By Pat Anson, PNN Editor

An experimental form of hydrocodone relieves moderate-to-severe acute pain without the risks of traditional opioids, according to the results of an early-stage Phase 1 clinical trial.

Elysium Therapeutics say its proprietary “SMART” formulation of hydrocodone – called Oral Overdose Protected (O2P) hydrocodone – releases therapeutic levels of the pain medication when exposed to trypsin, a digestive enzyme in the small intestine. Conversely, the drug can also inhibit production of trypsin – and slow the release of hydrocodone -- if a "supratherapeutic" (more than recommended) dose is ingested.

In theory, that will reduce the risk of abuse, diversion and overdose.

"Because non-opioid options are ineffective and existing opioids have no protection against their inherent risks, moderate-to-severe acute pain is not adequately managed in greater than 80% of patients in the US,” Greg Sturmer, CEO of Elysium Therapeutics said in a press release.

“As shown in our human study, our SMART opioids, led by O2P hydrocodone, mitigate the major risks associated with existing prescription opioids without sacrificing their superior analgesic efficacy, especially when compared to currently marketed non-opioid alternatives and those in development."

The proof-of-concept study included 93 healthy participants who were not in pain, but had previously used and tolerated prescription opioids. Their blood plasma levels were measured after taking O2P hydrocodone and compared to plasma levels after taking traditional hydrocodone. Participants were also given naltrexone as a safety measure to block the sedative effect of the drugs.

Investigators say the plasma concentrations of hydrocodone were significantly lower after taking the O2P formulation, but were high enough to be “potentially lethal” from traditional hydrocodone. No adverse events were reported from O2P hydrocodone, even when taken at supratherapeutic doses.

"The results from the O2P-001 study indicate that Elysium's O2P technology could yield safer opioids that address the key issues inherent in current opioids that have fueled the opioid crisis, while providing patients with highly effective pain relief," said Leela Vrishabhendra, MD, principal investigator of the study.

Many U.S. hospitals have started using non-opioid pain medications such as ibuprofen, acetaminophen and gabapentinoids to treat post-operative acute pain. Studies have found that some patients are not happy with the results and want more pain control. O2P hydrocodone would give them an alternative.

Phase I clinical studies are preliminary in nature and usually just measure the safety and tolerability of a drug, not its effectiveness. Elysium hopes its findings will lead to a “breakthrough therapy” designation from the FDA, which will speed up the development of its O2P technology and lead to larger clinical trials that would better assess pain relief.   

"Given the robust Phase 1 human proof-of-concept data, we plan to meet with the FDA to discuss next steps, finalize our dose form for remaining clinical studies, and seek partners and investors who share our passion to disrupt the pain and opioid use disorder markets with safer medicines that reduce trauma and save lives," said CEO Greg Sturmer.