Alderley Park, Cheshire, U.K. Infex Therapeutics, a leading anti-infectives specialist, announces that it has successfully completed dosing in its Phase I study for RESP-X, the Company’s new anti-virulence therapy to treat Pseudomonas aeruginosa (Pa) infections in non-cystic fibrosis bronchiectasis (NCFB) patients. No serious or adverse events (“SAEs”) or infusion reactions were reported, and pharmacokinetics (PK) was dose linear across all four dose escalations. RESP-X shows a long 30-day half-life, and the potential for a three-monthly dosing interval in patients.

Following this positive data, Infex has initiated a Phase IIa dose-ranging study for RESP-X in NCFB patients, which will consist of two cohorts to access safety and initial efficacy and determine the optimal dosing of RESP-X ahead of a wider Phase IIb efficacy study. The study will take place at the NIHR Clinical Research Facility in Liverpool. Infex is currently recruiting patients for the first patient cohort at 6mg/kg and has received approval to dose patient volunteers at 10mg/kg, provided there are no adverse events reported from the first patient cohort of the Phase IIa trial. Dosing for the first cohort of NCFB patients for the Phase IIa trial is expected to commence before the end of 2023.

RESP-X is a first-in-class immune infection antibody in-licensed from Japanese pharma company Shionogi targeting chronic Pa bacterial infections in NCFB patients. Colonisation with Pa increases the severity of NCFB, leading to recurring episodes of life-threatening infection. There are currently at least eight million NCFB patients in major global markets, of which 30% have chronic Pa colonisation. Despite its prevalence and severity, there are currently no approved treatments for Pa colonisation in NCFB patients.

Dr Peter Jackson, CEO of Infex Therapeutics, commented: “Across the four cohorts of our Phase I study, RESP-X has demonstrated a robust safety and PK profile, highlighting that the drug’s behaviour in the body was consistent and predictable as dosing increased. With this now complete, we can commence dosing our Phase IIa first-in-patient cohorts, in which we will gain insights into dosing and early indicators of RESP-X’s efficacy ahead of a wider Phase II efficacy study.”