FDA Approves Eltrombopag for Pediatric Patients With Chronic Immune Thrombocytopenia
The U.S. Food and Drug Administration approved eltrombopag (Promacta) for the treatment of thrombocytopenia in pediatric patients aged 1 year and older with chronic immune thrombocytopenia who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
The approval was based on two randomized, double-blinded, placebo-controlled trials enrolling pediatric patients with chronic immune thrombocytopenia. The PETIT trial was a phase II trial with the primary efficacy endpoint of the proportion of subjects achieving platelet counts greater than or equal to 50×109/L at least once between days 8 and 43 of the randomized period of the study. Patients were stratified by age cohort (12–17 years, 6–11 years, and 1–5 years), and 67 patients were randomly assigned (2:1) to receive eltrombopag or placebo for 7 weeks.
The eltrombopag dose was titrated to a target platelet count of 50 to 200×109/L. The percentage of responders was statistically significantly higher in patients treated with eltrombopag compared with placebo (62.2% vs 31.8%, P = .011).
The PETIT2 trial was a phase III trial with the primary efficacy endpoint of the proportion of subjects receiving eltrombopag, compared with placebo, who achieved platelet counts greater than or equal to 50×109/L for at least 6 of 8 weeks, between weeks 5 to 12 of the randomized period.
In the randomized period, 92 pediatric patients with chronic immune thrombocytopenia were randomly assigned (2:1) to receive eltrombopag or placebo for 13 weeks. The eltrombopag dose was titrated to a target platelet count of 50 to 200×109/L. More patients in the eltrombopag group met the primary endpoint than in the placebo group (41.3% vs 3.4%, P < .001).
Adverse Events
Safety data were evaluated in 107 patients who were randomly assigned to eltrombopag during both trials. The most common adverse reactions that occurred more frequently in patients treated with eltrombopag were upper respiratory tract infection, nasopharyngitis, cough, diarrhea, pyrexia, rhinitis, abdominal pain, oropharyngeal pain, toothache, alanine transaminase increased, rash, aspartate transaminase increased, and rhinorrhea.
Serious adverse reactions were reported in 8% of patients during the randomized part of both trials, with no serious adverse event occurring in more than one patient (1%). An elevation of alanine transaminase greater than or equal to three times the upper limit of normal occurred in 5% of patients in the eltrombopag group; of those patients, 2% had increases in alanine transaminase greater than or equal to five times the upper limit of normal. No deaths or thromboembolic events occurred during either study.
The recommended dose and schedule for pediatric patients 6 years and older is 50 mg daily or 25 mg daily of the tablet formulation for patients with East Asian ancestry. The recommended dose for all patients aged 1 to 5 years is 25 mg daily of the powder for the oral suspension formulation.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
