Menlo Therapeutics Inc. (NASDAQ: MNLO), a late-stage biopharmaceutical company focused on the development of serlopitant for the treatment of pruritus (itch), today announced positive top-line results from MTI-109 (PSORIXA), a 204-patient Phase 2 clinical trial of serlopitant for the treatment of pruritus associated with psoriasis. The trial successfully met its primary endpoint, showing a statistically significant reduction in pruritus based upon a 4-point improvement responder analysis. In the trial, 33% of patients treated with serlopitant 5 mg daily achieved a 4-point or greater improvement on the worst-itch numeric rating scale, or WI-NRS, at week 8 compared to baseline (primary efficacy endpoint) vs. 21% of patients treated with placebo (p= 0.028).
The trial also prospectively defined three key secondary endpoints for sequential step-down analyses at week 4 and days 7 and 3. The trial successfully met the secondary endpoint of WI-NRS responder rate at week 4. At week 4, 21% of patients treated with serlopitant achieved a 4-point or greater improvement on the WI-NRS vs. 11% of patients treated with placebo (p=0.039). Assessment of the secondary endpoints of the absolute change in WI-NRS from baseline to day 7 and day 3 for serlopitant compared to placebo showed a greater numerical, but not statistically significant, improvement for the serlopitant group. At every assessed time point in the trial (daily in week 1 and average weekly scores through week 8), the serlopitant treated group demonstrated greater numerical improvement than the placebo group in both the WI-NRS 4-point responder analysis and in the mean change in WI-NRS from baseline.
Serlopitant was well-tolerated in this clinical trial. No serious adverse events were reported for serlopitant treated patients. Treatment-emergent adverse events assessed as likely related to treatment were observed with similar frequency in both groups (4.0% for placebo and 4.9% for serlopitant). The consolidated safety summary for serlopitant now includes more than 1,600 evaluable patients, including patients who have received treatment for up to one year.
“We are pleased with the positive results demonstrated by serlopitant in this clinical trial for the treatment of pruritus associated with psoriasis. We have now completed four double-blind Phase 2 clinical trials in over 1,000 patients with pruritus and met the primary endpoint in three of the four trials. In all four of these trials, all serlopitant treated groups have shown numerically greater improvement from baseline as compared to placebo treated groups at every assessed timepoint,” stated Steve Basta, Chief Executive Officer of Menlo Therapeutics. “We plan to have an End of Phase 2 Meeting with the FDA in the first half of 2019 and to begin our Phase 3 program for pruritus associated with psoriasis in 2019.”
MTI-109 was a randomized, double-blind, placebo-controlled clinical trial which evaluated the efficacy, safety, and tolerability of serlopitant for the treatment of pruritus associated with psoriasis. The trial enrolled patients between 18 and 80 years of age with the diagnosis of plaque psoriasis for at least 6 months prior to randomization and with plaques covering ≤ 10% body surface area. In addition, patients had pruritus of at least 4 weeks duration prior to screening and a WI-NRS score consistent with severe pruritus at screening. Patients were randomized 1:1 to receive either serlopitant 5 mg or placebo orally once daily and were not allowed to use any other psoriasis therapy, other than bland emollients, for the duration of the trial. MTI-109 was intended to evaluate if treatment with serlopitant 5 mg daily for 8 weeks could improve pruritus compared with placebo. The primary efficacy endpoint was a responder analysis of the proportion of patients in each group achieving a 4-point WI-NRS improvement at week 8 compared to baseline. As a randomized Phase 2 trial, the pre-defined statistical threshold for significance was a p-value of < 0.05 (one-sided test).
Update on Serlopitant Clinical Development Program
Prurigo Nodularis: Menlo is currently enrolling patients in two Phase 3 clinical trials (one in the U.S. and one in Europe) to evaluate serlopitant as a treatment for pruritus associated with prurigo nodularis. The U.S. trial is over 50% enrolled, and the European trial is over 30% enrolled. Data from each trial is expected by the first quarter of 2020.
Psoriasis: Menlo plans to have an End of Phase 2 Meeting with the FDA in the first half of 2019 and expects to initiate a Phase 3 program in 2019 to evaluate serlopitant as a treatment for pruritus associated with psoriasis.
Chronic Pruritus of Unknown Origin: Menlo is currently screening patients for its Phase 2 clinical trial in patients with chronic pruritus of unknown origin and expects to enroll the first patient in this Phase 2 trial in December 2018 or January 2019.About Psoriasis
Psoriasis is a common chronic autoimmune disorder of the skin, causing redness, irritation and scaly lesions. Approximately 12 million people in the United States have psoriasis, of which, according to the National Psoriasis Foundation, approximately 75% have mild psoriasis and 25% have moderate to severe psoriasis. According to market research conducted by Menlo, approximately 75% of psoriasis patients have moderate to severe pruritus.