Nivolumab may help to significantly reduce tumor burden in patients with metastatic bladder cancer, regardless of whether their tumors have a biomarker related to the drug’s target, according to clinical trial results presented Sunday, June 5, at the 2016 American Society of Clinical Oncology Annual meeting (June 3-7. Chicago, IL).
Nivolumab is part of a new class of immunotherapy drugs that unleashes the immune system to attack cancer cells by blocking the activation of programmed cell death protein 1 (PD-1) on T-cells, which is how cancer is able to hide from the body’s natural defenses. PD-1 is activated by programmed death-ligand 1 (PD-L1), which is commonly found in cancer cells and has been associated with treatment response in various cancer types.
In a clinical trial enrolling 79 patients with bladder cancer—selected without consideration of PD-L1 expression—investigators led by Padmanee Sharma, MD, PhD, MD Anderson Cancer Center (Houston, TX), found that treatment with nivolumab led to complete responses in 5 patients (6.4%), partial responses in 14 patients (18%), and stable disease in 22 patients (28.2%). However, 30 patients did experience disease progression while on treatment.
In addition, treatment-related adverse events were mostly low grade. Grade 3 or 4 adverse events occurred in 20.5% of patients, though, 2 of whom had to discontinue treatment due to the severity of these events.
At a median follow-up of 213 days, 33.3% of patients remained on treatment and 45.6% had survived at for at least one year, which is significantly better than what has been found in past studies.
Further data on overall survival will be analyzed in a phase 2 portion of the clinical trial, but investigators concluded from these early results that nivolumab monotherapy may be effective and safe for previously untreated patients with bladder cancer.
