A Bayesian approach for two-stage multivariate Mendelian randomization with mixed outcomes.

Many research studies have investigated the relationship between baseline factors or exposures, such as patient demographic and disease characteristics, and study outcomes such as toxicities or quality of life, but results from most of these studies may be problematic because of potential confounding effects (eg, the imbalance in baseline factors or exposures). It is important to study whether the baseline factors or exposures have causal effects on the clinical outcomes, so that clinicians can have better understanding of the diseases and develop personalized medicine. Mendelian randomization (MR) provides an efficient way to estimate the causal effects using genetic instrumental variables to handle confounders, but most of the existing studies focus on a single outcome at a time and ignores the correlation structure of multiple outcomes. Given that clinical outcomes like toxicities and quality of life are usually a mixture of different types of variables, and multiple datasets may be available for such outcomes, it may be much more beneficial to analyze them jointly instead of separately. Some well-established methods are available for building multivariate models on mixed outcomes, but they do not incorporate MR mechanism to deal with the confounders. To overcome these challenges, we propose a Bayesian-based two-stage multivariate MR method for mixed outcomes on multiple datasets, called BMRMO. Using simulation studies and clinical applications on the CO.17 and CO.20 studies, we demonstrate better performance of our approach compared to the commonly used univariate two-stage method.

Complementary Medicine Use Amongst Patients with Metastatic Cancer Enrolled in Phase III Clinical Trials.

BACKGROUND: Complementary medicines (CM) are frequently used by patients with cancer. Controversy exists over the effectiveness and risk that CM may add to conventional cancer therapy. The incidence of CM use among patients enrolled in phase III clinical trials is unknown. METHODS: Medication lists from 6 international phase III clinical trials were retrospectively reviewed to identify patients using CM. Patients had metastatic breast, colorectal, or lung cancers. Quality of life, adverse events, overall survival, and progression-free survival were compared between CM users and non-users. Baseline differences between groups were adjusted with propensity score matching groups. RESULTS: Seven hundred and six of 3446 patients (20.5%) used at least one CM. CM use was highest among patients with breast cancer (35.6%). CM users had more favorable baseline prognostic factors (ECOG 0-1, non-smoking status, younger age, and fewer metastases). CM use was associated with lower rates of adverse events (50% vs. 62%, P = .002) and quality of life was similar between both groups. After adjustment with propensity score matching, CM use was also associated with longer overall survival in patients with lung cancer (adjusted hazard ratio 0.80, 95%CI, 0.68-0.94, P =.0054). However, several key control variables like EGFR status were not available. CONCLUSION: One in 5 patients in phase III clinical trials report using CM. CM was not associated with worse cancer-specific outcomes. However, CM users had more favorable baseline prognostic factors, and likely other confounders that may have contributed to improved outcomes observed in the lung cohort. Physicians should monitor for CM use and potential interactions with clinical trial drugs.

A phase Ib study of a PI3Kinase inhibitor BKM120 in combination with panitumumab in patients with KRAS wild-type advanced colorectal cancer.

Background Resistance to Epidermal Growth Factor inhibition (EGFRi) in patients with KRAS wild-type (wt) Colorectal Cancer (CRC) may occur as a result of PI3K/AKT/mTOR signaling. We conducted a study to establish the recommended phase II dose (RP2D) and response rate of panitumumab, an EGFRi, plus BKM120, a PI3K inhibitor, in advanced CRC. Methods Patients with chemotherapy refractory KRAS wt CRC, who were EGFRi naive were enrolled. A 3 + 3 dose escalation design was utilized. The starting dose of panitumumab was 6 mg/kg iv every 2 weeks with BKM120 at 60 mg oral daily. Results Nineteen patients were treated and 17 were evaluable for response. The starting dose was not tolerable (mucositis, fatigue). At dose level (DL) 1, three of six patients discontinued treatment due to toxicity, DL - 1 had no significant toxicity. Panitumumab 6 mg/kg iv q 2 weeks with BKM120 60 mg given 5 out of 7 days per week was declared the RP2D. One patient (5.9%) who was PTEN and PIK3CA negative by IHC had a partial response, seven had stable disease, and nine had disease progression. Conclusion Panitumumab (6 mg/kg iv q 2 weeks) with BKM120 60 mg given 5 out of 7 days per week was declared the RP2D. Toxicities including fatigue, rash and mucositis. There was little evidence of activity in this biomarker unselected cohort.

Accuracy and Prognostic Significance of Oncologists' Estimates and Scenarios for Survival Time in Advanced Gastric Cancer.

