Luspatercept for the treatment of anaemia in non-transfusion-dependent β-thalassaemia (BEYOND): a phase 2, randomised, double-blind, multicentre, placebo-controlled trial

Quality of life, mood disorders, and cognitive impairment in adults with β-thalassemia

Advances in understanding the disease process in β-thalassemia supported development of various treatment strategies that resulted in improved survival. Improved survival, however, allowed multiple morbidities to manifest and cemented the need for frequent, lifelong treatment. This has directly impacted patients' health-related quality of life and opened the door for various psychiatric and cognitive disorders to potentially develop. In this review, we summarize available evidence on quality of life, depression and anxiety, suicidality, and cognitive impairment in adult patients with β-thalassemia while sharing our personal insights from experience in treating patients with both transfusion-dependent and non-transfusion-dependent forms.

Αlpha-thalassemia: A practical overview

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and β globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.

Unmet needs in β-thalassemia and the evolving treatment landscape

β-thalassemias are genetic disorders causing an imbalance in hemoglobin production, leading to varying degrees of anemia, with two clinical phenotypes: transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT). Red blood cell transfusions and iron chelation therapy are the conventional treatment options for the management of β-thalassemia. Currently available conventional therapies in thalassemia have many challenges and limitations. Accordingly, multiple novel therapeutic approaches are currently being developed for the treatment of β-thalassemias. These strategies can be classified into three categories based on their efforts to address different aspects of the underlying pathophysiology of β-thalassemia: correction of the α/β globin chain imbalance, addressing ineffective erythropoiesis, and targeting iron dysregulation. Managing β- thalassemia presents challenges due to the many complications that can manifest, limited access and availability of blood products, and lack of compliance/adherence to treatment. Novel therapies targeting ineffective erythropoiesis and thus improving anemia and reducing the need for chronic blood transfusions seem promising. However, the complex nature of the disease itself requires personalized treatment plans for each patient. Collaborations and partnerships between thalassemia centers can also help share knowledge and resources, particularly in regions with higher prevalence and limited resources. This review will explore the different conventional treatment modalities available today for the management of β-thalassemia, discuss the unmet needs and challenges associated with them in addition to exploring the role of some novel therapeutic agents in the field.

Cellular and animal models for the investigation of β-thalassemia

β-Thalassemia is a genetic form of anemia due to mutations in the β-globin gene, that leads to ineffective and extramedullary erythropoiesis, abnormal red blood cells and secondary iron-overload. The severity of the disease ranges from mild to lethal anemia based on the residual levels of globins production. Despite being a monogenic disorder, the pathophysiology of β-thalassemia is multifactorial, with different players contributing to the severity of anemia and secondary complications. As a result, the identification of effective therapeutic strategies is complex, and the treatment of patients is still suboptimal. For these reasons, several models have been developed in the last decades to provide experimental tools for the study of the disease, including erythroid cell lines, cultures of primary erythroid cells and transgenic animals. Years of research enabled the optimization of these models and led to decipher the mechanisms responsible for globins deregulation and ineffective erythropoiesis in thalassemia, to unravel the role of iron homeostasis in the disease and to identify and validate novel therapeutic targets and agents. Examples of successful outcomes of these analyses include iron restricting agents, currently tested in the clinics, several gene therapy vectors, one of which was recently approved for the treatment of most severe patients, and a promising gene editing strategy, that has been shown to be effective in a clinical trial. This review provides an overview of the available models, discusses pros and cons, and the key findings obtained from their study.

Beta-thalassemia: is cure still a dream?

β-thalassemia is a monogenic disorder characterized by decreased hemoglobin production, resulting in chronic anemia. There are several factors affecting the clinical presentation of patients with β-thalassemia, and several complications such as iron overload or ineffective erythropoiesis have been linked to this disease. Until nowadays, several conservative therapies namely blood transfusions, iron chelation, and the FDA-approved drug Luspatercept have been adopted alongside other debatable permanent cures. Other clinical trials are being conducted to develop better and safer management techniques for these patients. This review will discuss the different treatment strategies of β-thalassemia including novel therapies, besides all possible curative therapies that are being developed for this disease.

