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Purpose Preclinical data and subset analyses from immunotherapy clinical trials indicate that prior radiation therapy was associated with better progression-free survival and overall survival when combined with immune checkpoint inhibitors in patients with non-small cell lung cancer. We present a prospective study of hypofractionated image guided radiation therapy (HIGRT) to a single site of metastatic disease concurrently with atezolizumab in patients with metastatic non-small cell lung cancer. Methods and Materials Patients meeting eligibility criteria received 1200 mg of atezolizumab intravenously every 3 weeks with concurrent 3- or 5-fraction HIGRT starting no later than the second cycle. The 3-fraction regimen employed a minimum of 8 Gy per fraction compared with 6 Gy for the 5-fraction regimen. Imaging was obtained every 12 weeks to assess response. Results From October 2015 to February 2017, 12 patients were enrolled in the study (median age 64; range, 55-77 years). The best response by the Response Evaluation in Solid Tumors criteria was partial response in 3 and stable disease in 3, for a disease control rate of 50%. Five patients had a grade 3 immune-related adverse event, including choreoretinitis (n = 1), pneumonitis (n = 1), transaminitis (n = 1), fatigue (n = 1), and peripheral neuropathy (n = 1). The median progression-free survival was 2.3 months, and the median overall survival was 6.9 months (range, 0.4-not reached). There was no clear association between peripheral blood T cell repertoire characteristics at baseline, PD-L1, or tumor mutations and response or outcome. One long-term survivor exhibited oligoclonal T cell populations in a baseline tumor biopsy that were consistently detected in peripheral blood over the entire course of the study. Conclusions HIGRT plus atezolizumab resulted in an overall response rate of 25% and disease control rate of 50% in this pilot study. The incidence of grade 3 adverse events was similar to that of atezolizumab alone. Alhough it was a pilot study with limited sample size, the results generated hypotheses worthy of further investigation.

BACKGROUND: Lung cancer death rates and incidence in both men and women have decreased over the past two decades. However, certain subsets of non-small cell lung cancer (NSCLC) have arisen with poor outcomes. Identifying factors which contribute to poorer outcomes as well as those that inform early detection strategies remain unmet needs. We present data from a contemporaneous group of NSCLC patients that received care at a single University teaching hospital to understand clinical and pathological factors influencing outcomes in the past decade. METHODS: A cohort of 2,289 patients with NSCLC who established care at the Rogel Cancer Center, University of Michigan between January 2011 and April 2019 were identified. Patient characteristics and clinical outcomes were recorded using electronic health records. The Kaplan-Meier method and the Cox proportional model were used to assess relationship between clinic-pathological factors and survival. RESULTS: Of the 2,289 patients, 92% were >50 years of age while 8% were

3079 Background: RET fusions are targetable oncogenic drivers in multiple solid tumor types. ARROW study (NCT03037385) data supported the US FDA approval of pralsetinib, a once-daily (QD) oral highly potent and selective RET inhibitor, for RET-altered metastatic non-small cell lung cancer (NSCLC) and advanced/metastatic thyroid cancer. Here we provide an update on the clinical activity of pralsetinib in patients (pts) with advanced RET fusion-positive solid tumors other than NSCLC and thyroid cancer (“other” RET fusion–positive solid tumors). Methods: The global ongoing ARROW study (84 sites in 13 countries) includes phase 1 dose-escalation (30–600 mg [QD or twice daily]) and phase 2 expansion cohorts (400 mg QD) defined by tumor type and RET alteration status. Primary objectives are overall response rate (ORR; blinded independent central review per RECIST v1.1) and safety. Results: Updated analyses were completed as of Nov 6, 2020 (data cut-off) for 21 pts with other RET fusion–positive solid tumors enrolled by May 22, 2020 (enrollment cut-off) (lung other than NSCLC, n = 4; pancreatic, n = 3; colon, n = 3; cholangiocarcinoma, n = 3; unknown primary [UP], n = 2; other, n = 6). Overall, 11 (52%) pts received ≥2 prior lines of therapy for metastatic disease. The most common RET fusion partners were CCDC6 and KIF5B (24% each), NCOA4 (19%), other (10%), and unknown (24%). Two pts with colon cancer were excluded from efficacy analyses due to other driver mutations ( KRAS, PIK3CB). In 19 evaluable pts, ORR was 53% (95% CI, 29–76) with 2 (11%) complete responses (CR) and 8 (42%) partial responses (PR). Responses occurred across multiple tumor types including 3/3 pts with pancreatic cancer (including a CR ongoing at 20.8 months on treatment), 2/2 pts with UP, 2/3 pts with cholangiocarcinoma, and in pts with mesenchymal, salivary duct, and lung carcinoid tumors. Median duration of response was 19.0 months (95% CI, 5.5–not estimable). Clinical benefit rate (proportion with CR, PR, or stable disease persisting ≥16 weeks) was 68% (95% CI, 43–87). Tumor shrinkage was observed in 89% of 18 evaluable pts with post-baseline tumor assessment. In all pts enrolled in ARROW who received pralsetinib 400 mg QD irrespective of tumor type (n = 471) the most common (≥25%) treatment-related adverse events (TRAEs) were increased aspartate aminotransferase (39%), anemia (35%), increased alanine aminotransferase (28%), constipation (26%), and hypertension (25%). Overall, 6% of pts discontinued treatment due to TRAEs. Conclusions: Pralsetinib showed robust, durable antitumor activity in patients with multiple RET fusion‒positive, heavily pre-treated, advanced solid tumors, and was well tolerated. These data highlight the need for broad RET testing to identify candidates who could benefit from treatment with pralsetinib. Enrollment of patients with other RET fusion–positive solid tumors in ARROW is ongoing. Clinical trial information: NCT03037385.

PURPOSE Pembrolizumab monotherapy has shown antitumor activity in patients with small-cell lung cancer (SCLC). The randomized, double-blind, phase III KEYNOTE-604 study compared pembrolizumab plus etoposide and platinum (EP) with placebo plus EP for patients with previously untreated extensive-stage (ES) SCLC. METHODS Eligible patients were randomly assigned 1:1 to pembrolizumab 200 mg once every 3 weeks or saline placebo for up to 35 cycles plus 4 cycles of EP. Primary end points were progression-free survival (PFS; RECIST version 1.1, blinded central review) and overall survival (OS) in the intention-to-treat population. Objective response rate (ORR) and duration of response were secondary end points. Prespecified efficacy boundaries were one-sided P = .0048 for PFS and .0128 for OS. RESULTS Of the 453 participants, 228 were randomly assigned to pembrolizumab plus EP and 225 to placebo plus EP. Pembrolizumab plus EP significantly improved PFS (hazard ratio [HR], 0.75; 95% CI, 0.61 to 0.91; P = .0023). Twelve-month PFS estimates were 13.6% with pembrolizumab plus EP and 3.1% with placebo plus EP. Although pembrolizumab plus EP prolonged OS, the significance threshold was not met (HR, 0.80; 95% CI, 0.64 to 0.98; P = .0164). Twenty-four-month OS estimates were 22.5% and 11.2%, respectively. ORR was 70.6% in the pembrolizumab plus EP group and 61.8% in the placebo plus EP group; the estimated proportion of responders remaining in response at 12 months was 19.3% and 3.3%, respectively. In the pembrolizumab plus EP and placebo plus EP groups, respectively, any-cause adverse events were grade 3-4 in 76.7% and 74.9%, grade 5 in 6.3% and 5.4%, and led to discontinuation of any drug in 14.8% and 6.3%. CONCLUSION Pembrolizumab plus EP significantly improved PFS compared with placebo plus EP as first-line therapy for patients with ES-SCLC. No unexpected toxicities were seen with pembrolizumab plus EP. These data support the benefit of pembrolizumab in ES-SCLC.

