Shionogi & Co., Ltd. and Grünenthal GmbH announced that they have entered into a licensing agreement to commercialize injectable resiniferatoxin, a pipeline product of Grünenthal, in Japan for the treatment of pain in patients with osteoarthritis of the knee. RTX, which is currently being developed by Grünenthal, is a highly potent Transient Receptor Potential Vanilloid 1 (TRPV1) agonist, which can reversibly desensitize TRPV1-expressing nociceptors. This mechanism may result in long-lasting pain relief.

A prior clinical trial shows a significant analgesic effect compared to placebo, with the effect persisting for about a half year after a single injection. RTX is currently in Phase III clinical development for the treatment of patients with moderate to severe pain associated with knee osteoarthritis in Europe, the US, Latin America, South Africa and Japan. Under the terms of the agreement, Shionogi obtained the exclusive rights to commercialize RTX in Japan.

Grünenthal will conduct the development, manufacturing and supply of RTX, and Shionogi will be responsible for distribution and commercialization of RTX, after obtaining an approval of Marketing Authorization in Japan. Shionogi will make an upfront payment to Grünenthal, and Grünenthal will be eligible to receive additional milestones for a total consideration of > $500 million, including an upfront payment of $75 million. Grünenthal will receive tiered royalties on sales of RTX, if the sales in Japan exceed a certain amount.

Osteoarthritis is a joint disease in which the tissues in the joint break down over time due to cartilage loss and tissue inflammation, and is common among people aged 65 and over. Current approaches to management of osteoarthritis pain include exercise regimens, systemic non-steroidal anti-inflammatory drugs (NSAIDs), intra- articular treatments such as hyaluronic acid, and surgery, but considerable medical needs remain and new treatment options are in demand. Shionogi has declared in STS2030 that it will focus on CNS diseases and pain, and infectious disease, as its priority disease area.