Splenic iron decreases without change in volume or liver parameters during luspatercept therapy

Splenic iron decreased whereas liver iron was stable during luspatercept therapy in some individuals with thalassemia. This suggests a reduction of ineffective erythropoiesis changes the organ distribution of iron and demonstrates that liver iron concentration alone may not accurately reflect total body iron content. This article describes data from subjects enrolled in BELIEVE (NCT02604433) and BEYOND (NCT03342404).

How I treat non-transfusion-dependent β-thalassemia

The intricate interplay of anemia and iron overload under the pathophysiological umbrella of ineffective erythropoiesis in non-transfusion-dependent β-thalassemia (NTDT) results in a complex variety of clinical phenotypes that are challenging to diagnose and manage. In this article, we use a clinical framework rooted in pathophysiology to present 4 common scenarios of patients with NTDT. Starting from practical considerations in the diagnosis of NTDT, we delineate our strategy for the longitudinal care of patients who exhibit different constellations of symptoms and complications. We highlight the use of transfusion therapy and novel agents, such as luspatercept, in the patient with anemia-related complications. We also describe our approach to chelation therapy in the patient with iron overload. Although tackling every specific complication of NTDT is beyond the scope of this article, we touch on the management of the various morbidities and multisystem manifestations of the disease.

Gene Therapy for Hemoglobinopathies

β-Thalassemia and sickle cell disease are autosomal recessive disorders of red blood cells due to mutations in the adult β-globin gene, with a worldwide diffusion. The severe forms of hemoglobinopathies are fatal if untreated, and allogeneic bone marrow transplantation can be offered to a limited proportion of patients. The unmet clinical need and the disease incidence have promoted the development of new genetic therapies based on the engineering of autologous hematopoietic stem cells. Here, the steps of ex vivo gene therapy development are reviewed along with results from clinical trials and recent new approaches employing cutting edge gene editing tools.

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).

Profile of Luspatercept in the Treatment of Anemia in Adults with Non-Transfusion-Dependent β-Thalassemia (NTDT): Design, Development and Potential Place in Therapy

Over the past decade, evidence has been mounting on the detrimental clinical sequelae of untreated anemia in patients with non-transfusion-dependent β-thalassemia (NTDT). There are no pharmacologic agents that are specifically approved for the management of anemia in NTDT, and available options such as splenectomy, transfusion therapy, and hydroxyurea each come with their own shortcomings, especially for long-term use. Luspatercept is an erythroid maturation agent that has been evaluated in a Phase 2, randomized trial and showed a significant benefit in raising hemoglobin level by at least 1 g/dL in adults with NTDT and a baseline hemoglobin level ≤10 g/dL. These data led to luspatercept's approval by the European Commission for the treatment of anemia in adults with NTDT and presents the first evidence-based approach for a novel agent that is able to ameliorate anemia in this patient population.

Emerging Therapies in β-Thalassemia

Advances in understanding the underlying pathophysiology of β-thalassemia have enabled efforts toward the development of novel therapeutic modalities. These can be classified into three major categories based on their ability to target different features of the underlying disease pathophysiology: correction of the α/β globin chain imbalance, targeting ineffective erythropoiesis, and targeting iron dysregulation. This article provides an overview of these different emerging therapies that are currently in development for β-thalassemia.

Therapeutic perspective for children and young adults living with thalassemia and sickle cell disease

