in this patient population. Agios Pharmaceuticals, Inc.
2026-09-06 | Contemporary Management of Thalassemia: A Perspective on Current Standards and the Emergence of FDA-Approved Oral Therapy.
Thalassemia is an inherited hemoglobin disorder characterized by ineffective erythropoiesis, chronic anemia, and progressive multisystem complications that require lifelong management. Current treatment relies on regular red blood cell transfusions, iron chelation therapy, and supportive multidisciplinary care, while hematopoietic stem cell transplantation offers a curative option for selected patients. Although gene-based therapies and novel pharmacological agents have expanded therapeutic options, their widespread implementation is limited by cost, accessibility, and long-term safety considerations. This article summarizes contemporary management strategies for α and β thalassemia, with particular emphasis on the recent emergence of the FDA-approved oral pyruvate kinase activator, mitapivat. A structured literature review was conducted using PubMed and PubMed Central. Searches included the terms "thalassemia," "mitapivat," "pyruvate kinase activator," "gene therapy," "hydroxyurea," and "luspatercept." Priority was given to recent systematic reviews, clinical practice guidelines, pivotal phase II and III clinical trials, regulatory publications, and peer-reviewed studies relevant to current therapeutic practice. Conventional therapies remain essential but are associated with significant limitations, including transfusion dependence, iron overload, and treatment-related complications. Curative strategies such as hematopoietic stem cell transplantation and gene therapy are effective in selected patients but remain constrained by donor availability, toxicity, cost, and limited accessibility. Emerging pharmacological therapies target ineffective erythropoiesis and iron dysregulation. Phase III ENERGIZE and ENERGIZE-T trials demonstrated that mitapivat significantly improved hemoglobin response in non-transfusion-dependent disease and reduced transfusion burden in transfusion-dependent disease, with an acceptable safety profile, leading to FDA approval as the first oral therapy for adults with α or β thalassemia. Mitapivat represents a significant advance in thalassemia management by targeting erythrocyte metabolism and providing the first FDA-approved oral treatment for anemia in adults with α or β thalassemia. Multi-year follow-up and real-world studies are needed to further define its durability, safety, and role within evolving treatment strategies.
2026-07-19 | Evaluating mitapivat for the treatment of alpha or beta thalassemia.
Thalassemia is a group of diverse genetic disorders with worldwide distribution that affects hemoglobin synthesis. Until recently, the therapeutic approach to thalassemia was symptomatic, relying on red blood cell transfusions, treatment of comorbidities and of disease-related complications. However, novel therapeutic agents have recently been developed and are gradually being integrated into routine clinical practice. One of the most promising agents is mitapivat (AG348), an oral pyruvate kinase activator that enhances the erythrocytic adenosine triphosphate (ATP) production. After series of preclinical and clinical studies, mitapivat has been suggested to be a safe and effective disease modifier for thalassemia. Large double blind randomized clinical trials have indicated that mitapivat may increase baseline hemoglobin levels, reduce transfusion burden, control ineffective erythropoiesis and hemolysis and improve quality of life. Mitapivat presents as a potential game-changer in the management of patients with both α- and β-thalassemia, regardless of transfusion dependency. However, further post-marketing evidence is required in order to evaluate mitapivat profile under real‑world conditions and routine clinical practice.
2026-05-20 | Recover aged/damaged erythrocytes and prevent them from aging by remodeling or enhancing their vital proteins: Hb and B3p.
This study investigates whether remodeling/enhancing the two vital proteins-hemoglobin and B3p-in erythrocytes with artificial interference can rejuvenate aged and damaged erythrocytes. Using Raman spectroscopy and SDS measurement, the study demonstrated that certain flavonoids, such as Hydroxysafflor Yellow A, could remodel/enhance the two proteins and restore their conformation, content, and distribution in aged erythrocytes within a few hours. As a result, it led to a restoration of nearly all cellular and molecular properties of old erythrocytes aged 90-120 days and cells stored under blood bank conditions for 21 days. The flavonoids could even recover erythrocytes of α/β-thalassemia. Moreover, pre-incubating the cells with flavonoids can prevent aging and damage caused by mechanical injury, hypoxic stress, acid-base imbalances, and storage lesions, with protective effects lasting for at least 21 days. In summary, this research reveals for the first time that remodeling hemoglobin and B3p with flavonoids is a promising intervention to enhance the longevity and resilience of erythrocytes against damage. It holds significant implications for biomedicine, including blood storage, the production of blood products, disease treatment, and high-altitude medicine related to hypoxic physiology.
2026-03-04 | Transforming the treatment of Alpha-Thalassemia: a single-center retrospective study on hematopoietic stem cell transplantation in transfusion-dependent pediatric patients.
Hematopoietic stem cell transplantation (HSCT) is the only definitive cure for transfusion-dependent α-thalassemia, though comprehensive studies on its effectiveness are limited. In this retrospective study, we analyzed the clinical characteristics of 21 pediatric patients with transfusion-dependent α-thalassemia who underwent HSCT, all of whom received a standardized conditioning regimen consisting of busulfan, cyclophosphamide, fludarabine, and anti-thymocyte globulin. After a median follow-up of 25 months (range: 7–92 months), the two-year overall survival (OS) and event-free survival (EFS) rates were both 90.2% (95% CI: 66.2–97.4%), and the two-year graft-versus-host disease-free, relapse-free survival (GRFS) rate was 82.3% (95% CI: 52.6–94.3%). The transplant-related mortality rate at two years was 5.0% (95% CI: 0.7–30.0%), with no cases of graft failure observed. Among the 19 surviving patients, hemoglobin levels significantly increased compared to pre-transplant levels (p < 0.05), and all became transfusion-independent. Hematopoietic stem cell transplantation is a curative treatment for α-thalassemia. For patients with transfusion-dependent α-thalassemia, HSCT should be performed as early as possible at an experienced transplant center when a suitable donor is available.
gene therapies
2026-09-09 | Molecular profiling of thalassemia in Southeastern Romania.
Thalassemias represent a major group of hereditary hemoglobin disorders with significant global health impact, yet molecular data from Eastern European populations, particularly from Romania, remain limited. This study was aimed at comprehensively characterizing the molecular spectrum of α-, β-, and δβ-thalassemia in the southeastern part of Romania using an expanded panel of molecular diagnostic techniques. A total of 324 patients with suspected thalassemia were evaluated between 2017 and 2025. Molecular testing included multiplex PCR with reverse dot-blot hybridization, Sanger sequencing, MLPA for α-globin deletions/duplications, and multiplex gap-PCR for δβ fusion gene detection. Pathogenic variants were identified in 137 individuals (42.28%). Of these, 21.89% had α-thalassemia, 66.42% had β-thalassemia, 10.21% had combined α and β defects, and 1.45% had Lepore Hb variants. The -α3·7 deletion and anti-α3·7 triplication were the predominant α-globin abnormalities, while IVS I-6 [T > C], IVS I-110 [G > A], codon 39 [C > T], and IVS II-745 [C > G] were the most frequent β-globin mutations. Two cases of the Hb Lepore Boston-Washington subtype were confirmed through gap-PCR and sequencing. The mutation distribution observed in southeastern Romania mirrors Mediterranean thalassemia patterns rather than those of Central or Northern Europe.
2026-09-08 | A transcription factor-focused CRISPR screen identifies SKI as a BCL11A-independent repressor of ζ-globin.
The regulation of α-like globin genes, particularly the embryonic ζ-globin gene (HBZ), remains incompletely understood. To identify transcriptional regulators of HBZ, we establish a GFP reporter system based on the HBZ-P2A-GFP allele in erythroid cell lines and conduct a CRISPR/Cas9 screen targeting 1639 transcription factors. This screen identifies SKI as a potent HBZ repressor. Functional validation shows that SKI loss increases HBZ expression without impairing erythropoiesis, whereas SKI overexpression suppresses HBZ. Tet-on-inducible SKI overexpression and auxin-inducible SKI degradation indicate that SKI rapidly represses HBZ transcription. Transcriptome profiling further reveals that SKI deletion activates HBZ while minimally affecting other erythroid genes. Mechanistically, genome-wide occupancy analyses show that SKI binds the distal enhancers HS-10 and HS-40, with partial co-occupancy by BCL11A. Despite this overlap, dual knockout of SKI and BCL11A synergistically increases HBZ expression, as does base editing of the SKI-binding site within HS-10. We also identify a naturally occurring variant (chr16:193207G>A) within this enhancer in α-thalassemia patients with elevated ζ-globin levels. Together, these findings establish SKI as a direct, BCL11A-independent transcriptional repressor of ζ-globin. This work advances our understanding of globin gene regulation and suggests targeted ζ-globin reactivation as a potential therapeutic strategy for α-thalassemia.
2026-09-03 | Hemoglobinopathies and Cellular Therapy: What Pediatricians Need to Know About Indications and Counseling.
Hemoglobinopathies are inherited disorders of hemoglobin structure or production. Sickle cell disease (SCD) results from a beta-globin mutation causing hemoglobin polymerization, red blood cell sickling, vaso-occlusion, and hemolytic anemia. Thalassemia results from reduced or absent alpha- or beta-globin synthesis, ranging from asymptomatic carrier states to transfusion-dependent anemia. This article summarizes the pathophysiology, diagnosis, management, and curative options for SCD and transfusion-dependent thalassemia, emphasizing allogeneic hematopoietic stem cell transplantation and approved gene therapies. We discuss indications, counseling, barriers to access, toxicity, donor availability, fertility counseling, and comparative features of cellular therapies. Advances in transplantation, gene addition, and gene editing may expand access to curative-intent therapy and improve outcomes for selected patients.
