Dr Liu on the 5-Year OS Data With Atezolizumab and Chemotherapy in ES-SCLC

Stephen V. Liu, MD, associate professor, medicine, Georgetown University, director, Thoracic Oncology, head, Developmental Therapeutics, Georgetown Lombardi Comprehensive Cancer Center, discusses the 5-year overall survival (OS) data with atezolizumab (Tecentriq) and chemotherapy in patients with extensive-stage small cell lung cancer (ES-SCLC).

At the 2023 IASLC World Conference on Lung Cancer, Liu presented the 5-year OS data from the phase 3 IMpower133 trial (NCT02763579), which investigated the use of chemotherapy with or without atezolizumab in patients with untreated ES-SCLC. In the presentation, Liu also discussed patients who were rolled over into the IMbrella A extension portion of the phase 3 trial. Patients who continued to receive atezolizumab or who were in survival follow-up at study close were given the option to roll over to IMbrella A, Liu begins, noting that 18 patients rolled over. Investigators then followed these patients for survival and long-term outcomes.

The patients who rolled over were younger, had a better ECOG performance status, and were less likely to have liver metastases than patients who did not roll over, Liu expands. The 5-year OS rate in patients who received chemotherapy and atezolizumab in the first line in the IMpower133 and IMbrella A populations combined (n = 201) was 12% (95% CI, 7%-17%). Furthermore, landmark OS rates were 16% (95%, 11%-21%) and 13% (95% CI, 8%-18%) at years 3 and 4, respectively. These outcomes emphasize the plateau of data, Liu explains. Although these results indicate an OS benefit with atezolizumab and chemotherapy compared with chemotherapy alone, these OS outcomes remain to be improved, Liu says.

Liu goes on to say that a subset of patients with ES-SCLC can achieve long-term survival with atezolizumab plus chemotherapy. Looking to the future, it may be beneficial to further investigate biomarkers for ES-SCLC because investigators are currently unable to predict which patients will benefit from these treatments, Liu continues. Overall, every patient with ES-SCLC deserves the opportunity to receive immunotherapy, and investigators will continue to work toward defining the population most likely to benefit from this treatment approach, he concludes.