Photo courtesy of GSK
The US Food and Drug Administration (FDA) has approved an expanded use for eltrombopag (Promacta) to include children 1 year of age and older with chronic immune thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
The updated label also includes a new oral suspension formulation of eltrombopag designed for younger children who may not be able to swallow tablets.
Eltrombopag was previously approved by the FDA in a tablet formulation in June 2015 for ITP patients ages 6 and older and in 2008 for use in adults with ITP.
The label expansion of eltrombopag was based on data from 2 double-blind, placebo-controlled trials—the phase 2 PETIT trial and the phase 3 PETIT2 trial.
PETIT trials: Efficacy
The PETIT trial included 67 ITP patients stratified by age cohort (12-17 years, 6-11 years, and 1-5 years). They were randomized (2:1) to receive eltrombopag or placebo for 7 weeks. The eltrombopag dose was titrated to a target platelet count of 50-200 x 109/L.
The primary efficacy endpoint was the proportion of subjects achieving platelet counts of 50 x 109/L or higher at least once between days 8 and 43 of the randomized period of the study.
Significantly more patients in the eltrombopag arm met this endpoint—62.2%—compared to 31.8% in the placebo arm (P=0.011).
The PETIT2 trial enrolled 92 patients with chronic ITP who were randomized (2:1) to receive eltrombopag or placebo for 13 weeks. The eltrombopag dose was titrated to a target platelet count of 50-200 x 109/L.
The primary efficacy endpoint was the proportion of subjects who achieved platelet counts of 50 x 109/L or higher for at least 6 out of 8 weeks, between weeks 5 and 12 of the randomized period.
Significantly more patients in the eltrombopag arm met this endpoint—41.3%—compared to 3.4% of patients in the placebo arm (P<0.001).
PETIT trials: Safety
For both trials, there were 107 eltrombopag-treated patients evaluable for safety.
The most common adverse events that occurred more frequently in the eltrombopag arms than the placebo arms were upper respiratory tract infection, nasopharyngitis, cough, diarrhea, pyrexia, rhinitis, abdominal pain, oropharyngeal pain, toothache, increased ALT or AST, rash, and rhinorrhea.
Serious adverse events were reported in 8% of patients during the randomized part of both trials, although no serious adverse event occurred in more than 1 patient (1%).
An ALT elevation of at least 3 times the upper limit of normal occurred in 5% of eltrombopag-treated patients. Of those patients, 2% had ALT increases of at least 5 times the upper limit of normal.
There were no deaths or thromboembolic events during either study.
Prescribing information
The recommended dose and schedule of eltrombopag for pediatric patients age 6 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 age 1 to 5 years is 25 mg daily of the powder for oral suspension formulation.
Eltrombopag is marketed as Promacta in the US and Revolade in most other countries. For more information on the drug, see the full prescribing information.