2026-07-20 | Roth Spots as the Initial Manifestation of Sickle Cell Trait with Suspected Co-inherited Alpha-Thalassemia: A Case Report
Roth spots are white-centered retinal hemorrhages representing a nonspecific morphologic endpoint of retinal capillary rupture. They have long been associated with infective endocarditis, but they are now recognized as a nonspecific sign of systemic microvascular injury. While sickle cell disease is a known cause of retinal vascular complications, their occurrence in sickle cell trait, particularly in association with co-inherited alpha-thalassemia, remains exceptionally rare. This is the case of a previously healthy 40-year-old man presented with sudden visual loss in the left eye, reduced to light perception at initial examination. Fundoscopy revealed multiple Roth spots across all quadrants, extensive macular hemorrhage, and Frisen grade 3 optic disc edema. Fluorescein angiography identified an inferior temporal branch retinal vein occlusion. An exhaustive workup excluded infectious, inflammatory, and malignant etiologies. Peripheral blood smear showed sickled erythrocytes, and hemoglobin electrophoresis demonstrated an HbS fraction of 33.6% with normal HbA2 (3.2%), a pattern consistent with sickle cell trait and suggestive of alpha-thalassemia co-inheritance.This case highlights that Roth spots may be the first ophthalmic sign of an underlying hemoglobinopathy, even in a patient with sickle cell trait. Careful systemic evaluation and multidisciplinary management are essential when white-centered retinal hemorrhages occur without an obvious cause.
2026-07-19 | [Alpha-thalassemia with Hb G-Philadelphia incidentally discovered during HbA1c testing].
Hemoglobin G-Philadelphia is an alpha-globin chain variant resulting from the substitution of asparagine by lysine at position 68 [α68(E17) Asn→Lys]. This hemoglobin (Hb) variant is generally clinically silent; however, its identification may be challenging, particularly when present in the homozygous state and co-inherited with the -α3.7 deletion. We report the case of a 28-year-old woman from southeastern Morocco presenting with refractory hypochromic microcytic anemia (Hb 10,6 g/dL, MCV 60.5 fL, MCH 20.3 pg). Owing to a family history of type 2 diabetes mellitus, HbA1c testing was performed and revealed a hemoglobin variant eluting in the D window (87.44 %) on the Bio-Rad D-100 HPLC system. Further laboratory investigations (HPLC Variant II, capillary electrophoresis, and acid pH gel electrophoresis) confirmed the presence of homozygous Hb G-Philadelphia. Molecular analysis confirmed the variant and demonstrated its association with mild α-thalassemia. Family study revealed that the daughter is a heterozygous carrier of Hb G-Philadelphia and a cis -α3.7 α-thalassemia trait.
cell therapies
2026-06-23 | Chronic Red Cell Exchange for the Management of Alpha Thalassemia Major Complicated by Iron Overload.
Alpha thalassemia major is a severe hemoglobinopathy characterized by absent or markedly reduced alpha-globin production, necessitating lifelong blood transfusions. Chronic simple transfusions can lead to significant iron overload, often requiring iron chelation therapy. However, some patients are unable to tolerate chelation or chelation is insufficient, highlighting the need for alternative strategies for managing iron overload. This study is one of the first to evaluate the feasibility, safety, and efficacy of red blood cell exchange (RBCX) as a therapeutic option for managing iron overload while improving hemoglobin function in an alpha thalassemia major patient with iron overload despite chelation therapy. RBCX therapy was performed approximately every 3 weeks over 1 year, with frequent adjustment of exchange parameters to meet pre-transfusion target levels of functional hemoglobin. Serum ferritin levels, hemoglobin electrophoresis, and functional hemoglobin levels were tracked with each exchange transfusion. For each RBCX treatment, variant hemoglobins decreased by 3.8-fold (from 19.9% to 8.9%) and functional hemoglobin levels increased approximately 3.0 g/dL. RBCX was well tolerated and associated with a marked reduction in systemic iron burden, with serum ferritin declining 7.4-fold (86.4%) over 1 year of therapy, followed by a rise after cessation of RBCX. Cardiac iron remained within normal limits throughout the study period. In contrast, liver iron demonstrated a transient increase shortly after initiation of RBCX, but ultimately declined to levels below baseline after 1 year, even during a period in the absence of iron chelation. These findings suggest that RBCX exerts a meaningful effect on iron homeostasis and raises the possibility of a synergistic benefit when combined with iron chelation. This case highlights that RBCX is a viable therapeutic strategy to treat iron overload in patients with alpha thalassemia major.
2026-06-08 | Derivation and Pluripotency Validation of Six iPSC Lines From Amniotic Fluid Carrying Intermediate α-Thalassemia Genotypes (--3.7/αSEA and --4.2/αSEA).
Thalassemia intermedia (TI), or hemoglobin H (Hb H) disease, presents significant clinical heterogeneity, and its pathogenesis remains unclear. This study aimed to establish induced pluripotent stem cells (iPSCs) from amniotic fluid (AF) cells of fetuses diagnosed with intermediate α-thalassemia genotypes (-α3.7/--SEA and -α4.2/--SEA) to provide a robust in vitro model for investigating disease mechanisms and exploring therapeutic strategies. AF cells from six TI fetuses were reprogrammed using nonintegrating episomal vectors via electro-transfection. The resulting iPSC lines underwent comprehensive characterization, including alkaline phosphatase (AP) staining, immunofluorescence (IF) for pluripotency markers (e.g., OCT-4, SOX-2, and TRA-1-60), quantitative reverse transcription real-time PCR (RT-qPCR) for the expression of pluripotency genes, G-band karyotyping, and genetic analysis for thalassemia. Differentiation potential was assessed in vivo via teratoma formation in immunodeficient mice and in vitro through directed hematopoietic differentiation. Six stable iPSC lines were successfully established. All lines retained the progenitor's intermediate α-thalassemia genotype and exhibited normal karyotypes. They displayed typical embryonic stem cell (ESC)-like morphology, were positive for AP, and expressed key pluripotency markers. In vivo, all lines robustly formed teratomas containing tissues derived from all three germ layers (endoderm, mesoderm, and ectoderm). Furthermore, in vitro hematopoietic differentiation protocols successfully induced the iPSCs to generate CD34+/CD43+ hematopoietic progenitors, which were functionally validated by their ability to form hematopoietic colonies in colony-forming unit (CFU) assays. We have successfully derived and comprehensively characterized six patient-specific iPSC lines from intermediate α-thalassemia fetuses. These cell lines demonstrate robust pluripotency and maintain the capacity for hematopoietic differentiation. They represent a valuable resource for investigating TI pathophysiology, screening novel drugs, and developing future cell-based therapeutic strategies.
2026-05-21 | Establishment of an immortalized erythroid model for Hb Bart's hydrops fetalis with homozygous α0-thalassemia Southeast Asian deletion.
Hemoglobin Bart's hydrops fetalis syndrome (BHFS) is the most severe form of α-thalassemia and is highly prevalent in Southeast Asia. It is most commonly caused by homozygosity for the α0-thalassemia Southeast Asian deletion (--SEA/--SEA), which eliminates α-globin production and results in profound fetal anemia. Current management is limited to intrauterine transfusions with only transient benefit, and no pharmacological or gene-based therapies are available. Progress toward therapy has been hampered by the lack of disease-relevant in vitro models. Here, we established Chery-Bart's, an immortalized erythroid progenitor cell line derived from umbilical cord blood CD34+ hematopoietic stem and progenitor cells of a fetus with --SEA/--SEA and βIVS I-1 (G> T)/β using a tetracycline-inducible HPV16 E6/E7 system. Chery-Bart's cells exhibit sustained proliferation beyond the Hayflick limit, stable recovery after cryopreservation, and enrichment in the basophilic erythroblast stage. In vitro erythropoiesis assays showed that the cell line retains key features of the parental cells, including the capacity for erythroid maturation, expression of fetal globin transcripts, and robust production of Hb Bart's (γ4), the hallmark pathological hemoglobin of BHFS. Although Chery-Bart's carries a β-thalassemia mutation, this is unlikely to modify disease severity, as γ-globin predominates in this model. Collectively, Chery-Bart's represents the first durable and disease-specific cellular model of BHFS with --SEA/--SEA genotype. This platform provides a scalable resource for mechanistic studies and preclinical evaluation of therapeutic approaches, including drug discovery, gene therapy, and α-like globin chain induction. Beyond BHFS, Chery-Bart's may also serve as a model for investigating severe α-thalassemia syndromes associated with the --SEA allele, such as deletional and non-deletional HbH disease.
2026-04-15 | In Utero Hematopoietic Cell Transplantation in Fetuses with Alpha Thalassemia Major: A Phase 1 Clinical Trial.
In utero hematopoietic cell transplantation (IUHCT) has the potential to treat patients who have hemoglobinopathies by harnessing the unique period of fetal tolerance to maternal cells, thereby enabling semi-allogeneic transplantation without conditioning or immunosuppression. We conducted a phase 1 clinical trial of IUHCT in fetuses with Alpha Thalassemia Major (ATM), a diagnosis that requires serial in utero transfusions (IUT) for survival. We also analyzed outcomes in fetuses with ATM treated with IUT alone in the same time period. Six fetuses underwent transplantation with maternal CD34+ cells (1.33 x 108 ± 2.67x107 cells/kg +1% T cells) at 23.1 ± 1.1 weeks' gestation. All received serial IUT and were delivered at or near term. Perinatal outcomes were broadly similar to those undergoing IUT alone. Two mothers received prophylactic antibiotics because of late positive cultures of harvested cells (without fetal adverse events). Low-level maternal microchimerism was detected in all recipients; T-cell hyporeactivity to maternal antigens was detected in 2/6 offspring but persisted in only one child. Cord blood from ATM-affected pregnancies demonstrated marked expansion of host hematopoietic stem and progenitor cells compared with healthy controls, suggesting a competitive disadvantage for donor cells in this disease context. Neurodevelopmental assessments were largely reassuring, with high quality of life scores. Overall, this protocol was safe and feasible but demonstrates the limitations of IUHCT for ATM without concurrent bone marrow conditioning. The favorable perinatal and neurologic outcomes in most offspring underscore the benefits of prenatal transfusions and the unmet medical need for developing definitive therapies for ATM. NCT02986698.
2025-11-11 | Tackling the challenge of in utero blood exchange transfusion for fetal anemia at 15 weeks' gestation.
