The U.S. Food and Drug Administration (FDA) initially granted Fast Track designation for tanezumab for the treatment of chronic pain in patients with osteoarthritis (OA) and chronic low back pain (CLBP). If approved, tanezumab would have been the first in a new class of non-opioid chronic pain medications and an important medical advance in the treatment of debilitating pain for patients who do not experience adequate pain relief or cannot tolerate currently available pain medications. Fast Track designation is a process designed to facilitate the development and expedite the review of new therapies to treat serious conditions and fill unmet medical needs.
FDA Arthritis Advisory and Drug Safety and Risk Management Committees reject Tanezumab (TAN) for the treatment of osteoarthritis (OA)
Two committees of the Food and Drug Administration however voted 19-1 against the approval of tanezumab, a nerve growth factor antibody, for the treatment of osteoarthritis Tanezumab has been in development for over 15 year with over 40 clinical trials. A number of clinical trials have been completed that have shown tanezumab to be better than placebo for the treatment of pain associated with osteoarthritis of the knee and hip.
The committees voted against approval of TAN because the low benefits of the agent would not warrant the risk of rapidly progressive osteoarthritis despite the absence of gastrointestinal or cardiovascular side effects usually associated with non-steroidal drugs used frequently for the therapy of OA. Also of concern was the incomplete safety and mitigation measures program from the companies.
Part of the concern mentioned by the members of the panels was the increased risk of more rapidly advancing OA with the concomitant use of NSAIDs and TAN. The chances of limiting this situation was unlikely in the setting of over-the-counter NSAID availability.
As part of the FDA process, individuals are encouraged to send letters to the Advisory committees in regard to the approval of the agent. I have helped design TAN clinical trials for low back pain. TAN was effective compared to placebo for the treatment of low back pain. I wrote a letter in support of the approval of the antibody. I believe that the number of pain therapies available for older patients with osteoarthritis is limited. Another agent without the toxicities associated with acetaminophen, NSAIDs, and opioids would be of overall benefit to these patients
Pfizer and Lilly who are co-promoting this antibody will continue to discuss with the FDA the potential other uses of TAN such as pain relief for metastatic bone pain.
More About Tanezumab
Tanezumab is a humanized monoclonal antibody that selectively targets, binds to and inhibits nerve growth factor (NGF). NGF levels increase in the body as a result of injury, inflammation or in chronic pain states. By inhibiting NGF, tanezumab may help to keep pain signals produced by muscles, skin and organs from reaching the spinal cord and brain. Tanezumab works in a different manner than opioids and other analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs), and in studies to date tanezumab has not demonstrated a risk of addiction, misuse or dependence.
In a recently reported clinical trial 698 patients with OA were treated with placebo (no treatment), two doses of tanezumab 2.5mg, or tanezumab 2.5mg followed by a dose of tanezumab 5mg eight weeks later and directly compared. Tanezumab was generally well tolerated, with approximately 1% of patients discontinuing treatment due to side effects.
Individuals who were treated with two doses of tanezumab separated by eight weeks experienced a statistically significant improvement in pain, physical function and an overall improvement in their OA compared to those receiving placebo.
According to a press release from the developers of tanezumab "There are more than 27 million Americans currently living with osteoarthritis and 23 million living with chronic low back pain, many of whom fail to achieve adequate pain relief despite treatment with various types of pain medications.” The recent opioid epidemic has clearly highlighted the need for new no addictive pain medications to bring relief to these patients.
Results were from a second Phase 3 study evaluating tanezumab in patients with moderate-to-severe OA pain of the knee or hip. Overall 849 individuals were treated with either tanezumab 2.5mg, tanezumab 5mg, or placebo once every 8 weeks over a 24-week treatment period. (3)
Results showed that at 24 weeks, a statistically significant improvement in pain and physical function in patients treated with either tanezumab dose compared with placebo. Tanezumab was found to be well-tolerated and no new safety concerns identified.
These findings add to the growing body of evidence supporting tanezumab as a potential innovative treatment option for individuals with osteoarthritis and other forms of chronic pain.