NRG-GI004/SWOG-S1610: Colorectal Cancer Metastatic dMMR Immuno-Therapy (COMMIT) study—A randomized phase III study of atezolizumab (atezo) monotherapy versus mFOLFOX6/bevacizumab/atezo in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) or microsatellite instability high (MSI-H) metastatic colorectal cancer (mCRC)

TPS258

Background: Despite the superiority in progression-free survival (PFS) of inhibition of programmed cell death-1 (PD-1) pathway in dMMR/MSI-H as compared to chemotherapy with either anti-vascular endothelial growth factor receptor (VEGFr) or anti-epithelial growth factor receptor (EGFr) antibodies in mCRC, more pts had progressive disease as the best response in the anti-PD1 monotherapy arm (29.4% v 12.3%) with mean PFS of 13.7 mos, with ~45% of pts in the immunotherapy arm progressed at 12 mos (KEYNOTE 177). We hypothesize that dMMR/MSI-H mCRC pts may be more effectively treated with the combination of PD-1 pathway blockade and mFOLFOX6/bevacizumab (bev) rather than with anti-PD-1 therapy (atezo) alone. Preclinical work demonstrated synergistic effects between anti-PD-1/anti-VEGF and between oxaliplatin/anti-PD-1 in murine CRC models and phase II data, which showed activity of anti-PD-1/anti-VEGF in chemotherapy refractory colon cancer. A recent randomized trial subgroup analysis of 8 pts with dMMR metastatic colon cancer treated with FOLFOXIRI+bev+atezo, with the first patient having progression ~16 mos (AtezoTRIBE). Additionally, in other solid tumor malignancies, anti-PD1 plus anti-VEGFr (i.e., HCC and RCC) as well as anti-PD1 plus chemotherapy (i.e., gastric and esophageal cancers) combinations are standard first-line treatments. Methods: The redesigned COMMIT study was reactivated on 1/29/2021 as a two-arm prospective phase III open-label trial randomizing (1:1) mCRC dMMR/MSI-H to atezo monotherapy v mFOLFOX6/bev+atezo combination. Assuming our control arm, atezo monotherapy (48% PFS at 24 mos as assessed by site investigator), we have 80% power to detect a hazard ratio of 0.6 (equivalent to 64.4% PFS at 24 mos) with alpha 0.025 one-sided. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Secondary endpoints include OS, objective response rate, safety profile, disease control rate, and duration of response. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2) or MSI-H by local CLIA-certified PCR or NGS panel; and measurable disease per RECIST. Enrollment actively continues to the target accrual of 211 patients randomized between the two immunotherapy arms. Clinical trial: NCT02997228. Support: U10CA180868, -180822, -180888, UG1CA189867, U24CA196067; Genentech, Inc. Clinical trial information: NCT05080673 .

A study of pembrolizumab (pembro) in combination with Y90 radioembolization in patients (pts) with poor prognosis hepatocellular carcinoma (HCC)

534

Background: HCC is an aggressive cancer as a sequela of cirrhosis. For pts with no extrahepatic metastases and well-compensated liver function, Y90 radioembolization is a therapeutic option. However, high-risk patients with macrovascular invasion (MVI) or multifocal disease treated with Y90 alone have a median time to progression of less than 6 months. Pembro is an anti-PD-1 monoclonal antibody that is FDA-approved for advanced HCC pts who have progressed on sorafenib. Given pre-clinical evidence that radiotherapy can increase PD-L1 expression and enhance tumoral T-cell recruitment, this study explored the safety and efficacy of pembro with Y90 radioembolization in pts with poor prognosis HCC. Methods: GI15-225 was a multi-center, single-arm study in poor prognosis HCC pts, defined as having multifocal disease, MVI, or diffuse disease. Eligible pts had disease amenable to 1-2 embolization procedures, Child Pugh A/B7 cirrhosis, no prior Y90 treatment; previous locoregional therapy and resection were allowed. Pts with extrahepatic mets were excluded. Treatment consisted of pembro 200mg every 3 weeks with standard dose Y90 performed 7-10 days after first dose of pembro. The primary objective was to estimate the progression free survival (PFS) rate at 6 months per RECIST 1.1; secondary endpoints included safety, time to progression (TTP), overall response rate (ORR) and overall survival (OS). Imaging was performed every 9 weeks. Results: A total of 29 pts were enrolled 10/23/17 to 11/24/20. Median age 66 years, 89% male, 7% Child’s Pugh B, and 47% with MVI. 27 pts were evaluable for primary endpoint having received Y90 and at least one dose of pembro. The 6-month PFS rate was 57.7% (95% CI 36.9 – 76.6). Median PFS was 9.95 months (95% CI 4.14 – 15.24) and median TTP was 9.95 months (95% 4.14 – 18.56). Median OS was 27.30 months (95% CI 10.15 – 39.52). The ORR was 30.8% (Table). Three patients (11%) have ongoing treatment response with one of these patients off treatment for 16 weeks. Most common treatment related grade 3-4 AEs were decreased lymphocytes (n=5), increased bilirubin (n=3), hypertension (n=3), ascites (n=2), and AST/ALT elevation (n=2). One pt experienced grade 5 toxicity of hepatic failure after receiving one dose of pembro and Y90 that was attributed to Y90 and disease progression. Conclusions: Concurrent administration of pembro with Y90 in pts with poor prognosis HCC demonstrated promising clinical activity with median TTP and OS that exceeds historical data with three patients having ongoing response. With a 6-month PFS rate of 57.7%, median OS of 27.30 months and an acceptable toxicity profile, the combination of checkpoint blockade and Y90 deserves further evaluation in larger randomized clinical trials. Clinical trial information: NCT03099564 .[Table: see text]

Myopenia and mechanisms of toxicity in older adults with colorectal cancer (CRC): The M&M study (WF-1806)

TPS3640

Background: CRC is the 2nd most common cause of cancer death in the US, and nearly 60% of CRC cases occur among older adults. There is a critical unmet need to understand the underlying cause(s) of observed variability in chemotherapy toxicity (chemotoxicity) outcomes to minimize adverse outcomes and appropriately personalize therapy for older adults. Low muscle mass, known as myopenia, is prevalent in older adults with CRC (̃60%) and is associated with chemotoxicity and decreased overall survival (OS). However, little is known about trajectories of myopenia and underlying mechanisms of increased toxicities and decreased survival in myopenic patients. We address these gaps in a prospective cohort study, with the central goal of examining the role of myopenia in chemotoxicity in older adults with metastatic CRC undergoing 5-Fluouracil (5FU) based chemotherapy, and to explore the mediating influence of germline genetic variants and pharmacokinetics (PKs) in the association between myopenia and chemotherapy toxicity. Methods: This prospective cohort study is accruing through the Wake Forest NCI Community Oncology Research Program Research Base (WF NCORP) and funded by the NCI grants 2UG1CA189824 and K08CA234225. The study examines the impact of myopenia on chemotoxicity and OS in older adults with newly diagnosed metastatic CRC planning to receive systemic 5FU-based chemotherapy (either as monotherapy or in combination with oxaliplatin and/or irinotecan +/- biologics) (NCT03998202). All patients undergo the Cancer & Aging Resilience Evaluation and Life-Space Evaluation at baseline, 3 and 6 months. Standard of care Computed Tomography (CT) images will be obtained to assess muscle measures (skeletal muscle area/density) at the L3 cross-section. The primary outcome is grades 3 to 5 chemotoxicity measured up to 6 months after initiation of chemotherapy using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 5.0. We will assess the association of baseline myopenia and trajectories of myopenia with severe chemotherapy toxicities. Secondary outcome measures include OS at 1 year and chemotoxicities using the Patient Reported Outcomes (PRO) version of the CTCAE. The study also explores the mediating/moderating influence of genetic variation and altered PKs (n = 60) in the association between myopenia and chemotherapy toxicity. To date, the study has accrued 73 of the 300 targeted patients from 110 NCORP practices. Clinical trial information: NCT03998202.

Comparative effectiveness of trimodal therapy versus definitive chemoradiation in older adults with locally advanced esophageal cancer

e16093

Background: The comparative effectiveness of trimodal therapy versus definitive chemoradiation for older adults with locally advanced esophageal cancer is uncertain. Only two randomized trials have considered this comparison, and older adults and patients with adenocarcinomas were underrepresented. Older adults have greater frailty and may not benefit from adding surgery to chemoradiation. Methods: A cohort of adults 66-79 years of age diagnosed with incident locally advanced esophageal cancer between 2004 and 2017 was identified using the Surveillance Epidemiology and End Results-Medicare database. We used observational data to emulate a hypothetical trial comparing trimodal therapy and definitive chemoradiation. Outcomes included overall mortality, esophageal cancer-specific mortality, functional adverse events, and healthy days at home. Results: The study population included 1,240 individuals with adenocarcinomas and 661 with squamous cell carcinomas. Amongst older adults diagnosed with adenocarcinomas, the five-year risk of mortality was 73.4% (95% CI: 69.1–77.4) in the trimodal therapy group and 83.8% (95% CI: 78.6–87.2) in the definitive chemoradiation group (RR= 0.88, 95% CI: 0.82–0.95). Amongst older adults diagnosed with squamous cell carcinomas, the five-year risk of mortality was 62.6% (95% CI: 50.9–73.5) in the trimodal therapy group and 72.3% (95% CI: 67.6–76.3) in the definitive chemoradiation group (RR= 0.87, 95% CI: 0.70–1.01). Results for all outcomes are presented in the Table. Conclusions: Trimodal therapy was associated with lower mortality than definitive chemoradiation. The benefits were smaller than suggested by prior observational studies. These findings can be used with clinical expertise and patient preferences to enhance shared decision-making. [Table: see text]

Colorectal cancer metastatic dMMR immuno-therapy (COMMIT) study: A randomized phase III study of atezolizumab (atezo) monotherapy versus mFOLFOX6/bevacizumab/atezo in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) or microsatellite instability high (MSI-H) metastatic colorectal cancer (mCRC)—NRG-GI004/SWOG-S1610

TPS3647

Background: Despite the superiority in progression-free survival (PFS) of inhibition of programmed cell death-1 (PD-1) pathway in dMMR/MSI-H as compared to chemotherapy with either anti-vascular endothelial growth factor receptor (VEGFr) or anti-epithelial growth factor receptor (EGFr) antibodies in mCRC, more pts had progressive disease as the best response in the anti-PD1 monotherapy arm (29.4% v 12.3%) with mean PFS of 13.7 mos, with ̃45% of pts in the IO arm progressed at 12 mos ( N Engl J Med 2020; 383:2207). We hypothesize that the dMMR/MSI-H mCRC pts may be more effectively treated with the combination of PD-1 pathway blockade and mFOLFOX6/bevacizumab (bev) rather than with anti-PD-1 therapy (atezo) alone. Preclinical work demonstrated synergistic effects between anti-PD-1/anti-VEGF and between oxaliplatin/anti-PD-1 in murine CRC models and phase II data, which showed activity of anti-PD-1/anti-VEGF in chemotherapy refractory colon cancer. A recent randomized trial subgroup analyses of 8 pts with dMMR metastatic colon cancer treated with FOLFOXIRI+bev+atezo, with the first patient having progression ̃16 mos ( ESMO 2021, Abstt LBA20). Additionally, in other solid tumor malignancies, anti-PD1 plus anti-VEGFr (i.e., HCC and RCC) as well as anti-PD1 plus chemotherapy (i.e., gastric and esophageal cancers) combinations are standard first-line treatments. Methods: The redesigned COMMIT study was reactivated on 1/29/2021 as a two-arm prospective phase III open-label trial randomizing (1:1) mCRC dMMR/MSI-H to atezo monotherapy v mFOLFOX6/bev+atezo combination. Assuming our control arm, atezo monotherapy (48% PFS at 24 mos as assessed by site investigator), we have 80% power to detect a hazard ratio of 0.6 (equivalent to 64.4% PFS at 24 mos) with alpha 0.025 one-sided. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Secondary endpoints include OS, objective response rate, safety profile, disease control rate, and duration of response. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2) or MSI-H by local CLIA-certified PCR or NGS panel; and measurable disease per RECIST. Enrollment actively continues to the target accrual of 211 patients randomized between the two immunotherapy arms. Support: U10CA180868, -180822, -180888, UG1CA189867, U24CA196067. Clinical trial information: NCT02997228.

