Reolysin® (Wild-Type Reovirus; Serotype 3 Dearing; Oncolytics Biotech), is a proprietary formulation of the human reovirus (reovirus) being developed for the treatment of various cancers and cell proliferative disorders. Reolysin is classified as an oncolytic virus, a virus that preferentially lyses cancer cells. Clinical trials have demonstrated that Reolysin may have activity across a variety of cancer types when administered alone and in combination with other cancer therapies.
Reolysin has been evaluated in phase II clinical trials in head & neck, melanoma, pancreatic, lung, ovarian, and colorectal cancers. The trial drug has successfully completed a number of phase I and II clinical trials across a variety of cancer types.
A number of clinical phase II and phase III trials are underway in a range of indications including squamous cell carcinoma of the lung, non-small cell lung cancer, pancreatic cancer, and ovarian cancer. The Company is also conducting a phase I trial in colorectal cancer.
The Gynecologic Oncology Group (GOG), a US-based national non-profit organization with the purpose of promoting excellence in the quality and integrity of clinical and basic scientific research in the field of gynecologic malignancies, is conducting a randomized Phase II trial of weekly paclitaxel versus weekly paclitaxel with Reolysin in patients with persistent or recurrent, ovarian, fallopian tube or primary peritoneal cancer (GOG186H). This study has been approved and will be sponsored by the Cancer Therapy Evaluation Program, Division of Cancer Treatment and Diagnosis, U.S. National Cancer Institute (NCI), which is part of the National Institutes of Health (NIH), under its Clinical Trials Agreement with Oncolytics.
Squamous Cell Carcinoma of the Head and Neck
Initial top line data from the first endpoint in a clinical study examining Reolysin, in combination with carboplatin and paclitaxel in second-line patients with platinum-refractory, taxane-naïve head and neck cancers (an amended version of a previously double-blinded randomized Phase III trial; NCT01166542) were presented in December 2012 showing that patients with metastatic only disease appeared to have a better response to Reolysin than chemotherapy alone in the sub-set of patients evaluated, although many patients were excluded from the analysis due to leaving the study before the first required assessment scan (more patients in the Reolysin arm than in the chemotherapy only arm were excluded for this reason).
The purpose of this trial is to evaluate overall survival and progression free survival following intravenous administration of Reolysin in combination with paclitaxel and carboplatin versus chemotherapy treatment alone, in patients with metastatic or recurrent Squamous Cell Carcinoma of the Head and Neck.
Metastatic Colorectal Cancer
Reolysin in combination with FOLFOX6 and Bevacizumab or FOLFOX6 and Bevacizumab alone is also evaluated in metastatic colorectal cancer (ClinicalTrials.gov Identifier: NCT01622543). The purpose of this trial is to find out if reolysin in combination with FOLFOX6/ bevacizumab offers better results than standard therapy with FOLFOX6/ bevacizumab. The study is expected to enroll 100 patients. The study started in August 2012 and is estimated to completed by May 2015 (with an eEstimated Primary Completion Date in May 2014).
Mechanism of action
Reovirus, an acronym for Respiratory Enteric Orphan virus, generally infects mammalian respiratory and bowel systems. Most people have been exposed to reovirus by adulthood; however, the infection does not typically produce symptoms.
Reovirus was noted to be a potential cancer therapeutic when early studies on reovirus suggested it reproduces well in certain cancer cell lines. It has since been shown to replicate specifically in cells that have an activated Ras (a cellular signaling pathway that is involved in cell growth and differentiation) with very little effect in cells that do not have active Ras pathways. Reovirus replicates in and eventually kills Ras-activated tumour cells, and as cell death occurs, progeny virus particles are then free to infect surrounding cancer cells. This cycle of infection, replication and cell death is believed to be repeated until all tumour cells carrying an activated Ras pathway are destroyed. Activating mutations of the Ras protein and upstream elements of the Ras protein may play a role in more than two thirds of all human cancers,including most metastatic disease, which suggests that Reolysin may be an effective therapeutic for many Ras-activated tumor types and potentially for some cell proliferative disorders.
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- REO 017 Meets Primary Endpoint for First Part of U.S. Phase II Pancreatic Cancer Clinical Trial - Onco'Zine - The International Cancer Network 
- Oncolytics Biotech® Inc. Collaborators to Present Positive Phase 2 REOLYSIN Clinical Data in Pancreatic Cancer at the AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference 
- Clinical Trials Overview
- Randomized Phase II Ovarian Cancer Study With Reolysin® To Be Conducted By The Gynecologic Oncology Group (GOG)
- Cancer Therapy Evaluation Program
- Efficacy Study of REOLYSIN® in Combination With Paclitaxel and Carboplatin in Platinum-Refractory Head and Neck Cancers 
- Positive Top Line Data Presented for Reolysin® in Randomized Phase III Study in Head and Neck Cancers 
- ClinicalTrials.gov Identifier: NCT01622543
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