Genentech's Atezolizumab Shrank Tumors in Phase II Lung Cancer Trial
August 17, 2015
By Alex Keown, BioSpace.com Breaking News Staff
SOUTH SAN FRANCISCO – Genentech ’s investigational cancer drug atezolizumab successfully shrank tumors in people with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose disease expressed PD-L1, the company announced this morning.
Atezolizumab, MPDL3280A, is an investigational monoclonal antibody designed to interfere with a protein called PD-L1 (Programmed Death Ligand-1). Atezolizumab is designed to target PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, preventing it from binding to PD-1 and B7.1 on the surface of T cells, the company said. By inhibiting PD-L1, atezolizumab may enable the activation of T cells in the treatment of cancer. During the Phase II BIRCH study, atezolizumab showed the amount of PD-L1 expressed by a person's cancer correlated with their response to the medicine, Genentech said.
According to the American Cancer Society, it is estimated that more than 221,000 Americans will be diagnosed with lung cancer in 2015, and NSCLC accounts for 85 percent of all lung cancers. It is estimated that approximately 60 percent of lung cancer diagnoses in the United States are made when the disease is in the advanced stages.
Sandra Homing, Genentech’s chief medical officer, said in a statement they are encouraged by patients’ responses to atezolizumab, particularly because the people receiving the medication had poor results from previous treatments for their cancer. She said the company plans to advance the drug to commercialization, but did not provide an expected timeline.
Atezolizumab was granted breakthrough therapy status by the U.S. Food and Drug Administration (FDA) earlier this year. The drug is also showing promise in the treatment of breast cancer and bladder cancers. Phase II data released earlier this month showed atezolizumab shrank tumors in people with locally advanced or metastatic urothelial bladder cancer.
Genentech said it has seven Phase III studies evaluating atezolizumab alone or in combination with other medicines as a potential new treatment for people with early and advanced stages of lung cancer.
Anti-PD-L1 is a hot area for cancer research, with a number of companies conducting clinical trials to bring their own treatments to market, particularly after the success of Merck & Co. ’s Keytruda. Keytruda, has been shown effective in treating three kinds of cancers -- melanoma, lung cancer and mesothelioma. Keytruda, also known as pembrolizumab, is a humanized monoclonal antibody that blocks the interaction between the protein PD-1 and its ligands, PD-L1 and PD-L2. By binding to the PD-1 receptor and blocking the interaction with the receptor ligands, Keytruda releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response, the company said. PD-1 inhibitors are seen as one of the best opportunities in treating lung cancers.
Immuno-oncology is an expanding field with large and small companies, such as Pfizer Inc. , AstraZeneca PLC , Bristol-Myers Squibb Company and Jounce Therapeutics carving out their niche in that area. Immuno-oncology harnesses the body’s own immune system to fight cancer cells. The immuno-oncology field is expected to grow to $40 billion by 2025, a Leerink analysis said. In June Amgen announced a collaboration with Roche on a Phase Ib clinical trial to evaluate talimogene laherparepvec combined with atezolizumab (MPDL3280A) for the treatment of triple-negative breast cancer and colorectal cancer with liver metastases.