Phase II single-arm study of palbociclib and cetuximab rechallenge in KRAS/NRAS/BRAF wild-type (KRAS WT) metastatic colorectal cancer (mCRC) patients (pts)

88

Background: Cetuximab is a monoclonal antibody (mAb) targeting the epidermal growth factor receptor (EGFR) and is given alone or in combination with chemotherapy in the 60% of mCRC that are KRAS WT. Unfortunately, resistance inevitably develops, which may be related to downstream upregulation of the extracellular-signal-regulated kinase (ERK) pathway. Rechallenge with anti-EGFR mAb may be effective in patients previously benefiting from anti-EGFR therapy, but median progression-free survival is < 4 months, indicating need for novel more effective combinations for rechallenge. Co-inhibition of EGFR and downstream cyclin-dependent kinases 4/6 (CDK4/6) may overcome ERK pathway reactivation. We hypothesized that the addition of the CDK4/6 inhibitor palbociclib to cetuximab would be effective for anti-EGFR rechallenge in KRAS-WT mCRC. Methods: LCCC1717 was a multicenter, single-arm, Simon’s two stage phase II study of cetuximab and palbociclib in KRAS WT mCRC treated with ≥2 prior regimens (NCT03446157). Eligible pts were enrolled to one of two cohorts depending on previous anti-EGFR mAb therapy; we report here on cohort B, which enrolled pts who had disease control for at least 4 months with anti-EGFR therapy. Cohort B was designed to initially enroll 10 evaluable pts; if ≥ 4 pts had disease control at least 4 months, then 11 more pts would be enrolled. Treatment included cetuximab 400 mg/m2 followed by 250 mg/m2 weekly, plus palbociclib 125 mg daily on days 1-21 of a 28-day cycle until progression, toxicity, or withdrawal. Primary endpoint was disease control rate (DCR) at 4 months by RECIST 1.1. Secondary endpoints were overall response rate (ORR), progression free survival (PFS), and overall survival (OS). Results: In cohort B, 10 evaluable pts were enrolled from 2/2018-8/2020 (1 additional pt withdrew after an infusion reaction with first dose of cetuximab). Median age 59, 70% male, 90% left-sided primary. The 4-mo DCR was 2/10 (20%; 95% CI 5-52%). Given this, enrollment in this cohort was halted after first stage. Median PFS was 1.8 mo (95% CI: 1.7, NE) and median OS was 6.6 mo (95% CI: 3.6, NE). No pts had a complete or partial response; 3 pts (30%) had stable disease (SD), including 1 patient with SD for 24.7 months. The regimen was well tolerated; most common treatment-related grade 3-4 adverse events were lymphopenia (27%) and leukopenia (18%). While 55% of pts had acneiform rash, none were grade 3-4. Conclusions: Selection of patients for anti-EGFR rechallenge using clinical criteria alone was insufficient to identify pts likely to respond to palbociclib + cetuximab rechallenge. This emphasizes the need for screening using circulating tumor (ct) DNA of known resistance mutations to select pts for anti-EGFR rechallenge approaches. Translational work assessing ctDNA in this study is planned. Cohort A with anti-EGFR naïve patients continues enrollment. Clinical trial information: NCT03446157.

NRG-GI004/SWOG-S1610: Colorectal cancer metastatic dMMR immuno-therapy (COMMIT) study—A randomized phase III study of atezolizumab (atezo) monotherapy versus mFOLFOX6/bevacizumab/atezo in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) or microsatellite instability high (MSI-H) metastatic colorectal cancer (mCRC)

TPS232

Background: Despite the superiority in progression-free survival (PFS) of inhibition of programmed cell death-1 (PD-1) pathway in dMMR/MSI-H as compared to chemotherapy with either anti-vascular endothelial growth factor receptor (VEGFr) or anti-epithelial growth factor receptor (EGFr) antibodies in mCRC, more pts had progressive disease as the best response in the anti-PD1 monotherapy arm (29.4% vs. 12.3%) with mean PFS of 13.7 months ( N Engl J Med 2020; 383:2207). We hypothesize that the dMMR/MSI-H mCRC pts may be more effectively treated by the combination of PD-1 pathway blockade and mFOLFOX6/bevacizumab (bev) rather than with anti-PD-1 therapy (atezo) alone. Preclinical work demonstrated synergistic effects between anti-PD-1/anti-VEGF and between oxaliplatin/anti-PD-1 in murine CRC models and phase II data showed activity of anti-PD-1/anti-VEGF in chemotherapy refractory colon cancer. Additionally, in other solid tumor malignancies, anti-PD1 plus anti-VEGFr (i.e., HCC and RCC) as well as anti-PD1 plus chemotherapy (i.e., gastric and esophageal cancers) combinations are standard first-line treatments. Methods: The redesigned COMMIT study was reactivated on 1/29/2021 as a two-arm prospective phase III open-label trial randomizing (1:1) mCRC dMMR/MSI-H (211 pts) to atezo monotherapy versus mFOLFOX6/bev+atezo combination. Assuming our control arm, atezo monotherapy, 48% PFS at 24 months, as assessed by site investigator, we have 80% power to detect a hazard ratio of 0.6 (equivalent to 64.4% PFS at 24 months) with alpha 0.025 one-sided. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Secondary endpoints include OS, objective response rate, safety profile, disease control rate, duration of response, and centrally-reviewed PFS. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2) or MSI-H by local CLIA-certified PCR or NGS panel; and measurable disease per RECIST. Enrollment actively continues to the target accrual of 211 patients randomized between the two immunotherapy arms. Support: U10CA180868, -180822, -180888, UG1CA189867, U24CA196067; Genentech, Inc. Clinical trial information: NCT02997228.

A study of pembrolizumab (pembro) in combination with Y90 radioembolization in patients (pts) with poor prognosis hepatocellular carcinoma (HCC) with preserved liver function

422

Background: HCC is an aggressive cancer that is challenging to treat due to the concomitant diagnosis of cirrhosis. For HCC pts with no extrahepatic metastases and well-compensated liver function, Y90 radioembolization is a standard therapy. In observational studies, pts with multifocal disease or portal vein thrombosis (PVT) had worse outcomes with short disease control intervals of less than 6 months. Pembro is an anti-PD-1 monoclonal antibody that is FDA-approved for advanced HCC pts who have progressed on sorafenib. Given pre-clinical evidence that radiotherapy can increase PD-L1 expression and enhance tumoral T-cell recruitment, this study explored the safety and efficacy of pembro with Y90 radioembolization in pts with poor prognosis HCC. Methods: GI15-225 was a multi-center, single-arm study in poor prognosis HCC pts, defined as having multifocal disease, branch PVT and/or diffuse disease (NCT03099564). Pts with extrahepatic metastatic disease were excluded; eligible pts had disease amenable to 1-2 embolization procedures. Pts had Child Pugh A/B7 cirrhosis with no prior Y90 treatment; previous TAE, TACE, SBRT, liver resection or ablation were allowed. Treatment consisted of pembro 200mg every 3 weeks with Y90 radioembolization performed 7-10 days after first dose of pembro. The primary objective was to estimate the progression free survival (PFS) rate at 6 months per RECIST 1.1; secondary endpoints included safety, time to progression (TTP), overall response rate (ORR) and overall survival (OS). Results: A total of 29 pts were enrolled 10/23/17 to 11/24/20. Median age 66 years, 89% male, and 47% with PVT. 26 pts were evaluable for primary endpoint having received Y90 and at least one dose of pembro. The 6 month PFS rate was 57.7% (95% CI 36.9 – 76.6). Median PFS was 8.6 months (95% CI 4.1 – 13.4) and median TTP was 9.9 months (95% 4.2 – NR). Median OS was 22 months (95% CI 8.4 – 32.0). The ORR was 27% (Table). Most common treatment related grade 3-4 AEs were decreased lymphocytes (18%), increased bilirubin (11%), hypertension (11%), ascites (7%), and AST/ALT elevation (7%). One pt experienced grade 5 toxicity of hepatic failure after receiving one dose of pembro and Y90 that was attributed to Y90 and disease progression. Conclusions: Concurrent administration of pembro with Y90 radioembolization in pts with poor prognosis HCC demonstrated promising clinical activity with median TTP and OS that exceeds historical data reported in similar patients treated with Y90 alone. With a 6 month PFS rate of 57.7% and a favorable toxicity profile, the combination of immune checkpoint blockade and Y90 deserves further evaluation in larger randomized clinical trials. Clinical trial information: NCT03099564. [Table: see text]

Integrated approach to collecting patient reported toxicities in a colorectal cancer trial

51

Background: Understanding the toxicities experienced by patients treated with advanced CRC is critical when considering appropriate dose modifications, standard drug dosing, and quality of life. A workflow that makes available Patient Reported Outcomes-Common Terminology Criteria for Adverse Events (PRO-CTCAE) to clinicians to inform overall toxicity assessment should be easy to use and focus on clinically relevant issues. The value of a system that not only collects PRO-CTCAE but integrates it with clinician grading to inform overall symptomatic adverse event assessment during clinical trials is unclear. Methods: Patients were simultaneously enrolled in a phase II multi-center clinical trial that evaluated a genotype-guided dosing strategy for irinotecan by prospectively analyzing efficacy in 100 mCRC patients receiving FOLFIRI (5-fluorouracil, leucovorin, irinotecan) and bevacizumab. On day 1 and day 15 of each cycle patients provided PRO-CTCAE responses on 13 symptoms (26 questions) which were made available to clinicians at the time of their toxicity assessment. Descriptive statistics were used to summarize patient demographic and clinical characteristics. Concordance was defined as both patient and clinician giving the same response (both positive or both negative). Results: 100 patients participated in the study, of which 48% were female and 83% White. Overall, 96% of both patients and providers completed at least 80% of PRO-CTCAE forms available to them, demonstrating the feasibility of an integrated workflow for patient-clinician toxicity grading. Across all symptoms, concordance was high (73%) for the patient and provider reporting severe symptoms. 39% of patient-provider pairs reported at least 1 severe symptom and 34% of pairs never reported a severe symptom. In 23% of pairs the patient reported a severe symptom and the provider never did, and in 3% of pairs, the provider reported a severe symptom, but the patient never did. On the symptom level, the concordance was highest (>90%) for dysphagia and vomiting, and lowest (74-82%) for abdominal pain, fatigue, and pain. 52 patients required dose decreases, with the first decrease most often due to hematologic toxicity (80%). In 46% of cases the patient reported at least one severe toxicity prior to or on the same day as the dose decrease, compared to 19% of cases where the provider reported at least severe toxicity prior to or on the same day as the dose decrease. Conclusions: A workflow that brings patient-reported toxicity to clinicians at the time of clinical toxicity rating is feasible. Nevertheless, discordance continues to exist between patient-reported and clinician-reported toxicity ratings, consistent with prior research. Further research could formally compare concordance when using an integrated vs a non-integrated toxicity rating workflow and could ascertain the reasons for continued discordance within an integrated workflow.

