Kathryn C. Arbour

Purpose Treatment of advanced non-small-cell lung cancer with immune checkpoint inhibitors (ICIs) is characterized by durable responses and improved survival in a subset of patients. Clinically available tools to optimize use of ICIs and understand the molecular determinants of response are needed. Targeted next-generation sequencing (NGS) is increasingly routine, but its role in identifying predictors of response to ICIs is not known. Methods Detailed clinical annotation and response data were collected for patients with advanced non-small-cell lung cancer treated with anti-programmed death-1 or anti-programmed death-ligand 1 [anti-programmed cell death (PD)-1] therapy and profiled by targeted NGS (MSK-IMPACT; n = 240). Efficacy was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, and durable clinical benefit (DCB) was defined as partial response/stable disease that lasted > 6 months. Tumor mutation burden (TMB), fraction of copy number-altered genome, and gene alterations were compared among patients with DCB and no durable benefit (NDB). Whole-exome sequencing (WES) was performed for 49 patients to compare quantification of TMB by targeted NGS versus WES. Results Estimates of TMB by targeted NGS correlated well with WES (ρ = 0.86; P < .001). TMB was greater in patients with DCB than with NDB ( P = .006). DCB was more common, and progression-free survival was longer in patients at increasing thresholds above versus below the 50th percentile of TMB (38.6% v 25.1%; P < .001; hazard ratio, 1.38; P = .024). The fraction of copy number-altered genome was highest in those with NDB. Variants in EGFR and STK11 associated with a lack of benefit. TMB and PD-L1 expression were independent variables, and a composite of TMB plus PD-L1 further enriched for benefit to ICIs. Conclusion Targeted NGS accurately estimates TMB and elevated TMB further improved likelihood of benefit to ICIs. TMB did not correlate with PD-L1 expression; both variables had similar predictive capacity. The incorporation of both TMB and PD-L1 expression into multivariable predictive models should result in greater predictive power.

Importance: Non-small cell lung cancer remains the leading cause of cancer death in the United States. Until the last decade, the 5-year overall survival rate for patients with metastatic non-small cell lung cancer was less than 5%. Improved understanding of the biology of lung cancer has resulted in the development of new biomarker-targeted therapies and led to improvements in overall survival for patients with advanced or metastatic disease. Observations: Systemic therapy for metastatic non-small cell lung cancer is selected according to the presence of specific biomarkers. Therefore, all patients with metastatic non-small cell lung cancer should undergo molecular testing for relevant mutations and expression of the protein PD-L1 (programmed death ligand 1). Molecular alterations that predict response to treatment (eg, EGFR mutations, ALK rearrangements, ROS1 rearrangements, and BRAF V600E mutations) are present in approximately 30% of patients with non-small cell lung cancer. Targeted therapy for these alterations improves progression-free survival compared with cytotoxic chemotherapy. For example, somatic activating mutations in the EGFR gene are present in approximately 20% of patients with advanced non-small cell lung cancer. Tyrosine kinase inhibitors such as gefitinib, erlotinib, and afatinib improve progression-free survival in patients with susceptible EGFR mutations. In patients with overexpression of ALK protein, the response rate was significantly better with crizotinib (a tyrosine kinase inhibitor) than with the combination of pemetrexed and either cisplatin or carboplatin (platinum-based chemotherapy) (74% vs 45%, respectively; P < .001) and progression-free survival (median, 10.9 months vs 7.0 months; P < .001). Subsequent generations of tyrosine kinase inhibitors have improved these agents. For patients without biomarkers indicating susceptibility to specific targeted treatments, immune checkpoint inhibitor-containing regimens either as monotherapy or in combination with chemotherapy are superior vs chemotherapy alone. These advances in biomarker-directed therapy have led to improvements in overall survival. For example, the 5-year overall survival rate currently exceeds 25% among patients whose tumors have high PD-L1 expression (tumor proportion score of ≥50%) and 40% among patients with ALK-positive tumors. Conclusions and Relevance: Improved understanding of the biology and molecular subtypes of non-small cell lung cancer have led to more biomarker-directed therapies for patients with metastatic disease. These biomarker-directed therapies and newer empirical treatment regimens have improved overall survival for patients with metastatic non-small cell lung cancer.

