Infusion reactions were most common with the first dose (27% active vs. 7% placebo). One patient taking the study drug withdrew at that time from a serious reaction, but the remainder were mild to moderate in severity. Reactions decreased over time, and all remained at the mild-moderate level.
Overall adverse events occurred at similar rates between those taking the drug and those taking placebo (95% vs. 90%). Infections were similar (70% vs. 68%) overall, although upper respiratory infections were more common among the active group (11% vs. 6%).
There were five deaths: one in the placebo arm (a motor vehicle accident) and four in the active arm (pulmonary embolism, pneumonia, pancreatic cancer, and pneumonia aspiration). These, as well as the malignancy findings, are still being evaluated, Dr. Montalbán said.
Based on the positive results, Genentech will be submitting the drug for approval in both the United States and Europe in the first quarter of 2016.
Dr. Montalbán disclosed ties with Genentech – the trial’s sponsor – and other pharmaceutical companies.
*Correction, 10/14/15: The timed 25-foot walk test results were previously misstated.