Phase III THRIVE-AA2 trial of CTP 543 meets endpoints in alopecia areata

The primary efficacy endpoint for THRIVE-AA2 was the percentage of patients achieving an absolute Severity of Alopecia Tool (SALT) score of 20 or less at Week 24 of treatment, which was met with statistical significance in both the 8 mg twice-daily and 12 mg twice-daily dose groups relative to placebo. Treatment with CTP-543 was generally well tolerated. A statistically significant proportion of patients treated with either 8 mg twice-daily or 12 mg twice-daily of CTP 543 experienced greater scalp regrowth compared to placebo.

The proportion of patients achieving a SALT score of 20 or less (meaning 20 percent or less scalp hair loss) was 38.3 percent in the 12 mg twice-daily dose group and 33.0 percent in the 8 mg twice-daily dose group, compared to 0.8 percent of patients in the placebo group, at the 24-week endpoint. The treatment difference for both dose groups of CTP 543 relative to placebo was statistically significant.

The key secondary endpoints were the percentage of responders on a Satisfaction of Hair Patient Reported Outcome (SPRO) scale at Week 24 and the percentage of patients achieving absolute SALT scores of 20 or less at each of Weeks 20, 16, 12 and 8. 47% of patients in the 8 mg twice-daily group and 52% of patients in the 12 mg twice-daily group reported being “satisfied” or “very satisfied,” as compared to 2% of patients in the placebo group. The treatment difference for both groups relative to placebo was statistically significant. SALT scores of 20 or less at Weeks 20, 16 and 12 were statistically significant in both dose groups. The safety profile seen with CTP 543 in THRIVE-AA2 was consistent with previous studies. The most common (at least 5%) side effects in any dose group were COVID-19 infection, nasopharyngitis, increased creatine kinase levels, acne and headache.