Meyerhardt, Jeffrey A.

Abstract Background Synthetic control arms (SCAs) derived from historical trial data can complement randomized controlled trials (RCTs), particularly in oncology where feasibility, ethical, and cost constraints may limit conventional trial designs. However, their validity for overall survival (OS) remains uncertain. We evaluated the feasibility and limitations of constructing SCAs from the ARCAD metastatic colorectal cancer (mCRC) database across multiple treatment lines. Methods Seven landmark RCTs representing first-, second-, and third-line settings were selected. External control arms were constructed from ARCAD individual patient-level data using propensity score matching based on key clinical and biological variables from a validated ARCAD prognostic score, with adjustment for geographic region and time era when needed. A prespecified two-step benchmarking framework assessed: (1) control-arm OS reproducibility and (2) virtual trial comparisons between matched synthetic controls and original RCT experimental arms. Agreement was evaluated using hazard ratios (HRs) and Z-tests. Results A total of 28,022 patients met the inclusion criteria. ARCAD-derived SCAs were successfully constructed for all selected RCTs and closely reproduced control-arm OS. After matching, baseline characteristics were well balanced, with minimal differences between included and excluded patients. Virtual trials showed concordant treatment-effect estimates with the original RCTs, with a median absolute HR deviation of 0.05 and no significant differences by Z-tests (P>.05). Survival outcomes were consistently reproduced across treatment lines. Conclusion ARCAD-derived SCAs reliably reproduced control-arm OS and benchmark treatment-effect estimates from landmark RCTs in mCRC. Despite limitations related to residual confounding and missing data, this framework supports benchmarking, trial design, and exploratory analyses when conventional control arms are impractical.

Importance In a phase 2 randomized clinical trial, high-dose vitamin D 3 added to standard treatment improved progression-free survival (PFS) compared with standard-dose vitamin D 3 in patients with metastatic colorectal cancer (mCRC). Objective To determine if high-dose vitamin D 3 added to standard chemotherapy improves outcomes in patients with previously untreated mCRC. Design, Setting, and Participants Double-blind phase 3 randomized clinical trial enrolling 455 patients with previously untreated mCRC, conducted in the US through the National Clinical Trials Network from October 2019 to December 2022 (database freeze: July 15, 2024). Interventions mFOLFOX6 (modified FOLFOX6 [5-fluorouracil, leucovorin, oxaliplatin]) or FOLFIRI (5-fluorouracil, leucovorin, irinotecan) plus bevacizumab every 2 weeks with either high-dose vitamin D 3 (8000 IU daily × 14 days as loading dose followed by 4000 IU daily) or standard-dose vitamin D 3 (400 IU daily) until disease progression, intolerable toxicity, or withdrawal of consent. Main Outcomes and Measures The primary end point was PFS assessed by the unstratified log-rank test. Secondary end points included objective response rate, overall survival, and toxicity. Prespecified subgroup analyses of PFS were performed according to known prognostic factors. Results Among 455 randomized patients (median age, 59 years; 181 [40%] female) with median follow-up 20 months, the median PFS for high-dose vitamin D 3 (n = 228) was 11.8 months (95% CI, 10.3-13.3) vs 10.3 months (95% CI, 9.4-12.2) for standard-dose vitamin D 3 (n = 227) (1-sided log-rank P = .25). There were no significant differences in objective response rate between high-dose and standard-dose vitamin D 3 (51% [95% CI, 44%-58%] vs 44% [95% CI, 37%-50%], respectively; P = .12), or in overall survival (median, 25.6 vs 27.0 months; 1-sided log-rank P = .66). There were no clinically meaningful differences in the most common grade 3 or greater adverse events between the high- and standard-dose groups, including neutropenia (n = 67 [32%] vs n = 62 [30%]) and hypertension (n = 42 [20%] vs n = 49 [23%]) or in incidence of vitamin D–associated toxicities. Conclusions and Relevance Among patients with previously untreated mCRC, addition of high-dose vitamin D 3 , vs standard-dose vitamin D 3 , to standard chemotherapy plus bevacizumab did not improve PFS. Trial Registration ClinicalTrials.gov Identifier: NCT04094688

