Pfizer Phase 2a study in alopecia areata met primary, secondary endpoints
Pfizer announced results from its Phase 2a study of PF-06651600, an oral Janus kinase 3 inhibitor, and PF-06700841, a tyrosine kinase 2/JAK1 inhibitor, compared to placebo, in patients with moderate to severe alopecia areata, an autoimmune disease characterized by hair loss and often associated with profound psychological consequences. Both JAK inhibitors met the primary efficacy endpoint in improving hair regrowth on the scalp relative to baseline at week 24 as measured by the Severity of Alopecia Tool score. The study found that the placebo-adjusted mean in SALT change from baseline scores at Week 24 were 33.6 points for PF-06651600 and 49.5 points for PF-06700841, with statistically significant separation from placebo occurring as early as Week 6 and Week 4, respectively. In addition to meeting the primary efficacy endpoint, the investigational candidates also met all secondary endpoints in this study. "We are pleased with these results and excited by the potential of kinase inhibition as a new therapeutic target for patients living with alopecia areata. This is the first well-controlled study of oral JAK inhibitors in alopecia areata, helping enhance our understanding of this disease with significant unmet need and advance the science of kinase inhibition," said Michael Vincent, M.D, Ph.D., Senior Vice President and Chief Scientific Officer, Pfizer Inflammation and Immunology. Pfizer said that based on the "totality of the data and the emerging clinical profiles," the investigational JAK3 inhibitor, which was recently granted Breakthrough Therapy designation from FDA for alopecia areata, is advancing to the next phase of development for moderate to severe alopecia areata and will continue to be evaluated for rheumatoid arthritis, Crohn's disease and ulcerative colitis. PF-06700841 will continue to be evaluated for psoriasis, CD and UC.