Oxaliplatin-based Regimens Research Articles

Resection of colorectal liver metastases with second-line aflibercept plus FOLFIRI: Results from the RESECTION prospective French cohort

AimTo evaluate R0/R1 resection rate in patients with colorectal liver metastases (CLM) treated with aflibercept plus FOLFIRI after failure of a prior oxaliplatin-based regimen in daily clinical practice. MethodsThis French, multicentre, prospective, observational cohort (NCT05178745) included patients with CLM (alone or predominant; up to 5 lung nodules <2 cm allowed) initiating aflibercept/FOLFIRI every 2 weeks per physician choice. Primary endpoint was R0/R1 resection rate. Secondary endpoints included overall survival (OS), progression-free survival (PFS), radiological and pathological responses, and safety. ResultsA total of 137 patients (median age 65 years, RAS/BRAF mutant 57%/9%) were enrolled at 22 French sites. CLM (median 4) were synchronous in 82%, bilobar in 71% and located in liver only in 54%. Overall, 17% of patients had R0/R1 resection (21% for patients with liver-only disease). A major pathological response per Blazer score was observed in 55% of resected patients, along with significantly longer OS (median 34.8 vs 9.1 months, p<0.0001) and PFS (median 11.4 vs 4.9 months, p<0.0001) compared to non-resected patients. Post-operative complications occurred in 17% of patients (all Dindo-Clavien grade I-II) with no post-operative deaths. Overall, 34% had grade ≥3 adverse events, mainly general health deterioration and diarrhea. ConclusionsResults suggest that aflibercept plus FOLFIRI, after failure of a prior oxaliplatin-based regimen, allows R0/R1 resection of CLM in almost 20% of patients with a major pathological response in most cases and a median OS prolonged by more than 3-fold versus non-resected patients.

Impact of Tumoral β2-Adrenergic Receptor Expression on Chemotherapeutic Response and Prognosis in Patients with Advanced Colorectal Cancer.

The β2-adrenergic receptor (β2-AR) is a therapeutic target for circulatory agonists and exhibits oncogenic activity in several cancers. However, its role in advanced colorectal cancer (CRC) treated using chemotherapy remains unclear. We investigated the potential of β2-AR as a novel chemosensitivity marker and therapeutic target in inoperable CRC. β2-AR expression was evaluated immunohistochemically in 80 advanced or recurrent CRC cases for which untreated resected specimens were available before systemic chemotherapy implementation. We assessed the relationship among β2-AR protein expression, clinicopathological factors, therapeutic response, and prognosis. Furthermore, we evaluated the significance of β2-AR as an in vitro and in vivo therapeutic target using CRC cell lines and a CRC xenograft model treated with the β-blocker, propranolol, and other anticancer agents. High tumoral β2-AR expression was associated with shorter progression-free survival and chemotherapeutic resistance in patients treated with oxaliplatin-based regimens and bevacizumab-based regimens. We found no synergistic effect between propranolol and oxaliplatin. However, combined administration of propranolol and bevacizumab induced significant tumor shrinkage in the CRC xenograft model. β2-AR is a possible biomarker for chemosensitivity and prognosis in advanced CRC. Repositioning existing β-blockers could be beneficial for treating CRC resistant to existing treatment regimens.

WTAP weakens oxaliplatin chemosensitivity of colorectal cancer by preventing PANoptosis

As the most abundant post-transcriptional modification in eukaryotes, N6-methyladenosine (m6A) plays a crucial role in cancer cell proliferation, invasion and chemoresistance. However, its specific effects on chemosensitivity to oxaliplatin-based regimens and the impact of these drugs on m6A methylation levels in colorectal cancer (CRC) remain largely unexplored. In this study, we demonstrated that the m6A methyltransferase Wilms tumor 1-associating protein (WTAP) weakens oxaliplatin chemosensitivity in HCT116 and DLD1 cells. Mechanistically, oxaliplatin treatment upregulated WTAP expression, preventing multiple forms of cell death simultaneously, a process known as PANoptosis, by decreasing intracellular oxidative stress through maintaining the expression of nuclear factor erythroid-2-related factor 2 (NRF2), a major antioxidant response element, in an m6A-dependent manner. In addition, high WTAP expression in CRC patients is associated with a poor prognosis and reduced benefit from standard chemotherapy by clinical data analysis of The Cancer Genome Atlas (TCGA) database and patient cohort study. These findings suggest that targeting WTAP-NRF2-PANoptosis axis could enhance the antitumor efficacy of oxaliplatin-based chemotherapy in CRC treatment.

