Nuedexta dextromethorphan/quinidine: Phase II data
Top-line data from the double-blind, placebo-controlled, international Phase II PRIME trial in 209 MS patients with central neuropathic pain showed that twice-daily AVP-923 missed the primary endpoint of reducing Numeric PRS scores from baseline to week 12 vs. placebo. Avanir said patients treated with AVP-923 in the trial "experienced levels of pain reduction commensurate with those observed in similar studies" and that the improvement in pain scores were significant when compared to baseline. The company said it believes that a higher-than-expected placebo response negatively impacted the results. AVP-923 was generally well tolerated. Patients received placebo or 45/10, 30/10 or 20/10 mg AVP-923 twice daily for 12 weeks. Avanir plans to review the PRIME data to determine next steps for AVP-923 in neuropathic pain.
In February, the company said it would reduce target enrollment in PRIME to 200 from 400 MS patients based on data from a Phase I trial with AVP-786, a deuterium-containing analog of dextromethorphan, plus low-dose quinidine to treat pain. The Phase I data showed that AVP-786 plus low-dose quinidine had a comparable pharmacokinetic, safety and tolerability profile to AVP-923, which contains a higher dose of quinidine (10 mg) than that given with AVP-786. Avanir said data from PRIME would guide further development of AVP-786, which the company said has the "potential to be a preferable development compound" over dextromethorphan/quinidine in pain indications (see BioCentury, Feb. 18). ...