Phase III Safety Study Success for Tamperproof Opioid Drug
Pfizer reported positive topline data from a Phase III, open-label long-term safety study of the investigational drug ALO-02 (oxycodone hydrochloride and naltrexone hydrochloride extended-release capsules) in patients with moderate-to-severe chronic noncancer pain. The trial involved 394t opioid-naive and opioid-experienced patients, who were treated using ALO-02 for either six months or a year.
ALO-02 has been developed to discourage common tampering methods associated with the misuse and abuse of prescription opioid medications. The drug comprises extended-release oxycodone pellets surrounding a core of naltrexone. Used as directed the naltrexone remains sequestered and the patients receive oxycodone in an extended release manner. However, if the pellets are crushed, the naltrexone is released and counteracts the effects of oxycodone.
The Phase III safety study showed that the most common treatment-related adverse events associated with ALO-02 therapy were nausea, constipation, vomiting, and headache. About 60% of patients discontinued from the study over the one-year period, with 19% citing adverse events as the primary reason for discontinuation. Pfizer says the discontinuation rate was within the expected range based on similar long-term safety studies with other extended-release opioid formulations.
“These topline data provide evidence of the long-term safety of ALO-02 in patients with moderate-to-severe noncancer pain, regardless of prior prescripton opioid treatment," states Steven J. Romano, M.D., senior vp and head of the medicines development group at Pfzizer’s global primary care business unit.