FDA declines to approve Indivior’s naloxone nasal spray for opioid overdose

Indivior received a complete response letter from the FDA focusing on clinical pharmacology that found the early stage uptake of naloxone nasal spray did not fully meet the agency’ threshold as determined by the reference product (0.4 mg naloxone by intramuscular injection).

Indivior CEO Shaun Thaxter said: "We are closely reviewing the FDA’s response.

"Our commitment to improving patient outcomes remains steadfast, and as part of this, our work with stakeholders across communities will continue."

Naloxone nasal spray is an intranasal naloxone product candidate for the emergency treatment of known or suspected opioid overdose.

It is designed to deliver naloxone via the nasal mucosa of an overdose victim.

Naloxone is an opioid receptor antagonist that binds to the opioid receptors in the brain to reverse the effects of natural and synthetic opioids.

Indivior said at present, only needle-based formulations of naloxone are FDA approved.

The number of unintentional overdose deaths involving opioid pain relievers in the US has increased four-fold between 1999 and 2013.

Opioid and heroin overdoses cause over 25,000 deaths in the US per year.