For the first time in 30 years, the U.S. Food and Drug Administration approved a new drug for the treatment of the most common form of bladder cancer known as called urothelial carcinoma. The drug, Tecentriq (atezolizumab) is an immunotherapy agent that works by boosting the ability of body’s immune system to kill the cancer cells.
“Tecentriq provides these patients with a new therapy targeting the PD-L1 pathway,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Products that block PD-1/PD-L1 interactions are part of an evolving story about the relationship between the body’s immune system and its interaction with cancer cells.”
Known as the programmed death ligand 1, PD-L1 binds to its receptors (PD-1), which are expressed by immune cells. The PD-L1/PD-1 pathway regulates the suppression of the immune system, and in under normal conditions, binding of the ligand to the PD-1 receptors protects healthy cells from tissue damage. However, cancer cells have learned to subvert this immune checkpoint by overexpressing the ligands, thus escaping the body’s natural defense attacks.
As a PD-L1 inhibitor, Tecentriq promotes more effective immune system attacks against the cancer. There are several anti-PD-1 drugs on the market. Most notably, nivolumab was recently approved for the treatment of non-small cell lung cancer (NSCLC). In the scope of bladder cancer, Tecentriq is the first of its class to be FDA approved.
The approval was based on clinical trial evidence showing that a significant number of patients with locally advanced or metastatic urothelial carcinoma responded well to Tecentriq. More specifically, of the 310 patients in the study, 15 percent experienced at least partial tumor shrinkage. These effects lasted from 2 to nearly 14 months, indicating good duration.
The study also found that patients with positive PD-L1 expression in the tumors responded better than those who didn’t express PD-L1. "While patients who received Tecentriq experienced a tumor response across the study, the greater effect in those who were classified as "positive" for PD-L1 expression suggests that the level of PD-L1 expression in tumor-infiltrating immune cells may help identify patients who are more likely to respond to treatment with Tecentriq."
Based on this, the FDA has also approved a corollary diagnostic test to detect PD-L1 expression in patients with bladder cancer. They hope this test will identify patients who will benefit most from Tecentriq.
As with most drugs, side-effects are unavoidable. For Tecentriq, these include fatigue, decreased appetite, nausea, urinary tract infection, fever, and constipation. The drug also increases risks for immune-related side effects involving major organs.
Additional source: MNT
