Nasal Nalmefene Produces Positive Results Reversing Respiratory Depression

Opiant Pharmaceuticals announced positive topline results from a head-to-head pharmacodynamic (PD) study that compared nasal nalmefene (OPNT003), to nasal naloxone. Nasal nalmefene mnalmefenenalmefeneet the primary endpoint of non-inferiority and produced a greatter reversal in remifentanil-induced respiratory depression than nasal naloxone.

Nasal nalmefenemefene is an investigationalational treatment for opioid overdose. In this crossover study, a 3 mg dose of nasal nalmefene hydrochloride was compared with a 4 mg dose of nasal naloxone hydrochloride to assess its capability of reversing the effects of an opioid overdose.

Investigators measured changes in minute ventilation after 1 of the 2 trial drugs was administered to the 50 healthy volunteers. The primary endpoint was at 5 minutes. The nalmefene increases in minute ventilation were 5.745 L/min and the naloxone increases were 3.011 L/min.

According to a preliminary analysis of the participants, nasal nalmefene produced a reversal of respiratory depression that was almost twice that produced by nasal naloxone at the 5 minute endpoint. The completion of this study concluded the planned clinical development program for nasal nalmefene and the company expects to file a New Drug Application (NDA) in the second half of 2022.

“The findings from this PD study are compelling and add to a body of non-clinical and clinical evidence demonstrating the potential of OPNT003, nasal nalmefene, to offer an important treatment option for opioid overdose,” Richard C. Dart, MD, PhD, Director, Rocky Mountain Poison & Drug Center, Denver Health and Hospital Authority, and member of Opiant’s Scientific Advisory Board, said in a statement.

“Synthetic opioids, such as fentanyl, are responsible for the great majority of overdoses today, are far more potent, have a more rapid onset, and can have a long duration of action," he continued. "They can quickly depress respiration and can continue to deprive the brain of oxygen even after administration of naloxone, the only current FDA-approved treatment for opioid overdose. Unless quickly reversed, this can cause severe hypoxic injury to the victim’s organs and brain, and potentially death.”