Efficacy data from Phase III STAR trial of Zenvia presented at AAN Annual Meeting

AVANIR Pharmaceuticals, Inc.Apr 15 2010

AVANIR Pharmaceuticals, Inc. (NASDAQ: AVNR) today announced long-term efficacy data from the 12-week double-blind phase and the 12-week open-label extension phase of the confirmatory Phase III STAR trial evaluating Zenvia™ (dextromethorphan/quinidine) in the treatment of pseudobulbar affect (PBA) in patients with underlying multiple sclerosis or amyotrophic lateral sclerosis. The detailed efficacy data were presented at the American Academy of Neurology (AAN) Annual Meeting in Toronto and were selected by the AAN as part of the Late-Breaking Science program. (Poster number: P02.295)

“We are very pleased that the Zenvia long-term efficacy data were selected for inclusion in the Late-Breaking Science program by the AAN”

LATE BREAKER POSTER HIGHLIGHTS

• Zenvia 30/10 mg demonstrated persistent long-term efficacy and tolerability as a therapy for PBA with 92.9% of patients completing the 12-week treatment period of the open-label extension study
• Patients who continued on Zenvia 30/10 mg or titrated up from Zenvia 20/10 mg to Zenvia 30/10 mg demonstrated statistically significant incremental improvement in their CNS-LS scores at end of study compared to open-label baseline (p<0.0001 for both groups)
• Patients originally on placebo in the double-blind phase who initiated Zenvia 30/10 mg in the open-label phase demonstrated statistically significant improvement in their CNS-LS scores at end of study compared to open-label baseline (p<0.0001)
• At the last study visit (Day 84) of the open-label extension, the mean CNS-LS score was below the cut-off value indicative of clinical PBA

"We are very pleased that the Zenvia long-term efficacy data were selected for inclusion in the Late-Breaking Science program by the AAN," said Randall Kaye, MD, AVANIR's Chief Medical Officer. "These data demonstrate that the new low-dose 30/10 mg formulation of Zenvia provides persistent long-term efficacy by significantly reducing the frequency and severity of PBA episodes over a six-month period. This was the first time that the efficacy of Zenvia has been studied beyond three months and we were very pleased to see such a durable response over the extended treatment period."

PATIENT DISPOSITION AND ADDITIONAL EFFICACY RESULTS

Of the 283 patients completing the 12-week double-blind phase of the STAR trial, 253 patients (or 89.4%) entered the open-label extension; 94 who originally received Zenvia 30/10 mg, 76 who originally received Zenvia 20/10 mg and 83 who originally received placebo. In general, the open-label cohort resembled the groups in the preceding double-blind phase of the trial. Patients enrolled in the open-label extension study within two weeks of completing the double-blind phase. Therefore, some patients were off study drug at the time of entering the open-label extension. All patients that enrolled in the open-label extension received Zenvia 30/10 mg twice daily; once in the morning and once in the evening. A total of 235 patients (or 92.9%) completed the open-label study.

During the open-label extension phase, the assessment of efficacy was exploratory and measured by the change from baseline to end of study using the Center for Neurologic Studies Lability Scale (CNS-LS). The CNS-LS is a validated instrument measuring the severity and intensity of PBA. In the open-label assessment of efficacy, CNS-LS scores continued to improve over the 12-week extension study and patients previously on placebo were the most incrementally improved. The efficacy results in all treatment groups and at comparable time points evaluated in both phases of the STAR trial are summarized in the table below:

In the open-label extension, patients originally receiving Zenvia 30/10 mg in the double-blind phase demonstrated statistically significant incremental improvement in their CNS-LS scores over the second 12 weeks of treatment compared to open-label baseline (p<0.0001). In addition, patients who switched to Zenvia 30/10 mg from either Zenvia 20/10 mg or placebo also achieved a statistically significant incremental improvement in their CNS-LS scores compared to baseline (p<0.0001 for both groups). The efficacy results of the open-label study are summarized in the table below:

CONCLUSIONS

• In the open-label phase, Zenvia 30/10 mg continued to improve CNS-LS scores over the additional 12-week treatment period demonstrating that the new low-dose formulation provides long-term efficacy as a treatment for reducing the frequency and severity of PBA.