PURPOSE Social determinants of health (SDOH) shape cancer treatment access, adherence, and outcomes, yet their collection and use within National Clinical Trials Network (NCTN) studies remain poorly defined. This study examined how demographic and SDOH-related variables were historically collected and published to identify gaps that constrain the study of social context within NCTN trials. METHODS Participant-level data from completed phase III trials for gastrointestinal (GI) cancers conducted by the Alliance for Clinical Trials in Oncology (Alliance) or its legacy groups from 1999 to 2018 were pooled. Thirteen measures were assessed: four demographic and nine SDOH-related. The proportion of individual participants with data collected for each measure was evaluated. Data utilization was evaluated for all primary articles and via targeted review of related publications using the number either reporting subgroups or publishing analyses for each measure. RESULTS A total of 12,701 participants across 11 trials were included. All trials collected demographic measures (<2% of patients missing), insurance status (1% missing), and ZIP code (3% missing). Education level was collected in two trials (28% missing) with marital and employment status collected in one trial (41% missing for both). No trials collected data on other SDOH-related measures. Education level was the only SDOH-related measure reported in primary articles, and none reported analysis of SDOH-related measures. Of the 149 related publications, <2% reported or analyzed any SDOH-related measure. CONCLUSION Across Alliance and NCTN legacy group phase III trials for GI cancers, demographic variables have been consistently collected and frequently reported or analyzed, whereas SDOH-related measures are inconsistently collected and rarely published in the literature. These findings demonstrate a historical absence of routine SDOH data capture and utilization within NCTN trials.

4178 Background: In the CABINET trial, CABO significantly prolonged progression-free survival (PFS) compared to placebo (PB) in patients (pts) with advanced, previously treated extrapancreatic NET (epNET) or pancreatic NET (pNET) (Chan et al., NEJM, 2025). Here we report outcomes according to functional status based on NET hormone secretion. Methods: Pts with locally advanced or metastatic epNET or pNET were randomized 2:1 in separate cohorts to receive CABO 60 mg daily vs PB. Eligibility included progression by RECIST within 12 months (mo) before registration, ≥ 1 prior systemic therapy not including somatostatin analogs (SSA). Pts with functional NET due to hormone secretion and non-functional NET were included. In this post hoc subgroup analysis, we analyzed PFS by blinded independent central review and adverse events for pts receiving CABO vs PB based on functional status. Cox regression models were used with stratification on primary tumor site (epNET vs pNET). Subset analyses to evaluate treatment arm differences were conducted in pts with functional and non-functional tumors. Due to small numbers, separate results for those with unknown functional status are not included. Results: Of the total 298 pts enrolled in both cohorts, 74 had a functional NET (CABO, n = 47; PB, n = 27); 179 had a non-functional NET (CABO, n = 123; PB, n = 56); 45 had unknown functional status (CABO, n = 28; PB, n = 17). For functional NET, primary tumor sites were GI tract (n = 50; 68%), pancreas (n = 15; 20%), unknown (n = 4; 5%), lung (n = 3; 4%), and thymus (n = 2; 3%). Secreted hormones that were reported included serotonin (55%), somatostatin (18%), gastrin (16%), glucagon (4%), insulin (4%), ACTH (1%), and vasoactive intestinal peptide (1%). For non-functional NET, primary tumor sites were pancreas (n = 75; 42%), GI tract (n = 42; 23%), lung (n = 30; 17%), unknown (n = 17; 9%), thymus (n = 8; 4%), and other (n = 7; 4%). Concurrent SSA was received by 91% and 53% of pts with functional and non-functional NET, respectively. In both subgroups, CABO was associated with improved PFS compared to PB (for functional NET: stratified hazard ratio [sHR], 0.40; 95% confidence interval [CI]: 0.20-0.82, P = 0.012; for non-functional NET: sHR, 0.26; 95% CI: 0.17-0.41, P < 0.001). The most frequent grade 3/4 adverse events (AEs) attributed to CABO vs PB in pts with functional NET included hypertension (21% vs 11%), diarrhea (9% vs 11%), and fatigue (2% vs 15%); in pts with non-functional NET, grade 3/4 AEs included hypertension (21% vs 4%) and fatigue (18% vs 4%). Conclusions: Subset analyses of the CABINET trial suggest that CABO is an effective treatment option for pts with functional and non-functional epNET or pNET. Efficacy and safety results for pts with functional or non-functional NET treated with CABO are consistent with results for the entire trial. Clinical trial information: NCT03375320 .