BACKGROUND: Worst-case, typical, and best-case scenarios for survival, based on simple multiples of an individual's expected survival time (EST), estimated by their oncologist, are a useful way of formulating and explaining prognosis. We aimed to determine the accuracy and prognostic significance of oncologists' estimates of EST, and the accuracy of the resulting scenarios for survival time, in advanced gastric cancer. MATERIALS AND METHODS: Sixty-six oncologists estimated the EST at baseline for each of the 152 participants they enrolled in the INTEGRATE trial. We hypothesized that oncologists' estimates of EST would be unbiased (∼50% would be longer or shorter than the observed survival time [OST]); imprecise (<33% within 0.67-1.33 times the OST); independently predictive of overall survival (OS); and accurate at deriving scenarios for survival time with approximately 10% of patients dying within a quarter of their EST (worst-case scenario), 50% living within half to double their EST (typical scenario), and 10% living three or more times their EST (best-case scenario). RESULTS: Oncologists' estimates of EST were unbiased (45% were shorter than the OST, 55% were longer); imprecise (29% were within 0.67-1.33 times observed); moderately discriminative (Harrell's C-statistic 0.62, p = .001); and an independently significant predictor of OS (hazard ratio, 0.89; 95% confidence interval, 0.83-0.95; p = .001) in a Cox model including performance status, number of metastatic sites, neutrophil-to-lymphocyte ratio ≥3, treatment group, age, and health-related quality of life (EORTC-QLQC30 physical function score). Scenarios for survival time derived from oncologists' estimates were remarkably accurate: 9% of patients died within a quarter of their EST, 57% lived within half to double their EST, and 12% lived three times their EST or longer. CONCLUSION: Oncologists' estimates of EST were unbiased, imprecise, moderately discriminative, and independently significant predictors of OS. Simple multiples of the EST accurately estimated worst-case, typical, and best-case scenarios for survival time in advanced gastric cancer. IMPLICATIONS FOR PRACTICE: Results of this study demonstrate that oncologists' estimates of expected survival time for their patients with advanced gastric cancer were unbiased, imprecise, moderately discriminative, and independently significant predictors of overall survival. Simple multiples of the expected survival time accurately estimated worst-case, typical, and best-case scenarios for survival time in advanced gastric cancer.

Advantages of the net benefit regression framework for trial-based economic evaluations of cancer treatments: an example from the Canadian Cancer Trials Group CO.17 trial.

BACKGROUND: Economic evaluations commonly accompany trials of new treatments or interventions; however, regression methods and their corresponding advantages for the analysis of cost-effectiveness data are not widely appreciated. METHODS: To illustrate regression-based economic evaluation, we review a cost-effectiveness analysis conducted by the Canadian Cancer Trials Group's Committee on Economic Analysis and implement net benefit regression. RESULTS: Net benefit regression offers a simple option for cost-effectiveness analyses of person-level data. By placing economic evaluation in a regression framework, regression-based techniques can facilitate the analysis and provide simple solutions to commonly encountered challenges (e.g., the need to adjust for potential confounders, identify key patient subgroups, and/or summarize "challenging" findings, like when a more effective regimen has the potential to be cost-saving). CONCLUSIONS: Economic evaluations of patient-level data (e.g., from a clinical trial) can use net benefit regression to facilitate analysis and enhance results.

Intravenous delivery of a multi-mechanistic cancer-targeted oncolytic poxvirus in humans.

The efficacy and safety of biological molecules in cancer therapy, such as peptides and small interfering RNAs (siRNAs), could be markedly increased if high concentrations could be achieved and amplified selectively in tumour tissues versus normal tissues after intravenous administration. This has not been achievable so far in humans. We hypothesized that a poxvirus, which evolved for blood-borne systemic spread in mammals, could be engineered for cancer-selective replication and used as a vehicle for the intravenous delivery and expression of transgenes in tumours. JX-594 is an oncolytic poxvirus engineered for replication, transgene expression and amplification in cancer cells harbouring activation of the epidermal growth factor receptor (EGFR)/Ras pathway, followed by cell lysis and anticancer immunity. Here we show in a clinical trial that JX-594 selectively infects, replicates and expresses transgene products in cancer tissue after intravenous infusion, in a dose-related fashion. Normal tissues were not affected clinically. This platform technology opens up the possibility of multifunctional products that selectively express high concentrations of several complementary therapeutic and imaging molecules in metastatic solid tumours in humans.

A phase I study of high-dose rosuvastatin with standard dose erlotinib in patients with advanced solid malignancies.