Severe fetal anemia due to parvovirus infection and alpha-thalassemia major can occur during the first trimester of pregnancy. In utero transfusion before 16 weeks of gestation is beneficial but challenging because the umbilical vein is too narrow to be precisely punctured. In addition, the fetal circulating volume is small, and the heart of an affected fetus is compromised. To avoid vascular overload, exchange transfusion may be considered. The technical difficulties make in utero simple transfusions seldom performed before 16 weeks of gestation, and exchange transfusion before 16 weeks of gestation has not been reported. Hence, we reported our technique of successful in utero exchange transfusion in a fetus with alpha-thalassemia major at 15 weeks of gestation. The keys of success were as follows: Fetal blood was not withdrawn for diagnostic investigation before the first transfusion for the following pragmatic reasons.
oligonucleotides
2024-04-18 | miR-214 aggravates oxidative stress in thalassemic erythroid cells by targeting ATF4.
Oxidative damage to erythroid cells plays a key role in the pathogenesis of thalassemia. The oxidative stress in thalassemia is potentiated by heme, nonheme iron, and free iron produced by the Fenton reaction, due to degradation of the unstable hemoglobin and iron overload. In addition, the levels of antioxidant enzymes and molecules are significantly decreased in erythrocytes in α- and β-thalassemia. The control of oxidative stress in red blood cells (RBCs) is known to be mediated by microRNAs (miRNAs). In erythroid cells, microR-214 (miR-214) has been reported to respond to external oxidative stress. However, the molecular mechanisms underlying this phenomenon remain unclear, especially during thalassemic erythropoiesis. In the present study, to further understand how miR-214 aggravates oxidative stress in thalassemia erythroid cells, we investigated the molecular mechanism of miR-214 and its regulation of the oxidative status in thalassemia erythrocytes. We have reported a biphasic expression of miR-214 in β- and α-thalassemia. In the present study the effect of miR-214 expression was investigated by using miR -inhibitor and -mimic transfection in erythroid cell lines induced by hemin. Our study showed a biphasic expression of miR-214 in β- and α-thalassemia. Subsequently, we examined the effect of miR-214 on erythroid differentiation in thalassemia. Our study reveals the loss-of-function of miR-214 during translational activation of activating transcription factor 4 mRNA, leading to decreased reactive oxygen species levels and increased glutathione levels in thalassemia erythroid cell. Our results suggest that the expression of activating transcription factor 4 regulated by miR-214 is important for oxidative stress modulation in thalassemic erythroid cells. Our findings can help to better understand the molecular mechanism of miRNA and transcription factors in regulation of oxidative status in erythroid cells, particularly in thalassemia, and could be useful for managing and relieving severe anemia symptoms in patients in the future.
2021-10-04 | Reduced hepcidin expression enhances iron overload in patients with HbE/β‑thalassemia: Α comparative cross‑sectional study
Iron homeostasis is regulated by hepcidin (HEPC) that controls the dietary iron absorption and iron recycling. HEPC deficiency contributes to iron overload in β-thalassemia patients. The present study aimed to investigate the correlation between HEPC concentration and serum iron status among hemoglobin E (HbE)/β-thalassemia patients and their parents (HbE trait and β-thalassemia trait) compared with healthy controls. This study is a comparative cross-sectional study in which iron profile and HEPC level were examined in 65 HbE/β-thalassemia patients (pretransfusion) and 65 parents at the Hospital Sultanah Nur Zahirah and in 130 students as healthy controls from Univesiti Sultan Zainal Abidin, Terengganu, Malaysia. Furthermore, six samples from each group (HbE/β-thalassemia patients, parents and healthy controls) were randomly selected for gene expression analysis of HEPC and ferroportin1 (FPN1) using reverse transcription quantitative PCR. The results demonstrated that serum HEPC level were significantly decreased in HbE/β-thalassemia patients and their parents (P<0.001) compared with healthy controls. In addition, the gene expression analysis showed a dramatically downregulated HEPC in HbE/β-thalassemia patients and their parents (P=0.001) compared with healthy controls. However, there was a marked upregulation of FPN1 in HbE/β-thalassemia patients and their parents (P=0.001) compared with healthy controls. Iron profiling results revealed a significantly increased serum ferritin in HbE/β-thalassemia patients and their parents compared with healthy controls (P<0.001). In summary, the present study demonstrated that HEPC expression level and serum level were significantly decreased in HbE/β-thalassemia patients and their parents, which was combined with a marked increased FPN1 expression level and serum ferritin level compared with healthy volunteers. These findings supported the hypothesis that downregulated HEPC could lose its function as a negative regulator of FPN1, resulting in iron overload in HbE/β-thalassemia patients. Subsequently, assessing HEPC and FPN1 gene expression may be a useful tool to determine the risk of iron toxicity in patients with HbE/β-thalassemia and their parents, and could therefore be considered as a therapeutic target in the management of iron burden in these patients.
2019-08-27 | miR-144 regulates oxidative stress tolerance of thalassemic erythroid cell via targeting NRF2.
Thalassemia has a high prevalence in Thailand. Oxidative damage to erythroid cells is known to be one of the major etiologies in thalassemia pathophysiology. Oxidative stress status of thalassemia is potentiated by the heme, nonheme iron, and free iron resulting from imbalanced globin synthesis. In addition, levels of antioxidant proteins are reduced in α-thalassemia and β-thalassemia erythrocytes. However, the primary molecular mechanism for this phenotype remains unknown. Our study showed a high expression of miR-144 in β- and α-thalassemia. An increased miR-144 expression leads to decreased expression of nuclear factor erythroid 2-related factor 2 (NRF2) target, especially in α-thalassemia. In α-thalassemia, miR-144 and NRF2 target are associated with glutathione level and anemia severity. To study the effect of miR-144 expression, the gain-loss of miR-144 expression was performed by miR inhibitor and mimic transfection in the erythroblastic cell line. This study reveals that miR-144 expression was upregulated, whereas NRF2 expression and glutathione levels were decreased in comparison with the untreated condition after miR mimic transfection, while the reduction of miR-144 expression contributed to the increased NRF2 expression and glutathione level compared with the untreated condition after miR inhibitor transfection. Moreover, miR-144 overexpression leads to significantly increased sensitivity to oxidative stress at indicated concentrations of hydrogen peroxide (H2O2) and rescued by miR-144 inhibitor. Taken together, our findings suggest that dysregulation of miR-144 may play a role in the reduced ability of erythrocyte to deal with oxidative stress and increased RBC hemolysis susceptibility especially in thalassemia.
2016-03-18 | Generation and Characterization of a Transgenic Mouse Carrying a Functional Human β -Globin Gene with the IVSI-6 Thalassemia Mutation.
Mouse models that carry mutations causing thalassemia represent a suitable tool to test in vivo new mutation-specific therapeutic approaches. Transgenic mice carrying the β-globin IVSI-6 mutation (the most frequent in Middle-Eastern regions and recurrent in Italy and Greece) are, at present, not available. We report the production and characterization of a transgenic mouse line (TG-β-IVSI-6) carrying the IVSI-6 thalassemia point mutation within the human β-globin gene. In the TG-β-IVSI-6 mouse (a) the transgenic integration region is located in mouse chromosome 7; (b) the expression of the transgene is tissue specific; (c) as expected, normally spliced human β-globin mRNA is produced, giving rise to β-globin production and formation of a human-mouse tetrameric chimeric hemoglobin (mu) α-globin2/(hu) β-globin2 and, more importantly, (d) the aberrant β-globin-IVSI-6 RNAs are present in blood cells. The TG-β-IVSI-6 mouse reproduces the molecular features of IVSI-6 β-thalassemia and might be used as an in vivo model to characterize the effects of antisense oligodeoxynucleotides targeting the cryptic sites responsible for the generation of aberrantly spliced β-globin RNA sequences, caused by the IVSI-6 mutation. These experiments are expected to be crucial for the development of a personalized therapy for β-thalassemia.
2014-09-26 | Structural determinants of human ζ-globin mRNA stability.
The normal accumulation of adult α and β globins in definitive erythrocytes is critically dependent upon processes that ensure that the cognate mRNAs are maintained at high levels in transcriptionally silent, but translationally active progenitor cells. The impact of these post-transcriptional regulatory events on the expression of embryonic ζ globin is not known, as its encoding mRNA is not normally transcribed during adult erythropoiesis. Recently, though, ζ globin has been recognized as a potential therapeutic for α thalassemia and sickle-cell disease, raising practical questions about constitutive post-transcriptional processes that may enhance, or possibly prohibit, the expression of exogenous or derepresssed endogenous ζ-globin genes in definitive erythroid progenitors. The present study assesses mRNA half-life in intact cells using a pulse-chase approach; identifies cis-acting determinants of ζ-globin mRNA stability using a saturation mutagenesis strategy; establishes critical 3'UTR secondary structures using an in vitro enzymatic mapping method; and identifies trans-acting effector factors using an affinity chromatographical procedure. We specify a tetranucleotide 3'UTR motif that is required for the high-level accumulation of ζ-globin transcripts in cultured cells, and formally demonstrate that it prolongs their cytoplasmic half-lives. Surprisingly, the ζ-globin mRNA stability motif does not function autonomously, predicting an activity that is subject to structural constraints that we subsequently specify. Additional studies demonstrate that the ζ-globin mRNA stability motif is targeted by AUF1, a ubiquitous RNA-binding protein that enhances the half-life of adult β-globin mRNA, suggesting commonalities in post-transcriptional processes that regulate globin transcripts at all stages of mammalian development. These data demonstrate a mechanism for ζ-globin mRNA stability that exists in definitive erythropoiesis and is available for therapeutic manipulation in α thalassemia and sickle-cell disease.
other
2026-04-20 | Hemoglobin alpha-like subunit mu is expressed during ontogeny and is elevated in alpha thalassemia.
The alpha globin gene cluster on chromosome 16 encodes alpha-like globins whose expression changes during development. HBM located in this cluster was considered a pseudogene until its transcript was discovered in 2005, but without a detectable protein product. Here, we provide the first detailed description of HBM-encoded globin at the protein level (hemoglobin mu chain [HBM]) across different age groups using liquid chromatography coupled with tandem mass spectrometry. Using targeted analysis, we demonstrate that HBM protein is readily detectable in circulation with its levels falling with increasing gestational age. We also report HBM levels in relation to other hemoglobin chains in neonatal, pediatric, and adult blood. Furthermore, analysis of alpha thalassemia patient samples revealed that HBM levels were elevated 3- to 17-fold, indicating a compensatory role, which could be explored for its therapeutic potential. This study enhances our understanding of erythropoiesis and globin chain production through ontogeny.
