from clinical trials of two drugs presented at a late-breaker research session at the annual meeting of the American Academy of Dermatology.
Based on phase 3 studies that document robust hair growth in about one third of patients, deuruxolitinib (CTP-543), an inhibitor of the JAK1 and JAK2 enzymes, has the potential to become the second JAK inhibitor available for the treatment of alopecia areata. If approved, it will join baricitinib (Olumiant), which received U.S. approval almost 1 year ago.
In his talk on THRIVE-AA2, a phase 3 trial of the investigational medicine deuruxolitinib, the principal investigator, Brett A. King, MD, PhD, displayed several before-and-after photos and said, “The photos tell the whole story. This is why there is so much excitement about these drugs.”
THRIVE-AA2 was the second of two phase 3 studies of deuruxolitinib. King was a principal investigator for both pivotal trials, called THRIVE-AA1 and THRIVE AA-2. He characterized the results of the two THRIVE trials as “comparable.”
Dr. King also was a principal investigator for the trials with baricitinib, called BRAVE-AA1 and BRAVE AA-2, which were published last year in the New England Journal of Medicine. The trials for both drugs had similar designs and endpoints.
Deuruxolitinib and the THRIVE studies
In the THRIVE-AA2 trial, 517 adult patients were enrolled with moderate to severe alopecia areata, defined as a SALT (Severity of Alopecia Tool) score of ≥ 50%, which signifies a hair loss of at least 50%. Like THRIVE-AA1, patients participated at treatment centers in North America and Europe. About two-thirds were female. The mean age was 39 years. The majority of patients had complete or near complete hair loss at baseline.
“Many of these patients are the ones we have historically characterized as having alopecia totalis or universalis,” Dr. King said.
Participating patients were randomly assigned to 8 mg deuruxolitinib twice daily, 12 mg deuruxolitinib twice daily, or placebo. The primary endpoint was a SALT score of ≤ 20% at week 24.
At 24 weeks, almost no patients in the placebo group (1%) vs. 33% and 38% in the 8 mg and 12 mg twice-daily groups, respectively, met the primary endpoint. Each active treatment group was highly significant vs. placebo.
Of the responders, the majority achieved complete or near complete hair growth as defined by a SALT score of ≤ 10%, Dr. King reported.
Based on a graph that showed a relatively steep climb over the entire 24-week study period, deuruxolitinib “had a really fast onset of action,” Dr. King said. By week 8, which was the time of the first assessment, both doses of deuruxolitinib were superior to placebo.
The majority of patients had complete or significant loss of eyebrows and eye lashes at baseline, but more than two-thirds of these patients had regrowth by week 24, Dr. King said. Again, no significant regrowth was observed in the placebo arm.
On the Satisfaction of Hair Patient Reported Outcomes (SPRO), more than half of patients on both doses reported being satisfied or very satisfied with the improvement when evaluated at 24 weeks.
“The patient satisfaction overshot what one would expect by looking at the SALT scores, but a lot of subjects were at the precipice of the primary endpoint, sitting on SALT scores of 21, 25, or 30,” Dr. King said.