Pfenex reports positive Phase Ia Px563L anthrax vaccine study results

8th August 2016 (Last Updated August 8th, 2016 18:30)

US-based, clinical-stage biotechnology company Pfenex has reported a positive outcome from its Phase Ia Px563L anthrax vaccine study.

US-based, clinical-stage biotechnology company Pfenex has reported a positive outcome from its Phase Ia Px563L anthrax vaccine study.

Px563L is Pfenex’s second generation recombinant anthrax vaccine, which has been developed based on the Pfenex Expression Technology.

The randomised, double-blind, placebo-controlled trial was divided into three cohorts and patients were administered with 10mcg, 50mcg and 80mcg of Px563L respectively in a dose-escalating manner.

Each cohort was treated with Px563L, RPA563 or placebo in 8:8:2 ratios.

The enrolled patients received two doses of the vaccine or placebo at a gap of 28 days.

An analysis of data derived after 70 days of the study demonstrated a tolerable safety and immunogenicity after an administration of two doses of Px563L.

Pfenex chief medical officer Dr Hubert Chen said: "The Px563L data from the Day 70 analysis of the phase I study are very encouraging, with the vaccine being well-tolerated and affording potentially superior protection after only two doses."

"Px563L is Pfenex’s second generation recombinant anthrax vaccine, which has been developed based on the Pfenex Expression Technology."

Anthrax is a malignant infectious disease triggered by gram-positive, rod-shaped bacteria known as Bacillus anthracis.

It causes symptoms such as severe illness in both humans and animals.

Domestic animals are vulnerable to anthrax infection as they breathe or consume soil, plants, or water infected by the anthrax causing bacteria.

Pfenex CEO Bertrand Liang has stated that the company will continue developing Px563L in collaboration with biomedical advanced research and development authority (BARDA) with a view to satisfy Strategic National Stockpile requirements.


Image: Table displaying Immunogenicity Results for Px563L. Photo: PRNewsFoto/Pfenex Inc.