Influence of social determinants of health on oncology care quality rankings

139

Background: Adjustment for social determinants of health (SDOH) when assessing provider care quality remains limited. The Oncology Care Model (OCM), for example, includes low-income status/dual eligibility (LIS/DE) as a part of the risk adjustment model for some quality measures, but does not account for any social risk variables in the hospice measure. No measures within the OCM account for additional social risk factors beyond LIS/DE such as patients’ race, rurality, and social deprivation. Additional SDOH adjustment could increase the accuracy of provider quality rankings and better align performance-based payments with true provider quality. Methods: North Carolina Medicare claims from 2015-2017 comprised the data for this study. The year 2015 was used to establish baseline covariates. Episodes were attributed to physician practices’ Tax Identification Number (TIN), lasted 6 months, and were divided into performance years beginning 1/1/2016 and 7/1/2016. Three measures were used: 1) all-cause hospital admissions; 2) all-cause emergency department visits or observation stays; and 3) admission to hospice for 3 days or more among patients who died. SDOH included patient-level race as well as county-level rurality and social deprivation, measured using the social deprivation index (SDI). TIN-level scores with and without expanded SDOH variables were divided into quintiles and compared descriptively as well as using weighted kappa statistics. Results: No SDOH were significantly associated with the hospitalization outcome (P = 0.118-0.944). For the ED measure, Black patients and rural patients were significantly more likely to have an ED visit or observation stay during an episode than white patients and urban patients (P < 0.0001). For the hospice measure, greater SDI values were associated with less hospice use (P < 0.05). Accordingly, including SDOH variables for ED visit/observation stay and hospice measures had a greater impact on TIN rankings than for the hospitalization measure (Table). Conclusions: Because quintile rankings in determine potential shared savings under models like the OCM, differences in rankings due to additional SDOH variables could have a meaningful impact on TIN-level revenue. Additional work is needed to expand the scope of patient-level SDOH variables used for risk adjustment and to explore differences across TINs which contribute to SDOH-sensitive changes in rankings.[Table: see text]

Reliability of claims-based measures used to assess cancer care quality

42

Background: As value-based payment models for cancer care expand, the need for measures which reliably assess the quality of care provided increases. This is especially true for models like the Oncology Care Model (OCM) that rely on quality rankings to determine potential shared savings. Under models like these, unreliable measures may result in arbitrary application of value-based payments. The goal of this project is to evaluate the extent to which measures used within the OCM are reliable indicators of provider performance. Methods: Data for this project came from North Carolina Medicare claims from 2015-2017. Episodes were attributed to physician practices at the tax identification number (TIN) level, lasted 6 months, and were divided into two performance years beginning 1/1/2016 and 7/1/2016. TINs with fewer than 20 attributed patients were excluded. Three claims-based OCM measures were used in this evaluation: 1) proportion of episodes with all-cause hospital admissions; 2) proportion of episodes with all-cause emergency department (ED) visits or observation stays; and 3) proportion of patients that died who were admitted to hospice for 3 days or more. Risk adjustment followed the method described by measure specifications from the OCM. Reliability was calculated as the ratio of between practice variation (e.g. signal) to the sum of between practice variation and within practice variation (e.g. noise). Variance estimates were derived from hierarchical logistic regression models used for risk adjustment. Results: For the hospitalization and ED visit measures, episode counts for years 1 and 2 were 30,746 and 28,430 and TIN counts were 86 and 84, respectively. Hospice use measures had fewer episodes (2,677 and 2,428) and TINs (36 and 33). Across all measures, median reliability scores failed to achieve the recommended 0.7 threshold and only hospice had a median reliability score above 0.5 (Table). Conclusions: These findings suggest claims-based measures included in the OCM may produce imprecise estimates of provider performance and are vulnerable to random variation. Consideration should be given to developing alternative measures which may be more reliable estimates of provider performance and to increasing minimum denominator requirements for existing measures.[Table: see text]

Comparing FOLFOX delivery in trial and real-world populations using longitudinal cumulative dose

1521

Background: Patterns of chemotherapy delivery are likely to differ between trial and real-world populations. Typical measures used to compare these patterns are calculated at treatment completion, potentially missing key differences in the timing and trajectory of delays and dose reductions. We used a new measure, longitudinal cumulative dose (LCD), to compare treatment delivery over time in trial and real-world populations. Methods: We compared chemotherapy delivery in patients with stage II-III colon cancer enrolled in the MOSAIC trial of 5-fluorouracil (5FU) vs oxaliplatin + 5FU (FOLFOX4) to patients treated from 2008-2019 in the US Oncology Network with FOLFOX4, FOLFOX6, or mFOLFOX6. For each patient, we computed oxaliplatin LCD as the cumulative oxaliplatin dose received at a given timepoint (t) divided by the final standard oxaliplatin dose. We then estimated the median and 25th and 75th percentiles for oxaliplatin LCD within each regimen at day 68 (before the standard timing of the 7th dose), 168 (two weeks after the standard end of treatment), and 250. Results: The table shows the number of patients receiving each treatment regimen and the median and interquartile range for oxaliplatin LCD at each time. Higher LCDs in the trial show delivery closer to standard treatment, meaning fewer delays, dose reductions, and discontinuations. Differences between the medians, 25th percentiles, and 75th percentiles of LCD in each regimen were small at day 68 but grew considerably by days 168 and 250. Conclusions: Divergence from the standard dosing schedule was larger in real-world versus trial settings and varied by oxaliplatin regimen. LCD, as a longitudinal measure, showed that differences in delivery between trial and real-world populations grew substantially over time (even after 168 days and the standard end of treatment) possibly as real-world patients experienced more side effects and barriers to treatment than trial participants. These discrepancies in LCD may cause poorer outcomes in real-world settings than expected based on randomized trials.[Table: see text]

Using randomized trial data to estimate effects of complex treatment regimens in real-world patients

e18706

Background: Real-world patients often differ from trial participants in prognostic factors such as age, sex, and cancer substage. New methods combine covariate data from real-world patients (the “target population”) with outcome and covariate data from a trial to estimate treatment effects in the target population that take these differences into account. With some assumptions, these methods can also estimate outcomes under treatment regimens not studied in the trial such as “what if we only gave six cycles of chemotherapy?” or “what if patients all perfectly followed a protocol?” Methods: Data from the MOSAIC trial of 5-fluorouracil (5FU) vs oxaliplatin + 5FU (FOLFOX) were combined with covariate data from a target population of stage III colon cancer patients in the US Oncology Network meeting trial eligibility criteria. We used weighting and G-computation to estimate five-year mortality and treatment-related paresthesia risk in the target population for four regimens: treatment with up to 12 cycles of 5FU, if providers used their discretion on dose reductions and delays (5FU-MD); up to 12 cycles of FOLFOX with similar physician discretion (FOLFOX-MD); up to 6 cycles of FOLFOX, with providers perfectly following a strict and specific protocol of dose reductions and delays (6-cycle FOLFOX-P, “P” for “per protocol”); and up to 12 cycles of FOLFOX, following the same strict protocol (12-cycle FOLFOX-P). Results: Tablepresents five-year all-cause mortality and paresthesia risk under each regimen in the stage III target population estimated from the models built in trial participants. Paresthesia risk increased with cumulative oxaliplatin dose. Estimated 5-year mortality was lowest with 12-cycle FOLFOX-P. Conclusions: In a target population of US Oncology Network patients with stage III colon cancer, strict protocols of 12 cycles of FOLFOX were predicted to improve survival compared to strict 6-cycle FOLFOX regimens or less strict 12-cycle FOLFOX and 5FU regimens at the cost of substantial increases in side effects. While estimates of risk differences in 5-year mortality were imprecise, combining trial and real-world data and then using weights and G-computation allowed estimation of benefits and harms of multiple regimens in a clinically relevant patient population.[Table: see text]

Colorectal Cancer Metastatic dMMR Immuno-Therapy (COMMIT) Study: A randomized phase III study of atezolizumab (atezo) monotherapy versus mFOLFOX6/bevacizumab/atezo in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) or microsatellite instability high (MSI-H) metastatic colorectal cancer (mCRC)—NRG-GI004/SWOG-S1610

TPS3618

Background: The superiority of inhibition of programmed cell death-1 (PD-1) pathway in dMMR/MSI-H over chemotherapy with either anti-vascular endothelial growth factor receptor (VEGFr) or anti- epithelial growth factor receptor (EGFr) antibodies in mCRC has been demonstrated in a phase III trial (N Engl J Med 2020; 383:2207). However, more patients had progressive disease as the best response in the anti-PD1 monotherapy arm (29.4% vs. 12.3%) with mean progression-free survival (PFS) of 13.7 months. Preclinical models have demonstrated synergistic interactions between FOLFOX, anti-VEGF, and anti-PD-1. We hypothesize that the dMMR/MSI-H mCRC patients may be more effectively treated by the combination of PD-1 pathway blockade and mFOLFOX6/bevacizumab (bev) rather than with anti-PD-L1 therapy (atezo) alone. Methods: Initially a three-arm study, the mFOLFOX6/bev arm was closed to new enrollment on 6-4-20 due to emerging data; the redesigned COMMIT trial was reactivated on 1/29/2021 as a prospective phase III open-label trial that randomizes (1:1) mCRC dMMR/MSI-H pts (N=211) to either atezo monotherapy or mFOLFOX6/bev+atezo combination. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Primary endpoint is PFS as assessed by site investigator. Secondary endpoints include overall survival (OS), objective response rate (RECIST v1.1), safety profile, disease control rate, duration of response, and centrally-reviewed PFS. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2) or MSI-H by local CLIA-certified PCR or NGS panel; and measurable disease per RECIST. Clinical trial: NCT02997228. Support: U10CA180868, -180822, -180888, -180819, UG1CA189867, U24CA196067; Genentech, Inc. Clinical trial information: NCT02997228.

NRG-GI004/SWOG-S1610: Colorectal Cancer Metastatic dMMR Immuno-Therapy (COMMIT) Study—A randomized phase III study of atezolizumab (atezo) monotherapy versus mFOLFOX6/bevacizumab/atezo in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) or microsatellite instability high (MSI-H) metastatic colorectal cancer (mCRC)

TPS158

Background: Despite activity of programmed cell death-1 (PD-1) pathway inhibition in dMMR/MSI-H mCRC, approximately one-third of patients demonstrate progressive disease as best response to anti-PD1 monotherapy. Preclinical models have demonstrated synergistic interactions between FOLFOX, anti-VEGF, and anti-PD-1. We hypothesize that the dMMR/MSI-H mCRC subset may be more effectively targeted by the combination of PD-1 pathway blockade and mFOLFOX6/bevacizumab (bev) rather than with anti-PD-1 therapy (atezo) alone. Methods: Initially a three-arm study, the mFOLFOX6/bev arm was closed to new enrollment on 6-4-20 due to emerging data; the redesigned COMMIT is a prospective phase III open-label trial that will randomize (1:1) mCRC dMMR/MSI-H pts (N=211) to either atezo monotherapy or mFOLFOX6/bev+atezo combination. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Primary endpoint is progression-free survival (PFS) as assessed by site investigator. Secondary endpoints include OS, objective response rate, safety profile, disease control rate, duration of response, and centrally-reviewed PFS. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2) or MSI-H by local CLIA-certified PCR or NGS panel; and measurable disease per RECIST. Support: U10CA180868, -180822, -180888, -180819, UG1CA189867, U24CA196067; Genentech, Inc. Clinical trial information: NCT02997228.

