GlaxoSmithKline plc, announced the start of a Phase III study, SUPPORT (TRC112121), to evaluate the platelet supportive care effects of eltrombopag (Promacta/Revolade) in combination with azacitidine (the current standard of care) versus placebo in combination with azacitidine in intermediate-1, intermediate-2 or high risk patients with myelodysplastic syndromes (MDS). The global study will assess the proportion of patients who are platelet transfusion free during the first four cycles of treatment.

MDS is a type of cancer in which the bone marrow does not make enough healthy blood cells and there are abnormal (blast) cells in the blood and/or bone marrow. The disease usually manifests itself with 1 or more cytopenias, or reductions in the number of blood cells, and patients typically present with complications related to anaemia (fatigue), neutropenia (infections), or thrombocytopenia (bleeding).  MDS may evolve into acute myeloid leukaemia (AML) in up to 45 per cent of patients.

Dr. Rafael Amado, senior vice president oncology R&D at GSK, said, “Cytopenias are important complications of MDS which tend to worsen with azacitidine treatment. Currently, there are no approved treatments for MDS that stimulate platelet production. The initiation of this study is an important step toward providing a potential treatment option that may support platelets and avoid transfusions in thromobocytopenic patients with MDS undergoing chemotherapy treatment.”

SUPPORT (Study of eltromboPag in myelodysPlastic Syndromes Receiving azaciTidine) is a Phase III, randomised, double-blind, placebo-controlled, multi-centre study of eltrombopag or placebo in combination with azacitidine in subjects with MDS. It is estimated that 350 patients across 30 countries and 156 study sites with a baseline platelet count of < 75Gi/L, and intermediate-1, intermediate-2 or high risk MDS (by International Prognostic Scoring System) will be enrolled in the study. Eligible patients will be randomised to receive either eltrombopag (200 mg once daily [100 mg for East Asians]) plus azacitidine (75 mg/m2 subcutaneously once daily for 7 days) every 28 days, for at least 6 cycles, or placebo plus azacitidine. Dose modifications of eltrombopag or placebo will be permitted to ensure that patient platelet counts remain at a safe and effective level.

The primary efficacy endpoint will determine the platelet supportive care effects of eltrombopag in combination with azacitidine versus placebo in combination with azacitidine by comparing the proportion of subjects receiving eltrombopag plus azacitidine who are platelet transfusion free during the first four cycles of azacitidine, versus those treated with placebo plus azacitidine. Secondary objectives will compare the following between treatment arms: overall survival, disease response, haematologic improvement, platelet and red blood cell transfusions, adverse events (= Grade 3), safety and tolerability, health related quality of life and medical resource utilisation.

Eltrombopag marketed as Promacta in the US. and as Revolade in Europe and other countries across the world—works by interacting with the TPO receptor leading to increased platelet production. Eltrombopag is not approved or licenced anywhere in the world for use in patients with myelodysplastic syndromes.