Background: Bone metastases and skeletal-related events (SREs) are a frequent cause of morbidity in patients with metastatic non–small cell lung cancer (mNSCLC). Data are limited on bone metastases and SREs in patients with mNSCLC treated using immune checkpoint inhibitors (ICIs), and on the efficacy of bone-modifying agents (BMAs) in this setting. Here we report the incidence, impact on survival, risk factors for bone metastases and SREs, and impact of BMAs in patients with mNSCLC treated with ICIs in a multi-institutional cohort. Patients and Methods: We conducted a retrospective study of patients with mNSCLC treated with ICIs at 2 tertiary care centers from 2014 through 2017. Overall survival (OS) was compared between patients with and without baseline bone metastases using a log-rank test. A Cox regression model was used to evaluate the association between OS and the presence of bone metastases at ICI initiation, controlling for other confounding factors. Results: We identified a cohort of 330 patients who had received ICIs for metastatic disease. Median patient age was 63 years, most patients were treated in the second line or beyond (n=259; 78%), and nivolumab was the most common ICI (n=211; 64%). Median OS was 10 months (95% CI, 8.4–12.0). In our cohort, 124 patients (38%) had baseline bone metastases, and 43 (13%) developed SREs during or after ICI treatment. Patients with bone metastases had a higher hazard of death after controlling for performance status, histology, line of therapy, and disease burden (hazard ratio, 1.57; 95% CI, 1.19–2.08; P=.001). Use of BMAs was not associated with OS or a decreased risk of SREs. Conclusions: Presence of bone metastases at baseline was associated with a worse prognosis for patients with mNSCLC treated with ICI after controlling for multiple clinical characteristics. Use of BMAs was not associated with reduced SREs or a difference in survival.

Radiation esophagitis (RE) is a common adverse event associated with radiotherapy for non–small cell lung cancer (NSCLC). While plasma cytokine levels have been correlated with other forms of radiation-induced toxicity, their association with RE has been less well studied. We analyzed data from 126 patients treated on 4 prospective clinical trials. Logistic regression models based on combinations of dosimetric factors [maximum dose to 2 cubic cm (D2cc) and generalized equivalent uniform dose (gEUD)], clinical variables, and pretreatment plasma levels of 30 cytokines were developed. Cross-validated estimates of area under the receiver operating characteristic curve (AUC) and log likelihood were used to assess prediction accuracy. Dose-only models predicted grade 3 RE with AUC values of 0.750 (D2cc) and 0.727 (gEUD). Combining clinical factors with D2cc increased the AUC to 0.779. Incorporating pretreatment cytokine measurements, modeled as direct associations with RE and as potential interactions with the dose-esophagitis association, produced AUC values of 0.758 and 0.773, respectively. D2cc and gEUD correlated with grade 3 RE with odds ratios (ORs) of 1.094/Gy and 1.096/Gy, respectively. Female gender was associated with a higher risk of RE, with ORs of 1.09 and 1.112 in the D2cc and gEUD models, respectively. Older age was associated with decreased risk of RE, with ORs of 0.992/year and 0.991/year in the D2cc and gEUD models, respectively. Combining clinical with dosimetric factors but not pretreatment cytokine levels yielded improved prediction of grade 3 RE compared to prediction by dose alone. Such multifactorial modeling may prove useful in directing radiation treatment planning.

Small-cell lung cancer (SCLC) is an aggressive tumor that accounts for 13–15% of all lung cancer cases and is the seventh most common cause of cancer-related death in the U.S. with a 5-year overall survival rate of 6.3% (1). At initial diagnosis, about 2/3 of patients have extensive-stage disease (ES-SCLC), for which all treatment is given with palliative intent. Platinum-based, two-drug chemotherapy has been the standard first-line treatment for patients with ES-SCLC for over 20 years. In the U.S., the most common regimens utilized are carboplatin plus etoposide (CE) or cisplatin plus etoposide (PE), which yield a response rate of 50–70% and a median overall survival time of 8–11 months (2). Despite the remarkable activity of initial chemotherapy, nearly all patients relapse within months and the benefits of second-line therapy are limited. Thus, there is a desperate need for more effective first-line therapy.

Background and purpose Current methods to estimate risk of radiation-induced lung toxicity (RILT) rely on dosimetric parameters. We aimed to improve prognostication by incorporating clinical and cytokine data, and to investigate how these factors may interact with the effect of mean lung dose (MLD) on RILT. Materials and methods Data from 125 patients treated from 2004 to 2013 with definitive radiotherapy for stages I-III NSCLC on four prospective clinical trials were analyzed. Plasma levels of 30 cytokines were measured pretreatment, and at 2 and 4 weeks midtreatment. Penalized logistic regression models based on combinations of MLD, clinical factors, and cytokine levels were developed. Cross-validated estimates of log-likelihood and area under the receiver operating characteristic curve (AUC) were used to assess accuracy. Results In prognosticating grade 3 or greater RILT by MLD alone, cross-validated log-likelihood and AUC were −28.2 and 0.637, respectively. Incorporating clinical features and baseline cytokine levels increased log-likelihood to −27.6 and AUC to 0.669. Midtreatment cytokine data did not further increase log-likelihood or AUC. Of the 30 cytokines measured, higher levels of 13 decreased the effect of MLD on RILT, corresponding to a lower odds ratio for RILT per Gy MLD, while higher levels of 4 increased the association. Conclusions Although the added prognostic benefit from cytokine data in our model was modest, understanding how clinical and biologic factors interact with the MLD-RILT relationship represents a novel framework for understanding and investigating the multiple factors contributing to radiation-induced toxicity.

© 2017 International Association for the Study of Lung Cancer Introduction In malignant pleural mesothelioma, targeting angiogenesis with cediranib, a vascular endothelial growth factor receptor and platelet-derived growth factor receptor inhibitor, may have therapeutic potential. Methods S0905 phase I combined cediranib (two dose cohorts [30 mg and 20 mg daily]) with cisplatin-pemetrexed for six cycles followed by maintenance cediranib in unresectable chemonaive patients with malignant pleural mesothelioma of any histologic subtype. The primary end point established the maximum tolerated dose in combination with cisplatin-pemetrexed in a dose deescalation scheme. Results A total of 20 patients were enrolled (seven to the 30-mg cohort and 13 to the 20-mag cohort). In the cediranib 30-mg cohort, two of the initial six patients reported dose-limiting toxicities and the dose was deemed too toxic to continue. In the next cohort, two patients experienced dose-limiting toxicities, and thus, the maximum tolerated dose of cediranib was established as 20 mg. During the six cycles of cisplatin-pemetrexed-cediranib, 20 mg, there were grade 3 toxicities (neutropenia and gastrointestinal) and grade 4 thrombocytopenia. No patients had any significant episodes of bleeding. According to the Response Evaluation Criteria in Solid Tumors (n = 17 evaluable patients), the median progression-free survival was 12.8 months (95% confidence interval [CI]: 6.9–17.2); according to the Modified Response Evaluation Criteria in Solid Tumors (n = 19 evaluable patients), the median progression-free survival was 8.6 months (95% CI: 6.1–10.9). For all patients, the disease control rate at 6 weeks was 90% and median overall survival time was 16.2 months (95% CI: 10.5–28.7). Conclusions Cediranib combined with cisplatin-pemetrexed has a reasonable toxicity profile and preliminary promising efficacy. The phase II S0905 trial will evaluate the efficacy of the triplet regimen compared with the current standard of care, cisplatin-pemetrexed.

