RAPT Therapeutics Announces Publication of Phase 1a/1b Clinical Trial of Zelnecirnon (RPT193) to Treat Atopic Dermatitis in Allergy
SOUTH SAN FRANCISCO, Calif., Nov. 27, 2023 (GLOBE NEWSWIRE) -- RAPT Therapeutics, Inc. (Nasdaq: RAPT), a clinical-stage, immunology-based biopharmaceutical company focused on discovering, developing and commercializing oral small molecule therapies for patients with significant unmet needs in inflammatory diseases and oncology, today announced that results from its previously disclosed Phase 1a/1b clinical trial of zelnecirnon (formerly RPT193) were published in Allergy. The Phase 1a portion of the trial was a standard single and multiple dose-escalation study in 72 healthy volunteers. The Phase 1b portion of the trial was a randomized, double-blind, placebo-controlled study examining zelnecirnon as monotherapy in 31 patients with moderate-to-severe atopic dermatitis (AD).
The findings showed that once-daily zelnecirnon treatment was generally well tolerated, with no serious adverse events reported, and all reported treatment-emergent adverse events were mild-to-moderate in nature across both patients with atopic dermatitis and healthy volunteers.
In the Phase 1b trial, after four weeks of treatment, patients with moderate-to-severe AD who received zelnecirnon showed a 36.3% change from baseline in the Eczema Area and Severity Index (EASI) score, a standard measure of disease severity, compared to 17.0% in the placebo group. Notably, in the two-week period following the end of treatment, the zelnecirnon group showed continued deepening of the response and a statistically significant difference compared to placebo with a 53.2% change from baseline in EASI at the six-week time point compared to 9.6% in the placebo group (p < .05). Further, significant changes in the transcriptional profile were seen in skin biopsies of zelnecirnon-treated versus placebo-treated subjects at Day 29, which were also significantly correlated with clinical efficacy measures.
The deepening of the response may be related to zelnecirnon’s mechanism of action, which is upstream of other agents targeting cytokines or signaling pathways.
“We are pleased to have these exciting data published in the prestigious, peer-reviewed journal Allergy,” said Brian Wong, M.D., Ph.D., President and CEO of RAPT Therapeutics. “These data strongly support the potential of zelnecirnon as a safe, once-daily, oral treatment for patients with atopic dermatitis which could be an attractive therapeutic alternative ahead of injectable drugs. We look forward to reporting top-line data from our Phase 2b trial in atopic dermatitis in mid-2024 and continuing to progress enrollment in our Phase 2a trial in asthma.”
Key Findings from the Phase 1b Study in Patients with Atopic Dermatitis
Based on exploratory statistical analyses, the difference between zelnecirnon and placebo on the percent change in EASI score and EASI-50 was statistically significant at Day 43 (p < 0.05). No other endpoints or timepoints achieved statistical significance.
Zelnecirnon was well tolerated in the Phase 1b study. No serious adverse events were reported, and all adverse events reported were mild or moderate in intensity. The overall safety profile of zelnecirnon in the Phase 1b study and from the Phase 1a study in healthy volunteers, suggests zelnecirnon is a well-tolerated oral drug that would not require any laboratory safety monitoring.
Based on the efficacy and safety data observed in the Phase 1b study, RAPT initiated a dose-ranging Phase 2b study in patients with moderate-to-severe AD and a Phase 2a study in asthma.
About the Phase 1a/1b Study of RPT193
The Phase 1b portion of the trial was a randomized, double-blind, placebo-controlled study of zelnecirnon as monotherapy in patients with moderate-to-severe AD. The study was conducted at multiple sites in the United States and enrolled 31 patients with moderate-to-severe AD who had an inadequate response to, or were intolerant of, topical corticosteroids. The primary endpoint of the Phase 1b study was safety. Secondary and exploratory endpoints include pharmacokinetics, biomarkers and clinical efficacy as evaluated by multiple measurements, including percent change in the Eczema Area and Severity Index (EASI) score, the validated Investigator Global Assessment (vIGA) and pruritis Numerical Rating Scale (NRS). The Phase 1b trial was not powered to achieve statistical significance for any particular endpoint.
About Atopic Dermatitis
About RAPT Therapeutics, Inc.