Why Is Bacterial Infection-Focused BiomX Stock Trading Lower Today?

BiomX Inc PHGE released safety and efficacy results from Part 2 of the Phase 1b/2a trial of BX004 for chronic pulmonary infections caused by Pseudomonas aeruginosa (P. aeruginosa) in patients with cystic fibrosis (CF).

The study drug was safe and well-tolerated, with no related SAEs (serious adverse events) or related APEs (acute pulmonary exacerbations) to the 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 ten days of treatment compared to 0 out of 10 (0%) in the placebo arm.

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 a 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).

Alternating/cycling background antibiotic regimen is likely associated with fluctuations in P. aeruginosa levels, potentially confounding the ability to observe a P. aeruginosa reduction in this subgroup.

Considering these results, the company plans to advance the BX004 program to a larger, pivotal Phase 2b/3 trial, subject to regulatory feedback and the availability of sufficient funding.

Price Action: PHGE shares are down 36.88% at $0.3535 on the last check Wednesday.