Lung Tumors Shrink in Genentech's Phase II Study Of Atezolizumab

Roche Group subsidiary, Genentech, recently announced that its pipeline cancer immunotherapy atezolizumab, used in the crucial large-scale Phase II trial BIRCH, has achieved its primary endpoint and had the ability to shrink tumors in patients diagnosed with locally advanced or metastatic non-small cell lung cancer (NSCLC) expressing PD-L1.

The BIRCH study was designed as an open-label, multicenter, single-arm Phase II study to determine the safety and efficacy profile of atezolizumab, an investigational monoclonal antibody. This investigational immunotherapy works by interfering with cell surface protein, PD-L1, leading to a boost in T cell activity. The study enrolled 667 patients who were treated with a 1,200-milligram intravenous dose of the drug every 3 weeks. The primary endpoint of the study was ORR. Secondary endpoints included duration of response (DoR), overall survival (OS), progression-free survival (PFS) and safety. Results from BIRCH will be presented at an upcoming medical meeting.

The study was able to quantify the amount of PD-L1 expressed by a cancer patient in relation to their response to the drug. Any adverse effects reported were similar to those noted in previously completed studies of atezolizumab.

“We are encouraged by the number of people who responded to atezolizumab and maintained their response during the study, which is particularly meaningful for people who had received several prior treatments,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development. “We plan to present results at an upcoming medical meeting and will discuss these data as well as results from our other lung cancer studies with health authorities to bring this medicine to patients as quickly as possible.’’

In February 2015, the US Food and Drug Administration granted atezolizumab Breakthrough Therapy Designation as a treatment for NSCLC expressing PD-L1, in patients whose disease progressed despite receiving standard cancer treatments. The designation grants the drug accelerated development and review with the FDA.

As a biomarker, PD-L1 can be used to identify which patients are most likely to benefit from treatment with atezolizumab alone, or from atezolizumab combined with another drug. At present, there are 11 Phase III studies in the works or already underway, testing atezolizumab on cancers of the lungs, kidney, breast, and bladder.