BACKGROUND: Synergistic cytotoxicity with high-dose statins and erlotinib has been demonstrated in preclinical models across a number of tumour types. In this phase I study, we evaluated the safety and potential anti-tumour activity of escalating doses of rosuvastatin in combination with the standard clinical dose of erlotinib in heavily pretreated patients with advanced solid tumours. METHODS: This was a single-center, phase I open-label study to determine the safety and recommended phase two dose (RPTD) of rosuvastatin in combination with 150 mg/day standard dose of erlotinib. Using a 3 + 3 study design and 28-day cycle, escalating doses of rosuvastatin from 1 to 8 mg/kg/day × 2 weeks (cycle 1) and 3 weeks (subsequent cycles) given concurrently with erlotinib were evaluated. In order to expand the experience and to gain additional safety and pharmacokinetic data, two expansions cohorts using concurrent or alternating weekly dosing regimens at the RPTD were also evaluated. RESULTS: All 24 patients enrolled were evaluable for toxicity, and 22 for response. The dose-limiting toxicity (DLT) of reversible muscle toxicity was seen at the 2 mg/kg/day dose level. Maximal tolerated dose (MTD) was determined to be 1 mg/kg/day. Thirty-three percent of patients developed at least 1 ≥ grade 2 muscle toxicity (rhabdomyolysis: 1/24, myalgia: 7/24) resulting in one study-related death. Durable stable disease for more than 170 days was seen in 25 % of patients that received concurrent treatment and were evaluable for response (n = 16). Plasma erlotinib levels on study were unaffected by the addition of rosuvastatin. CONCLUSIONS: The observed disease stabilization rate of 25 % with combination therapy in this heavily pretreated population is encouraging, however, the high levels of muscle toxicities observed limited this combination strategy.

A Phase I study of olaparib and irinotecan in patients with colorectal cancer: Canadian Cancer Trials Group IND 187.

Background Olaparib is an orally available inhibitor of PARP-1. In pre-clinical studies, olaparib was shown to potentiate anti-tumor effects of irinotecan in colon cancer cell lines. This phase I study was conducted to evaluate the safety and tolerability of olaparib in combination with irinotecan. Patients and Methods Patients with advanced colorectal cancer whose disease progressed after at least one systemic therapy regimen were enrolled. Dose escalation and de-escalation were based on toxicity assessment. Pharmacokinetic samples were collected in Cycle 1 for olaparib, irinotecan and SN-38. Results Twenty-five patients were enrolled, 11 patients on a schedule of continuous olaparib and irinotecan every 3 weeks (Part A) and 14 patients on a schedule of intermittent olaparib and irinotecan every 2 weeks (Part B). Continuous olaparib administration was associated with higher than expected toxicities and was not considered to be tolerable. Intermittent olaparib administration was better tolerated, and the recommended phase 2 doses were olaparib 50 mg p.o twice daily days 1-5 and irinotecan 125 mg/m(2) i.v. every 2 weeks. Common toxicities included fatigue, anorexia, diarrhea, nausea, vomiting, neutropenia, thrombocytopenia and abdominal pain. Nine patients had stable disease as the best response, 2 from Part A (3 and 9 months respectively), and 7 from Part B (median duration: 7.4 months; range: 4 to 13 months). There was no pharmacokinetic interaction between olaparib and irinotecan. Conclusions Olaparib can be combined with irinotecan if administered intermittently. Both olaparib and irinotecan required significant dose reductions. The lack of anti-tumor efficacy observed in this trial makes this combination of little interest for further clinical development. Trial Registration ID NCT00535353.

ABCC5 and ABCG1 polymorphisms predict irinotecan-induced severe toxicity in metastatic colorectal cancer patients.

OBJECTIVE: Irinotecan is a cytotoxic agent used widely for the treatment of solid tumors, particularly for metastatic colorectal cancers. Treatment with this drug frequently results in severe neutropenia and diarrhea that can markedly impact the course of treatment and patients' quality of life. Pharmacogenomic tailoring of irinotecan-based chemotherapy has been the subject of several investigations, but with limited data on ATP-binding cassette (ABC) and solute carrier (SLC) transporter genes. MATERIALS AND METHODS: In this study, we aimed to discover toxicity-associated markers in seven transporter genes participating in irinotecan pharmacokinetics involving the ABC transporter genes ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, and ABCG2 and the solute carrier organic anion transporter gene SLCO1B1 and using a haplotype-tagging single-nucleotide polymorphisms (n=210 htSNPs) strategy. The profiles of 167 metastatic colorectal cancer Canadian patients treated with FOLFIRI-based regimens were examined and the findings were replicated in an independent cohort of 250 Italian patients. RESULTS: In combined cohorts, a two-marker ABCC5 rs3749438 and rs10937158 haplotype (T-C) predicted lower risk of severe diarrhea [odds ratio (OR) of 0.43; P=0.001]. The co-occurrence of ABCG1 rs225440T and ABCC5 rs2292997A predicted the risk of severe neutropenia (OR=5.93; P=0.0002), which was further improved when incorporating the well-known risk marker UGT1A1*28 rs8175347 (OR=7.68; P<0.0001). In contrast, carriers of one protective marker (UGT1 rs11563250G) but none of these risk alleles experienced significantly less severe neutropenia (8.2 vs. 34.0%; P<0.0001). CONCLUSION: This combination of predictive genetic markers could potentially lead to better risk assessment and may thus improve personalized treatment.

