PARIS – Each of two oral Janus kinase inhibitors individually showed impressive efficacy and acceptable safety and tolerability for treatment of chronic moderate to severe alopecia areata in a phase 2 study that promises to alter the therapeutic landscape in this challenging disease, Rodney Sinclair, MD, reported at the annual congress of the European Academy of Dermatology and Venereology.
“My personal view is that these results represent a paradigm shift in the treatment of alopecia areata. Perhaps a line in the sand. On the one side, clinical observation, case reports, and small case series, but no reliably effective treatment. And on the other side of the line, investigational new drugs specifically targeting the pathogenesis, tested in prospective, multicenter, double-blind, placebo-controlled studies – and perhaps the first instance of evidence-based medicine arriving for alopecia areata. And I think that our patients with alopecia areata now have reason to be optimistic,” the dermatologist said.
“No reliably effective therapies now exist for alopecia areata, especially for patients with chronic extensive disease. There is an unmet need for a reliably effective therapy with a benefit-to-risk ratio that is appropriate for long-term use,” he added.
The phase 2 multicenter, placebo-controlled, double-blind study randomized 142 patients with chronic alopecia of at least 6 months duration and 50% or greater hair loss at baseline to an, or placebo for 24 weeks. The first 4 weeks of the double-blind trial involved induction dosing of the JAK3 inhibitor at 200 mg per day and the TYK2/JAK 1 inhibitor at 60 mg per day. Thereafter, participants switched to maintenance dosing at 50 mg and 30 mg per day, respectively.
Participants had a median 2.3 years of disease duration; 62 patients had alopecia totalis, and 42 had alopecia universalis.
The primary efficacy endpoint was the mean change from baseline to week 24 in the Severity of Alopecia Tool (SALT) score, a well-validated metric widely utilized in hair loss studies. The mean baseline score was 88.1. At week 24, the score had dropped by a mean of 33.6% in the JAK 3 inhibitor group, 49.5% in the TYK2/JAK1 inhibitor group, and zero in placebo-treated controls.
A key secondary endpoint known as the SALT 30, reflecting at least 30% improvement in SALT score, was achieved in 47.9% of patients on the oral JAK 3 inhibitor, 59.6% of those on the TYK2/JAK1 inhibitor, and by no one in the control group. The utter unresponsiveness of placebo-treated controls confirms the investigators’ success in recruiting a study population with truly chronic alopecia areata, Dr. Sinclair noted.
Of note, 25% of patients on the JAK 3 inhibitor and 31.9% on the TYK2/JAK1 inhibitor achieved a SALT 90 response, and 12.5% and 12.8% reached SALT 100.
Significant improvement on the Eyelash Assessment and Eyebrow Assessment Scales occurred in 45.2% and 36.2% of the JAK 3 inhibitor group and in 60.7% and 51.7% of the TYK2/JAK 1 inhibitor group.
The study is ongoing. It’s Dr. Sinclair’s anecdotal impression that further improvement is occurring in the active treatment arms with continued therapy after 24 weeks, but that remains to be seen.
Adverse events were similar in nature and frequency in all three study arms with one notable exception: two cases of rhabdomyolysis in the TYK2/JAK 1 inhibitor group.Session chair, homed in on that piece of information, pressing for further details.
“Are you concerned? Were there predictors?” asked Dr. Murrell, professor of dermatology at the University of New South Wales in Sydney.
The two affected patients had muscle pain and elevated creatinine kinase levels. “They didn’t feel particularly unwell but were withdrawn as a precaution, after which the condition quickly resolved,” Dr. Sinclair said.
The investigators were unable to identify any risk factors for rhabdomyolysis in the study population, he added.
Dr. Sinclair reported receiving research grants from and serving as a consultant to Pfizer, which sponsored the phase 2 study, as well as more than a dozen other pharmaceutical companies.