BiomX Launches Phase 2b Study Of BX004 In Cystic Fibrosis With First Patient Already Dosed

BiomX Inc., a clinical-stage biotechnology company developing natural and engineered phage therapies to target harmful bacteria, has announced the successful start of patient dosing in its Phase 2b clinical trial. The first patient has been dosed in the study, which is focused on evaluating BX004 as a potential treatment for cystic fibrosis (CF) patients suffering from chronic lung infections caused by “Pseudomonas aeruginosa”, a major contributor to illness and death in this patient group despite available treatments.

The Phase 2b trial is a randomized, double-blind, placebo-controlled study involving around 60 CF patients who have long-term “P. aeruginosa” infections. Participants are randomly assigned in a 2:1 ratio to receive either BX004 or a placebo. The treatment is given through inhalation twice daily over an eight-week period. The study will assess several key outcomes, including reduction in bacterial levels, improvement in lung function, and better quality of life, measured using tools such as the CFQ-R (Cystic Fibrosis Questionnaire-Revised) and CRISS (Cystic Fibrosis Respiratory Symptom Score). 

Jonathan Solomon, Chief Executive Officer of BiomX, stated, “This first patient dosing marks a significant milestone for our BX004 program and for CF patients with chronic P. aeruginosa infections who desperately need new options. We're seeing tremendous enthusiasm from both patients and investigators based on our encouraging Phase 1b/2a results, in which 14.3% of patients cleared infections completely after 10 days of treatment. Notably, this included individuals who had been living with chronic infections for over a decade, making these outcomes particularly meaningful and rarely seen in this population. 

He further continued, “In the second half of 2025, we anticipate feedback from the FDA regarding our plans on the analyses of real-world evidence to link bacterial reduction to clinical outcomes. Regulatory alignment on a microbiological endpoint would streamline the approval pathway and provide a means of addressing these patients with urgent unmet needs. With both Fast Track and Orphan Drug designations already secured, we believe we are well-positioned to further develop our phage-based therapy for these life-threatening infections, pending positive topline trial readout, which is expected in the first quarter of 2026.”

This trial follows promising results from a previous Phase 1b/2a study, which indicated that BX004 could effectively target and eliminate “P. aeruginosa”, even when standard treatments did not succeed. BiomX expects topline results from this Phase 2b trial in the first quarter of 2026. If successful, BX004 could become a leading phage-based therapy option for managing chronic “P. aeruginosa” infections in CF patients.