Roche's investigational immunotherapy atezolizumab met endpoint in specific type of lung cancer
Roche announced that in the large pivotal Phase II study, BIRCH, the investigational cancer immunotherapy atezolizumab (MPDL3280A; anti-PDL1) met its primary endpoint and shrank tumours (objective response rate; ORR) in people with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose disease expressed PD-L1 (Programmed Death Ligand-1). The study showed the amount of PD-L1 expressed by a person’s cancer correlated with their response to the medicine. Adverse events were consistent with what has been previously observed for atezolizumab.
Lung cancer is the leading cause of cancer death globally. Each year, 1.59 million people die as a result of the disease, which means more than 4,350 deaths worldwide every day. Lung cancer can be broadly divided into two major types, NSCLC and small cell lung cancer. NSCLC is the most prevalent type, accounting for around 85% of all cases.
Atezolizumab is an investigational monoclonal antibody designed to interfere with a protein called PD-L1. Atezolizumab is designed to target PD-L1 expressed on tumour cells and tumour-infiltrating immune cells, preventing it from binding to PD-1 and B7.1 on the surface of T cells. By inhibiting PD-L1, atezolizumab may enable the activation of T cells.
All studies of atezolizumab include the evaluation of an investigational IHC test that uses the antibody SP142 to measure PD-L1 expression on both tumour cells and infiltrating immune cells. The goal of PD-L1 as a biomarker is to identify those people most likely to benefit when treated with atezolizumab alone, and to determine which people may benefit most from a combination of atezolizumab and another medicine. There are 11 ongoing or planned Phase III studies of atezolizumab across certain kinds of lung, kidney, breast and bladder cancer.
BIRCH is an open-label, multicentre, single-arm Phase II study that evaluated the safety and efficacy of atezolizumab in 667 people with locally advanced or metastatic NSCLC whose disease expressed PD-L1. PD-L1 expression was assessed on both tumour cells (TC) and tumour-infiltrating immune cells (IC) with an investigational immunohistochemistry test (IHC) being developed by Roche Diagnostics. Eligibility criteria included people whose tumours were determined to express PD-L1 with an IHC score of TC2/3 or IC2/3. People in the study received a 1200-milligram intravenous dose of atezolizumab 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.
Earlier this year, the FDA granted atezolizumab a Breakthrough Therapy Designation for the treatment of people whose NSCLC expresses PD-L1 and who progressed during or after standard treatments (e.g. platinum-based chemotherapy and appropriate targeted therapy for EGFR mutation-positive or ALK-positive disease). This designation is designed to expedite the development and review of medicines intended to treat serious diseases. Roche have 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.