2025-11-03 | Transfusion independence in thalassemia patients after failure of gene therapy or with hemoglobin h constant spring and hb e using luspatercept: A case series
Abstract Background: Individuals with thalassemia who depend on blood transfusions to maintain adequate hemoglobin levels are at high risk of sequelae resulting from frequent blood products. As such, there is increased interest in decreasing transfusion frequency for such patients and limiting side effects. Luspatercept is a recombinant fusion protein that enhances erythropoiesis by binding to select TGF-b ligands and can increase hemoglobin for patients with thalassemia. Luspatercept use was associated with significantly greater reductions in transfusion burden than for the placebo group for transfusion-dependent b-thalassemia (TDT) patients in the BELIEVE trial. Luspatercept was also associated with a significant increase in hemoglobin level among non-transfusion-dependent beta thalassemia (NTDT) in the BEYOND trial. However, currently, there is very limited evidence for the utility luspatercept in thalassemia patients after a failed gene therapy or among those with alpha thalassemia. Here we describe two cases with significant clinical response to luspatercept achieving transfusion independence in distinct thalassemia populations that have not yet been reported in the literature. Case 1: This patient underwent LentiGlobin gene therapy for b-thalassemia (β0/β0) at the age of 34 years in 2015. Prior to gene therapy, she required regular packed red blood cell (pRBCs) transfusions every 4 weeks. After admission for gene therapy per protocol HGB-204, her transfusion needs initially decreased to every 6 to 9 months. However, she was not able to fully wean off transfusions which slowly increased in frequency to every 3 months. She began treatment with luspatercept at the age of 42, and has maintained hemoglobin levels above 10 g/dL without need for a blood transfusion for almost two years since then. Case 2: This patient was diagnosed with hemoglobin H Constant Spring and homozygous HbE by hemoglobin electrophoresis and hemoglobinopathy genetic testing (c.427T>C , Hb Constant Spring; c79G>A, HbE). Up to her third decade of life, she was requiring regular pRBCs transfusions every 3-4 weeks with a pre-transfusion hemoglobin goal of 9-10 g/dL. She also had evidence of significant iron overload due to her transfusion frequency and suboptimal adherence to iron chelation (maximum liver iron content (LIC) of 16.4 mg/g dry weight) with a normal cardiac T2* (42.7 +/- 2.6 msec). She started treatment with luspatercept at the age of 30 years and her transfusion needs soon decreased and she achieved transfusion independence for more than 2 years with occasional transfusion only every 18 months. Concurrently, she was weaned off iron chelation around two years following initiation of luspatercept with an LIC of <3.5 and a ferritin of less than 500 ng/mL. She continues to be on luspatercept with no tolerability issues. These two patient cases demonstrate that luspatercept can also reduce transfusion needs or achieve independence following gene therapy or in alpha thalassemia. Other case reports have previously explored the potential clinical benefits of luspatercept in other settings. Our cases add to the existing experiences by elucidating possible novel applications of luspatercept to additional thalassemia populations. Our findings suggest that luspatercept can successfully increase and stabilize baseline hemoglobin for these patients, and thus could represent a safe and efficacious long-term disease-modifying therapy option for transfusion-dependent alpha thalassemias and patients who failed or had a suboptimal or incomplete response to gene therapy. Further research, including prospective studies and/or randomized trials, will be necessary to evaluate these indications for luspatercept on a larger study population in the future.
2025-01-25 | Hemoglobin Variants as Targets for Stabilizing Drugs.
Hemoglobin is an oxygen-transport protein in red blood cells that interacts with multiple ligands, e.g., oxygen, carbon dioxide, carbon monoxide, and nitric oxide. Genetic variations in hemoglobin chains, such as those underlying sickle cell disease and thalassemias, present substantial clinical challenges. Here, we review the progress in research, including the use of allosteric modulators, pharmacological chaperones, and antioxidant treatments, which has begun to improve hemoglobin stability and oxygen affinity. According to UniProt (as of 7 August 2024), 819 variants of the α-hemoglobin subunit and 771 variants of the β-hemoglobin subunit have been documented, with over 116 classified as unstable. These data demonstrate the urgent need to develop variant-specific stabilizing options. Beyond small-molecule drugs/binders, novel protein-based strategies-such as engineered hemoglobin-binding proteins (including falcilysin, llama-derived nanobodies, and α-hemoglobin-stabilizing proteins)-offer promising new options. As our understanding of hemoglobin's structural and functional diversity grows, so does the potential for genotype-driven approaches. Continued research into hemoglobin stabilization and ligand-binding modification may yield more precise, effective treatments and pave the way toward effective strategies for hemoglobinopathies.
2024-12-05 | Sickle Trait and Alpha Thalassemia Increase NOS-Dependent Vasodilation of Human Arteries Through Disruption of Endothelial Hemoglobin-eNOS Interactions.
Severe malaria is associated with impaired nitric oxide (NO) synthase (NOS)-dependent vasodilation, and reversal of this deficit improves survival in murine models. Malaria might have selected for genetic polymorphisms that increase endothelial NO signaling and now contribute to heterogeneity in vascular function among humans. One protein potentially selected for is alpha globin, which, in mouse models, interacts with endothelial NOS (eNOS) to negatively regulate NO signaling. We sought to evaluate the impact of alpha globin gene deletions on NO signaling and unexpectedly found human arteries use not only alpha but also beta globin to regulate eNOS. The eNOS-hemoglobin complex was characterized by multiphoton imaging, gene expression analysis, and coimmunoprecipitation studies of human resistance arteries. Novel contacts between eNOS and hemoglobin were mapped using molecular modeling and simulation. Pharmacological or genetic disruption of the eNOS-hemoglobin complex was evaluated using pressure myography. The association between alpha globin gene deletion and blood pressure was assessed in a population study. Alpha and beta globin transcripts were detected in the endothelial layer of the artery wall. Imaging colocalized alpha and beta globin proteins with eNOS at myoendothelial junctions. Immunoprecipitation demonstrated that alpha globin and beta globin form a complex with eNOS and cytochrome b5 reductase. Modeling predicted negatively charged glutamic acids at positions 6 and 7 of beta globin to interact with positively charged arginines at positions 97 and 98 of eNOS. Arteries from donors with a glutamic acid-to-valine substitution at beta globin position 6 (sickle trait) exhibited increased NOS-dependent vasodilation. Alpha globin gene deletions were associated with decreased arterial alpha globin expression, increased NOS-dependent vasodilation, and lower blood pressure. Mimetic peptides that targeted the interactions between hemoglobin and eNOS recapitulated the effects of these genetic variants on human arterial vasoreactivity. Alpha and beta globin subunits of hemoglobin interact with eNOS to restrict NO signaling in human resistance arteries. Malaria-protective genetic variants that alter the expression of alpha globin or the structure of beta globin are associated with increased NOS-dependent vasodilation. Targeting the hemoglobin-eNOS interface could potentially improve NO signaling in diseases of endothelial dysfunction such as severe malaria or chronic cardiovascular conditions.
2023-08-08 | Concomitant Presence of Hb Agrinio and - -Med Deletion in a Greek Male Patient with Hemoglobinopathy H: More Severe Phenotype and Literature Review
Hemoglobin (Hb) Agrinio is a rare non-deletional a-globin mutation observed almost exclusively in Greek, Spanish or other Mediterranean families. The clinical manifestations of a carrier of a single Hb Agrinio mutation (single heterozygosity) depend on the concomitant presence or absence of other mutations or variants in the beta, alpha or other modifying genes. We present a Greek patient harboring a Hb Agrinio variant plus the - -Med alpha deletional allele, having an infrequent severe form of alpha thalassemia, in contrast to the typical alpha thalassemic patient and requiring regular red blood cell (RBC) transfusions and chelation treatment. We also provide a concise literature review regarding alpha thalassemic hemoglobin variants and their molecular and clinical combinations. A phase 2, double-blind, randomized, placebo-controlled, multicenter clinical trial to determine the efficacy and safety of luspatercept (BMS-986346/ACE-536) for the treatment of anemia in adults with alpha thalassemia with the participation of our center is currently recruiting patients (NCT05664737).
small molecules
2026-09-10 | Efficacy and safety of mitapivat in adults with transfusion-dependent α-thalassaemia or β-thalassaemia (ENERGIZE-T): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial.
The absence of disease-modifying therapies for patients with α-thalassaemia and oral disease-modifying therapies for patients with β-thalassaemia has been a substantial unmet need in these patients. We assessed the efficacy and safety of mitapivat, an oral allosteric activator of pyruvate kinase, in adults with transfusion-dependent thalassaemia. ENERGIZE-T is a global, double-blind, randomised, placebo-controlled, phase 3 trial, conducted across 19 countries in North America, Europe, Asia-Pacific, South America, and the Middle East. Patients aged 18 years or older with transfusion-dependent α-thalassaemia or β-thalassaemia were randomly allocated (2:1) with a central interactive response technology system, stratified by geographical region and thalassaemia genotype, to receive 100 mg mitapivat or placebo orally twice a day for 48 weeks. The primary endpoint was transfusion reduction response (TRR), defined as a reduction of at least 50% in transfused red blood cell units with a reduction of at least two units in any consecutive 12-week period until week 48 compared with baseline. Efficacy was analysed in the full analysis set, comprising all randomly allocated patients. Type, severity, and relationship of adverse events and serious adverse events were assessed in patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov (NCT04770779) and is active but not recruiting. Between Nov 30, 2021 and May 2, 2023, 305 patients were screened, of whom 258 were randomly allocated (median age 33·5 years [IQR 27·0-44·0]; 136 [53%] female and 122 [47%] male participants). Of 258 patients allocated, 238 (92%) completed the double-blind treatment period. All patients were required to have a safety follow-up approximately 4 weeks after the final dose of study drug, regardless of completion of the double-blind period or continuation into the open-label extension period. In the full analysis set, TRRs occurred in 52 (30%) of 171 patients in the mitapivat group and 11 (13%) of 87 in the placebo group (adjusted difference 18 percentage points [95% CI 8-27]; two-sided p=0·0003). The safety analysis set comprised 172 patients in the mitapivat group (including one patient allocated to the placebo group who received one dose of mitapivat in error) and 85 in the placebo group. Adverse events were reported in 155 (90%) patients treated with mitapivat and 71 (84%) treated with placebo; the most common events with mitapivat were headache, upper respiratory tract infection, initial insomnia, diarrhoea, and fatigue. Serious adverse events were reported in 19 (11%) patients treated with mitapivat and 13 (15%) treated with placebo. Ten (6%) patients who received mitapivat and one (1%) who received placebo discontinued study treatment due to adverse events. No deaths were reported. Mitapivat significantly reduced the transfusion burden and was generally well tolerated, showing a favourable benefit-risk profile. These findings support mitapivat as the first oral disease-modifying therapy for adults with transfusion-dependent α-thalassaemia or β-thalassaemia, providing a new treatment option to reduce transfusion burden in this patient population. Agios Pharmaceuticals, Inc.
