PGY2 Oncology Pharmacy Resident Southern Arizona VA Health Care System Tucson, Arizona, United States
Poster Abstract:
Background: Improvements in lung cancer mortality have been attributed to the integration of immune checkpoint inhibitors into most upfront treatment regimens. However, there is little real-world data examining this benefit in the veteran population.
Objective: To compare the safety and efficacy of first-line immunotherapy, chemoimmunotherapy, and chemotherapy in Veterans with newly diagnosed advanced/metastatic non-small cell lung cancer (NSCLC) or extensive-stage small cell lung cancer (SCLC).
Methods: This was a retrospective single-center, cohort study performed at the Southern Arizona VA Healthcare System. The primary endpoints were overall survival (OS), and progression free survival (PFS). Key secondary endpoints were OS and PFS compared to populations represented in clinical trials and primary literature, best response on imaging, incidence of treatment delays, causes of discontinuation, safety outcomes, and OS and PFS in predefined subgroups (e.g. histology, PD-L1 expression, ECOG score).
Results: From January 1, 2011 to December 31, 2022, 144 subjects were screened and 80 met the inclusion criteria. Of those, 64 (80%) were diagnosed with advanced/metastatic NSCLC, with the remaining 16 (20%) being diagnosed with SCLC. For NSCLC, median OS was 19.1 vs 7.6 months (HR=0.65, 95% CI [0.3, 1.4], p=0.276) for immunotherapy vs chemotherapy, and 27.7 vs 7.6 months (HR=0.58, 95% CI [0.27, 1.24], p=0.161) for chemoimmunotherapy vs chemotherapy. Median PFS was 10.8 vs 5.0 months (HR=0.65, 95% CI [0.3, 1.4], p=0.276) for immunotherapy vs chemotherapy, and 8.6 vs 5.0 months (HR=0.58, 95% CI [0.27, 1.24], p=0.161) for chemoimmunotherapy vs chemotherapy. Grade 3-4 adverse drug events (ADE) occurred in 35%, 9%, and 35% of patients in the chemotherapy, immunotherapy, and chemoimmunotherapy groups respectively. For SCLC, median OS was 27.7 vs 3.7 months (HR=0.13, 95% CI [0.02, 1.01], p=0.052) for chemoimmunotherapy vs chemotherapy. Median PFS was 6.6 vs 3.7 months (HR=0.73, 95% CI [0.2, 2.68], p=0.632) for chemoimmunotherapy vs chemotherapy. Grade 3-4 ADEs occurred in 31% and 67% of patients in the chemotherapy and chemoimmunotherapy groups respectively.
Conclusion: The integration of immunotherapy into clinical practice has demonstrated a numerically superior, but non-statistically significant improvement in OS and PFS outcomes within this Veteran population with advanced/metastatic lung cancer. The majors limitations of this study included the retrospective design and small sample size. The number of subjects experiencing grade 3-4 toxicities were similar among the chemotherapy containing regimens for NSCLC, but more common with chemoimmunotherapy containing group for SCLC.
References (must also be included in final poster): 1. Lahiri A, Maji A, Potdar PD, et al. Lung cancer immunotherapy: progress, pitfalls, and promises. Mol Cancer. 2023;22(1):40. Published 2023 Feb 21. doi:10.1186/s12943-023-01740-y
