Second Trial Approved for Cancer Pain Drug

Euphorbia resinifera plant (James Steakley, Wikimedia Commons)

29 June 2017. The U.S. Food and Drug Administration approved a new clinical trial to test the efficacy and safety of an experimental drug designed to relieve stubborn chronic pain associated with cancer. The approval clears the way for the study to proceed testing the drug resiniferatoxin, made by Sorrento Therapeutics in San Diego.

Resiniferatoxin is a non-opioid compound addressing the Transient Receptor Potential Vanilloid 1, or TRPV1, pathway activating sensory pain signals toward the central nervous system. The drug is derived from euphorbia resinifera plants, a type of cactus, whose ingredients include chemicals similar to capsaicin, the pain-relieving ingredient in hot pepper.

Sorrento is offering resiniferatoxin to help cancer patients suffering severe intractable pain, administered as an injection in the lumbar (lower) back region. The company says resiniferatoxin has been shown to interact with nerve cells expressing TRPV1 receptors, without affecting an individual’s sense of touch or muscle function.

Sorrento and two agencies of National Institutes of Health are collaborating on an early stage clinical trial testing resiniferatoxin with 12 terminal cancer patients at NIH in Bethesda, Maryland. The company says early results of the trial show a single injection of resiniferatoxin is well tolerated by recipients, who report less pain and reduced use of opioids. In addition, participants do not report adverse effects, such as cognitive impairment, sedation, or respiratory depression.

FDA’s action approves Sorrento’s investigational new drug application allowing further clinical trials to proceed. FDA earlier granted resiniferatoxin orphan drug status. The new trial is also expected to be an early-stage study, but will likely test the safety and tolerability of increasing doses of resiniferatoxin, or RTX, as well as track the extent of pain relief provided to patients. The company expects the study will be held in multiple locations, but no further details about the trial were provided.

Sorrento Therapeutics is a developer of synthetic antibodies for cancer immunotherapies, as well as treatments for inflammation and autoimmune disorders. Company president Henry Ji says in a statement, “Given its unique mechanism of action, we view RTX as a franchise molecule, uniquely positioned to halt the neurogenic inflammation cycle in a number of clinical indications. Our intention is to commence our clinical path in cancer since more than 80 percent of cancer patients experience uncontrolled pain during their disease and 20 percent of these patients remain unresponsive or intolerant to mainstay, opioid therapy.”

More from Science & Enterprise:

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• 23andMe, Grünenthal Partner on Pain Genetics
• Mobile App-Controlled Patch Reduces Migraine Pain
• Teva Licenses Pain Relief Antibody for $1.25 Billion
• Non-Addictive Pain Medication Shown Working in Animals

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