Phase II study of ipilimumab, nivolumab, and panitumumab in patients with KRAS/NRAS/BRAF wild-type (WT) microsatellite stable (MSS) metastatic colorectal cancer (mCRC)

7

Background: Panitumumab is a monoclonal antibody (mAb) targeting the epidermal growth factor receptor (EGFR) and is a standard therapy in KRAS/NRAS/BRAF WT mCRC. Preclinical data shows that anti-EGFR therapy causes a tumor-specific adaptive immune response and immunogenic apoptosis, with functional adaptive immunity required to mediate efficacy. However, resistance to anti-EGFR antibody therapy inevitably develops and is associated with increased expression of CTLA-4 and PD-L1. We hypothesized that addition of ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) to panitumumab will increase response rate in patients with KRAS/NRAS/BRAF WT MSS mCRC. Methods: LCCC1632 was a multicenter, single-arm, Simon’s two stage phase II clinical trial with a pre-specified safety run-in of panitumumab, ipilimumab, and nivolumab in KRAS/NRAS/BRAF WT, MSS mCRC (NCT03442569). Eligible patients must have received 1-2 prior lines of therapy and no prior anti-EGFR or immune checkpoint inhibitor therapy. Subjects received ipilimumab 1 mg/kg IV q6wk, nivolumab 240 mg IV q2wk, and panitumumab 6 mg/kg IV q2wk until progression, toxicity, or patient withdrawal. The primary endpoint was response rate at 12 weeks per RECIST 1.1, and key secondary endpoints included progression-free survival and duration of response. Results: A total of 56 subjects were enrolled 3/2018-6/2020. This included the 6-subject safety run-in, with 0/6 dose-limiting toxicities in first 12 weeks. The first stage of the Simon’s two-stage clinical trial (n=32) had sufficient response rate to merit full enrollment. There were 7 unevaluable subjects for the primary endpoint of 12-week response rate. Among 49 evaluable subjects, 12-week response rate was 35% (95% CI 21-48; n=17 responses). Twenty subjects had at least an unconfirmed response at any time. Median PFS was 5.7 months (95% CI 5.5-7.9). There was one treatment-related grade 5 adverse event of myocarditis. The most common treatment-related grade 3-4 AEs included lipase increased (9%), amylase increased (7%), ALT increased (5%), AST increased (5%), diarrhea (5%), hypophosphatemia (5%), and maculopapular rash (5%). Conclusions: The combination of panitumumab, ipilimumab, and nivolumab demonstrated evidence of activity and met its prespecified primary endpoint of 12-wk response rate criteria to merit further study. The PFS in this single-arm study compares favorably to expected PFS for anti-EGFR monotherapy in RAS wild-type patients, and results suggest activity of immune checkpoint inhibitors combined with anti-EGFR therapy in MSS mCRC. Clinical trial information: NCT03442569.

A pilot study of risk stratification and outreach to hematology/oncology patients during the COVID-19 pandemic

211

Background: Cancer patients have many medical and psychosocial needs, which may increase during the coronavirus pandemic and may be difficult to identify or address in the absence of in-person patient visits. We sought to (1) risk stratify hematology/oncology patients using general medicine and cancer-specific methods to identify those at high risk for acute care utilization, (2) measure the correlation between risk-stratification methods, and (3) perform a phone-based needs assessment with intervention for these patients. Methods: Patients were risk-stratified using a general medical health composite score (HCS) embedded in the electronic medical record, and a cancer-specific risk (CSR) stratification based on disease and treatment characteristics. The correlation between HCS and CSR was measured using Spearman’s correlation. A multi-disciplinary team developed a focused needs assessment script with recommended interventions for patients categorized as high-risk by either method. The number of patient needs identified and referrals for services made in the first month of outreach are reported. Results: 1,421 patients were risk stratified, with 15% high-risk using HCS and 21.2% high-risk using CSR. Overall correlation between HCS and CSR was modest (r = 0.39). During the first month of the pilot, 287 patients were called for outreach with 245 contacted (85%). Commonly identified needs were financial difficulties (17%), uncontrolled symptoms (15%), and interest in advance care planning (13%), resulting in referral for supportive services for 33% of patients. Conclusions: There is a high burden of unmet medical and psychosocial needs in hematology/oncology patients during the coronavirus pandemic. A phone-based outreach program results in identification of and intervention for these needs, however additional cancer-specific risk models are needed to improve targeting to high-risk patients. This process can serve as a framework for other institutions wishing to implement similar outreach programs during this pandemic. [Table: see text]

Effectiveness of adjuvant FOLFOX versus 5FU for colon cancer treatment in community oncology practice using a hybrid study approach

7067

Background: Treatment effects may differ between trials and community settings, in part due to underrepresentation of certain patient subgroups in trials. We used a hybrid approach combining clinical trial and real-world data to compare the effectiveness of adjuvant FOLFOX vs 5FU for stage II-III colon cancer in community oncology practice. Methods: We used Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer (MOSAIC) combined with patients who met trial eligibility criteria within US Oncology from 1/1/2008-5/31/2019. In the combined data, we used logistic regression to estimate the probability of trial enrollment as a function of age, sex, substage, body mass index (BMI), and performance status. We estimated inverse odds of sampling weights and weighted MOSAIC participants to reflect three US Oncology populations: 1) patients meeting trial eligibility, 2) stage III patients, and 3) stage III patients initiating FOLFOX. Within the weighted trial populations, we estimated mortality hazard ratios (HRs) and bootstrapped 95% confidence intervals (CIs) comparing FOLFOX with 5FU. Results: There were 2246 MOSAIC participants and 9335 US Oncology patients. MOSAIC participants were younger, had more stage II cancer, lower BMI, and worse performance status compared with US Oncology patients. After weighting MOSAIC participants to reflect the US Oncology populations, the HRs were attenuated (Table) compared with the original MOSAIC estimate (HR = 0.84; 0.71,1.00). Conclusions: When differences between trial and clinical populations exist and response to therapy varies across subgroups, treatment efficacy can differ from clinical effectiveness. Compared with trial results, we found that effectiveness of FOLFOX versus 5FU was attenuated in community oncology practice. [Table: see text]

Longitudinal cumulative dose: A novel measure to assess multiple dimensions of chemotherapy adherence over time

3522

Background: Adjuvant chemotherapy regimens take months to complete. Despite this, trials and observational studies evaluate chemotherapy adherence via measures assessed at the end of treatment (e.g. number of patients missing any dose, relative dose intensity [RDI]). This approach misses information that impacts outcomes, like treatment delays. We propose longitudinal cumulative dose (LCD) as a way to integrate the impact of dose reductions, missed doses, and dose delays at each cycle over time. Methods: We obtained data from the 2,246 participants in the Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer (MOSAIC). We evaluated proportions of patients stopping treatment early and reducing (based on protocol), missing, or delaying a dose in each arm for each chemo agent at each visit. We obtained LCD, the fraction of the final standard dose a participant reached by a given day, for each participant and each chemo agent. We compared LCD medians over time and at the end of a standard regimen (24 weeks) between treatment arms and by age and performance status. We assessed agreement between oxaliplatin LCD and RDI with Fleiss’ kappa (Table). Results: Participants randomized to FOLFOX were more likely than those randomized to 5FU to stop treatment, reduce doses, miss doses, or delay visits; these differences increased over time. Median LCD for oxaliplatin in the FOLFOX arm at 24 weeks was 77%. Graphs of median LCD for 5FU showed a clear difference between arms (FOLFOX arm median LCD: 81%; 5FU arm median LCD, 96%). While 5FU LCD decreased with age in the FOLFOX arm (median LCD in those age <40: 85%; 40-64, 82%; 65-75, 76%), it was similar across ages in the 5FU arm (median LCD 94%, 96%, and 96%, respectively), with smaller performance status trends. RDI and LCD showed fair agreement (Fleiss’ kappa=0.34); 19% of those with RDI over 85% had LCD under 60%. Conclusions: Visualizing LCD highlighted the timing and scale of deviations from standard administration, with major differences in 5FU LCD across arms. Next steps include evaluating if LCD predicts clinical outcomes. [Table: see text]

A randomized phase III study of mFOLFOX6/bevacizumab combination chemotherapy with or without atezolizumab or atezolizumab monotherapy in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) metastatic colorectal cancer (mCRC): Colorectal Cancer Metastatic dMMR Immuno-Therapy (COMMIT) study (NRG-GI004/SWOG-S1610)

TPS260

Background: Deficient DNA mismatch repair (dMMR) colorectal cancer (CRC) is highly immunogenic. Preclinical data showed synergistic interactions among FOLFOX, anti-VEGF, and programmed cell death-1 (PD-1) pathway blockade. Prior phase I study of mFOLFOX6/ bevacizumab (bev) + atezolizumab (atezo) was well tolerated and enhanced intratumoral infiltration of CD8+ T cells. We hypothesize that the dMMR subset of CRC may be effectively targeted with combination of PD-1 pathway blockade and mFOLFOX6/bev. Methods: This is a prospective randomized phase III open-label trial. Pts (N=347) with mCRC dMMR will be randomized to three trial arms (1:1:1): mFOLFOX6/bev; atezo monotherapy; or mFOLFOX6/bev + atezo. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Primary endpoint is progression-free survival (PFS) assessed by study investigator of mFOLFOX6/bev/atezo and atezo monotherapy compared to mFOLFOX6/bev. Secondary endpoints include OS, objective response rate, safety profile, disease control rate, duration of response, and PFS by retrospective central review. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; dMMR tumor determined by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2); availability of archived tumor tissue for central confirmation of dMMR status; and measurable disease per RECIST. Activated 11-7-17. As of 9-11-19, enrollment continues with 44/347 pts enrolled. Clinical trial: NCT02997228. Support:U10CA180868, -180822, -180888, -180819, UG1CA189867, U24CA196067; Genentech, Inc. Clinical trial information: NCT02997228.

Association of KRAS and BRAF mutations with progression-free survival (PFS) with second-line FOLFIRI +/- regorafenib in metastatic colorectal cancer (mCRC)

196

Background: LCCC1029 was a 2:1 randomized phase II trial of 2nd-line FOLFIRI plus either regorafenib or placebo in mCRC. The addition of regorafenib improved PFS (median PFS 6.1 vs 5.3 mo, HR 0.73, 95% CI 0.53-1.01). However, the effect of somatic mutations on regorafenib activity has not been tested. Methods: We performed whole exome sequencing on archival primary tumor tissue and paired normal tissue in 85 patients of LCCC1029. We compared PFS and OS using Kaplan-Meier method and log-rank tests, and hazard ratios (HR) were estimated using Cox proportional hazards method. Results: Among the 85 subjects, 54 (64%) had tumors wild-type (WT) for KRAS and BRAF, 26 (31%) had tumors with KRAS mutations in exons 2-4, and 5 (6%) had tumors with BRAF V600E. The addition of regorafenib to FOLFIRI improved PFS in the KRAS/ BRAF WT subgroup (median PFS 8.0 vs 4.9 mo, HR 0.68, 95% CI 0.48-0.97, log-rank p=0.028), but not in the KRAS mutant subgroup (median PFS 6.8 vs 5.5 mo, HR 0.90, 95% CI 0.61-1.35, log-rank p=0.617) or the BRAF mutant subgroup (log-rank p=0.156). In all of these subgroups, the addition of regorafenib was not associated with significant difference in OS. BRAF V600E was prognostic and associated with significantly worse OS (median OS 8.4 vs 18.0 mo, HR 2.59, 95% CI 1.01-6.66, log-rank p=0.04). Conclusions: The addition of regorafenib to FOLFIRI improves PFS among the subgroup of patients with KRAS and BRAF dual WT CRC, but not among the KRAS mutant subgroup. These results indicate that the addition of anti-angiogenic therapy to second-line chemotherapy backbones may be more effective in KRAS/ BRAF WT tumors in particular. More confirmatory studies are needed to corroborate this finding.

