Concert Pharmaceuticals’ alopecia drug met its primary endpoint in a phase 2a trial, reducing disease severity in nearly half of the patients who received a higher dose. The company has one more dosing group to wrap up before it completes the study and moves on.
Patients in the double-blind, placebo-controlled trial were randomized to receive a 4-mg, 8-mg or 12-mg dose of the drug, CTP-543, or placebo twice a day. Concert reported data from the two lowest doses after 24 weeks of treatment. The 8-mg dose met the trial’s primary endpoint in 47% of patients, in whom it reduced their overall severity of alopecia tool (SALT) score by 50% or more. The 4-mg dose did not fare as well, achieving that reduction in 21% of patients, which wasn’t “statistically different from placebo,” the company said.
"The data that we have are very promising because it has a high level of hair regrowth and also that the hair continues to grow throughout the course of the study. Even at the six-month, 24-week time point, it does not appear to have plateaued," said Concert CEO Roger Tung in an interview.
The investigators reported no serious adverse events, but some patients did experience side effects, the most common of which included headache, upper respiratory tract infection, cough, acne and nausea.
The company is still evaluating the group receiving the 12-mg dose and expects to report full data from the study in the third quarter of 2019. While Concert expects the 12-mg dose to perform even better than the 8-mg dose, Tung said that the lower dose still improved upon any treatments currently in use. The safety and efficacy at 8 mg were enough to take the drug forward at that dose level, he said.
Concert is trying to fill a gap in the treatment of alopecia areata, an autoimmune disease in which the immune system attacks hair follicles, causing hair to fall out in small patches. According to the National Alopecia Areata Foundation, current treatments are borrowed from other disease areas and may work for some people but not others. These include oral, topical and injected corticosteroids.
CTP-543 is a deuterated version of ruxolitinib, a JAK inhibitor marketed by Incyte in the U.S. as Jakafi. This means the drug has deuterium instead of hydrogen in some places but is otherwise the same molecule. Deuterating ruxolitinib “was found to alter its human pharmacokinetics in ways which may enhance its use as a treatment for alopecia areata,” the company says, and the FDA has fast-tracked the drug. However, this approach has resulted in an IP headache for Concert; in 2017, Concert filed a post grant review petition against Incyte in a bid to chip away at the scope of a patent covering ruxolitinib, but in January, a patent board disagreed with Concert and did not grant the petition.
“We remain committed to developing the first FDA-approved treatment for alopecia areata; however, we are reassessing whether to expand CTP-543 into additional indications,” Tung said at the time.
Editor's note: This story has been updated to include comments from Concert Pharmaceuticals' CEO Roger Tung.