Results from a Phase I trial demonstrated that Roche's experimental anti-PDL1 therapy MPDL3280A shrank tumours in 43 percent of patients previously treated for PD-L1-positive metastatic urothelial bladder cancer after six weeks of follow-up, the company announced. "To show this spectacular response in these end-stage patients is extremely unusual," remarked study author Thomas Powles.
The study consisted of 68 previously-treated patients with metastatic urothelial bladder cancer who were treated with MPDL3280A, including 30 patients who were identified as PD-L1 positive using an investigational diagnostic test being developed by Roche. Results, which were presented at the annual ASCO meeting, also demonstrated an objective response rate (ORR) of 52 percent in PD-L1-positive patients after 12 weeks, while a complete response was observed in 7 percent of these subjects.
Meanwhile, results showed an ORR of 11 percent in patients identified to have PD-L1-negative tumours. Roche noted that the safety profile in the study was consistent with what was previously reported for the immunotherapy, with no patients experiencing severe treatment-related toxicities.
Roche also indicated that MPDL3280A has been granted breakthrough therapy status by the FDA in metastatic bladder cancer. "Bladder cancer is the ninth most common cancer worldwide, for which there have been no new treatment advances in nearly 30 years," commented Roche chief medical officer Sandra Horning, adding "we are evaluating MPDL3280A in a broad range of tumours, and have begun pivotal studies that include a companion diagnostic test in lung and bladder cancers."
For related analysis, read ViewPoints: Roche looks to diversify immuno-oncology race with impressive bladder cancer data and FirstWord Lists: A revolution in cancer – a launch calendar for key immuno-oncology indications.
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