A comparison of treatment preferences, decision making, and psychosocial outcomes in advanced cancer patients with and without minor children: A matched cohort study

91

Background: Patients with advanced cancer who have minor children face unique challenges when coping with their life-limiting illness and the impact of their illness on their families. The goal of this study was to examine whether psychosocial functioning, treatment preferences, and treatment decisions in advanced cancer differ by parental status. Methods: A cohort of 60 parents with metastatic solid tumors age-matched with 60 non-parents (N = 120) participated in three structured interviews assessing treatment preferences and decisions over six months with complementary medical record review. Participants also completed validated measures of psychosocial functioning. Results: Seventy percent (n = 85) of the sample completed all study assessments. Mean age (45 years, SD 8), mean performance status score (ECOG = 1.2, SD 0.9), median duration of metastatic illness (19 months, range 1-115), gender ratio (66% female), and dropout rates were similar between groups. Parents and non-parents reported similar overall health-related quality of life, but parents were more likely to report poorer emotional well-being (p = 0.006) and more symptoms of depression (p = 0.04) and anxiety (p = 0.04) than non-parents. Parents and non-parents were equally likely to describe life-extension as their primary goal of anti-neoplastic treatment. Parents reported greater willingness to live in pain (48% “very willing” vs 27%, p = 0.007) and accept intubation/ventilation (40% vs 20%, p = 0.01) for life-extension. Compared to non-parents, parents were more likely to report their family members as the most influential factor in their decision-making (44% vs 12%) and less likely to cite their oncologist’s recommendation (25% vs 41%). There were no significant differences between groups for completion of a health care power of attorney or living will. Conclusions: Compared to similarly aged adults with metastatic cancer, parents experience greater psychological distress, are more willing to live in pain for life extension, and place greater importance on family-related factors in their cancer treatment decision-making.

Impact of brain metastases on end-of-life health care utilization

116

Background: Patients with brain metastases (BMets) represent a subset of cancer patients who may experience high costs and frequent healthcare utilization. This study aims to assess whether patients with BMets have higher likelihood of healthcare utilization at the end of life (EOL) compared to other patients with metastatic cancer. Methods: Using the Cancer Information and Population Health Resource, linking North Carolina Medicare, Medicaid, and private payer claims with state cancer registry data, we conducted an observational cohort study of decedents with metastatic melanoma, renal cell carcinoma, breast cancer, or lung cancer (diagnosed 2003-2014) with or without BMets. Multivariate logistic regression, adjusting for demographics, cancer type, systemic treatment, comorbidity, frailty, and hospice use, was used to examine the impact of BMets on use of the emergency department (ED), hospital, and intensive care unit (ICU) in the 30 days prior to death. Results: Patients with BMets are hospitalized at EOL more often than patients without BMets (44% vs 38%, p < 0.001), but experience no difference in ED or ICU use. BMets patients receiving systemic treatment were particularly high risk for hospital and ICU use (odds ratios in Table). Black race and Charlson comorbidity score 3+ increased risk of hospitalization and ICU use. Utilization did not vary by cancer type. Hospice care significantly reduced all utilization. Conclusions: Patients with BMets are high risk for hospitalization at the end of life. Further study is needed to determine if targeted health system interventions can decrease hospitalizations in this patient group.

[Table: see text]

Building a population management informatics infrastructure for oncology care

315

Background: While most primary care practices have informatics infrastructures to support population management, such infrastructures are not commonplace in oncology. Yet, value-based care requires that oncology practices be able to identify patients in real time, use risk stratification to target care efficiently, and monitor care quality to identify improvement opportunities. We describe an oncology informatics infrastructure development initiative in a large academic medical center. Methods: We convened a quality improvement team of administrators, analysts, clinicians, health services researchers and performance improvement staff. The team was sponsored by a senior leadership committee convened for a strategic planning initiative. We used PDSA cycles to develop and test ways to leverage data from an electronic health record (EHR) and billing system for oncology patient identification, risk stratification, and routine quality monitoring. We used clinician engagement, medical record review, and tumor registry comparisons to validate query strategies. Results: After considering different query strategies, we opted to identify patients via a new cancer treatment episode (as defined by a cancer diagnosis combined with evidence of pharmaceutical, radiation, and/or surgical treatment for cancer with no evidence of such treatment in the prior six months). This was done using diagnostic and procedural codes for chemo/immunotherapy and radiation treatment, and pathology reports and procedural codes for surgery. Using this approach, we identified over 7800 cancer treatment episodes within the health system in 2018. These episodes corresponded to 4178 chemo/immunotherapy, 1437 radiation, and 3440 surgical treatments. Quality monitoring has identified opportunities to enhance data capture, harmonize documentation processes across practitioners and practices, and initiate quality improvement efforts. Conclusions: Using data from the EHR and billing systems we are able to identify oncology patients as they initiate a cancer treatment episode. In so doing, we are able to track the quality of care delivered to oncology patients as they move across the care continuum from treatment to survivorship.

Impact of solid tumor brain metastases on end-of-life healthcare utilization

e18373

Background: Patients with brain metastases (BMets) represent a subset of cancer patients who may experience high costs and frequent healthcare utilization. This study aims to assess whether patients with BMets have higher likelihood of low-value healthcare utilization at the end of life compared to other patients with metastatic cancer. Methods: Using the Cancer Information and Population Health Resource, linking North Carolina Medicare and Medicaid and cancer registry data, we conducted an observational cohort study of decedents with metastatic cancer with or without BMets. The cohorts included adults with melanoma, renal cell carcinoma, breast cancer, or lung cancer, diagnosed 2003 to 2014. Multivariate logistic regression, adjusting for demographics, cancer type, systemic treatment, comorbidity, frailty, and hospice use, was used to examine the impact of BMets on emergency department (ED) use, hospitalization, and intensive care (ICU) in the 30 days prior to death. Results: Relative to patients without BMets, patients with BMets were more likely to experience a hospitalization (12.9% vs 9%, p < 0.001), but experience no difference in ED or ICU use. In adjusted analyses, BMets patients receiving systemic treatment were particularly high risk for hospitalization (OR 1.823, CI 1.504, 2.209). Black race; receipt of systemic therapy near the end of life; and Charlson comorbidity score of 3+ confers increased risk of ED use, hospitalization, and ICU use (Table). Utilization did not vary by cancer type. Conclusions: Patients with BMets are high risk for hospitalization at the end of life. Further study is needed to determine if targeted health system interventions can decrease hospitalizations in this patient group. [Table: see text]

Final analysis of phase II trial of regorafenib (REG) in refractory advanced biliary cancers (BC)

4083

Background: While gemcitabine plus cisplatin has demonstrated significant antitumor activity as 1st line therapy of BC, there is no effective treatment after failure of gemcitabine-based therapy. REG is an oral multi-kinase inhibitor that targets angiogenesis, oncogenesis and cancer proliferation/metastasis. We evaluated the efficacy of REG in BC. Methods: Patients (pts) with histologically proven BC who progressed on at least one line of systemic therapy received REG 160 mg daily 21 days on 7 days off, in 28 day cycles. The primary endpoint was 6-month (mo) overall survival (OS) and the secondary endpoints were median OS, progression free survival (PFS) and response rates (RR). Pre and post-treatment plasma were collected for cytokine evaluation. Results: A total of 39 pts received at least 1 dose of REG; 32 pts were evaluable for efficacy. Median age was 62 (range: 27-88) years and the primary sites of tumor were intrahepatic cholangiocarcinoma (68.8%), extrahepatic (18.8%), and gallbladder (12.5%). Pts were considered evaluable for efficacy if patients received more than 1 cycle of REG. For 32 evaluable pts, 6 mo OS was 52% with median PFS of 2.8 mo (95% CI: 1.1-4.5) and median OS of 7.9 mo (95% CI: 0-18.7). Median PFS and OS of the pts (n=20) failed 1 line of therapy were 3.7 mo (95% CI: 3.2-4.1) and 13.8 mo (95% CI: 1.8-25.8), respectively. Median PFS and OS of the pts (n=12) failed 2 lines were 1.8 mo (95% CI: 1.63-1.97) and 4.5 mo (95% CI: 2.6-6.3), respectively. RR was 9.4% (2 PR and 1 unconfirmed PR) and DCR was 62.5%. Total 71.8% of grade 3/4 adverse events (AE) were observed, and the most common AE were fatigue (56.4%) and hypertension (53.8%). Dose modification was required in 49% of the pts. Among the 23 cytokines analyzed, elevated baseline VEGF-A was associated with good prognosis (HR 0.62, p=0.01). Elevated baseline TIMP-1 (HR 1.79, p=0.04) and IL-6 (HR 1.33, p=0.05) were associated with poor prognosis. REG treatment decreased BMP-9, GP130, VEGF-R2 and VEGF-R3 and increased IL-6, PIGF, TIMP-1, VCAM-1 and VEGF-A significantly. Conclusions: The primary endpoint was met in this study. VEGF-A may be further evaluated as a predictive biomarker for REG in BC. Further randomized trials are warranted to confirm the efficacy and the correlative data. Clinical trial information: NCT02115542.

Association of consensus molecular subtypes (CMS) with time to progression (TTP), progression free survival (PFS), and overall survival (OS) with second-line FOLFIRI ± regorafenib in metastatic colorectal cancer (mCRC)

597

Background: LCCC1029 was a 2:1 randomized phase II trial of second-line FOLFIRI plus either regorafenib or placebo in mCRC that showed no statistically significant difference in PFS or OS. CMS, defined using gene expression, is prognostic for PFS and OS in previously untreated mCRC, but the impact of CMS in second-line treatment is unclear, as well as its impact on regorafenib efficacy. Methods: RNAseq on archival tumor tissue was successfully performed in 68 LCCC1029 patients (49 on regorafenib, 19 on placebo). A multinomial elastic net CMS classifier was trained using 6 CRC gene expression data sets with known CMS classification. We built our model with only CMS1-4 classified samples and then applied it to normalized and median adjusted RNASeq from LCCC1029 to classify all samples into CMS1-4. TTP, PFS, and OS were compared using Kaplan-Meier method and log-rank tests, and hazard ratios were estimated using Cox proportional hazards method. Results: Our model had > 93% sensitivity and specificity for CMS1-4 in the training data set; the 17% of non-consensus samples in the training data were predominantly labeled CMS2. We classified the LCCC1029 samples as CMS1 (12%), CMS2 (63%), CMS3 (4%), and CMS4 (21%). CMS was prognostic for TTP (log-rank p=0.03), with median for CMS1 of 2.0 months (95% CI 0.0-4.8) versus 5.6 months (5.3-5.9) for CMS2 and 7.8 months (5.5-10.1) for CMS4. There was a trend toward association between CMS and either PFS (log-rank p = 0.11) or OS (log-rank p = 0.085). CMS2 had superior OS compared to CMS1 (HR 0.39, 95% CI 0.17-0.87, p = 0.02). With our limited sample size, we found no significant interaction between CMS and treatment arm for TTP, PFS, or OS. Conclusions: CMS is associated with significant differences in TTP in second-line treatment of mCRC in LCCC1029, and specific CMS types also have differences in OS. Thus, the prognostic impact of CMS extends to second-line treatment in mCRC, meriting further study of CMS classification in additional non-first-line studies.