Introduction Most patients with lung cancer are elderly and poorly represented in randomized clinical trials. They are often undertreated because of concerns about their ability to tolerate aggressive treatment. We tested the hypothesis that elderly patients undergoing definitive lung radiation might tolerate treatment differently than younger patients. Methods A total of 125 patients who underwent definitive lung radiotherapy were identified from a prospective institutional database (University of Michigan cohort). Logistic regression modeling was performed to assess the impact of age on esophagitis grade 2 or higher or grade 2 or higher and pneumonitis grade 3 or higher or grade 2 or higher, with adjustment for esophageal and lung dose, respectively, as well as for chemotherapy utilization, smoking status, and performance status. The analysis was validated in a large cohort of 691 patients from the Michigan Radiation Oncology Quality Consortium registry, an independent statewide prospective database. Results In the University of Michigan cohort, multivariable regression models revealed a significant inverse correlation between age and rate of esophagitis for both toxicity levels, (adjusted OR = 0.93 for both models and 95% confidence intervals of 0.88–0.98 and 0.87–0.99), with areas under the curve of 0.747 and 0.721, respectively, demonstrating good fit. This same association was noted in the Michigan Radiation Oncology Quality Consortium cohort. There was no significant association between age and pneumonitis. Conclusions There is a lower incidence of esophagitis with increasing age even after adjustment for use of chemotherapy. This is a novel finding in thoracic oncology. No age dependence was noted for pulmonary toxicity. The elderly are able to tolerate definitive thoracic radiation well and should be offered this option when clinically warranted.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor characterized by early metastatic spread and responsiveness to initial therapy. The incidence of SCLC has been declining in the United States in parallel with the decreasing prevalence of cigarette smoking. Limited stage disease is potentially curable with chemoradiotherapy followed by cranial irradiation. Extensive stage disease is incurable, but systemic chemotherapy can improve quality of life and prolong survival. Nearly all patients relapse with chemoresistant disease. Molecularly targeted therapy has failed to yield convincing clinical benefits. Nevertheless, many biologically rational strategies, including immune checkpoint inhibition, show promise in ongoing clinical trials.

PURPOSE: Radiation-induced cardiac toxicity (RICT) is an increasingly well-appreciated source of morbidity and mortality in patients receiving thoracic radiotherapy (RT). Currently available methods to predict RICT are suboptimal. We investigated circulating microRNAs (c-miRNAs) as potential biomarkers of RICT in patients undergoing definitive RT for non-small cell lung cancer (NSCLC). METHODS: Data from 63 patients treated on institutional trials were analyzed. Prognostic models of grade 3 or greater (G3+) RICT based on pre-treatment c-miRNA levels (‘c-miRNA’), mean heart dose (MHD) and pre-existing cardiac disease (PCD) (‘clinical’), and a combination of these (‘c-miRNA + clinical’) were developed. Elastic net Cox regression and full cross-validation were used for variable selection, model building, and model evaluation. Concordance statistic (c-index) and integrated Brier score (IBS) were used to evaluate model performance. RESULTS: MHD, PCD, and serum levels of 14 c-miRNA species were identified as jointly prognostic for G3+ RICT. The ‘c-miRNA and ‘clinical’ models yielded similar cross-validated c-indices (0.70 and 0.72, respectively) and IBSs (0.26 and 0.28, respectively). However, prognostication was not improved by combining c-miRNA and clinical factors (c-index 0.70, IBS 0.28). The ‘c-miRNA’ and ‘clinical’ models were able to significantly stratify patients into high- and low-risk groups of developing G3+ RICT. Chi-square testing demonstrated a marginally significantly higher prevalence of PCD in patients with high- compared to low-risk c-miRNA profile (p=0.09), suggesting an association between some c-miRNAs and PCD. CONCLUSIONS: We identified a pre-treatment c-miRNA signature prognostic for G3+ RICT. With further development, pre- and mid-treatment c-miRNA profiling could contribute to multiparametric, patient-specific dose-selection and treatment-adaptation.

9089 Background: RET fusions are targetable oncogenic drivers in 1–2% of non-small cell lung cancer (NSCLC). ARROW (NCT03037385) supported the US FDA approval of pralsetinib, a highly potent oral selective RET inhibitor for RET-altered NSCLC and thyroid cancer. Here, we present updated results for a larger population of patients with RET fusion–positive NSCLC enrolled in ARROW. Methods: ARROW is a phase 1/2 open-label study conducted at 84 sites in 13 countries. Phase 2 expansion cohorts included patients with RET fusion–positive NSCLC. Initially, all treatment-naïve patients were not candidates for platinum-based therapy, a requirement removed by protocol amendment in July 2019. Primary objectives are overall response rate (ORR; blinded independent central review [BICR] per RECIST v1.1), assessed for patients with baseline measurable disease, and safety. Results: Updated analyses were completed as of Nov 6, 2020 (data cut-off), for patients who initiated pralsetinib 400 mg QD by May 22, 2020 (enrollment cut-off). Efficacy results, including analyses for treatment-naïve patients enrolled after eligibility criteria were revised to allow candidates for platinum-based therapy, are shown in the Table. Conclusions: Pralsetinib showed rapid, potent, and durable clinical activity in patients with RET fusion-positive NSCLC (regardless of prior therapies), including poor prognosis patients not eligible for platinum-based therapy. Overall, pralsetinib was well-tolerated. These data highlight the need for RET testing early in the course of disease to identify candidates who may benefit from treatment with pralsetinib. Clinical trial information: NCT03037385. [Table: see text]

Small cell lung cancer (SCLC) is a high-grade neuroendocrine tumor characterized by rapid growth, early metastatic spread, and initial responsiveness to therapy. Although the incidence of SCLC is declining, it remains one of the common causes of cancer-related mortality. Initial evaluation of patients with SCLC should focus on determining the extent of disease and the ability of the patient to tolerate specific therapy. Positron emission tomography (PET) can improve the accuracy of staging and treatment planning in many patients. Limited-stage (LS) SCLC is a potentially curable disease with long-term survival of 20 to 25% when treated with platinum-based chemotherapy plus concurrent thoracic radiation. Hyperfractionated (twice daily) thoracic radiation and prophylactic cranial irradiation (PCI) may improve survival in selected patients with LS-SCLC. For patients with extensive-stage (ES) SCLC, combination chemotherapy prolongs survival and improves quality of life, but long-term survival is rare. The use of PCI and sequential thoracic radiation has been reported to improve survival in selected patients with ES-SCLC. Many chemotherapeutic drugs have activity in SCLC, but little progress has been made in the systemic treatment of SCLC in almost three decades. Although many potential molecular targets have been identified in the preclinical studies of SCLC, molecularly targeted therapy has yet to demonstrate consistent clinical activity. Nevertheless, future advances in SCLC will depend on the development of rational therapeutic strategies which target the molecular mechanisms that drive cellular proliferation, survival, and immunological avoidance.

