Orexo Resubmits FDA Application for High-Dose Naloxone Nasal Powder

The Swedish drugmaker Orexo said it completed a resubmission of its new drug application for IZIPRY, a high-dose naloxone nasal powder built to reverse overdoses involving fentanyl and other potent synthetic opioids, on September 29, 2026. The filing answers a complete response letter the Food and Drug Administration issued in July 2024, when the agency asked for additional commercial manufacturing data on the finished product rather than raising questions about the drug's clinical performance.

Orexo said the new submission contains additional information and documentation addressing the observations in that letter, and that it has worked with manufacturing and development partners since then to close the identified gaps. The FDA is expected to notify the company in coming weeks about whether it accepts the resubmission and to set an updated review timeline.

What the company says about the product

IZIPRY uses AmorphOX, Orexo's proprietary powder-based delivery platform, which the company says delivers rapid absorption, high bioavailability and better stability than conventional liquid nasal formulations. The product pairs a higher naloxone strength with that powder format, an approach aimed at cutting the number of repeat doses a bystander or paramedic has to administer before someone starts breathing again.

"The NDA resubmission for IZIPRY represents an important milestone for Orexo and reflects a tremendous effort by our team and external partners," the company said in its announcement. "The opioid crisis continues to have devastating consequences across communities in the U.S., and we remain committed to bringing this innovative rescue medication to patients, caregivers and healthcare professionals in need of effective overdose treatment options."

Orexo is basing the case on a now-familiar pattern in overdose response. Research published in Substance Abuse Treatment, Prevention, and Policy and in Harm Reduction Journal has documented rising rates of multiple naloxone administrations by lay bystanders and emergency medical crews as the illicit supply shifted from heroin to fentanyl. The Drug Enforcement Administration has separately warned that fentanyl cut with emerging synthetic opioids may require several doses of naloxone to reverse.

The FDA has already rejected this application once

The July 2024 complete response letter was a setback for a product Orexo had positioned as its next big U.S. opportunity. A complete response letter is not a rejection of a drug's underlying data so much as a statement that the application is not complete enough to approve; the agency told Orexo it needed commercial-scale manufacturing information demonstrating that the final product would behave the way the clinical batches did.

That requirement reflects an old problem in nasal drug delivery: the spray pattern, particle size and dose a patient actually receives can shift when a formula moves from a small development lot to commercial production. Orexo has spent the intervening two years generating that data and preparing for launch, and it said it is also weighing commercial partnerships to secure market access if the product clears review.

A crowded market for overdose reversal

Any new entrant now lands in a much busier naloxone market than the one Orexo first targeted. Narcan became the first over-the-counter naloxone nasal spray in 2023, followed by other nonprescription options including RiVive and, more recently, Rextovy, a 4-milligram spray from Amphastar. Other manufacturers have pushed dose strengths higher, with Scienture's Rezenopy marketed as the highest-dose naloxone nasal spray the FDA has approved — a claim the company reinforced this week when it announced patent protection for the product.

The competitive logic behind higher doses is straightforward. If a single 4-milligram spray is not enough to rouse someone who took a fentanyl-laced counterfeit pill, the person doing the rescuing has to recognize that, fetch a second device and use it, all while the patient's breathing has stopped. A product that reliably works in one or two doses has an obvious appeal in emergency departments, on ambulances and in the hands of family members who may only carry one unit.

What the resubmission does and does not mean

An accepted resubmission starts a new review clock; it does not guarantee approval, and the FDA can still issue a second complete response letter or request further manufacturing validation. Orexo has not disclosed a target action date, and the company has not published the specific deficiencies list it received in 2024 beyond the manufacturing-data requirement.

For now, the practical effect is limited to the regulatory calendar. Naloxone remains available without a prescription in pharmacies, through community distribution programs and via mail-order programs in a growing number of states, and anyone who witnessed an overdose can administer it without legal risk in all 50 states. The question the resubmission raises is narrower but consequential: whether people who use drugs and the people around them will eventually have a rescue medication formulated for the fentanyl era rather than for the heroin era it displaced. For patients in opioid use disorder treatment, a more reliable rescue option would also reduce the odds that a single relapse becomes a death.