FDA expands approval of Promacta for pediatric patients with ITP

The FDA today expanded the approval of eltrombopag for children aged 1 year or older with chronic immune thrombocytopenia who experienced an insufficient response to corticosteroids, immunoglobulins or splenectomy.

In June, the FDA approved eltrombopag (Promacta, Novartis) for children aged 6 years or older with chronic immune thrombocytopenia (ITP) who do not achieve an appropriate response to other ITP medicines or splenectomy.

Eltrombopag is available as a tablet, or as a powder that is mixed with liquid for children aged 1 to 5 years to take orally. The therapy is intended for patients only whose degree of thrombocytopenia and clinical condition increase the risk for bleeding.

The FDA based its decision in part on results from two double-blind, placebo-controlled trials that evaluated the safety and efficacy of eltrombopag in patients aged 1 to 17 years with chronic ITP. One of these studies was the largest phase 3 clinical trial in this patient population, according to a press release from the FDA.

An increase in platelet counts served as the primary endpoint of both trials.

In the first trial, researchers randomly assigned 67 pediatric patients with chronic ITP eltrombopag or placebo daily for 7 weeks. Results showed 62% of patients assigned eltrombopag experienced an improvement in platelet counts without rescue therapy between weeks 1 and 6, compared with 32% who received placebo.

In the second trial — composed of 92 patients — those who received eltrombopag daily for 13 weeks experienced a 41% increase in platelet counts for at least 6 out of 8 weeks between weeks 5 and 12, compared with 3% of patients who received placebo.

Results of both trials showed that eltrombopag reduced the need for subsequent treatments to increase platelet counts, including corticosteroids or platelet transfusions.

Further, of the patients taking one or more ITP medications at the start of the trial, about half were able to reduce or discontinue their use of these medications, primarily corticosteroids.

The most common adverse events associated with the use of eltrombopag in children aged 1 year and older are infections of the upper respiratory tract or nose and throat, diarrhea, abdominal pain, rash and increase in liver enzymes.

The safety and efficacy of eltrombopag in children with ITP aged younger than 1 year, as well as those with thrombocytopenia associated with hepatitis C and severe aplastic anemia, has not yet been defined, according to the FDA.

“Today’s approval of Promacta emphasizes the FDA’s commitment to fully developing treatments in areas of pediatric hematology and oncology,” Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a press release. “This new use in ages 1 and up builds on a recent approval for ages 6 years and up, and fills an unmet need for young children whose disease has progressed after use of other available treatments.”