SLC12A8 upregulation promotes colorectal cancer progression and chemoresistance.

Colorectal cancer (CRC), a prevalent gastrointestinal malignant disease, causes substantial morbidity and mortality. Identification of novel prognostic biomarkers and therapeutic targets is critically needed to improve patient outcomes. Although solute carrier family 12 member 8 (SLC12A8) has high expression in various tumors and affects tumor progression, its role in CRC remains unclear. The aim of this study was to investigate the functions of SLC12A8 in CRC. SLC12A8 expression and its association with clinical significance in CRC patients were explored via multiple public databases, including The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), The Human Protein Atlas (HPA), The University of ALabama at Birmingham CANcer data analysis Portal (UALCAN), and Kaplan-Meier plotter. The effects of SLC12A8 on the CRC cell apoptosis, epithelial-mesenchymal transition (EMT), reactive oxygen species (ROS) production, and sensitivity to oxaliplatin were verified by in vitro experiments. SLC12A8 expression was upregulated in CRC tissues compared with normal colorectal tissues. Furthermore, high expression of SLC12A8 was associated with poorer prognosis in CRC patients. Pathway enrichment analyses revealed SLC12A8 involvement in oxidative stress and transforming growth factor-beta (TGF-β) signaling. Experiments in CRC cells showed that SLC12A8 upregulation promoted apoptosis resistance, EMT, and inhibited ROS production. Moreover, SLC12A8 knockdown enhanced the sensitivity of CRC cells to oxaliplatin chemotherapy. Our integrative analyses identify SLC12A8 as a candidate biomarker for CRC progression. Targeting SLC12A8 may improve patient responses to oxaliplatin-based treatment regimens.

A phase II clinical trial of metformin combined with FOLFIRI plus bevacizumab as second-line therapy in patients with RAS-mutant metastatic colorectal cancer.

3534 Background: Metastatic colorectal cancer (mCRC) patients with RAS mutations are confronted with limited novel targeted therapy. We previously reported that KRAS mutation mediated MATE1 down-regulation sensitizes colorectal cancer cells to metformin. Based on our preclinical research, we designed a study to explore whether metformin combined with FOLFIRI plus bevacizumab would improve efficacy in RAS mutant mCRC. Methods: This single-arm, multicenter trial (ChiCTR2000037943) recruited patients with RAS mutant mCRC that had failed to first-line bevacizumab plus an oxaliplatin-based regimen of systemic therapies. Patients received metformin 1000mg PO twice daily on day 1-14, plus irinotecan 180 mg/m² IV, calcium folinate 400 mg/m² IV, fluorouracil 400 mg/m² IV, and a 46-h CIV of fluorouracil 2400 mg/m², and bevacizumab 5 mg/kg IV, repeated every 14 days. We used Simon's two-stage design. The primary endpoint was objective response rate (ORR). The secondary endpoints were disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety. Results: One hundred sixteen patients were recruited between July 2020 and March 2023. KRAS codon 12 mutations were present in 81 cases (69.8%), codon 13 mutations in 17 cases (14.7%), codon 61 mutations in 6 cases (5.2%), and codon 146 mutations in 3 cases (2.6%). For the 81 patients with KRAS codon 12 mutation, 42 were with G12D (51.9%), 21 with G12V (25.9%), 7 with G12A (8.6%), and 6 with G12C (7.4%) mutation. The ORR was 21.6% (25/116), and DCR was 76.7% (89/116). The median PFS was 8.0 months, and patients without liver metastasis had longer PFS than those with liver metastasis (9.5 months vs. 5.6 months, P &lt; 0.001). For the 45 patients without liver metastasis, the administration of metformin combined with FOLFIRI plus bevacizumab as second-line therapy resulted in significantly longer PFS than the first-line bevacizumab plus an oxaliplatin-based regimen (9.5 months vs. 7.9 months, P = 0.037). The median OS was not reached. The most common treatment-emergent adverse events (TEAEs) were neutropenia (73.7%), nausea (56.9%), anemia (54.3%) and diarrhea (49.1%). Grade 3 and above TEAEs occurred in 52 (44.8%) patients. No treatment-related mortality occurred. Conclusions: Metformin combined with FOLFIRI and bevacizumab had promising efficacy and tolerable toxicity in RAS mutant mCRC patients as second-line therapy. Further study in phase 3 trials is warranted. Clinical trial information: ChiCTR2000037943.

