Menlo Therapeutics Announces Completion of Enrollment in Two Phase 3 Trials

Menlo Therapeutics Inc. recently announced it has completed enrollment of patients in its two Phase 3 clinical trials evaluating the safety and efficacy of once-daily oral serlopitant for the treatment of pruritus associated with prurigo nodularis (PN). The US and European Phase 3 trials enrolled 285 and 295 patients, respectively. The Phase 3 trials are designed to evaluate reduction in pruritus in patients treated with serlopitant compared to placebo over a 10-week treatment period.  The primary endpoint in these studies will compare the number of treated vs. control patients who experience a 4-point improvement on the worst-itch numeric rating scale (WI-NRS), which is a standard measure of itch. Serlopitant has received Breakthrough Therapy Designation by the FDA for the treatment of pruritus associated with PN, a severely itchy skin disease characterized by multiple, firm, itchy nodules on the skin. Currently, there is no therapy approved or indicated to treat the estimated 500,000-1,000,000 PN patients in the US.

“During 2019, Menlo has made solid progress on our clinical program and NDA preparations for serlopitant. Our primary focus has been our two Phase 3 trials in PN, our anticipated initial NDA indication,” said Steve Basta, Chief Executive Officer of Menlo Therapeutics. “We are pleased with how quickly and efficiently these Phase 3 trials enrolled and with our recently announced success enrolling our Phase 2 trial in CPUO. We look forward to key data on both programs in early 2020.”

Menlo Therapeutics expects to report the results of the PN trials in March or April of 2020.  If the PN trials are successful, Menlo plans to submit an NDA for pruritus associated with PN in the second half of 2020.

Both PN Phase 3 trials are multi-center, randomized, double-blind, placebo‑controlled trials evaluating treatment with 5 mg serlopitant daily for ten weeks and its ability to reduce pruritus associated with PN compared with placebo. Menlo has enrolled 285 patients at 46 sites in the US trial and has enrolled 295 patients at 39 sites in in the European trial. The trials enrolled patients with a WI‑NRS of at least seven at screening. The primary efficacy analysis for both trials is a 4‑point responder rate in the WI‑NRS at 10 weeks.

Prurigo nodularis is a severely pruritic chronic skin disorder affecting primarily older adults and is characterized by multiple, firm, itchy nodules typically found on a patient’s arms, legs and trunk. We estimate that there are approximately 500,000 – 1,000,000 people with prurigo nodularis in the United States. Prurigo nodularis results from a vicious cycle of repeated itching and scratching leading to formation of raised, inflamed skin nodules that can develop sores or become hard and crusty. The itching sensation in prurigo nodularis is extreme and often leads to scratching to the point of bleeding or pain. Prurigo nodularis may be associated with a variety of dermatologic and systemic diseases such as atopic dermatitis, psoriasis, diabetes, chronic renal failure and HIV infection, or may have an unknown cause.

Serlopitant is a small molecule, highly selective NK1 receptor antagonist. Two critical mediators of the urge to scratch are Substance P, or SP, and its receptor, the neurokinin-1 receptor, or NK1 receptor. SP is a naturally occurring peptide in the tachykinin neuropeptide family. Tachykinins have a broad range of functions in the nervous and immune systems. SP binding of NK1 receptor has been shown to be a key mediator of sensory nerve signaling, including the itch-scratch reflex and the vomiting reflex.

Menlo Therapeutics Inc. is a late-stage biopharmaceutical company focused on the development of serlopitant, a once-daily oral NK1 receptor antagonist, for the treatment of pruritus. The company’s clinical development program for serlopitant covers three indications and includes two ongoing Phase 3 clinical trials for the treatment of pruritus associated with prurigo nodularis, a Phase 3-ready clinical program for the treatment of pruritus associated with psoriasis, and a Phase 2 clinical trial for the treatment of chronic pruritus of unknown origin. For more information, visit