Photo courtesy of GSK
Eltrombopag (Promacta)
The U.S. Food and Drug Administration (FDA) has expanded the approved use of eltrombopag (Promacta®) in severe aplastic anemia (SAA).
Eltrombopag is now approved for use in combination with standard immunosuppressive therapy as first-line treatment for adults and pediatric patients age 2 and older with SAA.
Eltrombopag received breakthrough therapy designation and priority review for this indication.
Eltrombopag is also FDA-approved for SAA patients who have had an insufficient response to immunosuppressive therapy, for patients with chronic immune thrombocytopenia who have had an insufficient response to other treatments, and to treat thrombocytopenia in patients with chronic hepatitis C virus infection.
The FDA’s latest approval of eltrombopag is based on results from a phase 1/2 trial (NCT01623167), which were published in The New England Journal of Medicine in April 2017.
Updated results from the trial are available in the prescribing information for eltrombopag.
The trial included 153 previously untreated SAA patients age 2 and older. The patients received eltrombopag in combination with horse antithymocyte globulin and cyclosporine.
The starting dose of eltrombopag was:
- 150 mg once daily for patients age 12 and older (75 mg for East and Southeast Asians)
- 75 mg once daily for patients ages 6 to 11 (37.5 mg for East and Southeast Asians)
- 5 mg/kg once daily for patients ages 2 to 5 (1.25 mg/kg for East and Southeast Asians).
Patients were divided into three cohorts with different dosing schedules.
The recommended schedule, from the third cohort (n=92), was eltrombopag from day 1 to month 6, plus horse antithymocyte globulin and cyclosporine. All patients in this cohort were eligible to receive a low dose of cyclosporine for an additional 18 months if they achieved a hematologic response at 6 months.
Among the patients treated at the recommended dosing schedule, the 6-month overall response rate was 79%, and the complete response rate was 44%.
The median duration of both overall and complete response was 24.3 months.
The most common adverse events in these patients were ALT increase (29%), AST increase (17%), blood bilirubin increase (17%), rash (8%), and skin discoloration including hyperpigmentation (5%).
Eltrombopag is a product of Novartis.