The Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to CTP-543 (Concert Pharmaceuticals), an oral Janus kinase (JAK) inhibitor for alopecia areata.

CTP-543 was developed by modifying ruxolitinib, a selective JAK1 and JAK2 inhibitor, using the Company’s deuterated chemical entity platform. The designation is supported by data from a double-blind, placebo-controlled phase 2 study evaluating the safety and efficacy of CTP-543 in adult patients with moderate to severe alopecia areata. Patients were randomized to receive CTP-543 4mg (n=30), 8mg (n=38), 12mg (n=37) or placebo (n=44) twice daily for 24 weeks. 

The co-primary end points of the study were the proportion of patients with ≥50% relative reduction from baseline in the Severity of Alopecia Tool [SALT]) score, where 0% represents no scalp hair loss and 100% represents total scalp hair loss, as well as the number of patients with adverse events. The average baseline SALT score across all patients was roughly 88%.

Results showed that at week 24, a significantly greater percentage of patients treated with the 8mg twice daily (47%) and 12mg twice daily (58%) regimens had a ≥50% relative reduction in SALT, compared with those who received placebo (9%) (P <.001). Moreover, 26% of patients in the 8mg group and 42% of patients in the 12mg group achieved a SALT score of ≤20 at 24 weeks compared with 7% of patients in the placebo group. The treatment was found to be generally well tolerated. 

Related Articles

A phase 3 trial is expected to begin in the fourth quarter of 2020. 

For more information visit