Meyerhardt, Jeffrey A.

Abstract Background: In non-metastatic colorectal cancer, a body mass index (BMI) paradox is observed where overweight and early obese patients experience improved outcomes compared to patients with normal, low, or morbidly obese BMI. The influence of obesity on patients with advanced or metastatic colorectal cancer (mCRC) is relatively unexplored. Methods: We conducted a prospective BMI companion study in CALGB (now Alliance for Clinical Trials in Oncology)/SWOG 80405, a phase III mCRC treatment trial. BMI was measured at trial registration. Primary and secondary endpoints were overall and progression-free survival, respectively. To minimize confounding by poor and rapidly declining health, we used Cox proportional hazards regression to adjust for known prognostic factors, comorbidities, physical activity, and weight loss, and excluded individuals with low BMI <21 from statistical tests for trend. We also examined self-reported weight loss over the six months prior to trial enrollment as an independent predictor of patient outcome. Results: In this sub-study of a phase III mCRC trial, BMI was recorded for all 2,323 patients enrolled. Following adjustment for confounders, there were no significant associations between BMI and overall or progression-free survival (excluding BMI <21, Ptrend with increasing BMI = 0.12 and 0.42, respectively). Conversely, weight loss prior to treatment was associated with shorter overall and progression-free survival; compared to individuals with weight change <5%, individuals with weight loss >20% experienced an adjusted hazard ratio of 1.46 for all-cause mortality (95% confidence interval 1.15 to 1.85, Ptrend <.0001) and of 1.27 for disease progression or death (95% confidence interval 1.04 to 1.56, Ptrend = .009). Conclusion: In this prospective study of patients with mCRC, BMI at time of first-line chemotherapy initiation was not associated with patient outcome. Weight loss prior to study entry was associated with increased risk of patient mortality and disease progression. Citation Format: Brendan Guercio, Sui Zhang, Alan P. Venook, Fang-Shu Ou, Donna Niedzwiecki, Heinz-Josef Lenz, Federico Innocenti, Hanna Sanoff, Michelle R. Mahoney, Bert H. O'Neil, James E. Shaw, Blase N. Polite, Howard S. Hochster, James N. Atkins, Richard M. Goldberg, Robert J. Mayer, Charles D. Blanke, Charles S. Fuchs, Jeffrey A. Meyerhardt. Body mass index, weight loss, and progression and mortality in metastatic colorectal cancer: Results from CALGB/SWOG 80405 (Alliance) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3285.

4005 Background: Patients (pts) with progressive advanced well-differentiated neuroendocrine tumors arising outside of the pancreas have limited systemic treatment options. Pazopanib (PZ) is an oral multi-kinase inhibitor with activity against VEGFR-2,-3, PDGFR-α, and β, and c-KIT, with initial data suggesting efficacy in CARC. Methods: This was a multicenter, randomized, double-blind, phase II study of PZ (800 mg/day) versus placebo (PL) in progressive CARC. Key eligibility: low-intermediate grade CARC, radiologic progressive disease (PD) < 12 months (mo), and adequate end-organ function. Prior somatostatin analog (SSA) mandated for midgut tumors. Concurrent SSA allowed if previous PD on SSA documented. Primary endpoint was progression-free survival (PFS), defined as time from randomization to PD by central review or death. Secondary endpoints included overall survival (OS), objective response rate (ORR) and safety. The trial had 85% power to detect a difference in median PFS of 14 v 9 mo (hazard ratio [HR] 0.64) at one-sided alpha = 0.1. A stratified log-rank test based on the intend-to-treat (ITT) principle was used. Unblinding and crossover were allowed if PD confirmed by central review. Results: 171 (97 PZ, 74 PL) pts were randomized between 6/2013-10/2015: median age 63; 56% female; 66% small bowel primary; 87% concurrent SSA. Median follow-up of 31 mo; 112 (56 PZ, 56 PL) PFS events observed. 6 pts (4 PZ, 2 PL) remain on initial treatment. Median PFS was 11.6 and 8.5 mo in PZ and PL, respectively (HR = 0.53, 1-sided 90% upper confidence limit [UCL] 0.69, p = 0.0005) which crossed the pre-specified protocol efficacy boundary. 49 PL pts received PZ after PD. Median OS was 41 and 42 mo in PZ and PL, respectively (HR = 1.13, 1-sided 90% UCL 1.51, p = 0.70). RR data will be presented. Notable grade 3+ adverse events were (PZ v. PL %) hypertension (35 v. 8), fatigue (11 v. 4), ALT (10 v. 0), AST (10 v. 0), and diarrhea (7 v. 4). Conclusions: PZ compared to PL was associated with significant improvement in PFS in patients with progressive CARC. The results confirm that VEGF signaling pathway is a valid target for therapy in CARC. Support: U10CA180821, U10CA180882 https://acknowledgments.alliancefound.org . Clinical trial information: NCT01841736.