Hemoglobinopathies, including thalassemias and sickle cell disease, are the most common monogenic diseases worldwide, with estimated annual births of more than 330,000 affected infants. Hemoglobin disorders account for about 3.4% of deaths in children under 5 years of age. The distribution of these diseases is historically linked to current or previously malaria-endemic regions; however, immigration has led to a worldwide distribution of these diseases, making them a global health problem. During the last decade, new treatment approaches and novel therapies have been proposed, some of which have the potential to change the natural history of these disorders. Indeed, the first erythroid maturation agent, luspatercept, and gene therapy have been approved for beta-thalassemia adult patients. For sickle cell disease, molecules targeting vaso-occlusion and hemoglobin S polymerization include crizanlizumab, which has been approved for patients ≥ 16 years, voxelotor approved for patients ≥ 12 years, and L-glutamine for patients older than 5 years.    Conclusion: We herein present the most recent advances and future perspectives in thalassemia and sickle cell disease treatment, including new drugs, gene therapy, and gene editing, and the current clinical trial status in the pediatric populations. What is Known: • Red blood cell transfusions, iron chelation therapy and hematopoietic stem cell transplantation have been the mainstay of treatment of thalassemia patients for decades. • For sickle cell disease, until 2005, treatment strategies were mostly the same as those for thalassemia, with the option of simple transfusion or exchange transfusion. In 2007, hydroxyurea was approved for patients ≥ 2 years old. What is New: • In 2019, gene therapy with betibeglogene autotemcel (LentiGlobin BB305) was approved for TDT patients ≥ 12 years old non β0/β0 without matched sibling donor. • Starting from 2017 several new drugs, such as L-glutamine (approved only by FDA), crizanlizumab (approved by FDA and EMA for patients ≥ 16 years), and lastly voxelotor (approved by FDA and EMA for patients ≥ 12 years old).

Treating Thalassemia Patients with Luspatercept: An Expert Opinion Based on Current Evidence

Luspatercept has recently been approved for the treatment of beta-thalassemia and its use in clinical practice has been increasing. As it is the first erythroid maturation drug available for this diagnosis, the expertise about its use is still limited. To address this point, and to promote awareness and guide the clinical use of luspatercept in beta-thalassemia, this paper was developed as a consensus by experts from the Italian Society of Thalassemia and Hemoglobinopathies (SITE). After a brief presentation of the core features of luspatercept, a comprehensive set of questions is addressed, covering relevant aspects for the practical management of this new therapeutic option.

Psychometric evaluation of the NTDT-PRO questionnaire for assessing symptoms in patients with non-transfusion-dependent beta-thalassaemia

OBJECTIVES

The non-transfusion-dependent beta-thalassaemia-patient-reported outcome (NTDT-PRO) questionnaire was developed for assessing anaemia-related tiredness/weakness (T/W) and shortness of breath (SoB) among patients with NTDT. Psychometric properties were evaluated using blinded data from the BEYOND trial (NCT03342404).

DESIGN

Analysis of a phase 2, double-blind, randomised, placebo-controlled trial.

SETTING

USA, Greece, Italy, Lebanon, Thailand and the UK.

PARTICIPANTS

Adults (≥18 years) (N=145) with NTDT who had not received a red blood cell transfusion within 8 weeks prior to randomisation, with mean baseline haemoglobin level ≤100 g/L.

MEASURES

NTDT-PRO daily scores from baseline until week 24, and scores at select time points for the 36-Item Short Form Health Survey version 2 (SF-36v2), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and Patient Global Impression of Severity (PGI-S).

RESULTS

Cronbach's alpha at weeks 13-24 was 0.95 and 0.84 for the T/W and SoB domains, respectively, indicating acceptable internal consistency reliability. Among participants self-reporting no change in thalassaemia symptoms via the PGI-S between baseline and week 1, intraclass correlation coefficients were 0.94 and 0.92 for the T/W and SoB domains, respectively, indicating excellent test-retest reliability. In a known-groups validity analysis, least-squares mean T/W and SoB scores at weeks 13-24 were worse in participants with worse scores for the FACIT-F Fatigue Subscale (FS), SF-36v2 vitality or PGI-S. Indicating responsiveness, changes in T/W and SoB domain scores were moderately correlated with changes in haemoglobin levels, and strongly correlated with changes in SF-36v2 vitality, FACIT-F FS, select FACIT-F items and the PGI-S. Improvements in least-squares mean T/W and SoB scores were higher in participants with greater improvements in scores on other PROs measuring similar constructs.

CONCLUSIONS

The NTDT-PRO demonstrated adequate psychometric properties to assess anaemia-related symptoms in adults with NTDT and can be used to evaluate treatment efficacy in clinical trials.

