BiomX Inc. announced positive safety and efficacy results from Part 2 of the Phase 1b/2a trial evaluating the Company?s novel phage cocktail, BX004, for the treatment of chronic pulmonary infections caused by Pseudomonas aeruginosa (or P. aeruginosa) in patients with cystic fibrosis (?CF?). Considering these results, the Company plans to advance the BX004 program to a larger, pivotal Phase 2b/3 trial, subject to regulatory feedback and availability of sufficient funding. The objectives of Part 2 of the Phase 1b/2a trial were to evaluate the safety and tolerability of BX004 in a larger number of CF patients dosed for a longer treatment duration than Part 1 of the study, with the anticipation that the longer treatment might result in greater effects than in the Part 1. In Part 2, 34 CF patients received nebulized study drug twice daily for 10 days and were randomized in a 2:1 ratio with 23 CF patients receiving BX004 and 11 patients receiving placebo.

Endpoints included safety and tolerability, decrease in P. aeruginosa burden, sputum pharmacokinetics, FEV1, CFQ-R (CF Questionnaire Revised) and CFRSD-CRISS (Cystic Fibrosis Respiratory Symptom Diary - Chronic Respiratory Infection Symptom Score). Similar to Part 1, patients enrolled in Part 2 were also on standard of care inhaled antibiotics, which included either continuous regimen (same antibiotic before, during, and after study drug), alternating regimen (alternating between two types of antibiotics every month) or cycling regimen (one month on /one month off). Patients were on the same inhaled antibiotic (tobramycin, aztreonam, or colistin) from Day 1-10 (treatment period) and through Day 28 of the study.

Study drug was safe and well-tolerated, with no related SAEs (serious adverse events) or related APEs (acute pulmonary exacerbations) to study drug. BX004 vs. placebo showed a positive clinical effect in a predefined subgroup of patients with reduced baseline lung function (FEV1<70%).

Difference between groups at Day 17: relative FEV1 improvement of 5.67% (change from baseline +1.46 vs. -4.21) and +8.87 points in CFQR respiratory symptom scale (change from baseline +2.52 vs. -6.35).

In the BX004 arm, 3 out of 21 (14.3%) patients converted to sputum culture negative for P. aeruginosa after 10 days of treatment (including 2 patients after 4 days) compared to 0 out of 10 (0%) in the placebo arm3. In full population, BX004 vs. placebo P. aeruginosa levels were more variable in sputum, potentially driven by the standard of care antibiotic treatment regimen.

In a prespecified subgroup of patients on standard of care inhaled antibiotics on continuous regimen, BX004 vs. placebo reduced sputum P. aeruginosa levels at Day 10: difference in change from baseline between groups of -2.8 log10 CFU/g sputum (change from baseline -2.91 vs -0.11), exceeding Part 1 results. Alternating/cycling background antibiotic regimen likely associated with fluctuations in P. aeruginosa levels potentially confounding the ability to observe a P. aeruginosa reduction in this subgroup.

During the study period, based on current available data, no evidence of treatment-related phage resistance was observed in patients treated with BX004 compared to placebo.