Cara Therapeutics, Inc. (Nasdaq: CARA) saw its stock plunge by nearly 40% (as of this writing) when its new non-opioid drug, oral CR845, received mixed results in its phase 2 clinical trial seeking to test its effectiveness in reducing chronic pain in people with osteoarthritis of the hip and knee.
The company tested three different dosages of CR845 – 1mg, 2.5mg and 5mg. The 1mg and 2.5mg dosages failed to provide significant reductions in pain compared to placebo. The 5mg dose did show statistically significant reduction in joint pain for those who specifically had osteoarthritis of the hip, but did not show reduction in joint pain for the combined knee and hip group.
In a press release, Cara Therapeutics’ Joseph Stauffer, D.O., M.B.A., Chief Medical Officer said, “We believe that the present trial of oral CR845 has highlighted the potential of a peripherally acting kappa agonist to provide clinical benefit in a chronic pain population and we’re pleased that statistical significance was achieved for the 5.0 mg dose in patients with OA of the hip.” “The drug was observed to be well tolerated over the treatment period and this overall data set will inform both our dose selection and patient population in designing our next trial of oral CR845 in OA patients.”
According to STAT News (a health, science and medicine publication), “Cara Therapeutics tried to misdirect investors away from the failure of its osteoarthritis pain pill by burying negative results from a mid-stage clinical trial in the middle of a press release issued Thursday night. The ploy didn’t work. Cara shares plunged.”
Wall Street is as tough on details, and pharmaceutical companies are tackling very tough problems.
“Developing effective analgesics that lack the high abuse potential and serious side effects of currently available drug classes remains the most pressing need in chronic pain,” said Dr. Ajay D. Wasan, M.D., M.Sc., Professor of Anesthesiology and Psychiatry, Vice Chair for Pain Medicine, Department of Anesthesiology, University of Pittsburgh Medical Center (UPMC). “The magnitude of the reduction in mean joint pain scores observed in all patients in this trial together with an encouraging safety profile underscores the significant potential of CR845 as a new therapeutic approach for the treatment of chronic inflammatory pain.”
Unlike other narcotics, CR845 doesn’t act on opioid receptors in the brain and central nervous system – which can cause side effects such as respiratory depression, nausea, vomiting, and the euphoria that can lead to abuse and addiction. Instead, CR845 acts on receptors in nerve endings – in what is known as the peripheral nervous system.
National Pain Report wrote about the early clinical data of an injectable version of CR845 in November of 2014, reporting, “Pain Experts Say New Opioid Has ‘Enormous’ Potential”.