Atezolizumab Strengthens the Role of Immunotherapy in Small Cell Lung Cancer Treatment

At the 19th World Conference on Lung Cancer in Toronto, Canada, small cell lung cancer treatment was the subject of a noteworthy immunotherapy study that was presented.

According to this study, previously untreated patients receiving, as first-line treatment, carboplatin plus etoposide in combination with the immunotherapy atezolizumab (brand name Tecentriq) for advanced small cell lung cancer had longer overall survival than patients receiving standard treatment (carboplatin+etoposide) plus placebo .

IMpower133 was the name of this clinical trial , which randomized 201 patients to chemotherapy+immunotherapy and 202 to chemotherapy+placebo. Patients received 4 cycles, every 21 days, of carboplatin+etoposide+atezolizumab or carboplatin+etoposide+placebo. The study's primary endpoints were overall survival and the time disease was kept under control with treatment (progression-free survival).

According to the Study Results;

• At month 14 of the study, median overall survival was 12.3 months in patients receiving chemotherapy plus atezolizumab versus 10.3 months in those receiving chemotherapy plus placebo.
• Adding to chemotherapy an anti-PD-L1 immunotherapy drug, atezolizumab, reduced the risk of death from small cell lung cancer by %30.
• In this study, immunotherapy worked regardless of PD-L1 level.

Published simultaneously with the congress in the New England Journal of Medicine, this study is particularly noteworthy as the first phase-3 clinical trial showing positive survival data for an immunotherapy combination in first-line treatment of advanced small cell lung cancer.

However, there was no survival difference among patients with brain metastases. Another new finding, whose reason is not yet known, was that older patients benefited more from the chemotherapy+immunotherapy combination than younger patients.

Small cell lung cancer treatment had been an area with no new drug approvals for 20 years, until very recently. On 17 August 2018, nivolumab , an immunotherapy drug, for this cancer's second-line treatment, received FDA approval. Now, atezolizumab's efficacy as first-line treatment is a hopeful development for our patients and us.

• Advances in Lung Cancer Treatment—2017 and 2018