FDA Grants Breakthrough Therapy Designation to Abbisko’s Pimicotinib

Rare Daily Staff

The U.S. Food and Drug Administration granted Abbisko Therapeutics Breakthrough Therapy designation for pimicotinib, its experimental therapy for the treatment of the rare cancer tenosynovial giant cell tumor in patients who are not amenable to surgery.

Tenosynovial giant cell tumor (TGCT), also known as pigmented villonodular synovitis, is a locally aggressive neoplasm which affects synovial joints, mucous sacs, and tendon membranes, resulting in swelling, pain, stiffness, and decreased activity of the affected joints which seriously affect the patient’s quality of life. Overexpression of colony-stimulating factor 1 (CSF1) occurs in most TGCTs.

Pimicotinib is a novel, orally available, highly selective, and highly potent small molecule inhibitor of CSF-1R independently discovered and developed by Abbisko Therapeutics. Studies have shown that blocking the CSF-1R signaling pathway could effectively modulate and change macrophage functions, and potentially treat many macrophage-dependent human diseases. Pimicotinib is currently being investigated as a treatment for TGCT and chronic graft-versus-host disease (CGVHD), and is under evaluation as treatment for a number of other indications.

In addition to TGCT and cGVHD, Abbisko Therapeutics is actively exploring the potential of ABSK021 in treating many other types of solid tumors and has collaborated with Sperogenix MedTech in exploring its potential for treating amyotrophic lateral sclerosis (ALS) among other central nervous system disorders. Currently, no highly selective CSF-1R inhibitor has been approved in China.

The Breakthrough Therapy designation is based on results from the phase 1b clinical trial of pimicotinib in tenosynovial giant cell tumor. Abbisko Therapeutics also completed a phase 1a dose escalation study for ABSK021 in the United States and is conducting an ongoing phase 1b multi-cohort expansion trial in both the United States and China.

Breakthrough Therapy designation is a process designed by the US FDA, China CDE, and other regulatory agencies to expedite the development and review of drugs that are intended to treat a serious condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint.

“The granting of this designation also marks an essential step in the R&D and innovation of Abbisko Therapeutics in going global,” said Xu Yao-Chang, the chairman and CEO of Abbisko Therapeutics. “Pimicotinib’s U.S. Breakthrough Therapy designation shows FDA’s recognition of pimicotinib’s early data and affirmation of the company’s R&D strength. It will make our clinical development process and finished drug progress more efficient, which will help shorten the time to market and benefit patients worldwide as soon as possible.”