BRANFORD, Connecticut, October 29, 2026
Azitra, Inc., a clinical-stage biopharmaceutical company focused on precision dermatology, has announced expanded eligibility criteria for its ongoing Phase 1/2 clinical trial of ATR04-484 (ATR-04), an investigational topical live biotherapeutic designed to treat skin rashes associated with targeted cancer therapies. The amended clinical trial protocol now includes patients experiencing skin rashes caused by KRAS and MEK inhibitors, in addition to the previously evaluated epidermal growth factor receptor inhibitor (EGFRi)-associated skin conditions. The expanded eligibility also covers patients with neurofibromatosis type 1 (NF1) who develop MEK inhibitor-associated rashes. The company has additionally shortened the required washout periods for antibiotics and steroids, changes intended to make trial participation more accessible and facilitate patient recruitment. This development broadens the potential clinical applications of ATR-04 and represents another milestone in Azitra’s efforts to develop innovative treatments for dermatological complications associated with cancer therapies.
Expanded Clinical Trial Eligibility Includes KRAS and MEK Inhibitors
The expanded Phase 1/2 clinical trial will evaluate ATR04-484 in a broader population of patients experiencing treatment-associated skin rashes. KRAS and MEK inhibitors are targeted cancer medicines used in the treatment of several malignancies, including non-small cell lung cancer, melanoma, colorectal cancer and ovarian cancer. Although these precision medicines have improved treatment options for many patients, dermatological adverse events remain an important clinical challenge. Skin rashes, inflammation and other treatment-related skin complications can negatively affect patients’ quality of life and, in certain cases, require dose reductions, treatment interruptions or discontinuation of cancer therapy. According to Azitra, approximately 85,000 patients in the United States receive KRAS or MEK inhibitor treatments annually. The newly expanded eligibility criteria also include patients with NF1, a rare genetic disorder associated with tumour development along nerves. Approximately 100,000 people in the United States are affected by NF1. By including these additional patient populations, Azitra aims to evaluate the potential usefulness of ATR-04 across multiple types of targeted therapy-associated skin conditions. The company believes the revised protocol could also improve recruitment and accelerate enrolment in the ongoing study.
ATR-04 Advances to Cohort 2 Following Safety Review
The multicentre, randomized, double-blind, vehicle-controlled Phase 1/2 clinical trial (NCT06830863) is designed to evaluate the safety, tolerability, bioavailability, pharmacodynamics and preliminary efficacy of topical ATR04-484. The study previously received a recommendation from its independent safety review committee to proceed to Cohort 2, following an assessment of the available safety information from Cohort 1. The second cohort is expected to enrol approximately 24 patients, who will receive once-daily treatment for 28 days. The protocol amendments are intended to broaden the eligible population and reduce certain treatment-related restrictions that could otherwise limit participation. Shortening the required washout periods for antibiotics and steroids is expected to make enrolment more practical for patients who may need these medications. The company has not announced definitive efficacy results from the expanded patient population. The ongoing clinical programme will continue to generate information about the investigational treatment’s safety and potential therapeutic activity. The findings will be important in determining whether ATR-04 can provide a meaningful treatment option for patients experiencing skin toxicities associated with targeted cancer therapies.
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Live Biotherapeutic Technology Targets Skin Inflammation
ATR04-484 is an investigational topical live biotherapeutic product containing an isolated, naturally derived strain of Staphylococcus epidermidis, a bacterium naturally associated with human skin. Azitra selected the strain based on preclinical findings indicating its potential to reduce interleukin-36 gamma (IL-36γ), a pro-inflammatory cytokine, and levels of Staphylococcus aureus, both of which have been associated with cancer treatment-related skin rashes. The bacterial strain has been engineered to improve its safety characteristics through the deletion of an antibiotic resistance gene and the introduction of auxotrophy, a modification designed to make its growth dependent on specific nutrients. This approach is intended to support controlled bacterial growth while investigating its potential dermatological benefits. The U.S. Food and Drug Administration has granted Fast Track designation to ATR04-484 for cancer treatment-associated rash, recognizing the significant unmet medical need in this area. The company estimates that up to 300,000 people in the United States may be affected annually by cancer treatment-associated skin rashes. The investigational programme represents an emerging application of live biotherapeutic technology in precision dermatology.
The expanded eligibility criteria mark an important development in Azitra’s clinical development strategy, potentially extending ATR-04 beyond its initial focus on EGFR inhibitor-associated skin rashes. The inclusion of patients receiving KRAS and MEK inhibitors, together with individuals with NF1, creates opportunities to investigate the treatment across additional dermatological conditions. However, ATR04-484 remains an investigational product and has not received regulatory approval for the treatment of cancer therapy-associated skin rashes. Further clinical studies will be necessary to establish its safety and efficacy. The ongoing Phase 1/2 programme will provide important evidence regarding its potential role in managing treatment-related skin complications while helping patients maintain their prescribed cancer therapies.
Source: Azitra Inc press release
