Azitra, Inc. (NYSE American: AZTR) announced amendments to its ongoing Phase 1/2 clinical trial of ATR04-484 on October 29, 2026. The amendments significantly expand patient eligibility criteria to include individuals suffering from skin rashes caused by KRAS and MEK inhibitors, as well as patients with neurofibromatosis type 1 (NF1) experiencing rash due to MEK inhibitors.
The multicenter, randomized, double-blind, vehicle-controlled study (NCT06830863) is evaluating the safety, tolerability, bioavailability, pharmacodynamics, and preliminary efficacy of topical ATR04-484. The protocol modifications also shorten the required washout periods for antibiotics and steroids. These changes aim to broaden the potential treatment opportunities for ATR-04 beyond its initial focus on epidermal growth factor receptor inhibitor (EGFRi)-associated skin rash and facilitate patient recruitment.
According to the filing, Cohort 2 of the trial is expected to enroll approximately 24 patients who will receive once-daily treatment for 28 days. This cohort follows a recent safety review committee recommendation to proceed with the study following data review from Cohort 1.
ATR04-484 is a live biotherapeutic product candidate containing an engineered strain of Staphylococcus epidermidis. The candidate was selected based on its ability to reduce pro-inflammatory cytokine IL-36γ and Staphylococcus aureus levels, which are elevated in patients with cancer treatment-associated skin rash. The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to ATR04-484 for cancer treatment-associated rash.
The company estimates that approximately 85,000 patients undergo KRAS or MEK inhibitor treatment in the United States annually. Combined with the approximately 220,000 patients undergoing EGFRi treatment, the expanded eligibility criteria targets a total potential patient population of over 300,000 individuals annually.
