Azitra expands ATR-04 trial eligibility to KRAS, MEK inhibitor rash patients

Azitra, Inc. announced on October 29, 2026 that it had amended its ongoing Phase 1/2 trial of ATR04-484 to expand patient eligibility to include individuals with rash associated with KRAS and MEK inhibitors, moving beyond the drug's initial focus on EGFR inhibitor-associated skin rash.¹ The broadened criteria also cover patients with neurofibromatosis type 1 who have rash linked to MEK inhibitors.¹ Separately, the company shortened the washout periods required for antibiotics and steroids before enrollment.¹

The trial, officially "NCT06830863," is a multicenter, randomized, double-blind, vehicle-controlled Phase 1/2 study evaluating the safety, tolerability, bioavailability, pharmacodynamics, and preliminary efficacy of topical ATR04-484.¹ The protocol changes come after the company disclosed that the study's safety review committee had recommended advancing to Cohort 2 based on available safety data from Cohort 1.¹ Cohort 2 is expected to enroll about 24 patients, who will receive once-daily treatment for 28 days.¹

The company noted that roughly 85,000 patients undergo KRAS or MEK inhibitor treatment in the United States each year¹, compared with about 220,000 patients on EGFRi treatment annually.¹ NF1, a rare genetic disorder marked by tumors along nerves, affects about 100,000 patients in the U.S.¹

ATR04-484 is a live biotherapeutic candidate built from an isolated, naturally derived Staphylococcus epidermidis strain, selected for its preclinical ability to reduce pro-inflammatory cytokine IL-36γ and Staphylococcus aureus levels, both elevated in cancer treatment-associated skin rash.¹ The FDA has granted the candidate Fast Track designation for cancer treatment-associated rash, a condition the company says affects up to 300,000 patients annually in the U.S.¹