Impact of DNA damage repair alterations on real-world response to therapy in metastatic colorectal cancer.

e15557 Background: Alterations in the DNA damage repair (DDR) pathway genes contribute to tumor development. These alterations can be exploited by cytotoxic chemotherapy regimens that induce DNA damage. Platinum chemotherapy agents have been shown to be particularly effective in breast and ovarian cancer patients with alterations in the DDR pathway. However, the clinical impact of DDR alterations in metastatic colorectal cancer (mCRC) is still poorly understood. In this study, we utilize a large national database to evaluate clinical outcomes in patients with mCRC and alterations in DDR pathway genes. Methods: We reviewed 5602 patients that received standard fluorouracil based first-line chemotherapy regimens for mCRC using the nationwide Flatiron Health EHR-derived de-identified database. Chemotherapy regimens were categorized as a platinum-based doublet (FOLFOX, CAPOX), irinotecan-based doublets (FOLFIRI), or triplet (FOLFOXIRI). Overall survival (OS) was summarized within groups via Kaplan-Meier survival estimates. OS was compared between groups in the context of univariable and multivariable Cox proportional hazards models controlling for age, gender, DDR status, stage at diagnosis, ECOG, RAS/RAF status, MMR status, albumin and CEA at diagnosis. OS was defined as the time in months between date of first line therapy initiation to death. Results: DDR gene alterations were indentified in 35.7% (2001) patients.The most frequent mutations were in ATM (13.3%) and BRCA2 (8.3%). There was no significant difference in OS based on DDR mutation status. Within DDR altered patients, there was no difference in OS between those who received a platinum-based doublet, irinotecan-based doublet or triplet first-line therapy. Time to next treatment or death (TTNTD) was significantly improved with an irinotecan-containing doublet regimen and triplet regimen compared to a platinum-based doublet in a multivariable model (HR 0.79, p = 0.001 and HR 0.68, p = 0.002, respectively). There was no difference in OS in DDR-mutated patients that received an irinotecan-based regimen in the first line followed by an oxaliplatin-based regimen in the second line or the reverse sequence. When evaluating the impact of commonly co-mutated genes on survival we observed a worse OS in patients with a KRAS mutation in addition to a DDR mutation (HR 1.19, p = 0.045). An APC mutation was associated with an improved OS in the entire cohort, regardless of DDR status (HR 0.76, p &lt; 0.001). Conclusions: In this real-world population, approximately one third of patients with mCRC harbored an alteration in a DDR pathway gene. In these patients, TTNTD was greater with irinotecan-containing first line therapies (doublet or triplet). However, OS was similar regardless of which first-line chemotherapy was used.

Assessment of anticancer drug utilization pattern and patients’ survival—A single center experience from Saudi Arabia

Background In recent years, various advancements in anticancer therapy have led to the development of multiple regimens and protocols. This study endeavors to provide an extensive evaluation of anticancer therapy prescription patterns in correlation with patient outcomes. Methods From June 2014 to April 2022, we included adult cancer patients who received anticancer therapy in our cancer center. Collected data encompassed demographic characteristics of patients and cancer, chemotherapy protocols or agents, antiemetics, drug side effects, and the patient’s last status. The prescribed drugs were assessed using the Essential Medicines List, while the prescription’s rationality was determined using the World Health Organization indicators. Results The mean age was 55.16 ± 17.04 years, with 56.4% of the patients being males. Gastrointestinal (29.7%) and breast (25.8%) cancers were the most common malignancies. The main protocols included a combination of Adriamycin and cyclophosphamide (20.1%) and folinic acid, fluorouracil, and oxaliplatin-based (FOLFOX) regimen (13.5%). The most frequently used drugs were doxorubicin (14.0%), cyclophosphamide (13.3%), and docetaxel (9.9%). The majority of patients also did not report any acute adverse events related to chemotherapy (81.1%). Antiemetics, mainly metoclopramide-based, were used in 76.07% of cases. Remarkably, 86.7% of anticancer agents were from the EML, and 90.1% were prescribed generically. Conclusion In this study, gastrointestinal cancers were the most prevalent cancers observed, with more preponderance among males. Most anticancer agents were taken from the essential drug list, with the majority being prescribed under generic names, indicating rational use.