2026-09-06 | Contemporary Management of Thalassemia: A Perspective on Current Standards and the Emergence of FDA-Approved Oral Therapy.
Thalassemia is an inherited hemoglobin disorder characterized by ineffective erythropoiesis, chronic anemia, and progressive multisystem complications that require lifelong management. Current treatment relies on regular red blood cell transfusions, iron chelation therapy, and supportive multidisciplinary care, while hematopoietic stem cell transplantation offers a curative option for selected patients. Although gene-based therapies and novel pharmacological agents have expanded therapeutic options, their widespread implementation is limited by cost, accessibility, and long-term safety considerations. This article summarizes contemporary management strategies for α and β thalassemia, with particular emphasis on the recent emergence of the FDA-approved oral pyruvate kinase activator, mitapivat. A structured literature review was conducted using PubMed and PubMed Central. Searches included the terms "thalassemia," "mitapivat," "pyruvate kinase activator," "gene therapy," "hydroxyurea," and "luspatercept." Priority was given to recent systematic reviews, clinical practice guidelines, pivotal phase II and III clinical trials, regulatory publications, and peer-reviewed studies relevant to current therapeutic practice. Conventional therapies remain essential but are associated with significant limitations, including transfusion dependence, iron overload, and treatment-related complications. Curative strategies such as hematopoietic stem cell transplantation and gene therapy are effective in selected patients but remain constrained by donor availability, toxicity, cost, and limited accessibility. Emerging pharmacological therapies target ineffective erythropoiesis and iron dysregulation. Phase III ENERGIZE and ENERGIZE-T trials demonstrated that mitapivat significantly improved hemoglobin response in non-transfusion-dependent disease and reduced transfusion burden in transfusion-dependent disease, with an acceptable safety profile, leading to FDA approval as the first oral therapy for adults with α or β thalassemia. Mitapivat represents a significant advance in thalassemia management by targeting erythrocyte metabolism and providing the first FDA-approved oral treatment for anemia in adults with α or β thalassemia. Multi-year follow-up and real-world studies are needed to further define its durability, safety, and role within evolving treatment strategies.
2026-07-19 | Evaluating mitapivat for the treatment of alpha or beta thalassemia.
Thalassemia is a group of diverse genetic disorders with worldwide distribution that affects hemoglobin synthesis. Until recently, the therapeutic approach to thalassemia was symptomatic, relying on red blood cell transfusions, treatment of comorbidities and of disease-related complications. However, novel therapeutic agents have recently been developed and are gradually being integrated into routine clinical practice. One of the most promising agents is mitapivat (AG348), an oral pyruvate kinase activator that enhances the erythrocytic adenosine triphosphate (ATP) production. After series of preclinical and clinical studies, mitapivat has been suggested to be a safe and effective disease modifier for thalassemia. Large double blind randomized clinical trials have indicated that mitapivat may increase baseline hemoglobin levels, reduce transfusion burden, control ineffective erythropoiesis and hemolysis and improve quality of life. Mitapivat presents as a potential game-changer in the management of patients with both α- and β-thalassemia, regardless of transfusion dependency. However, further post-marketing evidence is required in order to evaluate mitapivat profile under real‑world conditions and routine clinical practice.
2026-05-20 | Recover aged/damaged erythrocytes and prevent them from aging by remodeling or enhancing their vital proteins: Hb and B3p.
This study investigates whether remodeling/enhancing the two vital proteins-hemoglobin and B3p-in erythrocytes with artificial interference can rejuvenate aged and damaged erythrocytes. Using Raman spectroscopy and SDS measurement, the study demonstrated that certain flavonoids, such as Hydroxysafflor Yellow A, could remodel/enhance the two proteins and restore their conformation, content, and distribution in aged erythrocytes within a few hours. As a result, it led to a restoration of nearly all cellular and molecular properties of old erythrocytes aged 90-120 days and cells stored under blood bank conditions for 21 days. The flavonoids could even recover erythrocytes of α/β-thalassemia. Moreover, pre-incubating the cells with flavonoids can prevent aging and damage caused by mechanical injury, hypoxic stress, acid-base imbalances, and storage lesions, with protective effects lasting for at least 21 days. In summary, this research reveals for the first time that remodeling hemoglobin and B3p with flavonoids is a promising intervention to enhance the longevity and resilience of erythrocytes against damage. It holds significant implications for biomedicine, including blood storage, the production of blood products, disease treatment, and high-altitude medicine related to hypoxic physiology.
2026-03-04 | Transforming the treatment of Alpha-Thalassemia: a single-center retrospective study on hematopoietic stem cell transplantation in transfusion-dependent pediatric patients.
Hematopoietic stem cell transplantation (HSCT) is the only definitive cure for transfusion-dependent α-thalassemia, though comprehensive studies on its effectiveness are limited. In this retrospective study, we analyzed the clinical characteristics of 21 pediatric patients with transfusion-dependent α-thalassemia who underwent HSCT, all of whom received a standardized conditioning regimen consisting of busulfan, cyclophosphamide, fludarabine, and anti-thymocyte globulin. After a median follow-up of 25 months (range: 7–92 months), the two-year overall survival (OS) and event-free survival (EFS) rates were both 90.2% (95% CI: 66.2–97.4%), and the two-year graft-versus-host disease-free, relapse-free survival (GRFS) rate was 82.3% (95% CI: 52.6–94.3%). The transplant-related mortality rate at two years was 5.0% (95% CI: 0.7–30.0%), with no cases of graft failure observed. Among the 19 surviving patients, hemoglobin levels significantly increased compared to pre-transplant levels (p < 0.05), and all became transfusion-independent. Hematopoietic stem cell transplantation is a curative treatment for α-thalassemia. For patients with transfusion-dependent α-thalassemia, HSCT should be performed as early as possible at an experienced transplant center when a suitable donor is available.
gene therapies
2026-09-09 | Molecular profiling of thalassemia in Southeastern Romania.
Thalassemias represent a major group of hereditary hemoglobin disorders with significant global health impact, yet molecular data from Eastern European populations, particularly from Romania, remain limited. This study was aimed at comprehensively characterizing the molecular spectrum of α-, β-, and δβ-thalassemia in the southeastern part of Romania using an expanded panel of molecular diagnostic techniques. A total of 324 patients with suspected thalassemia were evaluated between 2017 and 2025. Molecular testing included multiplex PCR with reverse dot-blot hybridization, Sanger sequencing, MLPA for α-globin deletions/duplications, and multiplex gap-PCR for δβ fusion gene detection. Pathogenic variants were identified in 137 individuals (42.28%). Of these, 21.89% had α-thalassemia, 66.42% had β-thalassemia, 10.21% had combined α and β defects, and 1.45% had Lepore Hb variants. The -α3·7 deletion and anti-α3·7 triplication were the predominant α-globin abnormalities, while IVS I-6 [T > C], IVS I-110 [G > A], codon 39 [C > T], and IVS II-745 [C > G] were the most frequent β-globin mutations. Two cases of the Hb Lepore Boston-Washington subtype were confirmed through gap-PCR and sequencing. The mutation distribution observed in southeastern Romania mirrors Mediterranean thalassemia patterns rather than those of Central or Northern Europe.
2026-09-08 | A transcription factor-focused CRISPR screen identifies SKI as a BCL11A-independent repressor of ζ-globin.
The regulation of α-like globin genes, particularly the embryonic ζ-globin gene (HBZ), remains incompletely understood. To identify transcriptional regulators of HBZ, we establish a GFP reporter system based on the HBZ-P2A-GFP allele in erythroid cell lines and conduct a CRISPR/Cas9 screen targeting 1639 transcription factors. This screen identifies SKI as a potent HBZ repressor. Functional validation shows that SKI loss increases HBZ expression without impairing erythropoiesis, whereas SKI overexpression suppresses HBZ. Tet-on-inducible SKI overexpression and auxin-inducible SKI degradation indicate that SKI rapidly represses HBZ transcription. Transcriptome profiling further reveals that SKI deletion activates HBZ while minimally affecting other erythroid genes. Mechanistically, genome-wide occupancy analyses show that SKI binds the distal enhancers HS-10 and HS-40, with partial co-occupancy by BCL11A. Despite this overlap, dual knockout of SKI and BCL11A synergistically increases HBZ expression, as does base editing of the SKI-binding site within HS-10. We also identify a naturally occurring variant (chr16:193207G>A) within this enhancer in α-thalassemia patients with elevated ζ-globin levels. Together, these findings establish SKI as a direct, BCL11A-independent transcriptional repressor of ζ-globin. This work advances our understanding of globin gene regulation and suggests targeted ζ-globin reactivation as a potential therapeutic strategy for α-thalassemia.
2026-09-03 | Hemoglobinopathies and Cellular Therapy: What Pediatricians Need to Know About Indications and Counseling.
