Behrens, Robert J.

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.

453 Background: A 12-gene assay (Oncotype DX Colon Cancer) has been clinically validated as a predictor of recurrence risk in stage 2 colon cancer patients following surgery. We conducted the first prospective study to characterize the impact of Recurrence Score results on medical oncologists’ recommendations regarding adjuvant chemotherapy in T3, Mismatch Repair-proficient (MMR-P) stage 2 colon cancer patients. Methods: Consecutive patients with resected stage 2A colon cancer who were candidates for adjuvant chemotherapy were consented and enrolled by 105 medical oncologists from 17 sites in the Mayo Clinic Cancer Research Consortium. Each patient’s tumor specimen was assessed by the Recurrence Score test (quantitative RT-PCR) and MMR (IHC). Prior to and after receiving these results, physicians completed surveys indicating their planned treatments given hypothetical or known MMR results, recorded as Observation (Obs), 5FU-based chemotherapy (5FU), or 5FU + Oxaliplatin (Oxal). Change in treatment recommendation intensity from baseline to follow-up was defined as: increased if change from Obs to 5FU +/- Oxal or from 5FU to 5FU+Oxal, decreased if change from 5FU + Oxal to 5FU or Obs, or from 5FU to Obs, or no change. Results: 187 of 221 patients enrolled were evaluable including 141 who were MMR-P (avg age 63, 65% ECOG PS 0, med tumor size 5 cm, 11% high grade, 91% with 12+ nodes examined). In the primary analysis treatment recommendations changed for 63 (45%) of 141 MMR-P patients, with intensity decreasing for 47 (33%) and increasing for 16 (11%). Recommendations for chemotherapy (5-FU +/- Oxal) decreased from 73 (52%) patients pre-assay to 42 (30%) post-assay. Increased treatment intensity was more likely at higher Recurrence Score values and decreased intensity at lower Recurrence Score values (p=0.011), and any change was more likely when MMR status was unknown at baseline (p = 0.041). Conclusions: In this prospective study, quantitative recurrence risk information provided by the Recurrence Score test was associated with treatment recommendation changes for 45% of T3 MMR-P stage II colon cancer patients. Use of the 12-gene assay may lead to overall reductions in chemotherapy.

391 Background: Prior economic analysis of a 12-gene assay (Oncotype DX), compared with patterns of care reported in the NCCN database of patients with stage II, T3, DNA mismatch repair proficient (MMR-P) colon cancer, predicted that the assay would save medical costs and improve patient well-being (Hornberger et al., Value Health, 2012). This study assessed the validity of those findings with actual adjuvant chemotherapy (aCT) recommendations. Methods: Outcomes and costs were estimated for patients with stage II, T3, MMR-P colon cancer using a Markov model. A study of 141 patients from 17 sites in the Mayo Clinic Cancer Research Consortium collected data on aCT recommended before and after knowledge of the 12-gene assay results (Srivastava et al. abstract). Quality-adjusted life years (QALY) and medical resource use after recurrence were computed using guideline-validated state-transition probability estimation methods. Risk of progression and incidence of adverse events with different aCT regimens were based on published literature. Drug and administration costs for aCT were obtained from 2012 Medicare fee schedules. One-way sensitivity analyses were conducted to evaluate parameter influence on economic impact. Results: After receiving the 12-gene assay results, physician recommendations in favor of aCT decreased 22% (95% CI 11%-32%; McNemar test p<0.001) from 73 (52%) to 42 (30%) patients. Oxaliplatin aCT and 5-FU monotherapy recommendations each declined 11%. Average aCT costs decreased $5,738 for drugs, $668 for administration, and $3,268 for adverse events management. Overall, average total direct medical costs decreased $4,203. The net effect on average patient well-being was a gain of 0.083 QALYs. Total medical costs are most influenced by change in aCT recommendations, 5-FU monotherapy efficacy, and oxaliplatin drug acquisition cost. Savings are expected to persist even if the cost of oxaliplatin dropped by >75% due to generic substitution. Conclusions: The 12-gene assayhas been shown to alter aCT recommendations for patients with stage II, T3, MMR-P colon cancer. This study provides real-world confirmation that these changes in aCT reduce direct medical costs and improve patient well-being.

