Search

Structured Abstract: Background Immune checkpoint inhibitors are now an approved treatment for patients with extensive- stage small cell lung cancer (SCLC), an aggressive and incurable malignancy. However, the median survival for patients remains around 1 year, and treatment in the second line and beyond is associated with a low likelihood of response. There currently are no data regarding the optimal treatment of patients who progress on upfront chemo-immunotherapy, and biomarkers are needed to aid patient selection. Obtaining sufficient tissue for advanced molecular testing is a challenge in SCLC due to often limited or crushed tissue specimens. Reliable blood based biomarkers may augment tissue based testing and allow for repeated assessments that is often not possible with tumor tissue, and changes in the peripheral blood may provide information regarding the tumor microenvironment. Myeloid-derived suppressor cells (MDSC) exert immunosuppressive function and have been investigated as a potential barrier to response to immune checkpoint inhibitor (ICI) therapy. Here we demonstrate that MDSC level and function can be readily assessed in the peripheral blood at multiple time points during treatment with combination immunotherapy and temozolomide. Results This report represents the first case of a patient with refractory SCLC treated with combination nivolumab and temozolomide as part of a clinical trial (NCT03728361), who sustained a deep and durable clinical response that was accompanied by an early decrease in MDSC and improved T cell function (increased CD8+ and CD4+ T cell proliferation). We review the literature regarding use of ICI in SCLC and the evidence supporting MDSC as a possible target to enhance the activity of immunotherapy, and emphasize the importance of assessing immune cell subsets as correlative studies in clinical trials. Conclusion An assessment of MDSC level and function during treatment, as well as other immune cell subsets, should be included in prospective studies to further evaluate these assays as possible blood-based biomarkers.

Background Next-generation sequencing of circulating cell-free DNA (cfDNA) can identify sensitizing and resistance mutations in non–small-cell lung cancer (NSCLC). cfDNA is helpful when tissue is insufficient for genomic testing or repeat biopsy is not feasible or poses unacceptable risk. Here we report the experience of cfDNA testing at the time of diagnosis and how this intervention can help avoid further invasive interventions, how it can be used to determine initiation of therapy, and how variation allele frequency of the somatic alteration affects response to subsequent treatment. Patients and Methods This is a single-institution retrospective study of patients with advanced NSCLC who had cfDNA from plasma tested using the Guardant360 panel, which identifies somatic genomic alterations by massive parallel sequencing of target genes. An institutional Clinical Laboratory Improvement Amendments tissue panel using fluorescence in situ hybridization (for MET, RET, ROS1, and ALK) and next-generation sequencing for selected genes was used for tissue analysis. Actionable mutations are those with US Food and Drug Administration–approved targeted therapies (EGFR, ALK, ROS, BRAF, NTRK fusions) or therapies soon to be approved (RET fusions and MET amplifications, or MET exon 14 skipping mutation). Results A total of 163 blood samples from 143 patients were evaluated, 82 at diagnosis and 81 at disease progression. A total of 94 cases had tissue and cfDNA testing performed within 12 weeks of each other. Seventy-six (81%) of 94 cases were concordant, of which 22 cases were concordantly positive and 54 concordantly negative. Eighteen (19%) of 94 cases were discordant, of which 11 had negative blood and positive tissue results, and 7 had positive blood and negative tissue results. cfDNA testing had a sensitivity of 67% (95% confidence interval [CI], 51%, 83%), specificity of 89% (95% CI, 81%, 97%), negative predictive value of 83% (95% CI, 74%, 92%), and positive predictive value of 76% (95% CI, 60%, 91%). Nineteen (21%) of 82 cfDNA samples analyzed at diagnosis had actionable mutations identified (4 EGFR exon 19 deletion, 2 EGFR exon 21 L858R, 2 EGFR L861Q, 1 L861R, 4 EML4-ALK fusion, 2 CD74-ROS1 fusion, 2 MET exon 14 skipping mutation, 2 KIF5B-RET fusion). Of the 82 patients with cfDNA testing performed at the time of diagnosis, 8 patients (10%) initiated targeted therapy on the basis of cfDNA results only, with 6 patients experiencing partial response, 1 patient complete response, and 1 patient stable disease. The response rate for patients who initiated targeted therapies on the basis of cfDNA only at diagnosis was 88%. Variant allele frequency had no impact on response. Conclusions Initiation of targeted therapy for advanced NSCLC was feasible based only on identification of actionable mutations by cfDNA testing in 9% of the cases for which tissue diagnosis could not be obtained. Actionable targets were identified by cfDNA in 20% of the samples sent at diagnosis. A substantial number of patients benefited from cfDNA testing at initial diagnosis because it identified actionable mutations that led to appropriate targeted treatments.

Immunotherapy is a mainstay of treatment for nonesmall-cell lung cancer. Serious immune-related adverse events (irAEs) occur; however, their effect on survival is unclear, and no defined risks factors have been elucidated. In the present study, we found no significant effect of irAE on survival in a landmark analysis, and no increased risk of pneumonitis in patients with previous radiation. Background: The risk factors for immune-related adverse events (irAEs) remain undefined. Recently, a correlation between irAEs and clinical benefit was suggested. We examined the risk factors for irAEs and their effect on survival in patients with nonesmall-cell lung cancer (NSCLC) who had received immunotherapy. Patients and Methods: We performed a retrospective review of patients with NSCLC treated with single-agent immunotherapy at our institution. irAEs were determined by treating physician diagnosis. A landmark analysis was performed at 3 months using log-rank tests and the Bonferroni method. Results: irAEs occurred in 27 of 91 patients (30%). The median overall survival (OS) for patients with irAEs was longer than that for patients without (24.3 vs. 5.3 months; hazard ratio, 2.75; 95% confidence interval, 1.54–4.92; P < .001). However, a landmark analysis of patients after 3 months of treatment revealed no difference in OS between patients with and without irAEs. No increased risk of pneumonitis was seen in patients with previous thoracic radiotherapy, although these patients had shorter survival (4.2 vs. 9.7 months; P =.004). Radiotherapy after the initiation of immunotherapy (n = 15) did not increase the risk of irAEs or pneumonitis; however, these patients had improved OS (17.3 vs. 6.0 months; P =.016). Conclusion: The development of irAEs did not significantly correlate with survival when controlling for the duration of therapy in a landmark analysis. We found no increased risk of pneumonitis or irAEs in patients who had received radiotherapy. Radiotherapy before immunotherapy was associated with shorter survival, and radiotherapy after immunotherapy was associated with improved survival.