3626 Background: For patients (pts) with dMMR stage III colon cancer, the addition of atezolizumab (atezo) to adjuvant 5-fluorouracil, leucovorin plus oxaliplatin (mFOLFOX6) significantly improved disease-free survival in ATOMIC (NCT02912559). Here we present HRQOL data. Methods: Pts with surgically resected stage III dMMR colon cancer were randomized (1:1) to receive mFOLFOX6 + atezo (840 mg IV q2 weeks) for 12 cycles (6 months [mo]) followed by atezo monotherapy for 13 cycles (12 mo total) versus mFOLFOX6 for 12 cycles. HRQOL was an exploratory endpoint measured using the FACT-C (includes FACT-G), FACT/GOG-NTX, EQ5D-5L, and PRO-CTCAE. Optional participation was by paper surveys at trial registration, prior to treatment cycles 4 and 7, and at 6, 12, and 36 mo after registration. Mean changes from baseline (BL) were compared between treatment arms using general linear mixed models (negative mean changes indicate worsening). At 6 mo, a two-sided 95% confidence interval excluding a difference of 1.9 points (FACT/GOG-NTX) and 6 points (FACT-C Trial Outcome Index [TOI]) favoring the mFOLFOX6 arm would indicate non-inferiority of the addition of atezo. Rates of side effect bother (FACT-G item GP5) and pt-reported adverse events (AEs) by PRO-CTCAE (composite scores, baseline adjusted) were compared using Fisher’s exact tests. Results: Of 712 randomized pts, 581 (285 atezo+mFOLFOX6; 296 mFOLFOX6) consented to participate in the survey. Pts completed 2398/3021 (79%) of expected surveys across all time points (1218/1489 [82%] atezo+mFOLFOX6; 1180/1532 [77%] mFOLFOX6). The difference in mean changes from BL between arms indicated non-inferiority of the addition of atezo at 6 mo (table); differences remained small at 12 and 36 mo. No significant differences in mean changes from BL between arms were found at 6, 12, or 36 mo for any scale. At 6 mo, 16% vs 20% of pts in each arm reported at least “quite a bit” of side effect bother (p=0.34), favoring atezo. Across cycles, atezo was associated with higher rates of pt-reported itchy skin (62% vs 48%), cough (53% vs 43%), and shortness of breath (51% vs 41%) [all p<0.05]. Conclusions: Addition of atezo to mFOLFOX6 slightly increases pt-reported AEs, but its effect on HRQOL is minimal and not clinically meaningful. Results support tolerability of atezo+mFOLFOX6 as standard of care adjuvant treatment for pts with dMMR stage III colon cancer. Support: UG1CA189823, U10CA180821, U10CA180882; Genentech, a member of the Roche group; https://acknowledgments.alliancefound.org. Clinical trial information: NCT02912559 . Scale Mo Mean change from BL – atezo+mFOLFOX6 Mean change from BL – mFOLFOX6 Diff (95% CI) FACT/GOG-NTX 6 -10.0 -10.6 0.6 (-0.8, 2.1) 12 -8.0 -9.4 1.4 (-0.2, 2.9) 36 -7.2 -6.9 -0.4 (-2.1, 1.4) FACT-C TOI 6 -4.1 -2.5 -1.6 (-3.7, 0.6) 12 2.1 1.8 0.3 (-1.9, 2.6) 36 0.7 1.8 -1.1 (-3.7, 1.5)

Abstract Background: Adhering to 2018 World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) Cancer Prevention Recommendations is reportedly associated with better survival among long-term colon cancer survivors (likely affected by immortal time bias). Thus, it is important to validate survival benefits by assessing adherence shortly after diagnosis, and further investigation is needed to examine its association with chemotherapy outcomes. Methods: Using an NCI-sponsored adjuvant chemotherapy trial conducted in patients with stage III colon cancer (CALGB/SWOG 80702; NCT01150045), we included 1,666 patients who returned valid Willett food frequency questionnaires (FFQ) at chemotherapy initiation and derived WCRF/AICR scores accordingly (higher score