Quality of life in patients with K-RAS wild-type colorectal cancer: the CO.20 phase 3 randomized trial.

BACKGROUND: The CO.20 trial randomized patients with K-RAS wild-type, chemotherapy-refractory, metastatic colorectal cancer to receive cetuximab (CET) plus brivanib alaninate (BRIV) or CET plus placebo (CET/placebo). METHODS: Quality of life (QoL) was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 at baseline and at 2, 4, 6, 8, 12, 16, and 24 weeks until disease progression. Predefined coprimary QoL endpoints were time to deterioration (first worsening from baseline of ≥ 10 points) on the Physical Function (PF) and Global (GHS) scales. RESULTS: Of 750 randomized patients, 721 (358 of whom received CET/BRIV) were assessable for QoL. QoL compliance and baseline PF and GHS scores did not differ by treatment arm. The median time to deterioration was 1.6 months versus 1.1 months for GHS (P =.02) and 5.6 months versus 1.7 months for PF (P <.0001) favoring CET/placebo. Secondary analysis favored CET/placebo for QOL response on the PF, Cognitive Function, Fatigue, Nausea, Appetite, and Diarrhea scales. A greater percentage of patients on the CET/BRIV arm had PF worsening at 6 weeks (31% vs 17%). Clinical adverse events of ≥ grade 3 were more common with CET/BRIV than with CET/placebo, including fatigue (25% vs 11%), hypertension, rash, diarrhea, abdominal pain, dehydration, and anorexia. CONCLUSIONS: Compared with CET/placebo, the combination of CET/BRIV worsened time to QoL deterioration for patients with K-RAS wild-type, chemotherapy-refractory, metastatic colorectal cancer on the PF and GHS scales of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. This result may be due to higher rates of fatigue and gastrointestinal adverse events.

Chemotherapy regimens for advanced pancreatic cancer: a systematic review and network meta-analysis.

BACKGROUND: Advanced pancreatic cancer confers poor prognosis and treatment advancement has been slow. Recent randomized clinical trials (RCTs) have demonstrated survival benefits for combination therapy compared to gemcitabine alone. However, the comparative benefits and harms of available combination chemotherapy treatments are not clear. We therefore conducted a systematic review and Bayesian network meta-analysis to assess the comparative safety and efficacy of chemotherapy regimens for the treatment of advanced pancreatic cancer. METHODS: MEDLINE, PubMed, EMBASE, Cochrane Central Registry of Clinical trials and abstracts from major scientific meetings were searched for RCTs published from 2002 to 2013. Key outcomes were overall survival (OS), progression free survival (PFS), and safety including grade 3-4 febrile neutropenia, neutropenia, vomiting, diarrhea, fatigue and sensory neuropathy. Bayesian network meta-analyses were conducted to calculate survival and safety outcomes using gemcitabine (GEM) as the reference comparator. Effect estimates and 95% credible intervals were calculated for each comparison. Mean ranks and the probability of being best were obtained for each treatment analyzed in the network meta-analysis. RESULTS: The search identified 23 studies involving 19 different treatment regimens and 9,989 patients. FOLFIRINOX, GEM/cisplatin/epirubicin/5FU (PEFG), GEM/NAB-paclitaxel (NAB-P), GEM/erlotinib+/-bevacizumab, GEM/capecitabine, and GEM/oxaliplatin were associated with statistically significant improvements in OS and PFS relative to gemcitabine alone and several other treatments. They were amongst the top ranked for survival outcomes amongst other treatments included. No significant differences were found for other combination chemotherapy treatments. Effect estimates from indirect comparisons matched closely to estimates derived from pairwise comparisons. Overall, combination therapies had greater risk for evaluated grade 3-4 toxicities over gemcitabine alone. CONCLUSIONS: In the absence of head-to-head comparisons, we performed a mixed-treatment analysis to achieve high-quality information on the effectiveness and safety of each treatment. This study suggests that some combination therapies may offer greater benefits in the treatment of advanced pancreatic cancer than others. To more fully elucidate the comparative benefits and harms of different combination chemotherapy regimens, rigorously conducted comparative studies, or network meta-analysis of patient-level data are required.