e15169 Background: In metastatic colorectal cancer with deficient DNA mismatch repair (dMMR), anti-PD-1 antibody monotherapy produced high tumor response rates and extended progression-free survival compared to lack of benefit for cancers with proficient MMR. In an ongoing phase III randomized trial, we will determine if the addition of the anti-PD-L1 antibody, atezolizumab (Genentech), to adjuvant FOLFOX can improve patient disease-free survival (DFS) vs FOLFOX alone in patients with stage III colon cancers with dMMR. By blocking the PD-1/PD-L1 interaction, atezolizumab may activate T cells, thereby, restoring their ability to detect and attack tumor cells. Limited data suggest that FOLFOX may increase intratumoral cytotoxic CD8+ T cells that could serve as ‘immune priming'. Methods: Patients with curatively resected stage III colon carcinomas with evidence of dMMR are randomized to modified FOLFOX6 for 6 months (12 cycles) alone (control arm) or combined with atezolizumab (840 mg IV q2 wk) with continuation of the antibody as monotherapy for an additional 6 months (total duration of 12 months) [experimental arm]. Patients will be stratified by T, N stage and tumor sidedness. Local testing for MMR proteins is allowed. Atezolizumab must begin by/with cycle 2. One cycle of FOLFOX is allowed pre-registration. The targeted accrual goal of 700 patients and 165 disease-free survival (DFS) events will provide 90% power to detect an effect size expressed as hazard ratio of 0.6 for the primary endpoint of DFS at two-sided alpha of 0.05. Interim analyses are planned at 50% and 75% of events. Secondary endpoints include overall survival, treatment tolerability, and quality of life. Results: This study is being conducted by the Alliance for Clinical Trials in Oncology, was approved by NCI CTEP and activated in 09/2017. The study is actively accruing and, as of 02/11/2019, 152 patients are enrolled. We are actively exploring an international collaboration. Conclusions: This is a current clinical trial in progress. Clinical trial information: NCT02912559.

3035 Background: Energy balance-associated biomarkers such as insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) have been associated with risk and prognosis of various malignancies. Their relationship to disease progression and mortality in metastatic colorectal cancer (mCRC) requires further study. Methods: In a prospective cohort study, baseline plasma IGFBP-3, IGFBP-7, C-peptide, IGF-I, and adiponectin were measured at trial registration among 1,086 patients participating in a National Cancer Institute-sponsored clinical trial of first-line therapy for mCRC. We used Cox proportional hazards regression to adjust for confounders and examine associations of biomarkers with overall (OS) and progression-free survival (PFS). Results: Higher plasma IGFBP-3 was associated with longer OS (adjusted Ptrend < .001) and PFS (adjusted Ptrend = .003). Compared to patients in the lowest IGFBP-3 quintile, patients in the highest quintile experienced an adjusted HR for all-cause mortality of 0.58 (95% CI 0.42 to 0.78) and for disease progression or mortality of 0.60 (95% CI 0.45 to 0.82). Higher plasma IGFBP-7 was associated with shorter OS (adjusted Ptrend < .001) and PFS (adjusted Ptrend = .02). Compared to patients in the lowest IGFBP-7 quintile, patients in the highest quintile experienced an adjusted HR for all-cause mortality of 1.52 (95% CI 1.24 to 1.88) and for disease progression or mortality of 1.28 (95% CI 1.05 to 1.57). C-peptide and IGF-I were not significantly associated with patient outcomes (adjusted Ptrend = .73 and .30 for OS). Adiponectin was not associated with OS; there was a U shaped association between adiponectin and PFS, wherein low and high values were associated with shorter PFS ( Pnon-linear trend = .03). Conclusions: In patients with mCRC, high plasma IGFBP-3 and low IGFBP-7 were associated with reduced risk of disease progression and mortality. These data suggest that energy-balance associated biomarkers may offer prognostic and biologic insights into mCRC. Support: U10CA180821, U10CA180882, BMS, Genentech, Pfizer, Sanofi; https://acknowledgments.alliancefound.org .

