Aeterna Zentaris announces results from perifosine Phase 3 trial on colorectal cancer

Aeterna Zentaris Inc. (NASDAQ: AEZS) (TSX: AEZ) (the "Company") today announced that Johanna Bendell, MD, Director of Gastrointestinal Cancer Research and Associate Director of Drug Development at the Sarah Cannon Research Institute in Nashville, Tennessee, presented Phase 3 results for perifosine in refractory colorectal cancer yesterday, at the American Society of Clinical Oncology (ASCO) Annual Meeting which is being held in Chicago. Dr. Bendell was the lead investigator of the trial. Data showed no benefit in overall survival when adding perifosine to capecitabine in the refractory colorectal cancer setting, confirming top line results previously disclosed by the Company on April 2, 2012.

The Study

This was a randomized (1:1), double-blind Phase 3 trial conducted in the United States by our former licensee Keryx Biopharmaceuticals, comparing the efficacy and safety of capecitabine + perifosine (P-CAP) vs capecitabine + placebo (CAP), involving 468 patients with metastatic colorectal cancer which was refractory to all standard therapies. Primary endpoint was overall survival (OS) with secondary endpoints including overall response-rate (ORR) (complete (CR) + partial responses (PR)), progression-free survival (PFS) and safety (clinicaltrials.gov NCT 01002248).

Results

For the total intent to treat (ITT) patient population, median OS was 6.9 months for the CAP group compared to 6.4 months for the P-CAP group. Median PFS was 11.4 months for the CAP group compared to 10.9 months for the P-CAP group. The differences were not statistically significant. There were 7 complete and partial responses in the CAP group compared to 6 complete and partial responses in the P-CAP group.

There was no significant difference in toxicity profiles between the two arms. The most frequent hematologic adverse event was grade 1/2 anemia (CAP = 30 vs P-CAP = 49). The most non-hematologic adverse event was grade 1/2 fatigue (CAP = 95 vs P-CAP = 125).

In one pre-defined subgroup to which patients were stratified, those who expressed the wild-type K-ras proto-oncogene and who had discontinued oxaliplatin for toxicity rather than for disease progression, there was a benefit in OS (P-CAP = 8 versus CAP = 6.2 months) and in PFS (P-CAP = 18.6 versus CAP = 6.6 months) for perifosine treated patients. The reason for this finding is not clear at present and further analysis, including biomarkers studies, are ongoing.

Juergen Engel, PhD, President and CEO at Aeterna Zentaris commented, "These data confirm the disappointing topline results disclosed in April. However, they do not deter us from our decision to continue the Phase 3 trial in multiple myeloma which, as previously stated, was based first and foremost on existing solid preclinical and clinical data, and on the support for this drug among key opinion leaders in this field. Additionally, we believe that market opportunity, examples of other drugs enjoying success after facing setbacks, as well as the reasonable investment required to move forward with this study up to the predefined interim analysis, also make this a sound decision for the Company. Perifosine in multiple myeloma remains a key component of our deep pipeline focused on providing novel, targeted treatment options for cancer patients facing unmet medical needs."