Patterns of recurrence following selective intraoperative radiofrequency ablation as an adjunct to hepatic resection for colorectal liver metastases.

BACKGROUND AND OBJECTIVES: The purpose of this study was to analyze the patterns of recurrence following intraoperative radiofrequency ablation (RFA) combined with hepatic resection for patients with colorectal liver metastases (CLM). METHODS: Patients undergoing liver resection (with or without RFA) for CLM were examined. Rates and patterns of disease recurrence, as well as overall survival were assessed using Kaplan-Meier and Cox analyses. RESULTS: A total of 174 patients underwent liver resection for CLM (150 without and 24 with intraoperative RFA). RFA was used to treat 41 tumors (median 1.6 cm). The 3-year overall survival was 65.5% and 61.4% (adjusted HR 1.02, 95% CI 0.55-1.88). Median recurrence-free survival was 7.4 versus 12.7 months with RFA versus non-RFA, respectively (adjusted HR 1.51, 95% CI 0.94-4.42). On multivariate analysis, neither survival nor recurrence-free survival was significantly associated with RFA. In total, there were two RFA ablation zone local failures. An ablation site recurrence was the sole site in one patient (4.2%). CONCLUSION: RFA was used as an adjunct to resection in patients with greater disease burden. Despite this, RFA was not significantly associated with a higher risk of local failure and was not associated with worse survival, when compared with liver resection alone.

The relationship between rash, tumour KRAS mutation status and clinical and quality of life outcomes in patients with advanced colorectal cancer treated with cetuximab in the NCIC CTG/AGITG CO.17.

BACKGROUND: The NCIC CTG/AGITG CO.17 trial demonstrated that cetuximab monotherapy improved overall and progression-free survival (OS and PFS) in patients previously treated for advanced colorectal cancer. A strong relationship was observed between benefit from cetuximab and development of rash. In this analysis, the association of rash and benefit from cetuximab is explored and presented by KRAS mutation status. MATERIAL AND METHODS: Rash was graded by NCI CTC 2.0 criteria. Landmark analysis was performed by excluding patients who died or dropped out within 28 days and then grouping by worst grade of rash experienced by day 28. Multivariate Cox models were conducted separately for patients with KRAS wild-type (WT) tumours and KRAS mutated (MUT) tumours. CO.17 primary outcome was OS. RESULTS: Development of grade 2 + rash on cetuximab was associated with a trend towards increased OS (HR 0.61 with 95% CI 0.36-1.02 and p = 0.06) and PFS (HR 0.68 with 95% CI 0.45-1.03 and p = 0.07) as compared to grade 0/1 rash in patients with WT tumours. In patients with WT tumours on cetuximab both grade 0/1 and grade 2 + rash were associated with increased PFS (HR 0.57 95% CI 0.38-0.86; p = 0.008; and HR 0.32 95% CI 0.21-0.49; p < 0.0001) respectively, in comparison with best supportive care (BSC). Only development of grade 2 + rash on cetuximab was associated with increased OS (HR 0.52 with 95% CI 0.34-0.80 and p = 0.003) in comparison with BSC. No significant difference was found in OS or PFS among patients on cetuximab with MUT tumours with either rash grade as compared to BSC. No consistent trend was observed for the association of severity of rash and quality of life (QoL). CONCLUSION: As all patients with WT tumours benefitted to some extent from cetuximab regardless of the grade of rash, grade of rash was not a useful predictive marker.

Bevacizumab plus capecitabine versus capecitabine alone in elderly patients with previously untreated metastatic colorectal cancer (AVEX): an open-label, randomised phase 3 trial.