588 Background: CALGB/SWOG 80405 found no difference in overall survival (OS) or progression-free survival (PFS) in 1137 patients with KRAS wild-type metastatic colorectal cancer (mCRC) treated with either the anti-VEGF agent bevacizumab (Bev) or the anti-EGFR agent cetuximab (Cet) in combination with chemotherapy (FOLFOX or FOLFIRI) as first-line therapy. Additional molecular biomarkers are required for the optimization of treatment choices for patients with mCRC. Methods: Levels of 24 proteins were assayed in EDTA-plasma samples using multiplex ELISA techniques. Plasma samples were collected at baseline and cycle 2 day 1 (C2D1). Analyses of baseline markers have been presented previously. Changes from baseline to C2D1 were expressed as an L-ratio (LR, log2 of C2D1 divided by baseline measure). LRs dichotomized at 0 were analyzed for potential prognostic and predictive effects on OS and PFS using Cox models while adjusting for confounders (post-hoc optimized cutpoints were used for PLGF, TIMP1, VCAM1, and VEGFR3 due to skew in the distributions of these markers). P-values are not corrected for multiple testing. Results: Baseline and matched C2D1 samples from 446 patients (212 Bev/234 Cet) were available for analysis. Thirteen markers were differentially modulated between arms (p < 0.05). Early increases in CD73 (p = 0.001), ICAM1 (p = 0.022), TIMP1 (p = 0.001), TSP2 (p = 0.024), and VEGFR3 (p = 0.006) were prognostic for shorter OS. Increases in ICAM1 (p = 0.008), TIMP1 (p = 0.042), and TGFB1 (p = 0.039) were prognostic for shorter PFS. Changes in VEGFR3 (pint = 0.097) and TGFBR3 (pint = 0.052) were predictive for OS and PFS, respectively. No other markers were predictive for OS or PFS (p < 0.1). Conclusions: Changes in circulating plasma protein biomarkers observed in patients enrolled in CALGB/SWOG 80405 were both prognostic and predictive for OS and PFS and warrant further study. Such changes could provide valuable information and help guide treatment decisions. Support: U10CA180821, U10CA180882, U10CA180888, U10CA180830; ClinicalTrials.gov: NCT00265850. [Table: see text]

Marine omega‐3 polyunsaturated fatty acids (MO3PUFAs) have anticancer properties and may improve colon cancer survival. However, it remains unknown whether the benefit differs by tumor molecular subtype. We examined data from a phase III randomized trial of FOLFOX or FOLFOX + cetuximab among 1,735 stage III colon cancer patients who completed a dietary questionnaire at enrollment. Multivariable hazard ratios and 95% confidence intervals (CIs) were calculated for the association between MO3PUFA and disease‐free survival (DFS) and overall survival according toKRASandBRAFV600Emutations and DNA mismatch repair (MMR) status. Higher MO3PUFA intake was associated with improved 3‐year DFS forKRASwild‐type tumors (77%vs. 73%; HR: 0.84; 95% CI: 0.67–1.05) but notKRAS‐mutant tumors (64%vs. 70%; HR: 1.30; 95% CI: 0.97–1.73;Pinteraction= 0.02). Similar heterogeneity was found by MMR (Pinteraction= 0.14): higher MO3PUFA was associated with better 3‐year DFS for tumors with deficient MMR (72%vs. 67%) but not proficient MMR (72%vs. 72%). No heterogeneity was found byBRAFV600Emutation. Similar findings were obtained for overall survival. In conclusion, we found a suggestive beneficial association between higher MO3PUFA intake and improved survival among stage III colon cancer patients with wild‐typeKRASand deficient MMR. Given the relatively small number of cases with tumor molecular assessments, further studies, preferably through pooled analyses of multiples cohorts, are needed to validate our findings.

