Clinical outcome following checkpoint therapy in renal cell carcinoma is associated with a burst of activated CD8 T cells in blood.

PURPOSE: Checkpoint therapy is now the cornerstone of treatment for patients with renal cell carcinoma (RCC) with advanced disease, but biomarkers are lacking to predict which patients will benefit. This study proposes potential immunological biomarkers that could developed for predicting therapeutic response in patients with RCC. METHODS: Using flow cytometry, RNA sequencing, and T-cell receptor (TCR) sequencing, we investigated changes in T cells in the peripheral blood of patients with advanced RCC after receiving immunotherapy. We used immunofluorescence (IF) imaging and flow cytometry to investigate how intratumoral T cells in patients' tumors (resected months/years prior to receiving checkpoint therapy) predicted patient outcomes after immunotherapy. RESULTS: We found that a small proportion of CD4 and CD8 T cells in the blood activate following checkpoint therapy, expressing the proliferation marker Ki67 and activation markers HLA-DR and CD38. Patients who had the highest increase in these HLA-DR +CD38+CD8 T cells after treatment had the best antitumor immune response and experienced clinical benefit. Using RNA sequencing, we found that while these cells expanded in most patients, their phenotype did not drastically change during treatment. However, when we analyzed the TCR repertoire of these HLA-DR +CD38+CD8+T cells, we found that only patients who clinically benefitted had a burst of new clonotypes enter this pool of activated cells. Finally, we found that abundant T cells in the untreated tumors predicted clinical benefit to checkpoint therapy on disease progression. CONCLUSIONS: Together, these data suggest that having a strong pre-existing immune response and immediate peripheral T-cell activation after checkpoint therapy is a predictor of clinical benefit in patients with RCC.

Efficacy and safety of immune checkpoint blockade in self-identified Black patients with advanced non-small cell lung cancer.

BACKGROUND: To the authors' knowledge, race-based differences in efficacy for the treatment of patients with advanced non-small cell lung cancer (NSCLC) have not been studied to date due to the underrepresentation of patients of minority backgrounds in pivotal trials. In the current study, the authors examined real-world differences in outcome in a diverse patient population. METHODS: The authors retrospectively analyzed the clinical outcomes of patients with advanced NSCLC who were treated with single-agent immune checkpoint blockade (ICB) between 2013 and July 2018 at Winship Cancer Institute of Emory University in Atlanta, Georgia. Primary efficacy comparison between Black patients and White patients was performed using bivariate and multivariate analyses for overall survival (OS) and progression-free survival (PFS). RESULTS: Data from 257 patients were analyzed. The median age of the patients was 69 years; 50.6% of the patients were female, 63.4% were White, 29.5% were Black, and 7.1% of the patients were of "other" race. ICB was the first-line treatment in 51 patients (19.9%), the second-line treatment in 161 patients (62.6%), and the third-line treatment in 33 patients (12.9%). The most commonly used agents were nivolumab (49.0%), pembrolizumab (25.2%), and atezolizumab (21.3%). No differences with regard to OS (P = .839) and PFS (P = .235) were noted between Black and White patients. The sample overall response rate was 20.6% (15.2% in Black patients and 23.1% in White patients). No differences with regard to OS (P = .081) and PFS (P = .176) were observed between female and male patients. The rate of immune-related adverse events was found to be similar in Black and White patients (20.0% vs 29.9%; P = .148). On multivariate analysis, race was not found to be significantly associated with OS or PFS. CONCLUSIONS: Real-world analysis of the authors' institutional experience demonstrated similar efficacy and tolerability of ICB in Black versus White patients with advanced NSCLC. Larger multi-institutional studies including other US minority populations would make the findings of the current study more generalizable.