BACKGROUND: Elderly patients are often under-represented in clinical trials of metastatic colorectal cancer. We aimed to assess the efficacy and safety of bevacizumab plus capecitabine compared with capecitabine alone in elderly patients with metastatic colorectal cancer. METHODS: For this open-label, randomised phase 3 trial, patients aged 70 years and older with previously untreated, unresectable, metastatic colorectal cancer, who were not deemed to be candidates for oxaliplatin-based or irinotecan-based chemotherapy regimens, were randomly assigned in a 1:1 ratio via an interactive voice-response system, stratified by performance status and geographical region. Treatment consisted of capecitabine (1000 mg/m(2) orally twice a day on days 1-14) alone or with bevacizumab (7·5 mg/kg intravenously on day 1), given every 3 weeks until disease progression, unacceptable toxic effects, or withdrawal of consent. Efficacy analyses were based on the intention-to-treat population. The primary endpoint was progression-free survival. The trial is registered with ClinicalTrials.gov, number NCT00484939. FINDINGS: From July 9, 2007, to Dec 14, 2010, 280 patients with a median age of 76 years (range 70-87) were recruited from 40 sites across ten countries. Patients were randomly assigned to receive either bevacizumab plus capecitabine (n=140) or capecitabine only (n=140). Progression-free survival was significantly longer with bevacizumab and capecitabine than with capecitabine alone (median 9·1 months [95% CI 7·3-11·4] vs 5·1 months [4·2-6·3]; hazard ratio 0·53 [0·41-0·69]; p<0·0001). Treatment-related adverse events of grade 3 or worse occurred in 53 (40%) patients in the combination group and 30 (22%) in the capecitabine group, and treatment-related serious adverse events in 19 (14%) and 11 (8%) patients. The most common grade 3 or worse adverse events of special interest for bevacizumab or chemotherapy were hand-foot syndrome (21 [16%] vs nine [7%]), diarrhoea (nine [7%] vs nine [7%]), and venous thromboembolic events (11 [8%] vs six [4%]). Treatment-related deaths occurred in five patients in the combination group and four in the capecitabine group. The most common any-grade adverse event of special interest for bevacizumab was haemorrhage (34 [25%] vs nine [7%]). INTERPRETATION: The combination of bevacizumab and capecitabine is an effective and well-tolerated regimen for elderly patients with metastatic colorectal cancer. FUNDING: F Hoffmann-La Roche.

A Randomized Phase III Study of Arfolitixorin versus Leucovorin with 5-Fluorouracil, Oxaliplatin, and Bevacizumab for First-Line Treatment of Metastatic Colorectal Cancer: The AGENT Trial.

PURPOSE: Suboptimal treatment outcomes with 5-fluorouracil (5-FU)/folate, the standard of care for metastatic colorectal cancer (mCRC), have generated interest in optimizing the folate. Arfolitixorin ([6R]-5,10-methylene-tetrahydrofolate) is an immediately active folate and may improve outcomes over the existing standard of care (leucovorin). EXPERIMENTAL DESIGN: AGENT was a randomized, phase III study (NCT03750786). Patients with mCRC were randomized to arfolitixorin (120 mg/m2 given as two intravenous bolus doses of 60 mg/m2) or leucovorin (400 mg/m2 given as a single intravenous infusion) plus 5-FU, oxaliplatin, and bevacizumab. Assessments were performed every 8 weeks. The primary endpoint was the superiority of arfolitixorin for overall response rate (ORR). RESULTS: Between February 2019 and April 2021, 490 patients were randomized (245 to each arm). After a median follow-up of 266 days, the primary endpoint of superiority for ORR was not achieved (48.2% for arfolitixorin vs. 49.4% for leucovorin, Psuperiority = 0.57). Outcomes were not achieved for median progression-free survival (PFS; 12.8 and 11.6 months, P = 0.38), median duration of response (12.2 and 12.9 months, P = 0.40), and median overall survival (23.8 and 28.0 months, P = 0.78). The proportion of patients with an adverse event of grade ≥3 severity was similar between arms (68.7% and 67.2%, respectively), as was quality of life. BRAF mutations and MTHFD2 expression were both associated with a lower PFS with arfolitixorin. CONCLUSIONS: The study failed to demonstrate clinical benefit of arfolitixorin (120 mg/m2) over leucovorin. However, it provides some useful insights from the first-line treatment setting, including the effect of gene expression on outcomes. SIGNIFICANCE: This phase III study compared arfolitixorin, a direct-acting folate, with leucovorin in FOLFOX plus bevacizumab in mCRC. Arfolitixorin (120 mg/m2) did not improve the ORR, potentially indicating a suboptimal dose.

Plasma versus tissue tumor mutational burden as biomarkers of durvalumab plus tremelimumab response in patients with metastatic colorectal cancer in the CO.26 trial.

