Spexis AG announced the successful completion of the first-in-human clinical trial with novel class antibiotic murepavadin, delivered via the oral inhalation route (iMPV). iMPV is a macrocycle compound derived from Spexis' proprietary platform and specifically targets the outer membrane of Pseudomonas aeruginosa (P. aeruginosa) including activity against highly resistant strains. P. aeruginosa is the key pathogen in cystic fibrosis (CF) lung infections.

The study was supported by the European Innovative Medicines Initiative (IMI). This Phase 1 trial was a single center, double-blind, randomized, placebo-controlled trial to investigate the safety, tolerability, and pharmacokinetics of single ascending doses of iMPV in healthy volunteers. A total of 39 subjects participated in the trial.

In Part A of the trial, three single dose levels (12.5 mg, 25mg, and 50 mg of iMPV) were evaluated in four subjects per cohort. In Part B, single doses of 75 mg, 150 mg, and 300 mg were evaluated in nine subjects per cohort. The pharmacokinetics (PK) of iMPV were assessed in blood samples and in epithelial lining fluid (ELF) obtained by bronchoalveolar lavage.

Analyses of the preliminary, blinded data from this study showed that iMPV was well tolerated at all dose levels, with all subjects completing the inhalation. No clinically relevant signs of irritation of the upper airways and no serious adverse events were reported. Serial pulmonary function tests were normal and did not show narrowing of the airways after administration of iMPV.

Vital signs, ECGs and safety laboratory data were within the normal range. At the highest single dose tested, systemic bioavailability of MPV was lower than 5%, and peak plasma concentrations were observed at 1-2 hours post start of inhalation. In the ELF, the concentration of MPV at the 24-hour timepoint was still above the concentration that would inhibit the growth of 90% of P. aeruginosa isolates (MIC90) obtained from people with CF.

These data indicate that iMPV leads to high inhibiting concentrations in the airways of the lung while systemic MPV levels remain substantially lower compared to the plasma level observed in previous clinical trials with intravenous administration of MPV. This observed favorable tolerability, safety and concentration profile of MPV after inhalation in the Phase 1 trial meets the company's expectations and clears the way for further clinical trials of iMPV in people with CF or non-CF bronchiectasis.