Luspatercept is under clinical development by Merck & Co and currently in the Phase II and Phase III in clinical pathway. The characteristics of the clinical trial as well as other attributes related to the drug, regulations, and company play a fundamental role in ensuring the likelihood of transition that the drug moves from its current development stage to next.

According to GlobalData, the latest event to affect Luspatercept’s likelihood of approval (LoA) and phase transition for Post-Essential Thrombocythemia Myelofibrosis (Post-ET MF) took place on 19 Oct 2022, which increased the likelihood that the drug progresses to the next phase in its clinical pathway and increased the likelihood of final approval for this indication.

In addition, the same event on 19 Oct 2022 increased Luspatercept’s LoA and decreased Phase Transition Success Rate (PTSR) for Myelofibrosis, and increased LoA and PTSR for Post-Polycythemia Vera Myelofibrosis (PPV-MF).

GlobalData uses proprietary data and analytics to provide a complete picture of this assessment in their Luspatercept Likelihood of Approval (LoA) and Phase Transition Success Rate (PTSR) Report.

Luspatercept overview

Luspatercept-AMT (Reblozyl) is a recombinant fusion protein, it is produced in chinese hamster ovary cells by recombinant DNA technology, acts as an erythroid maturation agent. It is formulated as lyophilized powder for solution for subcutaneous route of administration. Reblozyl is indicated for the treatment of anemia in adult patients with beta thalassemia who require regular red blood cell (RBC) transfusions,and for the treatment of adult patients with transfusion-dependent anemia due to very low-, low- and intermediate-risk myelodysplastic syndromes (MDS) with ring sideroblasts, who had an unsatisfactory response or are ineligible for erythropoietin-based therapy, and adult patients with transfusion-dependent anemia associated with beta thalassemia.

Luspatercept (ACE-536) is under development for the treatment of anemia due to myelodysplastic syndrome, non-transfusion dependent (NTD) beta thalassemia, alpha-thalassemia, beta-thalassemia, anemia in myelofibrosis, post polycythemia vera myelofibrosis, post essential thrombocythemia myelofibrosis. The drug candidate is a recombinant fusion protein administered subcutaneously as a solution. Luspatercept is a modified activin receptor type IIB fusion protein. It is a GDF11 and GDF-8 inhibitor. It was also under development for sickle cell disease.

Merck & Co overview

Merck & Co (Merck) is a biopharmaceutical company focused on the discovery, development, manufacturing and marketing of prescription medicines, biologic therapies, vaccines and animal health products. It offers prescription products for therapy areas related to cardiovascular, cancer, immune disorders, infectious, respiratory and women’s diseases, and diabetes. The company provides animal health products such as vaccines, poultry products, livestock products and aquaculture products. Merck sells medicines to drug wholesalers, retailers, hospitals, government agencies and managed health care providers; and animal health products to veterinarians, distributors and animal producers. The company and its subsidiaries operate in the Americas, Europe, the Middle East, Africa, Asia Pacific, and Latin America. Merck is known as MSD outside the US and Canada and is headquartered in Kenilworth, New Jersey, the US.

Quick View Luspatercept LOA Data

Report Segments
  • Innovator (NME)
Drug Name
  • Luspatercept
Administration Pathway
  • Subcutaneous
Therapeutic Areas
  • Hematological Disorders
  • Oncology
Key Developers
  • Sponsor Company: Merck & Co
  • Originator: Acceleron Pharma
Highest Development Stage
  • Marketed


GlobalData, the leading provider of industry intelligence, provided the underlying data, research, and analysis used to produce this article.

GlobalData’s Likelihood of Approval analytics tool dynamically assesses and predicts how likely a drug will move to the next stage in its clinical pathway (PTSR), as well as how likely the drug will be approved (LoA). This is based on a proprietary algorithm built from the drugs’ sales forecast, regulatory milestones, cost forecasts, WACC rate and other proprietary data sources found on GlobalData’s Pharmaceutical Intelligence Center.