Background The hepatocyte growth factor receptor gene ( MET ) exon 14 skipping ( METex14 ) has recently been described a potential driver alteration in lung cancer targetable by mesenchymal-to-epithelial transition factor (MET) tyrosine kinase inhibitors (TKIs). Methods Well-validated hybrid capture–based comprehensive genomic profiling was performed at the request of individual treating physicians. Results Of 11,205 lung cancers profiled by comprehensive genomic profiling, 298 (2.7%) carcinomas harbored alterations predicted to cause METex14 , including adenosquamous (8.2%), sarcomatoid (7.7%), histologic subtype not otherwise specified (3.0%), adenocarcinoma (2.9%), squamous cell (2.1%), large cell (0.8%), and SCLC (0.2%). Acinar features were present in 24% of the METex14 samples. Six cases (2%) harbored MET Y1003X mutations affecting binding of the MET-negative regulator, E3 ubiquitin protein ligase. The median age of all patients with METex14 was 73 years (range 43–95) and 60% were female. Concurrent, murine double minute gene ( MDM2 ) amplification, cyclin-dependent kinase 4 gene ( CDK4 ) amplification, and EGFR amplification were observed in 35%, 21%, and 6.4% of patients with METex14 , respectively. KRAS mutation was observed in 3% of cases. Concurrent MET amplification ( MET amp) (median copy number 10) was identified in 15% of METex14 samples. Significant differences in tumor mutational burden and type of the METex14 alterations were observed between the MET amp and non- MET amp samples. Response to MET TKI was observed in both in patients with MET amp and in patients without MET amp METex14 . Conclusion Diverse targetable METex14 alterations were identified in patients with NSCLC across age groups, including elderly patients, and in all major NSCLC histologic subtypes with an overall frequency of 2.7%. These findings support the use of hybrid capture–based molecular profiling across NSCLC subtypes to identify patients who will potentially benefit from MET TKIs.

9001 Background: Pembro monotherapy showed durable antitumor activity as third-line or later therapy for metastatic SCLC, leading to FDA approval in that setting. KEYNOTE-604 was a double-blind, phase 3 study of pembro + EP vs placebo + EP as first-line therapy for ES-SCLC (NCT03066778). Methods: Eligible patients (pts) with previously untreated ES-SCLC and no untreated CNS metastases were randomized 1:1 to pembro 200 mg Q3W or saline placebo for up to 35 cycles plus 4 cycles of standard-dose EP. Pts with CR or PR after cycle 4 could receive PCI at investigator discretion. Randomization was stratified by platinum choice (carboplatin vs cisplatin), ECOG PS (0 vs 1), and LDH (≤ULN vs > ULN). Primary endpoints were OS and PFS (RECIST v1.1, blinded central review) in the ITT population. ORR, DOR, and safety were secondary endpoints. OS and PFS treatment differences were assessed by the stratified log-rank test. The protocol specified 2 interim analyses (IAs) and a final analysis (FA). Prespecified efficacy boundaries were one-sided P = 0.0048 for PFS at IA2 (prespecified final PFS analysis) and 0.0128 for OS at FA. Results: 453 pts were randomized. 223/228 pts assigned to pembro + EP and 222/225 assigned to placebo + EP received ≥1 dose of assigned treatment; 1 pt assigned to pembro + EP received placebo + EP in error. Median age was 65 y, 74% had ECOG PS 1, and 57% had LDH > ULN; more pts in the pembro + EP arm had baseline brain metastases (14% vs 10%). At FA (median follow-up, 21.6 mo), 9% of pts in the pembro + EP arm and 1% in the placebo + EP arm remained on study treatment; 12% and 14% received PCI. At IA2 (median follow-up, 13.5 mo), pembro + EP significantly improved PFS in the ITT population (HR 0.75 [95% CI 0.61-0.91], P = 0.0023; median 4.5 vs 4.3 mo). At FA, pembro + EP prolonged OS in the ITT population, but the significance threshold was not met (HR 0.80 [95% CI 0.64-0.98], P = 0.0164; median 10.8 vs 9.7 mo). In a post hoc analysis of OS in the as-treated population, the nominal P value was smaller than the significance threshold (HR 0.78 [95% CI 0.63-0.97], P = 0.0124). ORR at FA was 71% for pembro + EP vs 62% for placebo + EP; median DOR was 4.2 vs 3.7 mo. Observed AEs were as expected; any-cause AEs were grade 3-4 in 77% vs 75%, grade 5 in 6% vs 5%, and led to discontinuation in 15% vs 6%. Conclusions: Pembro + EP significantly improved PFS and prolonged OS compared with placebo + EP as first-line therapy for pts with ES-SCLC. No unexpected toxicities were seen with pembro + EP. These data support the benefit of pembro-containing regimens for ES-SCLC. Clinical trial information: NCT03066778.

The NCCN Guidelines for Neuroendocrine and Adrenal Tumors provide recommendations for the management of adult patients with neuroendocrine tumors (NETs), adrenal gland tumors, pheochromocytomas, and paragangliomas. Management of NETs relies heavily on the site of the primary NET. These NCCN Guidelines Insights summarize the management options and the 2018 updates to the guidelines for locoregional advanced disease, and/or distant metastasis originating from gastrointestinal tract, bronchopulmonary, and thymus primary NETs.

Purpose To assess the utility of circulating serum microRNAs (c-miRNAs) to predict response to high-dose radiation therapy for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials Data from 80 patients treated from 2004 to 2013 with definitive standard- or high-dose radiation therapy for stages II-III NSCLC as part of 4 prospective institutional clinical trials were evaluated. Pretreatment serum levels of 62 miRNAs were measured by quantitative reverse transcription–polymerase chain reaction array. We combined miRNA data and clinical factors to generate a dose–response score (DRS) for predicting overall survival (OS) after high-dose versus standard-dose radiation therapy. Elastic net Cox regression was used for variable selection and parameter estimation. Model assessment and tuning parameter selection were performed through full cross-validation. The DRS was also correlated with local progression, distant metastasis, and grade 3 or higher cardiac toxicity using Cox regression, and grade 2 or higher esophageal and pulmonary toxicity using logistic regression. Results Eleven predictive miRNAs were combined with clinical factors to generate a DRS for each patient. In patients with low DRS, high-dose radiation therapy was associated with significantly improved OS compared to treatment with standard-dose radiation therapy (hazard ratio 0.22). In these patients, high-dose radiation also conferred lower risk of distant metastasis and local progression, although the latter association was not statistically significant. Patients with high DRS exhibited similar rates of OS regardless of dose (hazard ratio 0.78). The DRS did not correlate with treatment-related toxicity. Conclusions Using c-miRNA signature and clinical factors, we developed a DRS that identified a subset of patients with locally advanced NSCLC who derive an OS benefit from high-dose radiation therapy. This DRS may guide dose escalation in a patient-specific manner.

