FDA granted Breakthrough Therapy Designation to pexidartinib (formerly PLX3397) for the treatment of tenosynovial giant cell tumor where surgical removal of the tumor would be associated with potentially worsening functional limitation or severe morbidity.
Currently, there is no FDA-approved systemic therapy for the treatment of TGCT. The designation was granted based on results from an extension cohort of a single-arm, multi-center phase I study that assessed the safety and efficacy of pexidartinib. Results of this study were published in The New England Journal of Medicine.
A pivotal phase III trial of pexidartinib called ENLIVEN is currently enrolling patients with symptomatic TGCT for whom surgical removal of the tumor would be associated with potentially worsening functional limitation or severe morbidity.
Pexidartinib is an oral small molecule that potently and selectively inhibits colony stimulating factor-1 receptor, which is a primary growth driver of abnormal cells in the synovium that causes TGCT. Pexidartinib has not been approved by FDA or any other regulatory authority for uses under investigation.
In addition to Breakthrough Therapy Designation, pexidartinib has been granted Orphan Drug Designation by FDA for the treatment of PVNS and GCT-TS. Pexidartinib also has received Orphan Designation from the European Commission for the treatment of TGCT. Pexidartinib is sponsored by Daiichi Sankyo Inc. and Plexxikon Inc., a member of the Daiichi Sankyo Group.
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