The US Patent Trial and Appeal Board (PTAB) has instituted an inter partes review of US Patent No. 9,211,253, “Nasal drug products and methods of their use.” That patent, which covers Opiant Pharmaceutical’s Narcan intranasal naloxone for the reversal of opioid overdose through 2035, was granted to Lightlake Therapeutics (now Opiant) in December 2015.
Adapt Pharma, which has since been acquired by Emergent BioSolutions, licensed the naloxone nasal spray from Lightlake in 2014. Narcan nasal spray was initially approved by the FDA in November 2015, and a lower dose version was approved in January 2017.
Multiple petitions challenging the ‘253 patent and others covering Narcan were filed by a company called Nalox-1 Pharmaceuticals in February 2019. According to a Nalox-1 petition, the patent should be revoked on the grounds of obviousness because a “person of ordinary skill in the art” (POSA):
- “Would Have Been Motivated to Develop Improved Intranasal Naloxone Formulations to Combat the Opioid Epidemic”
- “Would Have Had the Know-How to Readily Develop an Improved Intranasal Naloxone Formulation”
- “would have been motivated to use a 4-6 mg naloxone dose to achieve desirable naloxone exposure levels”
- “would have had adequate know-how and ability to select commonplace excipients to make a stable, well-tolerated intranasal naloxone formulation.”
and - “would have been motivated to load an intranasal naloxone formulation into an easy-to-use single-dose, pre-primed nasal sprayer”
The PTAB found that the challenge meets the minimum requirement for such a review, that “there is a reasonable likelihood that the petitioner would prevail with respect to at least 1 of the claims challenged in the petition.” According to the PTAB’s August 27, 2019 order, the board found that multiple claims in the patent would likely be found to be obvious and therefore not patentable.
In October 2016, Opiant filed suit against Teva for patent infringement after Teva filed an ANDA for naloxone nasal spray; Opiant also filed suit against Perrigo in 2018 after that company submitted an ANDA for a generic of Narcan. The PTAB declined to deny the petition due to the existence of parallel challenges to the patents, noting that “It is undisputed that Petitioner [Nalox-1] is not involved in the Teva Case.”
Nalox-1 asserts that “The ’253 patent is a barrier wrongfully and shamefully preventing broader accessibility to this critically needed naloxone medication.” Recently, in response to the opioid epidemic, the FDA has been actively encouraging development of generic versions of Narcan. In January 2019, the agency published a model drug facts label for such a product and in April 2019 announced final approval of Teva’s generic Narcan. The agency also recently accepted an NDA from Insys for a naloxone nasal spray (that NDA has since been acquired by Hikma).
