Naloxegol, an orally administered peripherally acting mu-opioid receptor antagonist, has been approved by the Food and Drug Administration as a treatment for opioid-induced constipation in adults with chronic noncancer pain, the agency announced on Sept. 17.
The drug will be marketed by AstraZeneca Pharmaceuticals as Movantik and is expected to be available during the first half of 2015, according to a company statement. A company petition for the drug to be descheduled is under review at the US Drug Enforcement Administration. Because the drug is structurally related to noroxymorphone, naloxegol is considered a schedule II drug, but the FDA-approved labeling states that it has “no risk of abuse or dependency,” the company statement said.
Approval of the drug, which is taken once a day in a tablet formulation, was based on two 12-week studies of 1,352 patients who had taken opioids for noncancer related pain for at least 4 weeks and had opioid-induced constipation, according to a FDA statement. The two studies, KODIAC-04 and KODIAC-05, were published in June (N. Engl. J. Med. 2014;370:2387-96).
Patients with noncancer-related pain and opioid-induced constipation were randomized to receive one of two doses of naloxegol or placebo, once a day for 12 weeks. The 12-week endpoint was at least three spontaneous bowel movements per week and an increase of at least one spontaneous bowel movement per week from baseline for at least 9 of the 12 weeks and for at least 3 of the final 4 weeks of the study. In one study, 44% of those on the 25-mg dose and 41% of those on the lower dose met this endpoint, vs. 29% of those on placebo. In the second study, 40% of those on the higher dose and 35% of those on the lower dose met this endpoint, vs. 29% of those on placebo.
Abdominal pain, diarrhea, headache, and flatulence were among the common side effects of the drug, according to the FDA.
The manufacturer is required to conduct a postmarketing study to evaluate the possible cardiovascular risks of the drug in patients, according to the agency.
Naloxegol is under review by the European Medicines Agency in Europe, according to the company.