Despite high response rates to initial therapy, relapses are common in patients with small-cell lung cancer (SCLC). Systemic therapy after first-line failure remains important in the treatment paradigm of SCLC. Reinitiation of a previously administered first-line chemotherapy regimen is recommended for relapse > 6 months from completion of initial therapy. For relapse ≤ 6 months of initial therapy, sequential therapy with single agents is recommended. Clinical trial enrollment should be considered at all stages of treatment of SCLC. This review highlights the available treatment options in relapsed SCLC. In particular, we focus on prospective clinical trials demonstrating activity for the most commonly used agents in this setting. We end with a discussion on future directions and emerging targets with potential to improve outcomes in relapsed SCLC.

e20061 Background: Malignant pleural mesothelioma (MPM) is a disease that is resistant to chemotherapy and there remains an unmet need for better therapeutic options. Nintedanib (BIBF 1120) is an oral multikinase inhibitor impacting VEGFR, FGFR, PDGFR, and other kinase activity such as TGFß signaling pathways. VEGF, FGF, and TGFβ are commonly expressed in MPM. We conducted a phase II trial in patients with recurrent MPM after platinum-based chemotherapy. Methods: Patients (pts) with MPM previously treated with platinum-based chemotherapy, performance status (PS) 0-1, adequate organ function, and no contraindications to anti-angiogenic therapy were eligible for treatment. Nintedanib 200 mg twice per day was administered until disease progression or unacceptable toxicity. The primary endpoint was the 4-month progression-free survival (PFS). A two-stage design was used and > 4 pts had to have a PFS of ≥4 months to proceed to the second stage. Results: Twenty pts. were enrolled. The median age was 70 yrs. (32-81), 90% were male, and 80% were PS = 1. The histology was 70% epithelioidal, 5% sarcomatoid, 10% biphasic, and 15% unknown. 15% had prior bevacizumab. The median follow-up is 16.4 mo. A median of 2 treatment cycles (range 1-18) were delivered. There were no responses but 40% had stable disease. The median PFS was 1.8 mo. (95% CI: 1.68, 3.55) and the PFS rate at 4 mo. was 13%. The median OS was 4.2 mo. (95% CI: 2.53, 8.74) and the OS rate at 4 mo. was 55%. Toxicities were usually grade 1-2 and included diarrhea, fatigue, edema, transaminase elevation, anorexia, nausea, vomiting and dyspnea. Conclusions: The activity of nintedanib in previously treated MPM pts. was modest. The trial did not meet the primary PFS endpoint. However, there was a small subset of pts. that had prolonged stable disease for > 4 months thus potentially deriving some clinical benefit from treatment. Supported by Boehringer Ingelheim. Clinical trial information: NCT02568449.

Preclinical studies demonstrated antiproliferative synergy of 1,25-D3 (calcitriol) with cisplatin. The goals of this phase I/II study were to determine the recommended phase II dose (RP2D) of 1,25-D3 with cisplatin and docetaxel and its efficacy in metastatic non-small-cell lung cancer.Patients were ≥18 years, PS 0-1 with normal organ function. In the phase I portion, patients received escalating doses of 1,25-D3 intravenously every 21 days prior to docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) using standard 3 + 3 design, targeting dose-limiting toxicity (DLT) rate33 %. Dose levels of 1,25-D3 were 30, 45, 60, and 80 mcg/m(2). A two-stage design was employed for phase II portion. We correlated CYP24A1 tagSNPs with clinical outcome and 1,25-D3 pharmacokinetics (PK).34 patients were enrolled. At 80 mcg/m(2), 2/4 patients had DLTs of grade 4 neutropenia. Hypercalcemia was not observed. The RP2D of 1,25-D3 was 60 mcg/m(2). Among 20 evaluable phase II patients, there were 2 confirmed, 4 unconfirmed partial responses (PR), and 9 stable disease (SD). Median time to progression was 5.8 months (95 % CI 3.4, 6.5), and median overall survival 8.7 months (95 % CI 7.6, 39.4). CYP24A1 SNP rs3787554 (CT) correlated with disease progression (P = 0.03) and CYP24A1 SNP rs2762939 (CG) trended toward PR/SD (P = 0.08). There was no association between 1,25-D3 PK and CYP24A1 SNPs.The RP2D of 1,25-D3 with docetaxel and cisplatin was 60 mcg/m(2) every 21 days. Pre-specified endpoint of 50 % confirmed RR was not met in the phase II study. Functional SNPs in CYP24A1 may inform future studies individualizing 1,25-D3.

Neuroendocrine tumors account for approximately 20% of lung cancers; most (≈15%) are small cell lung cancer (SCLC). These NCCN Clinical Practice Guidelines in Oncology for SCLC focus on extensive-stage SCLC because it occurs more frequently than limited-stage disease. SCLC is highly sensitive to initial therapy; however, most patients eventually die of recurrent disease. In patients with extensive-stage disease, chemotherapy alone can palliate symptoms and prolong survival in most patients; however, long-term survival is rare. Most cases of SCLC are attributable to cigarette smoking; therefore, smoking cessation should be strongly promoted.

We investigated the novel combination of dose-dense pemetrexed, gemcitabine and bevacizumab as frontline treatment for advanced non–small cell lung cancer. Thirty-nine patients received pemetrexed (400 mg/m(2)), gemcitabine (1200 mg/m(2)), and bevacizumab (10 mg/kg), given every 14 days. Median progression-free survival was 6.1 months (95% confidence interval [CI], 4.2–7.9) and median overall survival was 18.4 months (95% CI, 13.1–29.5). Treatment met the primary endpoint and represents a reasonable therapeutic option. INTRODUCTION: Platinum-based chemotherapy is standard for untreated, advanced non-small-cell lung cancer (NSCLC). We investigated the activity and tolerability of the novel combination of dose-dense pemetrexed, gemcitabine, and bevacizumab in patients with advanced NSCLC. METHODS: This multicenter phase II trial evaluated the safety and efficacy of the combination of pemetrexed (400 mg/m(2)), gemcitabine (1200 mg/m(2)), and bevacizumab (10 mg/kg), given every 14 days in patients with untreated, advanced NSCLC. The primary endpoint was progression-free survival with secondary endpoints of response rate and overall survival. RESULTS: Thirty-nine patients were enrolled. Treatment was well tolerated; the most common grade 3–4 toxicities were neutropenia and fatigue. Of the 38 patients evaluable for tumor response, 1 (3%) had complete response, 15 (39%) had partial response, 12 (31%) had stable disease, and 10 (26%) had progressive disease. Median progression-free survival was 6.1 months (95% confidence interval [CI], 4.2–7.9) and median overall survival was 18.4 months (95% CI, 13.1–29.5). The 1-year overall survival rate was 64% (95% CI, 51%−81%) and the 2-year overall survival rate was 41% (95% CI, 28%−60%). CONCLUSIONS: Treatment with dose-dense pemetrexed, gemcitabine, and bevacizumab met the primary endpoint with promising efficacy and a manageable safety profile in patients with untreated advanced NSCLC. This regimen represents a reasonable therapeutic option.

