The FDA accepted for review the New Drug Application (NDA) for NKTR-181, a new, long-acting opioid developed to treat chronic low-back pain in patients new to opioid therapy.
NKTR-181 is thought to exhibit a low incidence of specific CNS-mediated side effects, such as euphoria, due to low permeability across the blood-brain barrier, which slows the rate of entry to the brain to reduce dopamine release. It is thought that reducing the rush of dopamine to the brain will lower the likelihood an individual will become addicted to the drug.
Fifteen clinical studies involving 2,234 patients were conducted for NKTR-181. One of the studies saw an average pain score reduction of over 65% for patients taking the drug, while another study found the abuse potential of NKTR-181 to be lower than oxycodone among recreational drug users.
Another study was for a 12-week, Phase 3 clinical trial of 1,189 patients, which found that taking NKTR-181 twice daily produced significant pain relief. When it came to patients who took NKTR-181, 2.9% of patients experienced withdrawal symptoms, while across the entire study only 0.2% of patients engaged in abusive behavior, some of whom were in the placebo group.
NKTR-181 will likely receive an FDA decision by May 28, 2019. While results thus far are positive, continued development of new opioids begs the question: is the answer to the opioid epidemic really more opioids? Healthesystems previously explored this question in “Future Opioids and the Injured Worker: Why ‘Safer’ Is a Relative Term.”