TPS4135 Background: Gastric cancer is a prevalent and morbid illness for which new treatment strategies are needed. Peri-operative therapy is a standard approach that is associated with only a 15% improvement in overall survival. Early FDG-PET scanning, performed prior to cycle 2, can distinguish patients (pts) responding to chemotherapy from those who are not. FDG-PET non-responding pts have poorer survival. This study addresses the question of salvage therapy in pts who are PET non-responders. Specifically, does salvage chemotherapy with docetaxel /irinotecan improve pt survival in FDG-PET-nonresponding pts with locally advanced gastric cancer. Methods: This is a multicenter, cooperative group, NCI supported, randomized phase II study of salvage chemotherapy + surgery versus surgery and post-operative chemoradiotherapy in pts who are FDG-PET non-responders (defined as a decrease in SUVmaxof the primary tumor of less than 35%). A total of 176 pts with locally advanced, resectable gastric cancer who were FDG-PET non-responders to cycle 1 of platinum/capecitabine based chemotherapy will be randomized in a 1:1 manner to receive either (Arm A) surgery followed by fluoropyrimidine-sensitized radiotherapy (4500 cGy), or (Arm B) salvage chemotherapy with docetaxel / irinotecan (DI) for 2 cycles followed by standard resection and 3 cycles DI post-operatively. DI is administered as D 30 mg/m2, I 50 mg/m2 given on D1, D8 of a 21 day cycle. 416 pts will be screened to yield 162 non-responders (81 FDG-PET non-responders per treatment group). With expected 120 events, the study will have 80% power to detect a hazard ratio of 0.625 for improved survival at the one-sided significant level of 0.15. Pts will be required to provide tissue at the time of resection, as well as whole blood prior to resection for correlative studies associated with platinum sensitivity, FDG avidity, and prognostic markers. This study is available through all cooperative groups (SWOG, ACRIN/ECOG, Alliance, and NRG) and the National Clinical Trials Network. Enrollment began in November 2015. Support: U10CA180821, U10CA180882; Clinical Trial Information: NCT02485834 .

TPS4151 Background: Borderline resectable pancreatic cancers infiltrate into adjacent vascular structures to an extent that makes an R0 resection unlikely when pancreatectomy is performed de novo. In a pilot study, Alliance for Clinical Trials in Oncology Trial A021101, the median survival of patients who received chemotherapy and radiation prior to anticipated pancreatectomy was 22 months, and an R0 resection was achieved in 64% of operations. However, the individual contributions of preoperative chemotherapy and radiation therapy are poorly defined.This study, Alliance for Clinical Oncology Trial A021501, will help define a standard preoperative treatment regimen for borderline resectable pancreatic cancer and position the superior arm for further evaluation in future phase III trials. Methods: In this recently activated randomized phase II trial, 134 patients with a biopsy-confirmed pancreatic ductal adenocarcinoma that meets centrally-reviewed radiographic criteria for borderline resectable disease are randomized to receive either 8 cycles of modified FOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 for 4 cycles) or to 7 cycles of modified FOLFIRINOX followed by stereotactic body radiation therapy (33-40 Gy in 5 fractions). Patients without evidence of disease progression following preoperative therapy undergo pancreatectomy and subsequently receive 4 cycles of postoperative modified FOLFOX6 (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 for 4 cycles). The primary endpoint is the 18-month overall survival rate of patients enrolled into each of the two treatment arms. An interim analysis of the R0 resection rate within each arm will be conducted to assess treatment futility after accrual of 30 patients. Secondary endpoints include rates of margin-negative resection and event-free survival. The trial is activated nationwide and eligible to be opened for accrual at any National Clinical Trials Network cooperative group member site. Clinical trial information: NCT02839343.

TPS3630 Background: In metastatic colorectal cancer with deficient DNA mismatch repair (MMR), anti-PD-1 antibody monotherapy produced high tumor response rates and extended progression-free survival compared to lack of benefit for proficient MMR tumors (Le, M, et al, NEJM 2016). We propose a phase III randomized trial to determine if the addition of the anti-PD-L1 antibody, atezolizumab (Genentech™), to adjuvant FOLFOX can improve patient disease-free survival (DFS) vs FOLFOX alone in patients with stage III colon cancers with dMMR or microsatellite instability (MSI). By blocking the PD-1/PD-L1 interaction, atezolizumab may activate T cells, thereby, restoring their ability to detect and attack tumor cells. Limited data suggest that FOLFOX may increase intratumoral cytotoxic CD8+ T cells that may serve as ‘immune priming.’ Methods: Patients with curatively resected stage III colon carcinomas with evidence of dMMR or MSI will be randomized to modified FOLFOX6 for 6 months (12 cycles) alone or combined with atezolizumab (840 mg IV q2 wk) continued as monotherapy for an additional 6 months (total duration of 12 months). Patients will be stratified by T, N stage and tumor sidedness. Local testing for MSI or MMR proteins is allowed. Atezolizumab must begin by/with cycle 2. The targeted accrual goal of 700 patients provides 90% power to detect an effect size expressed as hazard ratio of 0.6 for the primary endpoint DFS at two-sided alpha of 0.05. Interim analyses are planned at 50% and 75% of events. Secondary endpoints include overall survival, treatment tolerability, and quality of life. This study will be conducted by the Alliance for Clinical Trials in Oncology. The protocol has been approved by NCI CTEP and is expected to be activated in mid 2017. Clinical trial information: NCT02912559.