Etoposide and irinotecan are key drugs in the treatment of small-cell lung cancer. We did this study to investigate whether combined chemotherapy with cisplatin, etoposide, and irinotecan was superior to topotecan monotherapy as second-line chemotherapy in patients with sensitive relapsed small-cell lung cancer.We did this open-label, multicentre, randomised phase 3 trial at 29 institutions in Japan. Patients with small-cell lung cancer that responded to first-line treatment but showed evidence of disease relapse or progression at least 90 days after completion of the first-line treatment were eligible to participate. Enrolled patients were randomly assigned (1:1) to receive combination chemotherapy with cisplatin plus etoposide plus irinotecan or topotecan alone. Randomisation was done via the minimisation method with biased-coin balancing for Eastern Cooperative Oncology Group performance status, disease stage at enrolment, and institution. Combination chemotherapy consisted of five 2-week courses of intravenous cisplatin 25 mg/m(2) on days 1 and 8, intravenous etoposide 60 mg/m(2) on days 1-3, and intravenous irinotecan 90 mg/m(2) on day 8, with granulocyte colony-stimulating factor given by hypodermic injection every day starting from day 9 of the first course (except on the days anticancer drugs were given). Topotecan therapy consisted of four courses of intravenous topotecan 1·0 mg/m(2) on days 1-5, every 3 weeks. The primary endpoint was overall survival in the intention-to-treat population, which was analysed with a one-sided α of 5%, and safety was assessed in all patients who received at least one dose of study drug. The trial is registered with University Hospital Medical Information Network Clinical Trials Registry, number UMIN000000828.Between Sept 20, 2007, and Nov 30, 2012, 180 patients were enrolled, with 90 assigned to each treatment group. The median follow-up for censored patients was 22·7 months (IQR 20·0-35·3). Overall survival was significantly longer in the combination chemotherapy group (median 18·2 months, 95% CI 15·7-20·6) than in the topotecan group (12·5 months, 10·8-14·9; hazard ratio 0·67, 90% CI 0·51-0·88; p=0·0079). The most common grade 3 or 4 adverse events were neutropenia (75 [83%] patients in the combination chemotherapy group vs 77 [86%] patients in the topotecan group), anaemia (76 [84%] vs 25 [28%]), and leucopenia (72 [80%] vs 46 [51%]). Grade 3 or 4 febrile neutropenia was more common in the combination chemotherapy group than in the topotecan group (28 [31%] vs six [7%]), as was grade 3 or 4 thrombocytopenia (37 [41%] vs 25 [28%]). Serious adverse events were reported in four (4%) patients in the topotecan group and nine (10%) in the combination chemotherapy group. Two treatment-related deaths (one each of pneumonitis and pulmonary infection) occurred in the topotecan group and one (febrile neutropenia with sepsis) occurred in the combination chemotherapy group.Combination chemotherapy with cisplatin plus etoposide plus irinotecan could be considered the standard second-line chemotherapy for selected patients with sensitive relapsed small-cell lung cancer.National Cancer Center and the Ministry of Health, Labour and Welfare of Japan.

BACKGROUND: The objectives of this study were to evaluate survival among current smokers, former smokers, and never smokers who are diagnosed with non–small cell lung cancer (NSCLC). METHODS: The study included patients who participated in the National Comprehensive Cancer Network's NSCLC Database Project. Current, former, and never smokers were compared with respect to overall survival by fitting Cox regression models. RESULTS: Data from 4200 patients were examined, including 618 never smokers, 1483 current smokers, 380 former smokers who quit 1 to 12 months before diagnosis, and 1719 former smokers who quit >12 months before diagnosis. Among patients with stage I, II, and III disease, only never smokers had better survival than current smokers (hazard ratio, 0.47 [95% confidence interval, 0.26-0.85] vs 0.51 [95% confidence interval, 0.38-0.68], respectively). Among patients with stage IV disease, the impact of smoking depended on age: Among younger patients (aged ≤55 years), being a never smoker and a former smoker for ≥12 months increased survival. After age 85 years, smoking status did not have a significant impact on overall survival. CONCLUSIONS: Patients who were smoking at the time of diagnosis had worse survival compared with never smokers. Among younger patients with stage IV disease, current smokers also had worse survival compared with former smokers who quit >12 months before diagnosis. It is likely that tumor biology plays a major role in the differences observed; however, to improve survival, it is prudent to encourage all smokers to quit smoking if they are diagnosed with NSCLC. Cancer 2013. © 2012 American Cancer Society.

Introduction Vorinostat is an inhibitor of histone deacetylase 6, which acetylates tubulin and stabilizes microtubules. Since taxanes also stabilize microtubules, we hypothesized that the administration of vorinostat followed by docetaxel should result in synergistic cytotoxicity. We conducted a phase I trial to determine the dose level of vorinostat plus docetaxel that would result in dose-limiting toxicity (DLT) in ≤30% of patients. Methods Eligible patients had castration-resistant prostate cancer (CRPC) or relapsed urothelial or non-small-cell lung cancer (NSCLC) after ≥1 prior chemotherapy regimen not containing docetaxel, performance status of 0–2, and adequate organ function. Vorinostat was given orally for 14 days beginning on day 1 of a 21-day cycle, with docetaxel given intravenously over 1 h on day 4. The time-to-event continuous reassessment method (TITE-CRM) guided dose escalation. Dose levels (DL) -1, 0, 1 and 2 corresponded to vorinostat 100, 100, 200 and 200 mg plus docetaxel 50, 60, 60, and 75 mg/m2, respectively. Pharmacokinetic studies were performed on days 1 and 4 of cycle 1. Results Twelve patients were enrolled: median age 65 years (range 49–74); 9 male, 3 female; 4 CRPC, 5 urothelial, 3 NSCLC. The median number of cycles administered was 2. Two patients were treated at DL -1, 4 at DL 0, 5 at DL 1 and 1 at DL 2. Five DLTs occurred in 5 patients: neutropenic fever/sepsis (2), anaphylactic reaction (1), myocardial infarction (1) and gastrointestinal bleed (1). Other toxicities included grade 3/4 neutropenia (4), peripheral neuropathy (1), and gastrointestinal bleed (n = 1). The estimated probability of DLT for DL -1 was 0.32 (90% posterior probability interval [PI], 0.11 to 0.53) for DL 0, 0.38 (90% PI, 0.16 to 0.58) and for DL 1, 0.43 (90% PI, 0.23 to 0.64). The trial was stopped due to excessive toxicity. No responses were noted. Conclusions The combination of vorinostat and docetaxel was poorly tolerated with excessive DLTs that required early study termination. No responses were identified. Vorinostat and docetaxel pharmacokinetics were comparable to previous reports in the literature, without obvious drug-drug interactions.

Background The prognosis for patients with extensive-stage small-cell lung cancer remains poor. This trial was designed to evaluate irinotecan/cisplatin plus maintenance imatinib in patients with c-Kit–positive disease (the transmembrane receptor c-Kit is the product of the c-KIT protooncogene). Patients and Methods Immunohistochemistry for c-Kit was performed before enrollment. Treatment consisted of irinotecan 65 mg/m 2 on days 1 and 8 plus cisplatin 60 mg/m 2 on day 1 and every 21 days for 4 cycles. Imatinib was administered at 400 mg twice a day until progression or unacceptable toxicity occurred. Results Fourteen patients were enrolled. Slow accrual led to early study termination. Six patients did not begin treatment with imatinib because of disease progression, persistent toxicity, or referral for radiation therapy. Eight patients had a partial response with irinotecan/cisplatin and received imatinib. The median number of weeks on imatinib was 6.1 (range, 4.1-25.1 weeks). Reasons for imatinib discontinuation included disease progression (n = 7) and persistent neutropenia (n = 1). No objective responses to imatinib were evident, but 3 patients (21%) exhibited stable disease for 12, 15, and 25 weeks. The median progression-free survival was 4.3 months (95% CI, 2.9-4.8 months). The median overall survival was 7.8 months (95% CI, 5.7-10.0 months). The irinotecan/cisplatin regimen was well tolerated (grade 1/2 neutropenia, 29%; anemia, 43%; thrombocytopenia, 14%; and diarrhea, 29%), except in 1 patient with grade 3 vomiting. Imatinib toxicity included grade 1/2 nausea in 50% of the patients, peripheral edema in 75% of the patients, grade 3 fatigue in 13% of the patients, and neutropenia in 13% of the patients. Conclusion Despite the selection of tumors expressing c-Kit, imatinib did not appear to delay disease progression after response to chemotherapy. However, this trial was underpowered because of its early termination. Although disease stability with imatinib was evident in 3 patients and the therapy was well tolerated, this approach does not appear to warrant further clinical study.

e21175Background: Three immunotherapy agents are currently FDA-approved for the treatment of NSCLC after platinum-based chemotherapy. These agents have demonstrated superior outcomes and tolerabili...