suggesting higher adherence). The primary outcome was disease-free survival (time from FFQ completion to recurrence or death), and secondary outcomes were reduced relative dose intensity (RDI; &lt;85% suggesting worse completion) and severe toxicities (grade ≥3 for any chemotherapy-related toxicity). To estimate the associations of WCRF/AICR scores (quartiles) with survival and chemotherapy outcomes, we conducted multivariable Cox proportional hazards regression for disease-free survival and multivariable logistic regression for reduced RDI and severe toxicities. Results: Compared to those in the lowest quartile of the WCRF/AICR score, patients in the highest quartile had significantly better disease-free survival (hazard ratio: 0.75 [0.58, 0.98], Ptrend = 0.02) and lower risk of reduced RDI (odds ratio [OR]: 0.74 [0.54, 1.00], Ptrend = 0.03), but not for severe toxicities (OR: 1.24 [0.93, 1.67], Ptrend = 0.11). Conclusions: In patients with stage III colon cancer, higher adherence to WCRF/AICR recommendations was associated with better survival and chemotherapy completion, but not for severe toxicities. Funding: https://acknowledgments.alliancefound.org Citation Format: En Cheng, Chao Ma, Qian Shi, Anthony F. Shields, Peter T. Campbell, Ardaman P. Shergill, Katherine A. Guthrie, Felix Couture, Philip Kuebler, Pankaj Kumar, Benjamin Tan, Smitha S. Krishnamurthi, Kimmie Ng, Eileen M. O'Reilly, Justin C. Brown, Philip A. Philip, Jeffrey A. Meyerhardt. Associations of WCRF/AICR recommendations with survival and chemotherapy outcomes in colon cancer: CALGB/SWOG 80702 (Alliance) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5038.

PURPOSE The primary objective of this randomized, double-blind, placebo-controlled, multicenter phase II study (Alliance A221805) was to screen two doses of duloxetine for preventing sensory oxaliplatin-induced peripheral neuropathy (OIPN). METHODS Participants were randomly assigned 1:1:1 to receive once daily 30 mg duloxetine, 60 mg duloxetine, or placebo. Eligible participants had stage II to III colorectal cancer and no baseline neuropathy, had Eastern Cooperative Oncology Group performance status 0-2, were age 25 years and older, and received oxaliplatin via one of the following doses and schedules: 85 mg/m 2 every 2 weeks (6 or 12 doses) or 130 mg/m 2 every 3 weeks (4 doses). Duloxetine/placebo was taken once daily beginning day 1 of cycle 1 and continued for 17 weeks. The primary end point, a composite response reflecting sensory OIPN symptom severity and onset, was measured in weeks 19-21 using a validated participant-reported outcome survey assessing extremity numbness, tingling, and pain. Response was defined as a participant-reported highest score of ≤2 (ie, 1 = not at all; 2 = a little) on survey items. To be evaluable for the response end point, eligible participants must have initiated oxaliplatin and submitted ≥1 postbaseline OIPN survey. RESULTS Of the 199 participants (n = 66, 30 mg duloxetine; n = 66, 60 mg duloxetine; n = 67, placebo), 46, 47, and 50 (N = 143, 71.8%), respectively, were evaluable for primary end point analysis based on modified intention-to-treat criteria. Participant mean age was 55.1 years (standard deviation = 10.4). Most were White (n = 113, 80.7%) and male (n = 82, 58.6%). The proportion of responders among those receiving placebo (68.0%) was similar to those receiving duloxetine 30 mg (65.2%) or 60 mg (66.0%). Duloxetine adherence rates, measured via pill counts—30 mg (54%), 60 mg (57%), and placebo (59%) groups—were low (<75%). CONCLUSION Duloxetine is not more promising than placebo for preventing sensory OIPN.