Prospective, Observational Study of Aflibercept Use in Combination with FOLFIRI in Patients with Metastatic Colorectal Cancer: A Real-World Effectiveness Study.

This was an observational study prospectively evaluating the effectiveness and safety of aflibercept/FOLFIRI administered in second-line mCRC per the reimbursement criteria in Poland. Consecutive mCRC patients who progressed with first-line oxaliplatin-based chemotherapy received aflibercept (4 mg/kg IV) followed by FOLFIRI every 2 weeks until progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS); overall survival (OS) and safety were the secondary endpoints. A total of 93 patients were treated at 17 Polish sites. A median of 10 cycles was administered. Over a median treatment duration of 5.3 months, median PFS and median OS were 8.4 months [95% CI, 6.9-9.9] and 27.0 months [95% CI, 23.9-30.1], respectively. There was no significant impact of primary tumor location, metastatic site, or KRAS status on PFS and OS. Main grade ≥ 3 adverse events were neutropenia (16%), hypertension (8%), diarrhea (4%), and stomatitis (4%). The benefits/risks of Aflibercept plus FOLFIRI administered per the Polish reimbursement criteria in second-line treatment of mCRC after failure of a prior oxaliplatin-based regimen is confirmed.

Pembrolizumab Plus Binimetinib With or Without Chemotherapy for MSS/pMMR Metastatic Colorectal Cancer: Outcomes From KEYNOTE-651 Cohorts A, C, and E

BackgroundCohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. Patients and MethodsPatients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary. ResultsIn cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E. ConclusionPer DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.

In vitro 3D microfluidic peritoneal metastatic colorectal cancer model for testing different oxaliplatin-based HIPEC regimens.

Treatment of colorectal peritoneal metastases with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) is still evolving. Conducting a randomized trial is challenging due to the high heterogeneity in the presentation of peritoneal disease and various surgical approaches. Biological research may facilitate more rapid translation of information into clinical practice. There is an emerging need for a preclinical model to improve HIPEC treatment protocols in terms of drug doses and treatment durations. The aim of the study is to design a tool that serves as an invitro three-dimensional (3D) microfluidic peritoneal metastatic colorectal cancer model to test the efficacy of different HIPEC treatments. We determined the effects of current therapy options using a 3D static disease model on human colon carcinoma cell lines (HCT 116) and transforming growth factor-β1 induced epithelial-to-mesenchymal transition (EMT) HCT 116 lines at 37 °C and 42 °C for 30, 60, and 120 min. We determined oxaliplatin's half maximal inhibitory concentrations in a 3D static culture by using viability assay. Clinical practices of HIPEC were applied in the developed model. EMT-induced HCT 116 cells were less sensitive to oxaliplatin treatment compared to non-induced cells. We observed increased cytotoxicity when increasing the temperature from 37 °C to 42 °C and extending the treatment duration from 30 to 120 min. We found that 200 mg/m2 oxaliplatin administered for 120 min is the most effective HIPEC treatment option within the framework of clinic applications. The tool map provide insights into creating more realistic pre-clinical tools that could be used for a patient-based drug screening.

Optimal duration of oxaliplatin-based adjuvant chemotherapy in patients with different risk factors for stage II-III colon cancer: a meta-analysis.