Hemoglobinopathies are inherited disorders of hemoglobin structure or production. Sickle cell disease (SCD) results from a beta-globin mutation causing hemoglobin polymerization, red blood cell sickling, vaso-occlusion, and hemolytic anemia. Thalassemia results from reduced or absent alpha- or beta-globin synthesis, ranging from asymptomatic carrier states to transfusion-dependent anemia. This article summarizes the pathophysiology, diagnosis, management, and curative options for SCD and transfusion-dependent thalassemia, emphasizing allogeneic hematopoietic stem cell transplantation and approved gene therapies. We discuss indications, counseling, barriers to access, toxicity, donor availability, fertility counseling, and comparative features of cellular therapies. Advances in transplantation, gene addition, and gene editing may expand access to curative-intent therapy and improve outcomes for selected patients.
2026-07-20 | Roth Spots as the Initial Manifestation of Sickle Cell Trait with Suspected Co-inherited Alpha-Thalassemia: A Case Report
Roth spots are white-centered retinal hemorrhages representing a nonspecific morphologic endpoint of retinal capillary rupture. They have long been associated with infective endocarditis, but they are now recognized as a nonspecific sign of systemic microvascular injury. While sickle cell disease is a known cause of retinal vascular complications, their occurrence in sickle cell trait, particularly in association with co-inherited alpha-thalassemia, remains exceptionally rare. This is the case of a previously healthy 40-year-old man presented with sudden visual loss in the left eye, reduced to light perception at initial examination. Fundoscopy revealed multiple Roth spots across all quadrants, extensive macular hemorrhage, and Frisen grade 3 optic disc edema. Fluorescein angiography identified an inferior temporal branch retinal vein occlusion. An exhaustive workup excluded infectious, inflammatory, and malignant etiologies. Peripheral blood smear showed sickled erythrocytes, and hemoglobin electrophoresis demonstrated an HbS fraction of 33.6% with normal HbA2 (3.2%), a pattern consistent with sickle cell trait and suggestive of alpha-thalassemia co-inheritance.This case highlights that Roth spots may be the first ophthalmic sign of an underlying hemoglobinopathy, even in a patient with sickle cell trait. Careful systemic evaluation and multidisciplinary management are essential when white-centered retinal hemorrhages occur without an obvious cause.
2026-07-19 | [Alpha-thalassemia with Hb G-Philadelphia incidentally discovered during HbA1c testing].
Hemoglobin G-Philadelphia is an alpha-globin chain variant resulting from the substitution of asparagine by lysine at position 68 [α68(E17) Asn→Lys]. This hemoglobin (Hb) variant is generally clinically silent; however, its identification may be challenging, particularly when present in the homozygous state and co-inherited with the -α3.7 deletion. We report the case of a 28-year-old woman from southeastern Morocco presenting with refractory hypochromic microcytic anemia (Hb 10,6 g/dL, MCV 60.5 fL, MCH 20.3 pg). Owing to a family history of type 2 diabetes mellitus, HbA1c testing was performed and revealed a hemoglobin variant eluting in the D window (87.44 %) on the Bio-Rad D-100 HPLC system. Further laboratory investigations (HPLC Variant II, capillary electrophoresis, and acid pH gel electrophoresis) confirmed the presence of homozygous Hb G-Philadelphia. Molecular analysis confirmed the variant and demonstrated its association with mild α-thalassemia. Family study revealed that the daughter is a heterozygous carrier of Hb G-Philadelphia and a cis -α3.7 α-thalassemia trait.
cell therapies
2026-06-23 | Chronic Red Cell Exchange for the Management of Alpha Thalassemia Major Complicated by Iron Overload.
Alpha thalassemia major is a severe hemoglobinopathy characterized by absent or markedly reduced alpha-globin production, necessitating lifelong blood transfusions. Chronic simple transfusions can lead to significant iron overload, often requiring iron chelation therapy. However, some patients are unable to tolerate chelation or chelation is insufficient, highlighting the need for alternative strategies for managing iron overload. This study is one of the first to evaluate the feasibility, safety, and efficacy of red blood cell exchange (RBCX) as a therapeutic option for managing iron overload while improving hemoglobin function in an alpha thalassemia major patient with iron overload despite chelation therapy. RBCX therapy was performed approximately every 3 weeks over 1 year, with frequent adjustment of exchange parameters to meet pre-transfusion target levels of functional hemoglobin. Serum ferritin levels, hemoglobin electrophoresis, and functional hemoglobin levels were tracked with each exchange transfusion. For each RBCX treatment, variant hemoglobins decreased by 3.8-fold (from 19.9% to 8.9%) and functional hemoglobin levels increased approximately 3.0 g/dL. RBCX was well tolerated and associated with a marked reduction in systemic iron burden, with serum ferritin declining 7.4-fold (86.4%) over 1 year of therapy, followed by a rise after cessation of RBCX. Cardiac iron remained within normal limits throughout the study period. In contrast, liver iron demonstrated a transient increase shortly after initiation of RBCX, but ultimately declined to levels below baseline after 1 year, even during a period in the absence of iron chelation. These findings suggest that RBCX exerts a meaningful effect on iron homeostasis and raises the possibility of a synergistic benefit when combined with iron chelation. This case highlights that RBCX is a viable therapeutic strategy to treat iron overload in patients with alpha thalassemia major.
2026-06-08 | Derivation and Pluripotency Validation of Six iPSC Lines From Amniotic Fluid Carrying Intermediate α-Thalassemia Genotypes (--3.7/αSEA and --4.2/αSEA).
Thalassemia intermedia (TI), or hemoglobin H (Hb H) disease, presents significant clinical heterogeneity, and its pathogenesis remains unclear. This study aimed to establish induced pluripotent stem cells (iPSCs) from amniotic fluid (AF) cells of fetuses diagnosed with intermediate α-thalassemia genotypes (-α3.7/--SEA and -α4.2/--SEA) to provide a robust in vitro model for investigating disease mechanisms and exploring therapeutic strategies. AF cells from six TI fetuses were reprogrammed using nonintegrating episomal vectors via electro-transfection. The resulting iPSC lines underwent comprehensive characterization, including alkaline phosphatase (AP) staining, immunofluorescence (IF) for pluripotency markers (e.g., OCT-4, SOX-2, and TRA-1-60), quantitative reverse transcription real-time PCR (RT-qPCR) for the expression of pluripotency genes, G-band karyotyping, and genetic analysis for thalassemia. Differentiation potential was assessed in vivo via teratoma formation in immunodeficient mice and in vitro through directed hematopoietic differentiation. Six stable iPSC lines were successfully established. All lines retained the progenitor's intermediate α-thalassemia genotype and exhibited normal karyotypes. They displayed typical embryonic stem cell (ESC)-like morphology, were positive for AP, and expressed key pluripotency markers. In vivo, all lines robustly formed teratomas containing tissues derived from all three germ layers (endoderm, mesoderm, and ectoderm). Furthermore, in vitro hematopoietic differentiation protocols successfully induced the iPSCs to generate CD34+/CD43+ hematopoietic progenitors, which were functionally validated by their ability to form hematopoietic colonies in colony-forming unit (CFU) assays. We have successfully derived and comprehensively characterized six patient-specific iPSC lines from intermediate α-thalassemia fetuses. These cell lines demonstrate robust pluripotency and maintain the capacity for hematopoietic differentiation. They represent a valuable resource for investigating TI pathophysiology, screening novel drugs, and developing future cell-based therapeutic strategies.
2026-05-21 | Establishment of an immortalized erythroid model for Hb Bart's hydrops fetalis with homozygous α0-thalassemia Southeast Asian deletion.
Hemoglobin Bart's hydrops fetalis syndrome (BHFS) is the most severe form of α-thalassemia and is highly prevalent in Southeast Asia. It is most commonly caused by homozygosity for the α0-thalassemia Southeast Asian deletion (--SEA/--SEA), which eliminates α-globin production and results in profound fetal anemia. Current management is limited to intrauterine transfusions with only transient benefit, and no pharmacological or gene-based therapies are available. Progress toward therapy has been hampered by the lack of disease-relevant in vitro models. Here, we established Chery-Bart's, an immortalized erythroid progenitor cell line derived from umbilical cord blood CD34+ hematopoietic stem and progenitor cells of a fetus with --SEA/--SEA and βIVS I-1 (G> T)/β using a tetracycline-inducible HPV16 E6/E7 system. Chery-Bart's cells exhibit sustained proliferation beyond the Hayflick limit, stable recovery after cryopreservation, and enrichment in the basophilic erythroblast stage. In vitro erythropoiesis assays showed that the cell line retains key features of the parental cells, including the capacity for erythroid maturation, expression of fetal globin transcripts, and robust production of Hb Bart's (γ4), the hallmark pathological hemoglobin of BHFS. Although Chery-Bart's carries a β-thalassemia mutation, this is unlikely to modify disease severity, as γ-globin predominates in this model. Collectively, Chery-Bart's represents the first durable and disease-specific cellular model of BHFS with --SEA/--SEA genotype. This platform provides a scalable resource for mechanistic studies and preclinical evaluation of therapeutic approaches, including drug discovery, gene therapy, and α-like globin chain induction. Beyond BHFS, Chery-Bart's may also serve as a model for investigating severe α-thalassemia syndromes associated with the --SEA allele, such as deletional and non-deletional HbH disease.
2026-04-15 | In Utero Hematopoietic Cell Transplantation in Fetuses with Alpha Thalassemia Major: A Phase 1 Clinical Trial.
In utero hematopoietic cell transplantation (IUHCT) has the potential to treat patients who have hemoglobinopathies by harnessing the unique period of fetal tolerance to maternal cells, thereby enabling semi-allogeneic transplantation without conditioning or immunosuppression. We conducted a phase 1 clinical trial of IUHCT in fetuses with Alpha Thalassemia Major (ATM), a diagnosis that requires serial in utero transfusions (IUT) for survival. We also analyzed outcomes in fetuses with ATM treated with IUT alone in the same time period. Six fetuses underwent transplantation with maternal CD34+ cells (1.33 x 108 ± 2.67x107 cells/kg +1% T cells) at 23.1 ± 1.1 weeks' gestation. All received serial IUT and were delivered at or near term. Perinatal outcomes were broadly similar to those undergoing IUT alone. Two mothers received prophylactic antibiotics because of late positive cultures of harvested cells (without fetal adverse events). Low-level maternal microchimerism was detected in all recipients; T-cell hyporeactivity to maternal antigens was detected in 2/6 offspring but persisted in only one child. Cord blood from ATM-affected pregnancies demonstrated marked expansion of host hematopoietic stem and progenitor cells compared with healthy controls, suggesting a competitive disadvantage for donor cells in this disease context. Neurodevelopmental assessments were largely reassuring, with high quality of life scores. Overall, this protocol was safe and feasible but demonstrates the limitations of IUHCT for ATM without concurrent bone marrow conditioning. The favorable perinatal and neurologic outcomes in most offspring underscore the benefits of prenatal transfusions and the unmet medical need for developing definitive therapies for ATM. NCT02986698.