Background Alterations in retinoid signaling appear to be involved in the pathogenesis of small cell lung cancer (SCLC). Fenretinide [N-(4-hydroxyphenyl)retinamide], a synthetic retinoid, inhibits the growth of SCLC cells in vitro via the induction of apoptosis. Since these data suggested that SCLC is the adult solid tumor that is most susceptible to fenretinide, a trial to evaluate the clinical activity of fenretinide in patients with SCLC was considered the definitive test of its clinical potential in adult oncology. Methods Patients with progressive SCLC after one or two prior chemotherapy regimens and a performance status of 0–2 were eligible for the study. Patients with stable, treated brain metastases were eligible. Fenretinide 900 mg/m2 twice daily was administered orally on days 1–7 of each 21-day cycle. Blood and saliva were collected pre-treatment and on day 7 of cycle 1 to measure fenretinide and retinol levels by high-pressure liquid chromatography (HPLC). Results Nineteen patients were enrolled. Fifteen patients had one prior chemotherapy regimen and four patients had two prior regimens. The median time from diagnosis to enrollment was 10 months. A median of two cycles of fenretinide was administered. There were no objective responses, but four of 17 evaluable patients (24%) had stable disease after 2–17 cycles. The median time to treatment failure was 5.7 weeks overall, while the four patients with stable disease demonstrated treatment failure at 11, 13, 19, and 52 weeks. Median survival was 25 weeks, with one patient alive 22 months after the start of treatment. The 1-year survival rate was 29%. Toxicity included mild, reversible visual changes (haziness, altered night vision), grade 1–3 nausea/vomiting, and grade 1–2 diarrhea. The mean day 7 plasma fenretinide level was 2.90 ± 1.66 μg/ml (7.40 ± 4.25 μM; n = 14). The mean pre-treatment and day 7 plasma retinol levels were 0.47 ± 0.16 μg/ml and 0.05 ± 0.07 μg/ml (n = 8), respectively. The mean day 7 salivary fenretinide level was 0.08 ± 0.18 μg/ml, with no correlation between salivary and plasma drug levels. Conclusions Fenretinide is well tolerated in patients with SCLC and stabilization of disease was noted in 24% of patients with this aggressive disease. However, after the first stage of enrollment, the response rate did not meet criteria to proceed with full trial accrual. Plasma concentrations of fenretinide that induce cytotoxicity in vitro in SCLC cell lines are clinically achievable, but there were no objective responses. Non-invasive drug monitoring using saliva underestimates systemic exposure.

Introduction To evaluate the efficacy and toxicity of the combination of celecoxib and docetaxel in patients with advanced non-small cell lung cancer after failure of platinum-based therapy. Methods Patients with relapsed non-small cell lung cancer received celecoxib 400 mg orally twice daily beginning 7 days before the first cycle of docetaxel and the celecoxib was continued with no interruption. Docetaxel 75 mg/m 2 was administered intravenously on a 21-day cycle. The primary end point of the study was the 6-month survival rate. Results Twenty-four patients were enrolled and twenty patients were treated (median age 60, M:F 16:8). Most patients had a baseline performance status of 1. The objective response rate was 10% (95% confidence interval [CI], 0–25%) and the 6-month survival rate was 59% (95% CI 37–80%). Median survival time was 6.9 months (95% CI, 2.8–15.2 months) and the 1- and 2-year survival rates were 36% (95% CI, 15–57%) and 1% (95% CI, 0–10%), respectively. The most frequent grade ≥3 adverse events were neutropenia (58%) and neutropenic fever (21%) which resulted in early closure of the trial. Conclusions The addition of celecoxib to docetaxel did not seem to improve the response rate and survival compared with docetaxel alone. The combination demonstrated considerable neutropenia and complications from febrile neutropenia that suggests celecoxib may enhance the marrow toxicity of docetaxel.

We aimed to report the final toxicity results on a radiation-dose escalation trial designed to test a hypothesis that very high doses of radiation could be safely administered to patients with non-small-cell lung cancer (NSCLC) by quantifying the dose-volume toxicity relationship of the lung.A total of 109 patients with unresectable or medically inoperable NSCLC were enrolled and treated with radiation-dose escalation (on the basis of predicted normal-lung toxicity) either alone or with neoadjuvant chemotherapy by use of 3D conformal techniques. Eighty-four patients (77%) received more than 69 Gy, the trial was stopped after the dose reached 103 Gy. Estimated median follow-up was 110 months.There were 17 (14.6%) Grade 2 to 3 pneumonitis and 15 (13.8%) Grade 2 to 3 fibrosis and no Grade 4 to 5 lung toxicity. Multivariate analyses showed them to be (1) not associated with the dose prescribed to the tumor, and (2) significantly (p0.001) associated with lung-dosimetric parameters such as the mean lung dose (MLD), volume of lung that received at least 20 Gy (V20), and the normal-tissue complication probability (NTCP) of the lung. If cutoffs are 30% for V20, 20 Gy for MLD, and 10% for NTCP, these factors have positive predictive values of 50% to 71% and negative predictive value of 85% to 89%.With long-term follow-up for toxicity, we have demonstrated that much higher doses of radiation than are traditionally administered can be safely delivered to a majority of patients with NSCLC. Quantitative lung dose-volume toxicity-based dose escalation can form the basis for individualized high-dose radiation treatment to maximize the therapeutic ratio in these patients.

The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors and a crucial regulator of cellular differentiation. Differentiation-inducing and antiproliferative effects of PPAR-gamma suggest that PPAR-gamma agonists might be useful as effective anticancer agents. Few studies have examined the efficacy of these agonists in animal models of tumorigenesis, and their mechanism(s) of action are still not clear. Our studies indicate higher PPAR-gamma expression in primary tumors from non-small-cell lung cancer (NSCLC) patients when compared to normal surrounding tissue. The expression of PPAR-gamma was also observed in several NSCLC lines. The treatment of lung adenocarcinoma cells (A549) with troglitazone (Tro), a PPAR-gamma ligand, enhanced PPAR-gamma transcriptional activity and induced a dose-dependent inhibition of A549 cell growth. The observed growth arrest was predominantly due to the inhibition of cell proliferation without significant induction of apoptosis. Cell cycle analysis of Tro-treated cells revealed a cell cycle arrest at G(0)/G(1) with concomitant downregulation of G(0)/G(1) cyclins D and E. In addition, Tro treatment stimulated sustained Erk1/2 activation in A549 cells, suggesting the activation of a differentiation-inducing pathway. Furthermore, treatment of A549 tumor-bearing SCID mice with Tro or Pio inhibited primary tumor growth by 66.7% and significantly inhibited the number of spontaneous lung metastatic lesions. Collectively, our data demonstrate that activation of PPAR-gamma impedes lung tumor progression and suggest that PPAR-gamma ligands may serve as potential therapeutic agents for NSCLC.