PURPOSE: Tissue derived tumor mutation burden (TMB) of ≥10 mutations/Mb is a histology agnostic biomarker for the immune checkpoint inhibitor (ICI) pembrolizumab. However, the dataset on which this was validated lacked colorectal cancers (CRCs), and there is limited evidence for immunotherapy benefit in CRC using this threshold. PATIENTS AND METHODS: CO.26 was a randomized phase II study of 180 patients comparing durvalumab and tremelimumab (D+T, n=119 patients) versus best supportive care (BSC, n=61 patients). ctDNA sequencing was available for 168 patients (n=118 D+T, n=50), of which 165 had evaluable plasma TMB (pTMB). Tissue sequencing was available for 108 patients. Optimal thresholds for stratifying patients based on overall survival were determined using a minimal p-value approach. This report includes the final overall survival analysis. RESULTS: Tissue TMB ≥10 mutations/Mb was not predictive of benefit from D+T compared to BSC in microsatellite stable (MSS) metastatic CRC (HR 0.71 [95% CI:0.28-1.80], p=0.47). No tissue TMB threshold could identify a high TMB group that benefited from ICI. In contrast, plasma TMB (pTMB) ≥28 mutations/Mb was predictive of benefit from D+T (HR=0.34 [95%CI:0.13-0.85], p=0.022), as was clonal pTMB ≥10.6 mutations/Mb (HR=0.10 [95%CI:0.014-0.79], p=0.029) and subclonal pTMB ≥25.9/Mb (HR=0.20 [95% CI:0.061-0.69], p=0.010). Higher pTMB was associated with length of time on cytotoxic agents (p=0.021) and prior anti-EGFR exposure (p=2.44x10-06). CONCLUSION: pTMB derived from either clonal or subclonal mutations may identify a group more likely to benefit from immunotherapy, though validation is required. Tissue TMB provided no predictive utility for immunotherapy in this trial.

The association of healthcare contact days with physical function and survival in CCTG/AGITG CO.17.

INTRODUCTION: While contact days-days with healthcare contact outside home-are increasingly adopted as a measure of time toxicity and treatment burden, they could also serve as a surrogate of treatment-related harm. We sought to assess the association between contact days and patient-reported outcomes, and the prognostic ability of contact days. METHODS: We conducted a secondary analysis of CO.17 that evaluated cetuximab vs supportive care in patients with advanced colorectal cancer. CO.17 collected EORTC-QLQ-C30 instrument data. We assessed the association between number of contact days in a window and changes in physical function and global health status, and the association between number of contact days in the first 4 weeks with overall survival (OS). RESULTS: There was a negative association between the number of contact days and change in physical function (per each additional contact day at 4 weeks, 1.50 point decrease; and 8 weeks, 1.06 point decrease, p < .0001 for both), but not with global health status. This negative association was seen in patients receiving cetuximab, but not supportive care. More contact days in the first 4 weeks was associated with worse OS for all comers and patients receiving cetuximab (per each additional contact day; all comers, aHR 1.07, 95% CI, 1.05- 1.10; and cetuximab, aHR 1.08, 95%CI 1.05- 1.11, p < .0001 for both). CONCLUSIONS: In this secondary analysis of a clinical trial, more contact days early in the course was associated with declines in physical function and worse survival in all-comers and in participants receiving cancer-directed treatment. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00079066.

Transverse Colon Primary Tumor Location as a Biomarker in Metastatic Colorectal Cancer: A Pooled Analysis of CCTG/AGITG CO.17 and CO.20 Randomized Clinical Trials.

PURPOSE: Sidedness is prognostic and predictive of anti-EGFR efficacy in metastatic colorectal cancer (mCRC). Transverse colon has been historically excluded from several analyses of sidedness and the optimal division between left- and right-sided colorectal cancer is unclear. We investigated transverse colon primary tumor location as a biomarker in mCRC. EXPERIMENTAL DESIGN: Pooled analysis of CCTG/AGITG CO.17 and CO.20 trials of cetuximab in chemotherapy-refractory mCRC. Outcomes of patients with RAS/BRAF wild-type (WT) mCRC from CO.17 and KRAS WT mCRC from CO.20 were analyzed according to location. RESULTS: A total of 553 patients were analyzed, 32 (5.8%) with cancers from the transverse, 101 (18.3%) from right, and 420 from (75.9%) left colon. Transverse mCRC failed to reach significant benefit from cetuximab versus best supportive care (BSC) for overall survival [OS; median, 5.9 vs. 2.1 months; HR, 0.63; 95% confidence interval (CI), 0.28-1.42; P=0.26] and progression-free survival (PFS; median, 1.8 vs. 1.3 months; HR, 0.57; 95% CI, 0.26-1.28; P=0.16). Analyzing exclusively patients randomized to cetuximab, right-sided and transverse had comparable outcomes for OS (median, 5.6 vs. 5.9 months; HR, 0.82; 95% CI, 0.50-1.34; P=0.43) and PFS (median, 1.9 vs. 1.8 months; HR, 0.78; 95% CI, 0.49-1.26; P=0.31). Patients with left-sided mCRC had superior outcomes with cetuximab compared with transverse for OS (median, 9.7 vs. 5.9 months; HR, 0.42; 95% CI, 0.27-0.67; P=0.0002) and PFS (median, 3.8 vs. 1.8 months; HR, 0,49; 95% CI, 0.31-0.76; P=0.001). Location was not prognostic in patients treated with BSC alone. CONCLUSIONS: Transverse mCRC has comparable prognostic and predictive features with right-sided mCRC.

