The concept that potent and safe analgesics could be developed by taking advantage of the chemical environment in painful tissue injury was discovered by Drs. Christoph Stein and Marcus Weber at Charitè University, Berlin.

As shown below, they designed a prototype compound (NFEPP) that is only active in acidic tissues caused by inflammation, the site where pain is generated. Elsewhere in the body the pH is normal (e.g. in the brain) and consequently the analgesic is inactive, thus lacking the addictive potential and side effects of conventional opioids, including cognitive deficit, respiratory depression, tolerance, movement impairment, and paralysis of the gut that underlies nausea and constipation. These findings have been replicated in preclinical pain models of arthritis, colitis, post-operative pain, cancer and in human tissue in multiple independent laboratories (see publications). We are currently undertaking non-human primate and IND enabling studies to conduct a phase I clinical trial, while developing new compounds and exploring treatment of inflammation, itch and cancer.