Roche Holding AG said the U.S. Food and Drug Administration approved Tecentriq, combined with chemotherapy, for treating adults with a hard-to-treat type of lung cancer.

The approval is for Tecentriq, in combination with chemotherapy drugs carboplatin and etoposide, as a first-line treatment for adults with extensive-stage small cell lung cancer, or ES-SCLC.

ES-SCLC is a lung cancer type that has spread too far for surgery or radiation to work as initial therapy, leaving patients with limited options for treatment.

The approval is based on results from the phase 3 IMpower133 study, which showed Tecentriq plus chemotherapy extended the lives of patients with ES-SCLC longer compared with those receiving chemotherapy alone.

The Swiss drugmaker's Tecentriq is part of a class of tumor-targeting drugs called checkpoint inhibitors. The therapy blocks the PD-L1 protein on cancer cells from linking with a partner arm on healthy cells — an interaction that prevents the spread of the disease.

The FDA has approved Tecentriq in combination with Avastin and chemotherapy for patients with non-squamous non-small cell lung cancer that has spread to other parts of the body, and does not have an abnormal EGFR or ALK gene. The immunotherapy also received U.S. approval for treating metastatic NSCLC whose disease progressed during or following platinum-containing chemotherapy.

The drug, also known as atezolizumab, is also used for treating certain types of breast cancer and bladder cancer.