Colorectal Cancer Metastatic dMMR Immuno-Therapy (COMMIT) study (NRG- GI004/SWOG-S1610): A randomized phase III study of mFOLFOX6/bevacizumab combination chemotherapy with or without atezolizumab or atezolizumab monotherapy in the first-line treatment of patients (pts) with deficient DNA mismatch repair (dMMR) metastatic colorectal cancer (mCRC)

TPS728

Background: Deficient DNA mismatch repair (dMMR) colorectal cancer (CRC) cells are highly immunogenic. Preclinical data showed that oxaliplatin-containing chemotherapy combined with anti-VEGF enhances antitumor activity of programmed cell death-1 (PD-1) pathway blockade in murine CRC models. Prior phase I study showed mFOLFOX6/ bevacizumab (bev) + atezolizumab (atezo) was well tolerated and enhanced intratumoral infiltration of CD8+ T cells. We hypothesize that the dMMR subset of CRC may be effectively targeted with combination of PD-1 pathway blockade and mFOLFOX6/bev to promote tumor regression. Methods: This is a prospective randomized phase III open-label trial. Pts (N=347) with mCRC dMMR will be randomized to 3 trial arms (1:1:1): mFOLFOX6/bev; atezo monotherapy; or mFOLFOX6/bev + atezo. Stratification factors include BRAFV600E status, metastatic site, and prior adjuvant CRC therapy. Primary objective is to evaluate efficacy of mFOLFOX6/bev/atezo and atezo monotherapy compared to mFOLFOX6/bev. Primary endpoint is progression-free survival (PFS) assessed by study investigator. Secondary endpoints include overall survival, objective response rate, safety profile, surgical conversion rate, disease control rate, duration of response, and PFS by retrospective central review. Health-related quality of life is an exploratory objective. Archived tumor tissue and blood samples will be collected for correlative studies. Key inclusion criteria are: mCRC without prior chemotherapy for advanced disease; tumor determined to be dMMR by local CLIA-certified IHC assay (MLH1/MSH2/MSH6/PMS2); availability of archived tumor tissue for central confirmation of dMMR status; and measurable disease per RECIST. Activated 11-7-17. As of 9-24-18, 13/347 pts have been enrolled. Clinical trial: NCT02997228. Support: U10CA180868, -180822, -180888, -180819, UG1CA189867, U24CA196067; and Genentech, Inc. Clinical trial information: NCT02997228.

Blood-based biomarkers in metastatic colorectal cancer patients treated with FOLFIRI plus regorafenib or placebo: Results from LCCC1029

587

Background: The LCCC1029 trial demonstrated that addition of the multitargeted kinase inhibitor regorafenib (Rego) to FOLFIRI in metastatic colorectal cancer (mCRC) patients (pts) modestly prolonged progression-free survival (PFS). In this preplanned analysis, circulating angiogenic and inflammatory proteins were explored as potential prognostic and predictive biomarkers of Rego benefit. Methods: Plasma samples from 149 mCRC pts (107 in Rego + FOLFIRI and 42 in placebo + FOLFIRI) were evaluated for 20 markers at baseline (n = 149) and cycle 1 day 21 (C1D21, n = 81). Predictive and prognostic values of each marker at baseline were analyzed for both PFS and overall survival (OS) using Cox proportional hazard models. On-treatment changes were quantified as fold change [log2(C1D21/baseline)] and differences between arms were evaluated using the Mann-Whitney test. Results: The primary objective of this study was to determine whether any marker was predictive of benefit with Rego for PFS. Although no treatment by marker interactions were significant after adjusting for multiple testing, the top three markers of interest were OPN (unadjusted p-values of 0.02), VCAM-1 (0.02), and PDGF-AA (0.04). VCAM-1 was also predictive for OS benefit in pts treated with Rego (unadjusted p = 0.01). Baseline levels of multiple markers (including HGF, IL-6, PlGF, VEGF-R1, OPN) were prognostic for both PFS and OS. Higher levels of these markers were associated with worse survival. Biomarker changes in response to treatment were explored and compared between arms. Fold change of three markers (PlGF, VEGF-A, VCAM-1) were significantly different between arms (p < 0.0001), all being markedly up-regulated in the Rego arm compared to the placebo after treatment. Conclusions: In this hypothesis generating report, VCAM-1, OPN, and PDGF-AA were the top biomarkers when analyzing the potential predictive association with PFS, where a lower hazard was observed for pts receiving Rego. Candidate prognostic markers were identified, including PlGF and VEGF-R1, key factors in VEGF biology. Biomarker changes observed here may offer insights into potential combinatorial strategies with Rego for future studies.

A qualitative evaluation of barriers and facilitators to hepatocellular carcinoma care in North Carolina

72

Background: Hepatocellular carcinoma (HCC) is a common cause of cancer-related morbidity and mortality worldwide, yet many patients with HCC never receive cancer-directed therapy, for reasons that are not well documented. In order to tailor interventions to increase access to appropriate therapy, it is critical to understand the barriers and facilitators to access to care and receipt of treatment in HCC. Methods: This study includes 10 patients with HCC, within 6 months of diagnosis, identified through either the University of North Carolina (UNC) multidisciplinary HCC clinic or the UNC Rapid Case Ascertainment (RCA) Core which identifies cancer patients through registrars at local hospitals. Recruitment is ongoing with a target of 20 patients, expected to complete in July 2018. In-depth, semi-structured interviews were conducted by two qualitative researchers. Interviews were audiotaped, transcribed verbatim, and coded independently by two coders, using a common codebook. Coding discrepancies were reconciled by consensus. Results: Most participants described that they had been incidentally diagnosed with HCC during evaluation for another health issue. Key facilitators of care were: physician knowledge about HCC; clear, honest, and timely communication regarding test results, plan of care, and prognosis; access to transportation; strong social support; and financial support through friends, family, insurance, or charity care. Barriers to care included: lack of transportation; delays in receipt of information or in scheduling appointments; or poor communication with the medical team. Conclusions: This study identifies key facilitators and barriers to accessing care for HCC in North Carolina (NC). Further investigation of a broader sample of HCC patients is warranted, and the qualitative data from this study will be used to create a survey to be administered to all patients with incident HCC in NC. Ultimately, this information will serve as the basis for tailored interventions aimed at improving access to appropriate, life-prolonging care for patients with HCC.

Phase Ib/II study of neoadjuvant chemoradiotherapy with CRLX101 and capecitabine for locally advanced rectal cancer

e15144

Background: There is strong interest in the development of novel agents to further improve the therapeutic ratio of neoadjuvant chemoradiotherapy for rectal cancer. CRLX101 is an investigational nanoparticle-drug conjugate with a camptothecin payload. The purpose of this Phase Ib/II study is to assess toxicity and to evaluate whether the addition of CRLX101 to chemoradiotherapy can improve pathologic complete response (pCR) for rectal cancer. Methods: This is a single-arm multicenter Phase Ib/II study examining the addition of CRLX101 to a standard capecitabine-based chemoradiotherapy regimen. Phase Ib employs a 3+3 dose escalation design with starting dose of 12 mg/m2 every other week (QOW). Dose level +1 was 15 mg/m2 (MTD for CRLX101 single agent QOW). Upon reaching MTD for QOW dosing, protocol was modified to evaluate QW CRLX101 dosing starting at 12 mg/m2 and 15 mg/m2as +1 level. Secondary endpoints included pCR and clinical outcome. Results: A total of 32 patients were enrolled on the trial. 26/32 had T3-4, 9/32 had N2 and 16/32 had N1 disease. For QOW dosing, 9 patients completed treatment without DLT and MTD was identified as 15 mg/m2 QOW. 14 patients were treated on the Phase II portion of the study at 15 mg/m2 QOW prior to the initiation of weekly dosing Phase Ib cohorts. For QW dosing, 0/3 patients experienced DLT at 12 mg/m2 and 1/6 patients experienced DLT at 15 mg/m2. The DLT was skin desquamation requiring treatment delay. QW MTD was identified as 15 mg/m2. Toxicities (all grade 3 except lymphopenia) that could possibly be attributed to CRLX101 are in Table 1. Full clinical and pathologic staging were available for 29/32 patients. Mean neoadjuvant rectal (NAR) score was 19 with standard deviation of 15. At the weekly MTD, 3/6 patients had pCR. Conclusions: CRLX101 weekly at 15 mg/m2+ standard capecitabine-based chemoradiotherapy appears to be well tolerated, with promising pCR rates that warrants further evaluation. A larger PhII trial should be considered with this regimen. Clinical trial information: NCT02010567. [Table: see text]

Somatic DNA mutations, MSI status, mutational load (ML): Association with overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC) of CALGB/SWOG 80405 (Alliance)

3504

Background: CALGB 80405 was a randomized phase III trial that found no difference in OS in first-line mCRC pts treated with either bevacizumab (Bev) or cetuximab (Cet). Primary tumor DNA from 361 pts, including KRAS mutant (mut) pts, has been profiled for somatic gene mutations/ML/MSI to discover molecular markers of OS. Methods: Mutations in 11 genes were determined by PCR, MSI by microsatellite analysis, and ML by next-generation sequencing (FoundationOne). Cox proportional hazard models are used, stratified by prior XRT and +/- adjuvant chemotherapy; adjusted by age, race, gender, synchronous vs. metachronous, liver metastases, sidedness, all RAS. Results: BRAF: Mut pts had shorter OS than wild-type (wt) pts (HR 1.92, 95% CI 1.34,2.75; p<0.001); HR 1.65 (1.09,2.50) after adjusting for sidedness (p 0.022). In mut pts longer OS is observed in Bev arm vs. Cet arm (p 0.041); in wt pts no arm difference is observed (p 0.291, table). MSI: OS does not differ between MSI-H and MSI-S pts (HR 0.78 [0.40, 1.52], p 0.450). In MSI-H pts longer OS is observed in Bev arm vs. Cet arm (p 0.002); in MSI-S pts no difference is observed (p 0.305, table). ML: Hypermutated MSI-H pts are excluded. In a subset of 205 pts, pts with ML>5 (N=93) have longer OS than pts with ML≤5 (N=112) (HR 0.65 [0.42,1.00], p 0.048). In Bev arm higher ML confers longer OS than lower ML (HR 0.85 [0.80,0.96], p 0.004); in Cet arm no difference is observed (HR 0.99 [0.90,1.09], p 0.862). Conclusions: BRAF is a strong negative prognostic factor in mCRC, even when sidedness is taken into account. ML is a novel marker for further evaluation. The effect of Bev and Cet in either BRAF mut or MSI-H pts should be tested in larger datasets. Updated results from more screened samples will be presented. [Table: see text]

Primary (1°) tumor location as an independent prognostic marker from molecular features for overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC): Analysis of CALGB / SWOG 80405 (Alliance)

