The FDA expanded the approval of eltrombopag to include the first-line treatment of patients with severe aplastic anemia.
The indication applies to use of eltrombopag (Promacta, Novartis) with standard immunosuppressive therapy for adults and children aged 2 years and older.
Eltrombopag — an oral thrombopoietin receptor agonist — is designed to boost low platelet counts via once-daily tablets. It is the first new treatment in several decades in the United States for newly diagnosed severe aplastic anemia.
“Severe aplastic anemia can be a fatal diagnosis if left untreated, and many patients fail to respond to current initial treatment options,” Liz Barrett, CEO of Novartis Oncology, said in a company-issued press release. “[This] U.S. approval for Promacta is an important step forward for people living with this challenging disease and shows how Novartis continues to reimagine care in areas where few treatment options exist.”
Eltrombopag previously had been approved for patients with severe aplastic anemia who had insufficient response to immunosuppressive therapy. It also had been approved for adults and children with chronic immune thrombocytopenia refractory to other treatments, as well as for treatment of thrombocytopenia among patients with chronic hepatitis C virus infection.
The FDA based the new indication on results of NHLBI-sponsored research that included immunosuppressive therapy-naive patients with severe aplastic anemia. All study participants received eltrombopag concurrently with standard immunosuppressive therapy.
At 6 months, 79% (95% CI, 69-87) had responded to therapy and 44% (95% CI, 33-55) achieved a complete response. The complete response rate was 27% higher than that historically observed with standard immunosuppressive therapy alone.
Median duration of response was 24.3 months among patients who received 6 months of eltrombopag in combination with horse antithymocyte globulin and cyclosporine followed by maintenance cyclosporine.
The most common adverse reactions reported among at least 5% of the study population included abnormal liver function tests, rash and skin discoloration, including hyperpigmentation.
The FDA also granted breakthrough therapy designation to eltrombopag (Promacta, Novartis) as a counter measure for hematopoietic subsyndrome of acute radiation syndrome, also known as radiation sickness.
This condition — which arises after exposure to ionizing radiation — can lead to several symptoms, including thrombocytopenia.