e20607 Background: The PD-1 inhibitors nivolumab and pembrolizumab are approved for the treatment of advanced non-small cell lung cancer (NSCLC), but little is known about patterns of disease progression when these agents fail. Understanding patterns of failure is key to developing strategies to improve duration of response to these agents. Methods: We gathered clinical and radiographic data on patients treated at the University of Michigan and the Ann Arbor VA for advanced NSCLC with standard-dose nivolumab (n = 68) or pembrolizumab (n = 23) after progression on platinum-based chemotherapy. Sites of disease progression were described as local (within the same lobe as primary disease), nodal (thoracic), or distant. Results: 91 patients were evaluable, of whom 56 (61.5%) had progression of disease after an average duration of therapy of 3.2 months (95%CI, 2.6-3.8). 10 (17.9%) patients had progression at local sites alone, 3 (5.4%) at nodal sites alone, 12 (21.4%) at distant sites alone, and 31 (55.4%) at a combination of sites. Overall, 41 (73.2%) had progression at distant sites. There was no statistically significant difference in clinical factors ( i.e. age, histology, comorbidity index) between progressors vs. non-progressors or distant-progressors vs. non-distant progressors. Of 37 patients who had prior radiation, 17 (45.9%) had progression at an irradiated site, with patients who had local and/or nodal progression more likely to have received radiation at site of progression (p = 0.01). The most common distant sites of progression were liver (13), bone (10), and brain (9). Conclusions: The most common site of disease progression was distant, with the liver being the most commonly involved site. This may be due to the immunotolerogenic environment of the liver, which is characterized by high IL-10 concentration and propagation of suppressive regulatory T cells, which can dampen activation of cytotoxic T cells. Prior irradiation did not seem to prevent disease progression. Our preliminary analysis suggests that the efficacy of checkpoint inhibitors is hindered in immune-privileged sites. Strategies to overcome immune tolerance should be investigated to improve duration of response to these agents.

8504 Background: The median progression free survival (PFS) and overall survival (OS) following initial chemotherapy in ES-SCLC pts are 2 and 7 months, respectively (Ready N, J Clin Oncol 2015). We evaluated the benefits of maintenance pembro in ES-SCLC pts who had response/stable disease after 4-6 cycles of platinum/etoposide. Methods: Pts were required to begin pembro within 8 weeks of completion of chemotherapy, with restaging scans no more than 3 weeks prior to start of pembro. Prophylactic cranial radiation was permitted. Pts were treated with pembro 200 mg I.V. every 3 weeks for a maximum of 2 years. Disease assessment was done every 2 cycles for the first 6 cycles and then as per investigator discretion. Primary end point of the study was PFS. PFS according to immune related response criteria (irPFS) and OS were also assessed. Tumor tissue was analyzed for PD-L1 expression by the DAKO 22C3 antibody. Any level of expression was considered as positive for PDL1. Blood for circulating tumor cells (CTCs) was collected prior to first, second and third cycle of pembro. Results: Of the 45 pts enrolled, 55% were males and 22% had brain metastases. Median age was 66 years. The median time from end of chemotherapy to start of pembro was 5 weeks. Median number of pembro cycles was 4 (1-20 cycles). 35 pts had measurable disease at study entry. The disease control rate with pembro was 42% (1 CR, 3 PR, 15 SD). At a median follow up of 6 months, the median PFS was 1.4 months (90% CI-1.3-4.0) and the irPFS was 4.7 months (90% CI- 1.8-6.7). The median OS was 9.2 months (90% CI-6.1-15.2). 11 pts are still on therapy (3-20 cycles). The median CTC prior to pembro was 1 (0-256, n=37 pts). Each unit increase in baseline CTC correlated with worse PFS (p = 0.052; adjusted for brain mets, age and sex). PDL1 could be assessed in 35 pts and was positive in 1 pt. Most common adverse events were fatigue, nausea, cough and dyspnea. One pt developed atrio-ventricular conduction block and 1 pt type 1 diabetes. Conclusions: Maintenance pembro did not improve PFS in these patients but favorable OS suggests that some SCLC patients can benefit from maintenance pembro. Biomarkers to identify patients most likely to benefit from pembro need to be defined. Clinical trial information: NCT02359019.

Small cell lung cancer (SCLC) is characterised by neuroendocrine differentiation, early metastatic potential and initial responsiveness to cytotoxic therapy. Unfortunately, despite recent therapeutic advances, most patients relapse and the overall five-year survival rate is only 5%. Standard treatment of SCLC consists of platinum-based combination chemotherapy, with thoracic irradiation added for patients with limited-stage disease. Several newer chemotherapeutic drugs have recently been shown to have significant activity in patients with untreated or relapsed SCLC. These agents include: the topoisomerase I inhibitors, topotecan and irinotecan; the taxanes, paclitaxel and docetaxel; the pyrimidine analogue, gemcitabine; and the vinca alkaloid, vinorelbine. Recent advances in our understanding of the molecular events involved in the pathogenesis and progression of SCLC have led to the identification of a variety of potential targets for novel therapeutic interventions. Strategies aimed at inhibiting the myriad of growth factor pathways that control the proliferation of SCLC cells, include: broad spectrum neuropeptide antagonists (e.g., substance P analogues); growth factor/receptor-specific inhibitors (e.g., anti-GRP monoclonal antibodies, bradykinin antagonist dimers); and a variety of selective protein kinase inhibitors. The importance of cell death pathways in carcinogenesis and treatment-resistance has led to several novel strategies targeting apoptotic mediators, such as bcl-2, that are frequently dysregulated in SCLC (e.g., bcl-2 antisense). Our current challenges are to further refine these promising therapeutic strategies, efficiently evaluate their activity in the clinical setting and integrate them into more effective treatment regimens to improve the overall prognosis of patients with SCLC.

Standard chemotherapeutic regimens, such as cisplatin and etoposide, may improve quality of life and prolong survival in patients with incurable non-small cell lung cancer (NSCLC). This trial was designed to evaluate the activity and toxicity of a regimen combining three of the most active agents against advanced-stage NSCLC: mitomycin C, etoposide, and cisplatin (MEP). Sixty-eight patients with stage IIIB (pleural effusion) or IV NSCLC received cisplatin 80 mg/m2 i.v. on day 1 and etoposide 80 mg/m2 i.v. on days 1, 2, and 3 every 3 weeks along with mitomycin C 10 mg/m2 i.v. on day 1 of the first and third cycles for a median of four cycles (range, 1-11). Median age was 59 years, and nine patients were enrolled after relapse from previously treated early-stage NSCLC. Eighty-eight percent of patients had stage IV disease, and 14 (21%) had brain metastases at diagnosis. Palliative radiotherapy was given to 10 patients (15%) before MEP and to 17 (25%) concurrent with MEP. The major toxicity of MEP was myelosuppression, with grade 3-4 neutropenia in 74% of patients. Sixteen patients (24%) had documented infections, and there were eight (12%) treatment-related deaths. Partial response was observed in 24 patients (35%) with a median duration of 4.4 months, (range 1.4-13 months). Median survival was 8.1 months (range, 1-34 months), and 1-year survival was 32%. The addition of mitomycin C to cisplatin and etoposide resulted in response and survival rates comparable with those achieved with standard regimens in patients with advanced NSCLC but was associated with substantial hematologic toxicity and unacceptable treatment-related mortality.