Pexidartinib


Pexidartinib, sold under the brand name Turalio, is a kinase inhibitor drug for the treatment of adults with symptomatic tenosynovial giant cell tumor associated with severe morbidity or functional limitations and not amenable to improvement with surgery.
On 2 August 2019, it was approved by U.S. FDA for treatment of giant-cell tumor of the tendon sheath.
Common side effects are increased lactate dehydrogenase, increased aspartate aminotransferase, loss of hair color, increased alanine aminotransferase and increased cholesterol. Additional side effects include neutropenia, increased alkaline phosphatase, decreased lymphocytes, eye edema, decreased hemoglobin, rash, dysgeusia and decreased phosphate.
The US prescribing information for pexidartinib includes a boxed warning about the risk of serious and potentially fatal liver injury.
Pexidartinib is available in the US only through the Turalio Risk Evaluation and Mitigation Strategy Program.

History

The approval of pexidartinib was based on the results of a multi-center international clinical trial of 120 subjects, 59 of whom received placebo. The primary efficacy endpoint was the overall response rate analyzed after 25 weeks of treatment. The clinical trial demonstrated a statistically significant improvement in ORR in subjects who received pexidartinib, with an ORR of 38%, compared to no responses in subjects who received placebo. The complete response rate was 15% and the partial response rate was 23%. A total of 22 out of 23 responders who had been followed for a minimum of six months following the initial response maintained their response for six or more months, and a total of 13 out of 13 responders who had been followed for a minimum of 12 months following the initial response maintained their response for 12 or more months.
The U.S. Food and Drug Administration granted the application for pexidartinib breakthrough therapy designation, orphan drug designation, and priority review designation. The FDA granted the approval of Turalio to Daiichi Sankyo.