2025-11-11 | Tackling the challenge of in utero blood exchange transfusion for fetal anemia at 15 weeks' gestation.
Severe fetal anemia due to parvovirus infection and alpha-thalassemia major can occur during the first trimester of pregnancy. In utero transfusion before 16 weeks of gestation is beneficial but challenging because the umbilical vein is too narrow to be precisely punctured. In addition, the fetal circulating volume is small, and the heart of an affected fetus is compromised. To avoid vascular overload, exchange transfusion may be considered. The technical difficulties make in utero simple transfusions seldom performed before 16 weeks of gestation, and exchange transfusion before 16 weeks of gestation has not been reported. Hence, we reported our technique of successful in utero exchange transfusion in a fetus with alpha-thalassemia major at 15 weeks of gestation. The keys of success were as follows: Fetal blood was not withdrawn for diagnostic investigation before the first transfusion for the following pragmatic reasons.
oligonucleotides
2024-04-18 | miR-214 aggravates oxidative stress in thalassemic erythroid cells by targeting ATF4.
Oxidative damage to erythroid cells plays a key role in the pathogenesis of thalassemia. The oxidative stress in thalassemia is potentiated by heme, nonheme iron, and free iron produced by the Fenton reaction, due to degradation of the unstable hemoglobin and iron overload. In addition, the levels of antioxidant enzymes and molecules are significantly decreased in erythrocytes in α- and β-thalassemia. The control of oxidative stress in red blood cells (RBCs) is known to be mediated by microRNAs (miRNAs). In erythroid cells, microR-214 (miR-214) has been reported to respond to external oxidative stress. However, the molecular mechanisms underlying this phenomenon remain unclear, especially during thalassemic erythropoiesis. In the present study, to further understand how miR-214 aggravates oxidative stress in thalassemia erythroid cells, we investigated the molecular mechanism of miR-214 and its regulation of the oxidative status in thalassemia erythrocytes. We have reported a biphasic expression of miR-214 in β- and α-thalassemia. In the present study the effect of miR-214 expression was investigated by using miR -inhibitor and -mimic transfection in erythroid cell lines induced by hemin. Our study showed a biphasic expression of miR-214 in β- and α-thalassemia. Subsequently, we examined the effect of miR-214 on erythroid differentiation in thalassemia. Our study reveals the loss-of-function of miR-214 during translational activation of activating transcription factor 4 mRNA, leading to decreased reactive oxygen species levels and increased glutathione levels in thalassemia erythroid cell. Our results suggest that the expression of activating transcription factor 4 regulated by miR-214 is important for oxidative stress modulation in thalassemic erythroid cells. Our findings can help to better understand the molecular mechanism of miRNA and transcription factors in regulation of oxidative status in erythroid cells, particularly in thalassemia, and could be useful for managing and relieving severe anemia symptoms in patients in the future.
2021-10-04 | Reduced hepcidin expression enhances iron overload in patients with HbE/β‑thalassemia: Α comparative cross‑sectional study
Iron homeostasis is regulated by hepcidin (HEPC) that controls the dietary iron absorption and iron recycling. HEPC deficiency contributes to iron overload in β-thalassemia patients. The present study aimed to investigate the correlation between HEPC concentration and serum iron status among hemoglobin E (HbE)/β-thalassemia patients and their parents (HbE trait and β-thalassemia trait) compared with healthy controls. This study is a comparative cross-sectional study in which iron profile and HEPC level were examined in 65 HbE/β-thalassemia patients (pretransfusion) and 65 parents at the Hospital Sultanah Nur Zahirah and in 130 students as healthy controls from Univesiti Sultan Zainal Abidin, Terengganu, Malaysia. Furthermore, six samples from each group (HbE/β-thalassemia patients, parents and healthy controls) were randomly selected for gene expression analysis of HEPC and ferroportin1 (FPN1) using reverse transcription quantitative PCR. The results demonstrated that serum HEPC level were significantly decreased in HbE/β-thalassemia patients and their parents (P<0.001) compared with healthy controls. In addition, the gene expression analysis showed a dramatically downregulated HEPC in HbE/β-thalassemia patients and their parents (P=0.001) compared with healthy controls. However, there was a marked upregulation of FPN1 in HbE/β-thalassemia patients and their parents (P=0.001) compared with healthy controls. Iron profiling results revealed a significantly increased serum ferritin in HbE/β-thalassemia patients and their parents compared with healthy controls (P<0.001). In summary, the present study demonstrated that HEPC expression level and serum level were significantly decreased in HbE/β-thalassemia patients and their parents, which was combined with a marked increased FPN1 expression level and serum ferritin level compared with healthy volunteers. These findings supported the hypothesis that downregulated HEPC could lose its function as a negative regulator of FPN1, resulting in iron overload in HbE/β-thalassemia patients. Subsequently, assessing HEPC and FPN1 gene expression may be a useful tool to determine the risk of iron toxicity in patients with HbE/β-thalassemia and their parents, and could therefore be considered as a therapeutic target in the management of iron burden in these patients.
2019-08-27 | miR-144 regulates oxidative stress tolerance of thalassemic erythroid cell via targeting NRF2.
Thalassemia has a high prevalence in Thailand. Oxidative damage to erythroid cells is known to be one of the major etiologies in thalassemia pathophysiology. Oxidative stress status of thalassemia is potentiated by the heme, nonheme iron, and free iron resulting from imbalanced globin synthesis. In addition, levels of antioxidant proteins are reduced in α-thalassemia and β-thalassemia erythrocytes. However, the primary molecular mechanism for this phenotype remains unknown. Our study showed a high expression of miR-144 in β- and α-thalassemia. An increased miR-144 expression leads to decreased expression of nuclear factor erythroid 2-related factor 2 (NRF2) target, especially in α-thalassemia. In α-thalassemia, miR-144 and NRF2 target are associated with glutathione level and anemia severity. To study the effect of miR-144 expression, the gain-loss of miR-144 expression was performed by miR inhibitor and mimic transfection in the erythroblastic cell line. This study reveals that miR-144 expression was upregulated, whereas NRF2 expression and glutathione levels were decreased in comparison with the untreated condition after miR mimic transfection, while the reduction of miR-144 expression contributed to the increased NRF2 expression and glutathione level compared with the untreated condition after miR inhibitor transfection. Moreover, miR-144 overexpression leads to significantly increased sensitivity to oxidative stress at indicated concentrations of hydrogen peroxide (H2O2) and rescued by miR-144 inhibitor. Taken together, our findings suggest that dysregulation of miR-144 may play a role in the reduced ability of erythrocyte to deal with oxidative stress and increased RBC hemolysis susceptibility especially in thalassemia.
2016-03-18 | Generation and Characterization of a Transgenic Mouse Carrying a Functional Human β -Globin Gene with the IVSI-6 Thalassemia Mutation.
Mouse models that carry mutations causing thalassemia represent a suitable tool to test in vivo new mutation-specific therapeutic approaches. Transgenic mice carrying the β-globin IVSI-6 mutation (the most frequent in Middle-Eastern regions and recurrent in Italy and Greece) are, at present, not available. We report the production and characterization of a transgenic mouse line (TG-β-IVSI-6) carrying the IVSI-6 thalassemia point mutation within the human β-globin gene. In the TG-β-IVSI-6 mouse (a) the transgenic integration region is located in mouse chromosome 7; (b) the expression of the transgene is tissue specific; (c) as expected, normally spliced human β-globin mRNA is produced, giving rise to β-globin production and formation of a human-mouse tetrameric chimeric hemoglobin (mu) α-globin2/(hu) β-globin2 and, more importantly, (d) the aberrant β-globin-IVSI-6 RNAs are present in blood cells. The TG-β-IVSI-6 mouse reproduces the molecular features of IVSI-6 β-thalassemia and might be used as an in vivo model to characterize the effects of antisense oligodeoxynucleotides targeting the cryptic sites responsible for the generation of aberrantly spliced β-globin RNA sequences, caused by the IVSI-6 mutation. These experiments are expected to be crucial for the development of a personalized therapy for β-thalassemia.
2014-09-26 | Structural determinants of human ζ-globin mRNA stability.
The normal accumulation of adult α and β globins in definitive erythrocytes is critically dependent upon processes that ensure that the cognate mRNAs are maintained at high levels in transcriptionally silent, but translationally active progenitor cells. The impact of these post-transcriptional regulatory events on the expression of embryonic ζ globin is not known, as its encoding mRNA is not normally transcribed during adult erythropoiesis. Recently, though, ζ globin has been recognized as a potential therapeutic for α thalassemia and sickle-cell disease, raising practical questions about constitutive post-transcriptional processes that may enhance, or possibly prohibit, the expression of exogenous or derepresssed endogenous ζ-globin genes in definitive erythroid progenitors. The present study assesses mRNA half-life in intact cells using a pulse-chase approach; identifies cis-acting determinants of ζ-globin mRNA stability using a saturation mutagenesis strategy; establishes critical 3'UTR secondary structures using an in vitro enzymatic mapping method; and identifies trans-acting effector factors using an affinity chromatographical procedure. We specify a tetranucleotide 3'UTR motif that is required for the high-level accumulation of ζ-globin transcripts in cultured cells, and formally demonstrate that it prolongs their cytoplasmic half-lives. Surprisingly, the ζ-globin mRNA stability motif does not function autonomously, predicting an activity that is subject to structural constraints that we subsequently specify. Additional studies demonstrate that the ζ-globin mRNA stability motif is targeted by AUF1, a ubiquitous RNA-binding protein that enhances the half-life of adult β-globin mRNA, suggesting commonalities in post-transcriptional processes that regulate globin transcripts at all stages of mammalian development. These data demonstrate a mechanism for ζ-globin mRNA stability that exists in definitive erythropoiesis and is available for therapeutic manipulation in α thalassemia and sickle-cell disease.
other
2026-04-20 | Hemoglobin alpha-like subunit mu is expressed during ontogeny and is elevated in alpha thalassemia.
