On Friday, shares in Cara Therapeutics (CARA -7.67%) shot higher after management reported that the U.S. Food and Drug Administration had awarded "breakthrough therapy" designation to the IV formulation of its anti-pain and anti-itch medicine CR845, for uremic pruritis, or chronic itch, in patients with kidney disease. Today, shares are up an additional 9.5% at 3:30 p.m. EDT.
Earlier this year, Cara Therapeutics reported phase 2/3 data from part A of its study showing that CR845 might provide welcome relief of uremic pruritis.
Specifically, CR845 patients had a 68% reduction in pain versus a placebo, based on a 0-to-10 rating scale after eight weeks of treatment. CR845 also delivered a 100% greater reduction versus a placebo on the Skindex-10 scale, which measures quality of life.
The findings were good enough for the FDA to award the drug breakthrough status because current treatments, including antihistamines and corticosteroids, often fall short for many patients. Since uremic pruritus can be a big cause of diminishing quality of life in these patients, new treatment options are necessary.
There are 468,000 Americans with kidney failure who are on dialysis. About 60% of them suffer from uremic pruritus, and between 30% and 40% of them report it to be moderate to severe.
While winning breakthrough designation doesn't guarantee future FDA approval, it does provide management with ongoing FDA assistance that can help it avoid pitfalls and improve the likelihood of crossing the finish line. Of course, any filing for FDA approval will depend on the phase 3 part of this study confirming the strong efficacy and safety observed in part A.
Investors should also know that CR845 is being evaluated in other indications, including postoperative pain and osteoarthritis. Unlike opioids, CR845 doesn't cross the blood-brain barrier, and thus it may have fewer side effects and produce less euphoria than opioids. Because there's significant desire to reduce the use of opioids, CR845 has the potential to reshape pain treatment.