Elysium Therapeutics Announces Development of Overdose Rescue Technology Specifically Designed for Oral Fentanyl

Synthetic Opioid Overdose Prevention and Reversal (SOOPR™) targets an unmet challenge in the illicit opioid crisis as current rescue medications are not designed for synthetic opioids, including oral fentanyl.

LYONS, Colo., April 7, 2025 /PRNewswire/ -- Elysium Therapeutics, an emerging biopharmaceutical company developing treatments specifically designed to rescue and reverse overdoses caused by oral opioids, including synthetic opioids like fentanyl, announced its plan to accelerate development of its Synthetic Opioid Overdose Prevention and Reversal (SOOPR™) technology. The company has completed in vivo proof-of-concept studies and expects to file an Investigational New Drug (IND) application in 2026.

SOOPR is a rapid-onset, long-acting rescue agent specifically designed to address overdose from synthetic opioids, including oral fentanyl. SOOPR utilizes a proprietary long-acting naloxone prodrug formulation with faster onset kinetics versus Narcan^® delivered via long-acting injection (LAI) technology. The technology is designed to rapidly restore respiration and provide 18 to 24 hours of effective opioid blockade to minimize the risk of re-narcotization, while also providing protection from same-day re-use of opioids.

"Fentanyl overdoses often require very high, or repeated, doses of short-acting opioid antagonists to effect a successful rescue," said Greg Sturmer, Co-Founder and CEO of Elysium Therapeutics. "Unfortunately, many who overdose face a rapid recurrence of symptoms, known as re-narcotization, which can lead to respiratory depression and increase the likelihood of hypoxic brain injury or death. SOOPR is designed to address this situation, and Elysium is now focused on advancing its development as a potential first-ever, faster-onset, longer-acting opioid rescue therapy specifically intended to treat fentanyl overdose."

Currently approved short-acting opioid antagonists like Narcan and Opvee^® were designed to effectively counteract overdoses from opioids such as heroin and oxycodone. However, these rescue agents are frequently ineffective in the management of synthetic opioid overdoses¹, with 20 to 45% of overdose victims initially rescued with naloxone experiencing a re-narcotization event. According to reports from multiple state-affiliated health agencies, 31 to 39% of fentanyl overdose decedents had been administered naloxone.²

Data from in vivo proof-of-concept studies of SOOPR demonstrated a more rapid onset of action versus naloxone (Narcan) and a significantly longer duration of action. This profile is especially useful in counteracting oral fentanyl overdoses associated with prolonged fentanyl absorption and exposure that often outlast the short-acting profile of Narcan.

"In designing SOOPR, Elysium recognized that synthetic opioids – now the number one killer of adults aged 18 to 45 in the U.S. – are particularly lethal," said Tom Jenkins, Ph.D., Co-Founder and Chief Scientific Officer of Elysium Therapeutics. "Patients initially treated with a rapid-acting, long-duration reversal agent, such as SOOPR, are expected to have less risk of hypoxic brain injury, cardiovascular events, re-narcotization, and death. Further, rescue interventions with SOOPR are expected to require less intensive monitoring in both the ambulance and emergency department and increase the likelihood of survival. Additionally, SOOPR is designed to be delivered by intramuscular injection, either using a pre-filled syringe or autoinjector, which has been demonstrated to be more rapid and predictable than intranasal delivery in urgent settings, where every second counts."

"In addition to preventing overdose deaths from recreational, illicit use, the Department of Defense (DOD) has made clear the importance of improving opioid overdose rescue as a needed medical countermeasure," added Sturmer. "The DOD reported that the availability of synthetic opioids, such as fentanyl and its derivatives, represents a significant threat as a chemical weapon, which could be easily disseminated as a weapon of mass destruction into air, water or food supplies, putting countless lives at risk. We look forward to working with defense and government organizations as we develop SOOPR as a tool to prevent injury and death in these worrisome scenarios."

About SOOPR™ (Synthetic Opioid Overdose Prevention and Rescue)

SOOPR (Synthetic Opioid Overdose Prevention and Reversal) is a rapid-onset, long-acting rescue agent specifically designed to address overdose from synthetic opioids, including oral fentanyl. SOOPR utilizes a proprietary long-acting naloxone reversal formulation with faster onset kinetics versus Narcan^® delivered via long-acting injection (LAI) technology. The technology is designed to rapidly restore respiration and provide 18 – 24 hours of effective opioid blockade to minimize the risk of re-narcotization, while also providing protection from same-day re-use of opioids. SOOPR has been endorsed by first responders and OUD treatment professionals as the effective solution urgently needed to address the global opioid overdose epidemic.

About Elysium Therapeutics

Elysium is an emerging biopharmaceutical company developing treatments specifically designed to rescue and reverse overdoses caused by oral synthetic opioids, including fentanyl. Elysium is working to establish new standards of safety in the opioid industry by developing SMART™ (Safer Medicines Alleviate Risks and Trauma) products, first- and best-in-class medicines that address the limitations and dangers associated with opioids and overdose rescue agents to reduce suffering from opioid-use disorder, opioid overdose, and acute pain. Elysium's lead technology, SOOPR™ (Synthetic Opioid Overdose Prevention and Reversal), is a long-acting opioid antagonist specifically designed to address oral synthetic opioid, including fentanyl, overdose. Tens of thousands of unnecessary overdose deaths each year exemplifies the critical shortcomings of currently available rescue agents, including naloxone and nalmefene. In addition, Elysium is developing oral-overdose protected (O2P™) hydrocodone for the treatment of moderate-to-severe acute pain. For more information, please visit https://www.elysiumrx.com.

¹ Rachael Rzasa Lynn and JL Galinkin Ther Adv Drug Saf 2018, Vol. 9(1) 63–88 (Also see footnotes 8, 9, and 10 for additional discussion).
² Watson, W.A., Steele, M.T., Muelleman, R.L., Rush, M.D., 1998. Opioid toxicity recurrence after an initial response to naloxone. J. Toxicol. Clin. Toxicol. 36 (1-2), 11–17. https://doi.org/10.3109/15563659809162577.

SOURCE Elysium Therapeutics