Canada's Oncolytics Biotech ($ONCY) trumpeted some promising late-stage results for its viral head and neck cancer therapy, but a distortion in the company's overall survival data rattled investors, sending its shares down as much as 8.6% on Thursday.
First, the good news: In a Phase III study on 118 patients, those who received a cocktail of Oncolytics' Reolysin, carboplatin and paclitaxel charted median progression-free survival of 94 days, beating out the 50-day mark for patients who got just the two cancer drugs. Furthermore, of the 88 patients who didn't get further treatment after the trial, those in the treatment arm posted a median overall survival of 150 days, above the 115 days of the control arm.
But therein lies the problem: Because 30 of the 118 patients received at least one therapy with other agents after the study, Oncolytics' OS figures are distorted, and the company acknowledged a "confounding" effect on its data's efficacy, as "such additional therapy can extend the patients' lifespan beyond that expected from receiving the study therapy."
So, now what? Oncolytics is keeping things cheery, saying this Phase III effort was a "separate supportive study" meant to inform the design of a soon-to-come registration trial aimed at FDA approval.
"We are excited to move forward with our head and neck program, and intend to discuss the design and execution of a follow-on registration study with regulators in the near future," CEO Brad Thompson said.
Investors, however, are less optimistic, and Oncolytics' shares fell as low as $2.24 on the announcement, down more than 50% since the company's February peak.
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