Researches and develops synthetic vaccines and targeted small molecules for the treatment of cancer. The company's cancer vaccines are designed to stimulate an individual's immune system to recognize cancer cells and control the growth and spread of cancers and its small molecule compounds are designed to inhibit the activity of specific cancer-related proteins. The company's lead vaccine product candidate is Stimuvax®, a cancer vaccine for non-small cell lung cancer (Phase III) which has been licensed to Merck KGaA. Targeted small molecule product candidates include PX-12 (Phase II), PX-478 (Phase I) and PX-866 (pre-clinical).