271 Background: Epidermal growth factor inhibitors show some benefit in the treatment of advanced pancreatic cancer. A trial to evaluate the incorporation of Pmab into a conventional multimodality regimen and continuation as maintenance therapy was conducted in pts with LA disease. Methods: Pts with ECOG PS 0-1, preserved organ function and tumor encompassed within standard radiation fields were eligible. Pmab 6 mg/kg on days 1, 15, 29 and continuous infusion 5-FU 225 mg/m2/d or capecitabine 825 mg/m2 were given with RT. Pts then received weekly gemcitabine 1000 mg/m2 and Pmab on days 1, 15 for three 4-week cycles. Maintenance Pmab was then continued for additional 6 months. RT consisted of 45 Gy to the tumor and regional nodes with a 5.4 Gy boost using conformal techniques. Primary endpoint of one-year survival (OS) with secondary endpoints progression-free survival (PFS), confirmed tumor response, and adverse events (at least possibly related) are reported. Results: 51 pts (23 M: 28 F) were enrolled with a median age of 65 (range: 43-84). Twenty-two pts (43%) received at least 1 cycle of post-chemo-RT, while 29 patients only received chemo-RT. All 51 pts have ended treatment with pts going off study because of: progression (39%), adverse events (27%), refusal (25%), and other reasons (8%). Frequently occurring maximum grade 3/4 AEs across the entire treatment course (chemo-RT + post-chemo-RT chemo) are shown below. With a median follow-up of 12.3 months, survival at 12 months is 50.2% (95% CI: 37.9-66.5%), median survival 12.1 mos (95% CI: 6.8-15.9) and median PFS 7.4 mos (95% CI: 3.7-8.6). Confirmed response rate was 5.9% (1-CR, 2-PR). Conclusions: The addition of Pmab to a conventional chemo-RT regimen provides benefit in terms of median survival. This is similar to reports of other EGFR inhibitors in LA disease. Adverse events, especially during the chemo-RT portion, were considerable and affected administration of subsequent systemic maintenance therapy. [Table: see text]

Abstract Purpose. The Oncotype DX colon cancer assay is a clinically validated predictor of recurrence risk in stage II colon cancer patients. This prospective study evaluated the impact of recurrence score (RS) results on physician recommendations regarding adjuvant chemotherapy in T3, mismatch repair-proficient (MMR-P) stage II colon cancer patients. Patients and Methods. Stage IIA colon cancer patients were enrolled in 17 centers. Patient tumor specimens were assessed by the RS test (quantitative reverse transcription-polymerase chain reaction) and mismatch repair (immunohistochemistry). For each patient, the physician's recommended postoperative treatment plan of observation, fluoropyrimidine monotherapy, or combination therapy with oxaliplatin was recorded before and after the RS and mismatch repair results were provided. Results. Of 221 enrolled patients, 141 patients had T3 MMR-P tumors and were eligible for the primary analysis. Treatment recommendations changed for 63 (45%; 95% confidence interval: 36%–53%) of these 141 T3 MMR-P patients, with intensity decreasing for 47 (33%) and increasing for 16 (11%). Recommendations for chemotherapy decreased from 73 patients (52%) to 42 (30%), following review of RS results by physician and patient. Increased treatment intensity was more often observed at higher RS values, and decreased intensity was observed at lower values (p = .011). Conclusion. Compared with traditional clinicopathological assessment, incorporation of the RS result into clinical decision making was associated with treatment recommendation changes for 45% of T3 MMR-P stage II colon cancer patients in this prospective multicenter study. Use of the RS assay may lead to overall reduction in adjuvant chemotherapy use in this subgroup of stage II colon cancer patients.

BACKGROUNDChemotherapy‐induced peripheral neuropathy (CIPN) is a significant side effect of taxane and platinum‐based chemotherapy. Several studies have supported the potential benefit of glutathione for the prevention of platinum‐induced CIPN. The current trial was designed to determine whether glutathione would prevent CIPN as a result of carboplatin/paclitaxel therapy.METHODSIn total, 185 patients who received treatment with paclitaxel and carboplatin were accrued between December 4, 2009 and December 19, 2011. Patients were randomized to receive either placebo (n = 91) or 1.5 g/m2 glutathione (n = 94) over 15 minutes immediately before chemotherapy. CIPN was assessed using the European Organization for Research and Treatment of Cancer Quality‐of‐Life (EORTC‐QLQ) 20‐item, CIPN‐specific (CIPN20) sensory subscale and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 4.0.RESULTSThere were no statistically significant differences between the 2 study arms with regard to: 1) peripheral neurotoxicity, as assessed using both the EORTC‐QLQ‐CIPN20 (P = .21) and the CTCAE scales (P = .449 for grade ≥2 neurotoxicity; P = .039 for time to development of grade ≥2 neuropathy, in favor of the placebo); 2) the degree of paclitaxel acute pain syndrome (P = .30 for patients who received paclitaxel every 3‐4 weeks and P = .002, in favor of the placebo, for patients who received weekly paclitaxel); 3) the time to disease progression (P = .63); or 4) apparent toxicities. Subgroup analyses did not reveal any evidence of benefit in any particular subgroup.CONCLUSIONSThe results from this study do not support the use of glutathione for the prevention of paclitaxel/carboplatin‐induced CIPN. Cancer 2014;120:1890–1897. © 2014 American Cancer Society.