PURPOSE: Treatment with programmed cell death-1 or programmed death ligand 1 (PD-(L)1) inhibitors is now standard therapy for patients with lung cancer. The immunosuppressive effect of corticosteroids may reduce efficacy of PD-(L)1 blockade. On-treatment corticosteroids for treatment of immune-related adverse events do not seem to affect efficacy, but the potential impact of baseline corticosteroids at the time of treatment initiation is unknown. Clinical trials typically excluded patients who received baseline corticosteroids, which led us to use real-world data to examine the effect of corticosteroids at treatment initiation. METHODS: We identified patients who were PD-(L)1-naïve with advanced non-small-cell lung cancer from two institutions-Memorial Sloan Kettering Cancer Center and Gustave Roussy Cancer Center-who were treated with single-agent PD-(L)1 blockade. Clinical and pharmacy records were reviewed to identify corticosteroid use at the time of beginning anti-PD-(L)1 therapy. We performed multivariable analyses using Cox proportional hazards regression model and logistic regression. RESULTS: Ninety (14%) of 640 patients treated with single-agent PD-(L)1 blockade received corticosteroids of ≥ 10 mg of prednisone equivalent daily at the start of the PD-(L)1 blockade. Common indications for corticosteroids were dyspnea (33%), fatigue (21%), and brain metastases (19%). In both independent cohorts, Memorial Sloan Kettering Cancer Center (n = 455) and Gustave Roussy Cancer Center (n = 185), baseline corticosteroids were associated with decreased overall response rate, progression-free survival, and overall survival with PD-(L)1 blockade. In a multivariable analysis of the pooled population, adjusting for smoking history, performance status, and history of brain metastases, baseline corticosteroids remained significantly associated with decreased progression-free survival (hazard ratio, 1.3; P = .03), and overall survival (hazard ratio, 1.7; P < .001). CONCLUSION: Baseline corticosteroid use of ≥ 10 mg of prednisone equivalent was associated with poorer outcome in patients with non-small-cell lung cancer who were treated with PD-(L)1 blockade. Prudent use of corticosteroids at the time of initiating PD-(L)1 blockade is recommended.

Background: The composition of gut microbiota affects antitumor immune responses, preclinical and clinical outcome following immune checkpoint inhibitors (ICI) in cancer. Antibiotics (ATB) alter gut microbiota diversity and composition leading to dysbiosis, which may affect effectiveness of ICI. Patients and methods: We examined patients with advanced renal cell carcinoma (RCC) and non-small-cell lung cancer (NSCLC) treated with anti-programmed cell death ligand-1 mAb monotherapy or combination at two academic institutions. Those receiving ATB within 30 days of beginning ICI were compared with those who did not. Objective response, progression-free survival (PFS) determined by RECIST1.1 and overall survival (OS) were assessed. Results: Sixteen of 121 (13%) RCC patients and 48 of 239 (20%) NSCLC patients received ATB. The most common ATB were β-lactam or quinolones for pneumonia or urinary tract infections. In RCC patients, ATB compared with no ATB was associated with increased risk of primary progressive disease (PD) (75% versus 22%, P < 0.01), shorter PFS [median 1.9 versus 7.4 months, hazard ratio (HR) 3.1, 95% confidence interval (CI) 1.4-6.9, P < 0.01], and shorter OS (median 17.3 versus 30.6 months, HR 3.5, 95% CI 1.1-10.8, P = 0.03). In NSCLC patients, ATB was associated with similar rates of primary PD (52% versus 43%, P = 0.26) but decreased PFS (median 1.9 versus 3.8 months, HR 1.5, 95% CI 1.0-2.2, P = 0.03) and OS (median 7.9 versus 24.6 months, HR 4.4, 95% CI 2.6-7.7, P < 0.01). In multivariate analyses, the impact of ATB remained significant for PFS in RCC and for OS in NSCLC. Conclusion: ATB were associated with reduced clinical benefit from ICI in RCC and NSCLC. Modulatation of ATB-related dysbiosis and gut microbiota composition may be a strategy to improve clinical outcomes with ICI.

PURPOSE: Approximately 3% to 10% of EGFR (epidermal growth factor receptor) -mutant non-small cell lung cancers (NSCLCs) undergo transformation to small-cell lung cancer (SCLC), but their clinical course is poorly characterized. METHODS: We retrospectively identified patients with EGFR-mutant SCLC and other high-grade neuroendocrine carcinomas seen at our eight institutions. Demographics, disease features, and outcomes were analyzed. RESULTS: We included 67 patients-38 women and 29 men; EGFR mutations included exon 19 deletion (69%), L858R (25%), and other (6%). At the initial lung cancer diagnosis, 58 patients had NSCLC and nine had de novo SCLC or mixed histology. All but these nine patients received one or more EGFR tyrosine kinase inhibitor before SCLC transformation. Median time to transformation was 17.8 months (95% CI, 14.3 to 26.2 months). After transformation, both platinum-etoposide and taxanes yielded high response rates, but none of 17 patients who received immunotherapy experienced a response. Median overall survival since diagnosis was 31.5 months (95% CI, 24.8 to 41.3 months), whereas median survival since the time of SCLC transformation was 10.9 months (95% CI, 8.0 to 13.7 months). Fifty-nine patients had tissue genotyping at first evidence of SCLC. All maintained their founder EGFR mutation, and 15 of 19 with prior EGFR T790M positivity were T790 wild-type at transformation. Other recurrent mutations included TP53, Rb1, and PIK3CA. Re-emergence of NSCLC clones was identified in some cases. CNS metastases were frequent after transformation. CONCLUSION: There is a growing appreciation that EGFR-mutant NSCLCs can undergo SCLC transformation. We demonstrate that this occurs at an average of 17.8 months after diagnosis and cases are often characterized by Rb1, TP53, and PIK3CA mutations. Responses to platinum-etoposide and taxanes are frequent, but checkpoint inhibitors yielded no responses. Additional investigation is needed to better elucidate optimal strategies for this group.