The U.S. Patent Trials and Appeals Board has agreed to launch an inter partes review of a GlaxoSmithKline patent aimed at a vaccine component.

Pfenex, a San Diego-based developer of vaccines, biologics and biosimilars, challenged the GSK patent aimed at the expression of bacterial toxins, in particular diphtheria toxins, arguing that anyone with prior skill in fields such as molecular biology or genetic engineering could have  combined prior art to arrive at the patented invention.

In a Nov. 13 decision, the board found that Pfenex had a “reasonable likelihood” of proving that its cited prior art would have rendered two of the challenged claims unpatentable as obvious