Feb. 1, 2021 -- Lung cancer experts have been impressed by long-term study results that continue to show the combination of immunotherapy and chemotherapy doubles survival compared with chemotherapy alone.
The results are from a 4-year follow-up of 160 patients with previously untreated stage IV non-small cell lung cancer (NSCLC) taking part in the trial of immunotherapy drug pembrolizumab (Keytruda) plus pemetrexed–platinum chemotherapy.
After a median follow-up of 46.3 months, the median overall survival was 22.0 months with the combination versus 10.6 months with chemotherapy alone.
A similar pattern was seen for progression-free survival Patients receiving the combination had a median 9.0 months progression-free survival, versus 4.9 months with chemotherapy alone).
Charu Aggarwal, MD, MPH, Leslye M. Heisler associate professor for lung cancer excellence, Penn Medicine, Philadelphia, said the outcomes with the combination of chemotherapy and immunotherapy were "terrific."
Sandip P. Patel, MD, medical oncologist, associate professor of medicine, UC San Diego Health, agreed that these long-term results were "very impressive."
However, he noted the "full effect" of chemotherapy plus immunotherapy has not "fully been captured in our overall cancer mortality statistics in the U.S. yet."
The new results were presented January 28 at the 2020 World Conference on Lung Cancer, held virtually because of the ongoing pandemic.
Previous results from study had already demonstrated that, after a median follow-up of 10.5 months, adding pembrolizumab to chemotherapy significantly improves both overall survival and progression-free survival compared with chemotherapy alone.
The latest results show that the combination "continued to provide overall survival and progression-free survival benefit" in extended follow-up, said study presenter Jhanelle Elaine Gray, MD, chair, Department of Thoracic Oncology, Moffitt Cancer Center, Tampa, Florida.
Crucially, substantial improvements were even seen in patients with tumors with a low level of PD-L1 expression PD-L1 is a protein that lies on the surface of tumor cells.
In addition, overall response rate and duration of response were also improved with combination therapy, regardless of tumor PD-L1 expression.
Side effects were "manageable," Gray said.
The combination group in the study was associated with more serious side effects than the chemotherapy alone group, at 52.1% versus 42.1.
Events leading to treatment discontinuation were also more common with pembrolizumab plus chemotherapy than chemotherapy, at 27.4% versus 9.9%.
The combination of pembrolizumab plus pemetrexed–platinum has already become "a standard-of-care-therapy for patients with newly diagnosed metastatic nonsquamous NSCLC," Gray said.
The study was funded by MSD. Gray has reported receiving grant support and/or honoraria from Array, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Genentech, Merck, and institutional funding from MSD.