3503

Background: 80405 found no OS or Progression Free Survival (PFS) difference when bevacizumab (BV) or cetuximab (Cet) was added to 1st-line FOLFOX or FOLFIRI in All RAS wild type (wt) mCRC pts. There was a significant 1° side by biologic interaction (P int: OS = 0.008, PFS = 0.001) favoring pts with left-sided (L) 1°. Analyses of 1° tumors beyond All RAS includes Consensus Molecular Subtype (CMS), BRAF and MSI. (CMS results - see Lenz et al; BRAF -see Innocenti et al) We asked whether 1° tumor location - L vs right (R) - is an independent prognostic marker when these other molecular features are considered. Methods: We used a Cox proportional hazard model stratified by prior XRT and +/- adjuvant chemo; adjusted for age, gender, synchronous vs metachronous, CMS, MSI and BRAF status. Pts with transverse (T) tumors were excluded in this analysis. Results: Sidedness was determined in 782 pts (L - 472; R - 256; T -54). Molecular data from 728 pts (with L - and R-sided 1°s) was available as follows: KRAS -- 291, NRAS -393, BRAF - 393, MSI - 378, CMS - 533. L vs R mOS: 32.9 v 19.6 months (mo) (p < 0.0001). See Table for OS results in All RAS / BRAF wt and BRAF mutant (mut) pts. Sidedness (R vs L) is an independent prognostic marker even after adjusting for all these molecular features: HR = 1.392 (1.032, 1.878), p = 0.031. Conclusions: Primary tumor location is an independent prognostic factor when adjusted for age, gender, synchronous/metachronous, CMS, MSI and BRAF status. We are exploring clinical variables such as tumor burden, metastatic sites and measurability of disease in an attempt to explain the impact of sidedness. Support: U10CA188021, U10CA180882. Eli Lilly and Co, Genentech/Roche, Pfizer, Sanofi. Clinical trial information: NCT002655850. [Table: see text]

Understanding the non-curative potential of palliative chemotherapy: Do patients hear what they want to hear?

6575

Background: Misconceptions about the curative potential of PC are common, and may arise from gaps in informed consent. Another contributing factor could be patients’ desire, or lack of desire, for information about prognosis and PC outcomes. Methods: We surveyed 137 patients with advanced colorectal (N = 102) or pancreatic cancer (N = 35) within 2 weeks of consultation about 1st or 2ndline PC, as part of randomized trial of a PC education intervention at 6 US sites. Patients rated how much information they wanted about PC risks/benefits, including impact on prognosis. Responses ranged from no information to as much as possible on a 5-point Likert scale. They reported decision-making preferences; whether a doctor discussed curability, and how likely they thought PC was to cure their cancer. Chi square and Wilcoxon tests examined whether information and decision-making preferences, or curability discussions were associated with expectations of cure. Multivariable logistic regressions evaluated whether associations were modified by age, race, gender, marital status, or cancer type. Results: Only 44.5% of patients accurately reported that their cancer was not at all likely to be cured by PC. Most patients wanted a lot, or as much information as possible about PC risks/benefits, including likelihood of cure (81.7%), cancer control (84.7%), and impact on length of life (80.3%). Most patients preferred shared (70.8%) versus active or passive decision-making. Neither decision-making nor prognostic information preferences were associated with expectations of cure. Patients (13.9%) who did not recall curability discussions were less likely to have accurate expectations (21% v 48%; OR, 0.29; 95% CI, 0.07-.97). Patient characteristics did not significantly confound this association. Conclusions: Most patients value shared decision-making and want maximal information about PC risks/benefits, including impact on prognosis. Despite wanting prognostic information and reporting curability discussions, many patients report inaccurate expectations about cure from PC. Future studies should examine whether these assertions reflect misunderstandings, differences in belief, or expressions of hope.

Changes in p16INK4a (p16) expression, a biomarker of aging, in peripheral blood T-cells (PBTC) in patients receiving anthracycline (A) vs non-anthracycline (NoA) chemotherapy (CRx) for early-stage breast cancer (EBC)

10060

Background: Age-related accumulation of senescent cells plays a causal role in some aspects of mammalian aging. We have shown that the total-body burden of senescent cells can be estimated by measuring the expression of the p16 tumor suppressor, a canonical effector of senescence, in human CD3+ PBTC (Liu et al, Aging Cell, 2009). Expression of p16 increases more than 10-fold over an adult human lifespan, and this rate of accumulation is accelerated by age-promoting exposures such as CRx or stem cell transplant (Sanoff et al, JNCI 2014; Wood et al, EbioMed 2016). Increased molecular age as evidenced by increased expression of p16 prior to CRx predicts a patient’s risk of CRx toxicity independently of chronological age (DeMaria et al, Cancer Discovery, 2017).This study investigates the impact of different types of CRx (A vs NoA) regimens on PBTC p16expression in pts with EBC. Methods: EBC pts who received neoAdj or Adj CRx had blood samples drawn for p16 assay prior to CRx initiation and again between 2 months and 1.5 years after the end of CRx. Expression of p16 mRNA in PBTC was determined using TaqMan real-time quantitative reverse transcription PCR. T-test compared p16change between A and NA groups. Results: 70 pts were evaluable. Pt. characteristics: median age 49 (range 32-76); 52 (74%) White, 14 (20%) black, 4 unknown; 39 (56%) ER or PR+ and HER2 neg, 18 (26%) triple negative, 13 (19%) HER-2 pos (all received trastuzumab). 53 pts (76%) had A (47 AC + taxane, 6 AC no taxane) and 17 (24%) NoA (all TC). Expression of p16 increased 2.0-fold in patients who received A-based CRx compared to 1.2-fold in NoA CRx (p = 0.04). There was no relationship of race, ER, PR or HER-2 status on change in p16expression. Conclusions: This study is ongoing and further results will be presented at the ASCO meeting. In this sample of EBC patients treated with A vs. NoA CRx regimens, A-based CRx is more strongly associated with increased biologic aging of T-cells compared to NoA CRx. These changes are equivalent of increased biologic aging of PBTC of 11 years (A) vs.6 years (NoA) and may have major consequences on the long-term survival of these pts.

A phase IB study of the combination of selumetinib (AZD6244, ARRY-142886) and cyclosporin A (CsA) in patients with advanced solid tumors with an expansion cohort in metastatic colorectal cancer (mCRC)

2587

Background: MEK inhibition is of interest in cancer drug development. However, better strategies are needed to overcome acquired resistance to MEK inhibitors. Preclinical studies have shown Wnt pathway overexpression in KRAS mutant cell lines resistant to the MEK inhibitor, selumetinib. The combination of selumetinib and cyclosporin A (CsA), a non-canonical Wnt pathway modulator, demonstrated antitumor activity in patient-derived xenograft (PDX) models. We conducted an NCI CTEP-approved Phase I/IB trial (NCI # 9571/COMIRB # 13-2628/NCT02188264) of selumetinib and CsA combination. Biomarkers of response are being co-developed. Methods: Patients with advanced solid tumors were treated with the combination of selumetinib and CsA in dose escalation followed by an expansion cohort in patients with irinotecan and oxaliplatin-refractory mCRC (n = 20). The expansion cohort utilized a selumetinib “run-in” to evaluate efficacy in RAS-WT and RAS-MT mCRC to identify those patients most likely to respond to the combination. Results: As of January 2017, 18 patients were enrolled in the dose escalation phase and 20 patients were enrolled in the dose expansion phase. The most common adverse events and grade 3/4 toxicities were rash, hypertension, and edema. Three DLTs - Grade 3 hypertension, rash and increased creatinine were reported. The maximum tolerated dose was identified as selumetinib 75 mg BID and CsA 2 mg/kg BID on a 28-day cycle. The selumetinib “run-in” did not favor a specific RAS type. Two partial responses were noted. Sixteen patients had stable disease, and 6 patients had progression of disease as their best response to therapy. Conclusions: Selumetinib in combination with cyclosporin A appears to be well tolerated with evidence of activity in mCRC. Tumor response data are currently being updated. FZD will be evaluated as a potential biomarker of response. Clinical trial information: NCT02188264.

Biopsy practices for the diagnosis of hepatocellular carcinoma (HCC)

e15646

Background: American Association for the Study of Liver Disease (AASLD) guidelines endorse radiographic diagnosis of HCC if key features are present on dynamic contrast-enhanced imaging (arterial hyperenhancement and venous washout) with biopsy for those without these features. As many HCC patients (pts) are diagnosed outside liver transplant centers, we sought to describe the methods of diagnosis of HCC and factors associated with biopsy in routine care in the US. Methods: HCC cases were identified from 2 data sources: SEER-Medicare (M) 2004-2011 and North Carolina Central Cancer Registry (NCCCR) linked to Medicare, Medicaid and private claims 2004-2013. Diagnostic confirmation was identified from registries as pathologic (path) or clinical. Key covariates included age, cancer stage, cause and severity of cirrhosis, and comorbid disease. Specialty consultation, prediagnosis imaging, AFP testing were determined from claims -3 to 0 months from diagnosis. Multivariable logistic regression was used to identify factors associated with path. Results: Path was obtained in a majority of HCC pts: 68% of 10,989 in SEER-M, 72% of 1,809 in NCCCR. In SEER-M, claims for contrasted abdominal CT were more common in those with path than those without (34 vs 30%) but not for MRI (14 vs 14%). Odds of path was higher in pts with contrasted CT (adjusted odds ratio [OR] 1.48, 95% confidence interval [CI] 1.30-1.69) or MRI (OR 1.53, CI 1.31-1.80) vs pts without imaging. In NCCCR, CT (51 vs 41%) and MRI (35 vs 34%) were performed more. Both were associated with increased odds of biopsy vs pts without imaging: contrasted CT scan (OR 1.74, CI 1.22-2.47) or MRI (OR 1.48, CI 1.02-2.13). In neither cohort did ultrasound increase odds of path over no imaging. Pts seen by an oncologist (OR SEER-M 1.66, CI 1.46-1.89) were more likely to have path than pts not seen by oncology. In SEER-M, pts seen at abdominal transplant centers were less likely to have path (OR 0.87, CI 0.77-0.98). Conclusions: Most pts diagnosed with HCC had path confirmation of cancer despite internationally accepted guidelines supporting radiographic diagnosis. The use of biopsy was greater among those with cross-sectional imaging, suggesting this high biopsy rate cannot solely be explained by nondiagnostic imaging.

Patient-reported comorbidity and survival in older adults with cancer

10033

Background: Our ability to optimize the care of older adults with cancer and comorbid illnesses is insufficient as most clinical trials lack systematic measurement of comorbidities. The primary purpose of this study was to evaluate the prevalence and impact of patient-reported comorbidity on survival using various comorbidity scoring algorithms. Methods: We utilized a unique linkage of the Carolina Senior Registry, an institutional registry (NCT01137825) that contains geriatric assessment data, with the North Carolina Central Cancer Registry to obtain mortality data. Comorbidity was assessed using a patient-reported version of the Older Americans Resources and Services Questionnaire (OARS) Physical Health subscale that includes information regarding 13 specific comorbid conditions and the degree to which each impairs function (“not at all” to “a great deal”). Multivariable Cox proportional hazard regression models were used to evaluate the association between comorbidities and all-cause mortality. Results: 539 patients were successfully linked to mortality data. Median age 72, 72% female, 85% Caucasian, 47% breast cancer, and 12% lung cancer. 92% of participants reported at least one comorbid condition, mean of 2.7 conditions (range 0-10), with arthritis and hypertension the most common (52 and 50%, respectively). 62% of patients with a comorbid illness reported a functional limitation related to comorbidity. Both the presence of 3 or more total comorbidities (hazard ratio (HR) 1.44, CI 1.08-1.92) and 2 or more comorbidities impacting function (HR 1.46, CI 1.09-1.95) increased mortality. After adjusting for age, cancer type, and stage, the risk of death increased 12% for each comorbid condition impacting function (HR 1.12, CI 1.02-1.24), but did not significantly increase for the number of comorbid conditions alone (HR 1.07, CI 0.99-1.15). Conclusions: Comorbid conditions in older adults with cancer are highly prevalent, frequently impair function, and impact survival. Comorbid conditions that impair function have a greater impact on survival than the presence of comorbidity alone. Comorbidity assessment should be incorporated in clinical trials and can be measured via a simple one-page patient-reported questionnaire.