Erythropoiesis in lower-risk myelodysplastic syndromes and beta-thalassemia

The hematologic disorders myelodysplastic syndromes and beta-thalassemia are characterized by ineffective erythropoiesis and anemia, often managed with regular blood transfusions. Erythropoiesis, the process by which sufficient numbers of functional erythrocytes are produced from hematopoietic stem cells, is highly regulated, and defects can negatively affect the proliferation, differentiation, and survival of erythroid precursors. Treatments that directly target the underlying mechanisms of ineffective erythropoiesis are limited, and management of anemia with regular blood transfusions imposes a significant burden on patients, caregivers, and health care systems. There is therefore a strong unmet need for treatments that can restore effective erythropoiesis. Novel therapies are beginning to address this need by targeting a variety of mechanisms underlying erythropoiesis. Herein, we provide an overview of the role of ineffective erythropoiesis in myelodysplastic syndromes and beta-thalassemia, discuss unmet needs in targeting ineffective erythropoiesis, and describe current management strategies and emerging treatments for these disorders.

TGF-beta signal transduction: biology, function and therapy for diseases

The transforming growth factor beta (TGF-β) is a crucial cytokine that get increasing concern in recent years to treat human diseases. This signal controls multiple cellular responses during embryonic development and tissue homeostasis through canonical and/or noncanonical signaling pathways. Dysregulated TGF-β signal plays an essential role in contributing to fibrosis via promoting the extracellular matrix deposition, and tumor progression via inducing the epithelial-to-mesenchymal transition, immunosuppression, and neovascularization at the advanced stage of cancer. Besides, the dysregulation of TGF-beta signal also involves in other human diseases including anemia, inflammatory disease, wound healing and cardiovascular disease et al. Therefore, this signal is proposed to be a promising therapeutic target in these diseases. Recently, multiple strategies targeting TGF-β signals including neutralizing antibodies, ligand traps, small-molecule receptor kinase inhibitors targeting ligand-receptor signaling pathways, antisense oligonucleotides to disrupt the production of TGF-β at the transcriptional level, and vaccine are under evaluation of safety and efficacy for the forementioned diseases in clinical trials. Here, in this review, we firstly summarized the biology and function of TGF-β in physiological and pathological conditions, elaborated TGF-β associated signal transduction. And then, we analyzed the current advances in preclinical studies and clinical strategies targeting TGF-β signal transduction to treat diseases.

Right in time: Mitapivat for the treatment of anemia in α- and β-thalassemia

Kuo and colleagues¹ evaluated the safety and efficacy of mitapivat, an oral pyruvate kinase activator, in adults with non-transfusion-dependent α-thalassemia or β-thalassemia. The high rate of hemoglobin response and good tolerability encourages further development in thalassemia.

The Roles of Mitophagy and Autophagy in Ineffective Erythropoiesis in β-Thalassemia

β-Thalassemia is one of the most common genetically inherited disorders worldwide, and it is characterized by defective β-globin chain synthesis leading to reduced or absent β-globin chains. The excess α-globin chains are the key factor leading to the death of differentiating erythroblasts in a process termed ineffective erythropoiesis, leading to anemia and associated complications in patients. The mechanism of ineffective erythropoiesis in β-thalassemia is complex and not fully understood. Autophagy is primarily known as a cell recycling mechanism in which old or dysfunctional proteins and organelles are digested to allow recycling of constituent elements. In late stage, erythropoiesis autophagy is involved in the removal of mitochondria as part of terminal differentiation. Several studies have shown that autophagy is increased in earlier erythropoiesis in β-thalassemia erythroblasts, as compared to normal erythroblasts. This review summarizes what is known about the role of autophagy in β-thalassemia erythropoiesis and shows that modulation of autophagy and its interplay with apoptosis may provide a new therapeutic route in the treatment of β-thalassemia. Literature was searched and relevant articles were collected from databases, including PubMed, Scopus, Prospero, Clinicaltrials.gov, Google Scholar, and the Google search engine. Search terms included: β-thalassemia, ineffective erythropoiesis, autophagy, novel treatment, and drugs during the initial search. Relevant titles and abstracts were screened to choose relevant articles. Further, selected full-text articles were retrieved, and then, relevant cross-references were scanned to collect further information for the present review.