Importance Observational studies have associated use of aspirin and selective cyclooxygenase inhibitors with decreased recurrence and improved survival in patients with colon cancer. While randomized clinical trials have not shown benefit across all patients, these findings suggest that select subgroups may benefit from their use. Despite the well-established prognostic value of circulating tumor DNA (ctDNA), its role in guiding treatment remains unclear. Objective To investigate the predictive value of postoperative ctDNA for survival outcomes with adjuvant celecoxib alongside conventional chemotherapy in patients with stage III colon cancer. Design, Setting, and Participants This was a post hoc analysis of the phase 3 Cancer and Leukemia Group B (now Alliance)/Southwest Oncology Group 80702 randomized clinical trial (2010-2015) assessing adjuvant celecoxib vs placebo and 3 vs 6 months of adjuvant 5-fluorouracil, leucovorin, and oxaliplatin for stage III colon cancer. Patients consented to biospecimen collection and had ctDNA analysis performed. Data analysis was performed from September 2024 to June 2025. Exposures Postoperative ctDNA positivity was determined using a clinically validated, tumor-informed 16-plex-polymerase chain reaction-next-generation sequencing assay (Signatera; Natera Inc) performed between surgery and initiation of adjuvant therapy. Main Outcomes and Measures Disease-free survival (DFS) and overall survival (OS). Survival by ctDNA status and adjuvant celecoxib use were assessed as part of a post hoc companion study with prespecified statistical analysis plan. Results Among 940 patients (mean [SD] age, 60.9 [10.8] years; 426 female [45.3%] and 515 male [54.7%] individuals; 222 [23.6%] with prior low-dose aspirin use; and median follow-up of 6.0 [95% CI, 6.0-6.0] years), 767 (81.6%) were ctDNA negative and 173 (18.4%) were ctDNA positive. ctDNA positivity was highly prognostic of worse DFS (reference, ctDNA negativity; adjusted hazard ratio [aHR], 6.12; 95% CI, 4.66-8.03) and OS (aHR, 5.86; 95% CI, 4.19-8.19). In patients with ctDNA positivity, celecoxib was associated with improved DFS (aHR, 0.61; 95% CI, 0.42-0.89) and OS (aHR, 0.62; 95% CI, 0.40-0.96) compared to placebo. Among patients with ctDNA negativity, celecoxib did not provide survival benefit (DFS: aHR, 0.76; 95% CI, 0.53-1.09; OS: aHR, 0.85; 95% CI, 0.54-1.36), although the interaction was not significant ( P for interaction, .41 and .33 for DFS and OS, respectively). These findings persisted when stratifying patients by microsatellite instability status and PIK3CA mutational status. Conclusion and Relevance The findings of this post hoc analysis suggest that ctDNA status has the potential to inform clinical decision-making among patients with stage III colon cancer who should consider adjuvant celecoxib in addition to conventional chemotherapy. Trial Registration ClinicalTrials.gov Identifier: NCT01150045