REO 004 was an open-label, dose-escalation Phase I study of REOLYSIN® monotherapy in patients with various advanced or metastatic solid tumours. Eighteen patients were enrolled, and received escalating doses of intravenously administered REOLYSIN®. The primary objectives were to determine the maximum tolerated dose, dose-limiting toxicity and safety profile of REOLYSIN®. The secondary objectives were to evaluate viral replication, and to observe tumour and immune system responses to the treatment.
The Company announced final results from the study in June 2007. The treatment was found to be safe and well tolerated by patients. The trial was originally designed to demonstrate the safety of a single, one-hour infusion of REOLYSIN®; however, Oncolytics applied for and was granted approval to allow later patients to receive repeat monthly treatments of REOLYSIN®. Of the patients eligible for retreatment, three patients received a range of two to seven one-hour infusions of REOLYSIN®. Toxicities possibly related to REOLYSIN® treatment in this trial were generally mild (Grade 1 or 2) and included chills, fever and fatigue. Of the 18 patients treated, eight demonstrated stable disease as measured by RECIST, including a patient with progressive breast cancer who experienced a 28.5% shrinkage in tumour volume.