The alpha globin gene cluster on chromosome 16 encodes alpha-like globins whose expression changes during development. HBM located in this cluster was considered a pseudogene until its transcript was discovered in 2005, but without a detectable protein product. Here, we provide the first detailed description of HBM-encoded globin at the protein level (hemoglobin mu chain [HBM]) across different age groups using liquid chromatography coupled with tandem mass spectrometry. Using targeted analysis, we demonstrate that HBM protein is readily detectable in circulation with its levels falling with increasing gestational age. We also report HBM levels in relation to other hemoglobin chains in neonatal, pediatric, and adult blood. Furthermore, analysis of alpha thalassemia patient samples revealed that HBM levels were elevated 3- to 17-fold, indicating a compensatory role, which could be explored for its therapeutic potential. This study enhances our understanding of erythropoiesis and globin chain production through ontogeny.
2025-11-03 | Transfusion independence in thalassemia patients after failure of gene therapy or with hemoglobin h constant spring and hb e using luspatercept: A case series
Abstract Background: Individuals with thalassemia who depend on blood transfusions to maintain adequate hemoglobin levels are at high risk of sequelae resulting from frequent blood products. As such, there is increased interest in decreasing transfusion frequency for such patients and limiting side effects. Luspatercept is a recombinant fusion protein that enhances erythropoiesis by binding to select TGF-b ligands and can increase hemoglobin for patients with thalassemia. Luspatercept use was associated with significantly greater reductions in transfusion burden than for the placebo group for transfusion-dependent b-thalassemia (TDT) patients in the BELIEVE trial. Luspatercept was also associated with a significant increase in hemoglobin level among non-transfusion-dependent beta thalassemia (NTDT) in the BEYOND trial. However, currently, there is very limited evidence for the utility luspatercept in thalassemia patients after a failed gene therapy or among those with alpha thalassemia. Here we describe two cases with significant clinical response to luspatercept achieving transfusion independence in distinct thalassemia populations that have not yet been reported in the literature. Case 1: This patient underwent LentiGlobin gene therapy for b-thalassemia (β0/β0) at the age of 34 years in 2015. Prior to gene therapy, she required regular packed red blood cell (pRBCs) transfusions every 4 weeks. After admission for gene therapy per protocol HGB-204, her transfusion needs initially decreased to every 6 to 9 months. However, she was not able to fully wean off transfusions which slowly increased in frequency to every 3 months. She began treatment with luspatercept at the age of 42, and has maintained hemoglobin levels above 10 g/dL without need for a blood transfusion for almost two years since then. Case 2: This patient was diagnosed with hemoglobin H Constant Spring and homozygous HbE by hemoglobin electrophoresis and hemoglobinopathy genetic testing (c.427T>C , Hb Constant Spring; c79G>A, HbE). Up to her third decade of life, she was requiring regular pRBCs transfusions every 3-4 weeks with a pre-transfusion hemoglobin goal of 9-10 g/dL. She also had evidence of significant iron overload due to her transfusion frequency and suboptimal adherence to iron chelation (maximum liver iron content (LIC) of 16.4 mg/g dry weight) with a normal cardiac T2* (42.7 +/- 2.6 msec). She started treatment with luspatercept at the age of 30 years and her transfusion needs soon decreased and she achieved transfusion independence for more than 2 years with occasional transfusion only every 18 months. Concurrently, she was weaned off iron chelation around two years following initiation of luspatercept with an LIC of <3.5 and a ferritin of less than 500 ng/mL. She continues to be on luspatercept with no tolerability issues. These two patient cases demonstrate that luspatercept can also reduce transfusion needs or achieve independence following gene therapy or in alpha thalassemia. Other case reports have previously explored the potential clinical benefits of luspatercept in other settings. Our cases add to the existing experiences by elucidating possible novel applications of luspatercept to additional thalassemia populations. Our findings suggest that luspatercept can successfully increase and stabilize baseline hemoglobin for these patients, and thus could represent a safe and efficacious long-term disease-modifying therapy option for transfusion-dependent alpha thalassemias and patients who failed or had a suboptimal or incomplete response to gene therapy. Further research, including prospective studies and/or randomized trials, will be necessary to evaluate these indications for luspatercept on a larger study population in the future.
2025-01-25 | Hemoglobin Variants as Targets for Stabilizing Drugs.
Hemoglobin is an oxygen-transport protein in red blood cells that interacts with multiple ligands, e.g., oxygen, carbon dioxide, carbon monoxide, and nitric oxide. Genetic variations in hemoglobin chains, such as those underlying sickle cell disease and thalassemias, present substantial clinical challenges. Here, we review the progress in research, including the use of allosteric modulators, pharmacological chaperones, and antioxidant treatments, which has begun to improve hemoglobin stability and oxygen affinity. According to UniProt (as of 7 August 2024), 819 variants of the α-hemoglobin subunit and 771 variants of the β-hemoglobin subunit have been documented, with over 116 classified as unstable. These data demonstrate the urgent need to develop variant-specific stabilizing options. Beyond small-molecule drugs/binders, novel protein-based strategies-such as engineered hemoglobin-binding proteins (including falcilysin, llama-derived nanobodies, and α-hemoglobin-stabilizing proteins)-offer promising new options. As our understanding of hemoglobin's structural and functional diversity grows, so does the potential for genotype-driven approaches. Continued research into hemoglobin stabilization and ligand-binding modification may yield more precise, effective treatments and pave the way toward effective strategies for hemoglobinopathies.
2024-12-05 | Sickle Trait and Alpha Thalassemia Increase NOS-Dependent Vasodilation of Human Arteries Through Disruption of Endothelial Hemoglobin-eNOS Interactions.
Severe malaria is associated with impaired nitric oxide (NO) synthase (NOS)-dependent vasodilation, and reversal of this deficit improves survival in murine models. Malaria might have selected for genetic polymorphisms that increase endothelial NO signaling and now contribute to heterogeneity in vascular function among humans. One protein potentially selected for is alpha globin, which, in mouse models, interacts with endothelial NOS (eNOS) to negatively regulate NO signaling. We sought to evaluate the impact of alpha globin gene deletions on NO signaling and unexpectedly found human arteries use not only alpha but also beta globin to regulate eNOS. The eNOS-hemoglobin complex was characterized by multiphoton imaging, gene expression analysis, and coimmunoprecipitation studies of human resistance arteries. Novel contacts between eNOS and hemoglobin were mapped using molecular modeling and simulation. Pharmacological or genetic disruption of the eNOS-hemoglobin complex was evaluated using pressure myography. The association between alpha globin gene deletion and blood pressure was assessed in a population study. Alpha and beta globin transcripts were detected in the endothelial layer of the artery wall. Imaging colocalized alpha and beta globin proteins with eNOS at myoendothelial junctions. Immunoprecipitation demonstrated that alpha globin and beta globin form a complex with eNOS and cytochrome b5 reductase. Modeling predicted negatively charged glutamic acids at positions 6 and 7 of beta globin to interact with positively charged arginines at positions 97 and 98 of eNOS. Arteries from donors with a glutamic acid-to-valine substitution at beta globin position 6 (sickle trait) exhibited increased NOS-dependent vasodilation. Alpha globin gene deletions were associated with decreased arterial alpha globin expression, increased NOS-dependent vasodilation, and lower blood pressure. Mimetic peptides that targeted the interactions between hemoglobin and eNOS recapitulated the effects of these genetic variants on human arterial vasoreactivity. Alpha and beta globin subunits of hemoglobin interact with eNOS to restrict NO signaling in human resistance arteries. Malaria-protective genetic variants that alter the expression of alpha globin or the structure of beta globin are associated with increased NOS-dependent vasodilation. Targeting the hemoglobin-eNOS interface could potentially improve NO signaling in diseases of endothelial dysfunction such as severe malaria or chronic cardiovascular conditions.
2023-08-08 | Concomitant Presence of Hb Agrinio and - -Med Deletion in a Greek Male Patient with Hemoglobinopathy H: More Severe Phenotype and Literature Review
Hemoglobin (Hb) Agrinio is a rare non-deletional a-globin mutation observed almost exclusively in Greek, Spanish or other Mediterranean families. The clinical manifestations of a carrier of a single Hb Agrinio mutation (single heterozygosity) depend on the concomitant presence or absence of other mutations or variants in the beta, alpha or other modifying genes. We present a Greek patient harboring a Hb Agrinio variant plus the - -Med alpha deletional allele, having an infrequent severe form of alpha thalassemia, in contrast to the typical alpha thalassemic patient and requiring regular red blood cell (RBC) transfusions and chelation treatment. We also provide a concise literature review regarding alpha thalassemic hemoglobin variants and their molecular and clinical combinations. A phase 2, double-blind, randomized, placebo-controlled, multicenter clinical trial to determine the efficacy and safety of luspatercept (BMS-986346/ACE-536) for the treatment of anemia in adults with alpha thalassemia with the participation of our center is currently recruiting patients (NCT05664737).
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Drug Discovery Landscape
2 orphan drug designations for Alpha-thalassemia, including 1 approved therapy.
2 orphan drug designations for Alpha-thalassemia, including 1 approved therapy.
Drug | Therapy type | Orphan designation | Clinical trial status | Sponsor |
|---|---|---|---|---|
luspatercept | proteins | FDA | Celgene Corporation | |
deferasirox [Exjade; Jadenu Sprinkles] | small molecules | FDA | Approved | Novartis Pharmaceuticals Corporation |
“Terminated” – programs with discontinued clinical trials, or with no updates reported for 5 years after completion or 12 years after the last trial started.
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