Refining the UGT1A haplotype associated with irinotecan-induced hematological toxicity in metastatic colorectal cancer patients treated with 5-fluorouracil/irinotecan-based regimens.

Despite the importance of UDP-glucuronosyltransferase (UGT) 1A1*28 in irinotecan pharmacogenetics, our capability to predict drug-induced severe toxicity remains limited. We aimed at identifying novel genetic markers that would improve prediction of irinotecan toxicity and response in advanced colorectal cancer patients treated with folic acid (leucovorin), fluorouracil (5-FU), and irinotecan (camptosar)-based regimens. The relationships between UGT1A candidate markers across the gene (n = 21) and toxicity were prospectively evaluated in 167 patients. We included variants in the 3'untranscribed region (3'UTR) of the UGT1A locus, not studied in this context yet. These genetic markers were further investigated in 250 Italian FOLFIRI-treated patients. Several functional UGT1A variants, including UGT1A1*28, significantly influenced risk of severe hematologic toxicity. As previously reported in the Italian cohort, a 5-marker risk haplotype [haplotype II (HII); UGTs 1A9/1A7/1A1] was associated with severe neutropenia in our cohort [odds ratio (OR) = 2.43; P = 0.004]. The inclusion of a 3'UTR single-nucleotide polymorphism (SNP) permitted refinement of the previously defined HI, in which HIa was associated with the absence of severe neutropenia in combined cohorts (OR = 0.55; P = 0.038). Among all tested UGT1A variations and upon multivariate analyses, no UGT1A1 SNPs remained significant, whereas three SNPs located in the central region of UGT1A were linked to neutropenia grade 3-4. Haplotype analyses of these markers with the 3'UTR SNP allowed the identification of a protective HI (OR = 0.50; P = 0.048) and two risk haplotypes, HII and HIII, characterized by 2 and 3 unfavorable alleles, respectively, revealing a dosage effect (ORs of 2.15 and 5.28; P ≤ 0.030). Our results suggest that specific SNPs in UGT1A, other than UGT1A1*28, may influence irinotecan toxicity and should be considered to refine pharmacogenetic testing.

Sunitinib combined with pemetrexed and carboplatin in patients with advanced solid malignancies--results of a phase I dose-escalation study.

OBJECTIVES: The maximum tolerated dose (MTD) and overall safety of sunitinib plus pemetrexed and carboplatin was determined in patients with advanced solid malignancies. METHODS: In this phase I dose-escalation study, patients received oral sunitinib on a continuous daily dosing (CDD) schedule (37.5 mg/day) or Schedule 2/1 (2 weeks on treatment, 1 week off treatment; 37.5 or 50 mg/day). Pemetrexed (400-500 mg/m(2) IV) and carboplatin (AUC = 5 mg·min/ml IV) were administered q3w. At the MTD for the chosen schedule, a cohort of patients with non-small cell lung cancer (NSCLC) or mesothelioma was further evaluated. RESULTS: Twenty-one patients were enrolled on Schedule 2/1 (expansion cohort included) and 3 patients on the CDD schedule. The MTD on Schedule 2/1 was sunitinib 37.5 mg/day with pemetrexed 500 mg/m(2) and carboplatin AUC = 5 mg·min/ml; MTD on the CDD schedule was not established. Dose-limiting toxicities included grade 3/4 neutropenia, grade 3 thrombocytopenia, and grade 3 hand-foot syndrome. The most common grade 3/4 drug-related non-hematologic adverse events at Schedule 2/1 MTD were fatigue/asthenia and diarrhea (both n = 4). Grade 3/4 hematologic abnormalities included neutropenia (83%) and leukopenia (83%). Pharmacokinetic data revealed no clinically significant drug-drug interactions. Best response at the Schedule 2/1 MTD was stable disease ≥8 weeks in 3/5 evaluable patients (60%). CONCLUSIONS: With this combination, in patients with advanced solid malignancies, sunitinib MTD on Schedule 2/1 was 37.5 mg/day. Sunitinib plus pemetrexed and carboplatin were tolerable at the MTD, although sunitinib dose delays and reductions were often required due to myelosuppression.