FDA Approves Pexidartinib for Symptomatic TGCTs

The FDA has approved pexidartinib (Turalio; Daiichi Sankyo) in capsule form for the treatment of adults with symptomatic tenosynovial giant cell tumors (TGCTs) that cannot be improved with surgery and is associated with severe morbidity or functional limitations. The application for this drug was granted Breakthrough Therapy, Orphan Drug, and Priority Review designations.

“TGCT can cause debilitating symptoms for patients such as pain, stiffness and limitation of movement. The tumor can significantly affect a patient’s quality of life and cause severe disability,” said Richard Pazdur, MD, Director of the FDA’s Oncology Center of Excellence, in a press statement.

“Surgery is the primary treatment option, but some patients are not eligible for surgery, and tumors can recur, even after the procedure. Today’s approval is the first FDA-approved therapy to treat this rare disease,” he continued.

This approval was based on an international, multi-center clinical trial of 120 patients (59 of whom were given placebo) that had a primary efficacy end point of overall response rate (ORR) following 25 weeks of therapy.

Patients who received pexidartinib had a statistically significant improvement in ORR (38%) compared with no responses in recipients of placebo. The complete and partial response rates were 15% and 23%, respectively.

Of 23 responders, 22 patients who had been followed for a minimum of 6 months maintained their initial response for ≥6 months, and 13 responders who had been followed for a minimum of 12 months maintained their initial response for at least a year.

Side effects most frequently reported with pexidartinib include increased lactate dehydrogenase, increased aspartate aminotransferase, hair color loss, increased alanine aminotransferase, and increased cholesterol. Other side effects include neutropenia, increased alkaline phosphatase, decreased lymphocytes, eye edema, reduced hemoglobin, rash, dysgeusia, and decreased phosphate.—Hina Khaliq

Source: US Food and Drug Administration. FDA approves first therapy for rare joint tumor. August 2, 2019. https://www.fda.gov/news-events/press-announcements/fda-approves-first-therapy-rare-joint-tumor. Accessed August 5, 2019.