The U.S. Patent Trial and Appeal Board (PTAB) has decided to conduct an inter partes review of Opiant Pharmaceutical’s patent covering its opioid-overdose treatment Narcan (naloxone).

The patent’s challenger, Nalox-1 Pharmaceuticals, claims that Opiant’s patent (9,211,253) for the nasal spray version of the drug is invalid because it is common knowledge available to anyone experienced in solutions-based drug development. PTAB agreed that this argument would likely prevail. 

The board threw out several parallel challenges filed by Nalox-1 to avoid redundancy. PTAB asked the parties to rank the challenges in order of importance and they chose this Nalox-1 claim for review.