Food and Drug Administration Panel Supports Pexidartinib for Tenosynovial Giant Cell Tumor

The Food and Drug Administration (FDA)’s Oncologic Drugs Advisory Committee (ODAC) voted 12 to 3 in favor of the agency approving pexidartinib to treat adult patients with symptomatic tenosynovial giant cell tumor — a rare, benign lesion that can be locally aggressive and often recurring.

With this, the FDA will now make a decision on the pexidartinib indication by Aug. 3, 2019.

The purpose of the Oncologic Drugs Advisory Committee is to review and evaluate data concerning the safety and effectiveness of marketed and investigational human drug products for their use in the treatment of cancer. In turn, the committee makes appropriate recommendations to the FDA’s commissioner.

For this meeting, the committee was tasked to assess the clinical benefit of pexidartinib in this patient population, as the interpretation of the activity was limited due to a proportion of data missing at 25 weeks for several secondary endpoints, including range of motion, physical function and worst stiffness in the multicenter, double-blind phase 3 ENLIVEN study.

Moreover, the panel also aimed to characterize the risk of liver injury in patients with tenosynovial giant cell tumor who received therapy with pexidartinib. In the trial, which comprised the majority of data that were submitted to the FDA, the overall response rate was 39.3% with pexidartinib versus 0% with placebo following 24 weeks of treatment based on central review of MRI scans.

In addition, pexidartinib was associated with increases in alanine aminotransferase (ALT; 67%), aspartate aminotransferase (AST; 90%) and total bilirubin (12%) — which all reached grade 3 or higher severity in one-third of patients. The FDA briefing document for ODAC also stated the long-term safety profile of pexidartinib was unknown.

TGCT, which is also known as pigmented villonodular synovitis or giant cell tumor of the tendon sheath, is a nonmalignant tumor of the joint or tendon sheath. The disease can be locally aggressive and debilitating, and is associated with severe morbidity or function limitations. Currently surgery is the primary treatment for patients with TGCT; there are no FDA-approved systemic therapies.

The FDA’s ODAC is an independent panel of experts that evaluates data concerning the efficacy and safety of marketed and investigational products for use in the treatment of cancer and makes appropriate recommendations to the FDA. While the agency considers these panel recommendations, of note, the FDA solely makes the final decision regarding the approval of agents and the recommendations by the panel are non-binding.

This article was adapted from an article that originally appeared on OncLive, titled “FDA Panel Backs Pexidartinib for Tenosynovial Giant Cell Tumor.”