Chemotherapy toxicity risk score (CTRS) for treatment decision in older patients with advanced solid cancer

10030

Background: The decision whether to treat older patients (pts) with advanced cancer with standard (ST) or reduced therapy (RT) is complicated by heterogeneity in aging. Currently, clinical impression based largely on age and performance status, determines whether a pt is fit or unfit for ST. We evaluated the potential utility of the CTRS (Hurria JCO 2011) for treatment decision in older cancer pts. Methods: This is a prospective observational study of older pts (+65) receiving first-line chemotherapy for locally advanced or metastatic cancer for which combination chemotherapy is the standard of care. CTRS was calculated before therapy initiation assuming the pts received ST (combination therapy at the standard dose). Pts were categorized as high risk (CTRS ≥10; RT (dose reduced combination or single agent chemotherapy) deemed appropriate) or non-high risk (CTRS <10; ST deemed appropriate) for grade 3-5 adverse events (gr3-5 AEs). Treatment decision was left to the treating physician who was blinded to the CTRS result. We estimated the agreement in chemotherapy choice (ST vs RT) between treating physician and CTRS using the kappa statistic. Results: 44 pts (median 71 years) with GI (68%), GU (14%), lung (14%) or HEENT (5%) cancer were enrolled. 29 pts received ST (11 had CTRS ≥10 and 18 had CTRS <10) and 15 pts received RT (10 had CTRS ≥10 and 5 had CTRS <10). The kappa statistic showed only modest agreement in chemotherapy choice (0.26, 95%CI = -0.01 to 0.54) between physician and CTRS. Gr3-4 AEs and hospitalization due to AE occurred in 50% and 29% of 42 pts with follow-up data, respectively. There was no fatal AE. Among pts receiving ST, pts with CTRS ≥10 had a significantly higher incidence of gr3-4 AEs and hospitalization than those with CTRS <10 using Fisher's exact test (Table). In the RT group, there was no significant difference in incidence of gr3-4 AEs or hospitalization between pts with CTRS ≥10 and CTRS <10. Conclusions: Incorporation of CTRS in treatment decision may increase the proportion of elderly pts with advanced cancer who receive tolerable treatment. [Table: see text]

The impact of sarcopenia on toxicity and pharmacokinetics of 5-fluorouracil (5FU) in colorectal cancer

633

Background: Great heterogeneity exists in the ability of adults with cancer to tolerate treatment. Variability in body composition may affect rates of metabolism of cytotoxic agents and contribute to the variable chemotherapy toxicity observed. The goal of this study was to explore the impact of body composition, in particular sarcopenia, on the pharmacokinetics of 5-fluorouracil (5FU) in a cohort of patients receiving FOLFOX +/- bevacizumab for colorectal cancer. Methods: We performed a secondary analysis of a completed multicenter trial that investigated pharmacokinetic-guided 5FU in patients receiving mFOLFOX6 +/- bevacizumab [Patel et al. The Oncologist 2014]. Computed Tomography (CT) images that were performed as part of routine care were used to for body composition analysis. Skeletal muscle area (SMA) and density (SMD) were analyzed from CT scan L3 lumbar segments using radiological software. SMA and height (m2) were used to calculate skeletal muscle index (SMI = SMA/m2). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD. Differences were compared using two group t-tests and fisher’s exact tests. Results: Of the 70 patients from the original study, 25 had available CT imaging. The mean age was 59, 52% female, 80% Caucasian, and 92% with either stage III or IV disease. Eleven patients (44%) had grade 3/4 toxicity, and 12 patients were identified as sarcopenic (48%) [per Martin et al. JCO 2013]. Sarcopenic patients had numerically higher first cycle 5FU AUCs compared to non-sarcopenic patients (19.3 vs. 17.3 AUC, p= 0.43) and higher grade 3/4 toxicities (50 vs 38.5%, p= 0.70). Patients with low SMG ( < 1475 AU) had higher grade 3/4 toxicities (62 vs 25%, p= 0.11) and higher hematologic toxicities (46 v 8%, p= 0.07). Conclusions: CRC patients with sarcopenia had numerically higher first cycle AUCs of 5FU and a higher incidence of severe toxicities; however, this was not statistically significant, possibly due to limited sample size. SMG, an integrated muscle measure, was more highly correlated with toxicity outcomes than either SMI or SMD alone. Further research exploring the role of body composition in pharmacokinetics is needed with a focus on alternative dosing strategies in sarcopenic patients.

A phase IB study of the combination of selumetinib (AZD6244; ARRY-142886) and cyclosporin A (CsA) in patients with advanced solid tumors with an expansion cohort in metastatic colorectal cancer (mCRC)

609

Background: Targeting MEK is of interest in the development of novel agents for treatment of many malignancies. However, better strategies are needed to overcome acquired resistance to MEK inhibitors. Preclinical studies have shown Wnt pathway overexpression in KRAS mutant cell lines resistant to the MEK inhibitor, Selumetinib. The combination of selumetinib and cyclosporin A (CsA), a non-canonical WnT pathway modulator, demonstrated antitumor activity in patient-derived xenograft (PDX) models. We are conducting an NCI CTEP-approved Phase I/IB trial (NCI # 9571/COMIRB # 13-2628) of selumetinib and CsA combination. Biomarkers of response to therapy are being co-developed. We hypothesize that this combination will be safe and potentially effective in patients with mCRC and that upregulation of FZD2 may predict for sensitivity. Methods: Phase I trial with initial dose escalation investigating the combination of selumetinib and CsA in patients with advanced solid tumors (n = 18) followed by an expansion cohort in patients with irinotecan and oxaliplatin-refractory mCRC (n = 20). The expansion cohort utilizes a selumetinib “run-in” to evaluate efficacy in RAS-WT and RAS-MT mCRC to identify those patients most likely to respond to the combination. Results: 18 patients were enrolled in the dose escalation phase and 10 patients have been enrolled in the dose expansion phase as of September 2016. Grade 1 or 2 nausea and rash were reported as the most common AEs. Most commonly reported Grade 3 or 4 toxicities were hypertension, elevated liver enzymes and rash. Three DLTs were reported with Grade 3 hypertension noted at dose level 1 and 2 and grade 3 rash reported at dose level 2. The maximum tolerated dose was defined as Selumetinib 75 mg BID and CsA 2 mg/kg BID on a 28-day cycle. Two partial responses and sixteen stable disease responses have been observed. Six patients have exhibited progressive disease. Conclusions: Selumetinib in combination with cyclosporin A appears to be well-tolerated with evidence of activity in solid tumors. Expansion cohort will complete enrollment this month. Clinical trial information: NCT02188264.

Molecular and clinical characterization of a claudin (CLDN)-low subtype of gastric cancer (GC)

67

Background: A CLDN-low subtype has been identified in breast and bladder cancers and is characterized by low expression of tight junction proteins CLDN, enrichment for epithelial-to-mesenchymal transition (EMT) and tumor initiating cell (TIC) features. Given the genomically stable (GS) subtype of GC defined by TCGA has features suggestive of CLDN-low tumors, we evaluated whether the CLDN-low subtype also exists in GC. Methods: 415 tumors from TCGA GC mRNA dataset were clustered on the CLDN, EMT and TIC gene sets with significance testing using SigClust2 to identify CLDN-low GC. A minimal set of genes that could accurately classify CLDN-low GC was defined by prediction analysis of microarrays (PAM). Tumors identified by SigClust2 or the PAM were called CLDN-low GC regardless of the original subtype call. The 300 GCs in the Asian Cancer Research Group (ACRG) dataset [GSE62254] were used to validate the predictor. We characterized clinical and molecular (gene expression, mutation and copy number alteration) features of CLDN-low GC. Results: We identified 46 tumors that had consensus enrichment for CLDN-low features in TCGA. CLDN-low tumors were most commonly diffuse (35/42=83%, 4 tumors=mixed) and GS (36/46=78%). CLDN-low GC showed high expression of immune gene signatures including T and NK cell signatures, but not an immunosuppression signature. Compared to GS subtype, CLDN-low GC had increased frequency of CD44, GATA4, and GATA6 amplification. In ACRG, 28/300 GCs were CLDN-low using the PAM predictor. The CLDN-low GC in ACRG was phenotypically similar to the CLDN-low GC in TCGA based on the CLDN, EMT and TIC gene signatures. Clinically, CLDN-low GC was associated with the shortest overall survival of the 5 subtypes (CLDN-low plus TCGA defined 4 subtypes). Notably, a hazard ratio comparing CLDN-low GC vs GS was 2.10 (95%CI; 1.07-4.11) in TCGA and 2.32 (95%CI; 1.18-4.55) in ACRG cohort, adjusting for age and pathological stage. Conclusions: We identified a CLDN-low GC which has a poor prognosis likely related to the resistance to conventional chemotherapy due to its EMT and TIC-like properties. Further development of targeted therapies against these molecular features is warranted to improve the outcome of CLDN-low GC.

Association between cetuximab response and differential immunologic gene expression signatures in colorectal cancer metastases

558

Background: Different immune cell infiltrates into colorectal cancer (CRC) tumors are associated with different prognoses. Tumor-associated macrophages contribute to immune evasion and accelerated tumor progression. Conversely, tumor infiltrating lymphocytes at the invasive margin of CRC liver metastases are associated with improved outcomes with chemotherapy. Cetuximab is an IgG1 monoclonal antibody against epidermal growth factor receptor (EGFR) and stimulates antibody-dependent cellular cytotoxicity (ADCC) in vitro. However, it is unclear in humans if response to cetuximab is modulated by the immune response. We hypothesized that different immune patterns detected in gene expression profiles of CRC metastases are associated with different responses to cetuximab. Methods: We retrieved gene expression data from biopsies of metastases from 80 refractory CRC patients treated with cetuximab monotherapy (GEO GSE5851). Samples were dichotomized by cetuximab response as having either disease control (DC) or progressive disease (PD). We performed gene set enrichment analysis (GSEA) with GenePattern 3.9.4 using gene sets of immunologic signatures obtained from the Molecular Signatures Database v5.0. Results: Among the 68 patients with response annotated, 25 had DC and 43 had PD. In the PD cohort, 59/1910 immunologic gene sets had false discovery rate (FDR) < 0.1. Notably, multiple gene sets upregulated in monocyte signatures were associated with PD. Also, gene sets consistent with PD1-ligated T cells compared to control activated T cells (FDR = 0.052) or IL4-treated CD4 T cells compared to controls (FDR = 0.087) were associated with PD. Conclusions: Cetuximab-resistant patients tended to have baseline increased expression of gene signatures reflective of monocytic infiltrates, consistent with also having increased expression of the IL4-treated T-cell signature. Cetuximab resistance was also associated with increased expression of the PD1-ligated T cell signature. These preliminary findings support further evaluation of the effect of differential immune infiltrates in prognosis of metastatic CRC treated with cetuximab.