Oncolytics Biotech Inc. developed a new drug, RT3D that will be marketed under the trade name of Reolysin. The drug is based on a virus, i.e. reovirus type 3 Dearing that is commonly found in the respiratory and gastrointestinal tracts of almost every adult without causing any symptoms. RT3D can grow and kill certain types of cancer cells, but it does not grow in normal cells.
Earlier trials whereby patients were injected with only the virus displayed limited effectiveness, however, the team discovered that the effects of platin and taxane-based chemotherapy on tumor cells seemed to be magnified by RT3D.
Dr Kevin Harrington and his team decided to start a clinical trial in which they examined intravenous RT3D in combination with chemotherapeutics carboplatin and paclitaxel in 31 patients with advanced cancers that had become unresponsive to standard treatments.
They conducted an initial Phase I study in patients with a variety of advanced cancers, which demonstrated that the drug combination was safe, with generally mild side effects that were consistent with chemotherapy alone.
The best responses were observed in patients with head and neck cancers, including tumors of the nasal cavity, eye, tongue, gums, lip, cheeks, voice box and esophagus. Worldwide, each year about 650,000 people are diagnosed with squamous cell cancer of the head and neck, of which annually around 350,000 die.
The findings led the researchers to conduct a Phase II expansion study at The Royal Marsden Hospital in London and at the St James’s Hospital in Leeds, which specifically targeted patients with these types of cancers. The results revealed that in about one third of patients who could be evaluated, the cancers shrank, whilst it stabilized in another third of the patients, whilst in one patient all symptoms of cancer disappeared completely.
Lead researcher of the ICR’s Targeted Therapy Team Dr Harrington, who is a Consultant Oncologist at The Royal Marsden declared:
“We saw really very impressive response rates in these patients. These are patients, whose cancers had grown despite a great deal of previous treatment, including platinum-based chemotherapy for many. Under those circumstances, we’d expect that the average response rate to chemotherapy alone might be as low as single digits figures and the average survival would be somewhere between three to four months.
In our Phase I/II study we show this had been prolonged to an average of seven months, albeit not in a randomized trial. Based on the results of this study we’ve now started recruiting patients with advanced head and neck cancer to a randomized Phase III trial, in which all patients will receive chemotherapy and half will receive Reolysin as well. We are extremely excited about this progress.”
The study findings furthermore revealed that the virus was not shed following treatment, which means that the drug can be administered to outpatients, as there is no risk that the virus could be transmitted to others.
Written by Petra Rattue