Resiniferatoxin Gets Breakthrough Therapy Status for Knee OA Pain

The Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to resiniferatoxin for the treatment of pain associated with osteoarthritis of the knee.

Resiniferatoxin is a highly potent transient receptor potential vanilloid 1 (TRPV1) agonist that is extracted from a cactus-like plant. It is similar to capsaicin, with some differences in potency. The investigational product is administered via intra-articular injection and is expected to provide pain relief through reversible defunctionalization of TRPV1-expressing nociceptors. 

“Millions of patients suffering from knee osteoarthritis are waiting for additional treatment options,” said Jan Adams, MD, Chief Scientific Officer Grünenthal. “Resiniferatoxin targets one of the most common and severe symptoms of this currently incurable disease: pain.”

The Company is initiating a global phase 3 program, with a goal of enrolling more than 1800 patients with knee osteoarthritis who have insufficient pain relief with available nonsurgical treatment options. The efficacy endpoints will focus on an improvement in the pain and physical function score in the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index from baseline up to 52 weeks.

“We are hopeful that the Breakthrough Therapy Designation will help us to bring this non-opioid therapy option more quickly to patients,” added Adams.

This article originally appeared on MPR


  1. Grünenthal’s resiniferatoxin receives Breakthrough Therapy designation from US FDA for pain associated with osteoarthritis of the knee. News release. Grünenthal Group. Accessed May 22, 2023.