REO 021 was a single arm, open-label Phase II study of REOLYSIN® in combination with paclitaxel and carboplatin in patients with squamous cell carcinoma of the lung. Patients received paclitaxel and carboplatin on day 1 of each twenty-one day cycle, with REOLYSIN® administered on days 1 through 5. Approximately 25 evaluable were enrolled in the study. The primary objective was to assess the objective response rate (complete response (CR) plus partial response (PR)) of the treatment regimen. Secondary objectives included safety and tolerability, progression rates at six months, progression-free survival, and overall survival.
The Company presented interim findings from the study in March 2013, announcing that the study met its primary statistical endpoint. The endpoint was designed to be met if 9 or more patients had a PR or better, yielding a true response rate of 35% or more. Of the 21 evaluable patients enrolled at that time, 9 exhibited PRs, a further 9 showed SD and three, progressive disease (PD), for a response rate of 42.8% and a disease control rate (complete response (CR) + PR + SD) of 85.7%.
In September 2013, the Company announced final tumour response data from the study. The analysis examined best overall percentage tumour responses between pre-treatment and up to 6 treatment cycles. Of 25 evaluable patients who had received more than one cycle of therapy, 23 (92%) exhibited overall tumour shrinkage, with a mean shrinkage of 32.7%. Ten (40%) had partial responses, while a further 13 (52%) showed stable disease and two (8%), had progressive disease, for a disease control rate of 92%.
Progression-free survival (PFS) data for the study was presented by Oncolytics collaborators at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in October 2013. The investigators reported that each of the 25 evaluable patients had received between two and 12 cycles of therapy. Of these, 23 (92%) exhibited overall tumour shrinkage. When evaluated for best response, which is the best percentage response recorded on study compared to baseline, 10 patients (40%) had partial responses, while a further 14 (56%) showed stable disease, and one (4%), had progressive disease. Using RECIST criteria to evaluate best overall response, 10 patients (40%) had partial responses, 12 (48%) showed stable disease and three (12%), had progressive disease (PD). 31.8% of patients with sufficient follow up had progression-free survivals greater than six months.