The duration of oxaliplatin-based chemotherapy in high-risk stage II, low-risk stage III, and high-risk stage III colon cancer (CC) patients is controversial. To reduce the risk of adverse events (AEs) without compromising efficacy while improving chemotherapy compliance is crucial. The authors searched Cochrane, Embase, Pubmed, and Web of Science databases for articles from inception to August 8, 2023, the main outcomes were disease-free survival, overall survival, chemotherapy completion rates, and AE frequency. Six randomized controlled trials (RCTs) involving 10332 patients were included. Disease-free survival analysis revealed that only the high-risk stage III CC patients experienced better results with the 6-month FOLFOX regimen when compared with the 3-month regimen [Hazard ratio (HR): 1.32, 95% CI: 1.15-1.51, P <0.0001). Overall survival (OS) analysis revealed that extending the use of FOLFOX and CAPEOX regimens did not provide survival benefits for stage III CC patients (HR: 1.16, 95% CI: 0.9-1.49, and HR: 0.89, 95% CI: 0.67-1.18, P =0.40). The completion rate of the 3-month oxaliplatin-based adjuvant chemotherapy regimen was significantly higher than that of the 6-month regimen [Relative risk (RR): 1.16, 95% CI: 1.06-1.27, P =0.002]. Moreover, the 3-month regimen had significantly lower AE rates than the 6-month regimen (RR: 0.62, 95% CI: 0.57-0.68, P <0.00001), with differences mainly concentrated in grade 3/4 neutropenia (RR: 0.70, 95% CI: 0.59-0.85, P =0.0002), peripheral sensory neuropathy at ≥grade 2 (RR: 0.45, 95% CI: 0.38-0.53, P <0.00001), and hand-foot syndrome at ≥grade 2 (RR: 0.36, 95% CI: 0.17-0.77, P =0.009). The 6-month FOLFOX regimen should only be recommended for high-risk stage III CC, while the 3-month regimen can be recommended for other stages. A 3-month CAPEOX regimen can be recommended for stage II-III CC.

Incidence, Severity and Clinical Correlation of Oxaliplatin Induced Neuropathy in Patients with Colorectal Cancer: A Single Institutional Experience

Background: Colorectal cancer is the third most commonly diagnosed cancer worldwide, and its incidence is increasing in developing countries. Chemotherapy plays a significant role in the treatment of locally advanced and metastatic colorectal cancer. Oxaliplatin has remained the backbone of the treatment of colorectal carcinoma. The primary dose-limiting toxicity of oxaliplatin is neuropathy, which can reduce compliance during therapy and impair daily living activities. With limited data regarding the occurrence of oxaliplatin-induced peripheral neuropathy (OIPN) in the Indian population, we aimed to determine the incidence and severity of oxaliplatin-induced neurotoxicity and its clinical correlation with various clinical parameters in patients with colorectal carcinoma in a cancer care centre from North-East India. Material and Methods: A prospective observational analysis was performed on all histologically confirmed cases of colorectal adenocarcinoma who received oxaliplatin-based chemotherapy either in an adjuvant setting or first-line palliative setting at Dr. B. Borooah Cancer Institute between April 2019 to March 2020. Results: Our study evaluated 76 patients with colorectal carcinoma with a mean age of 54.07 ± 10 years. The majority (65.8%) of the patients had adenocarcinoma of the colon, and 34.2% had rectal adenocarcinoma. Twenty-three (30.3%) patients presented with metastatic disease. Oxaliplatin-based chemotherapy regimens were either CAPOX (72.4%) or FOLFOX (27.6%). Acute OIPN was observed in 59 patients (77.6%), and the most common symptom was cold-induced perioral paraesthesia. The most frequent grade for acute OIPN was grade II (30.3%). Chronic OIPN was seen in 47 (61.8%) patients, with the majority developing grade II neuropathy and was manifested mainly after 4th cycle of chemotherapy. The incidence of OIPN was higher in the patients aged ≥60 years, with a cumulative oxaliplatin dose of &gt; 1000 mg/m2 and baseline low serum magnesium or calcium level. Conclusion: Oxaliplatin is one of the essential chemotherapy drugs used in colorectal cancer with significant dose-limiting toxicity of peripheral neuropathy. Well-timed identification of neuropathic symptoms can increase treatment adherence and improve the patient’s quality of life.&#x0D;

A phase 1b study of the OxPhos inhibitor ME-344 in combination with bevacizumab in refractory metastatic colorectal cancer.

TPS222 Background: ME-344 is a synthetic small molecule that inhibits oxidative phosphorylation, resulting in energy starvation and cell death via caspase-dependent and -independent mechanisms. The activity of mitochondrial inhibitors is enhanced when mitochondrial respiration is upregulated, a situation achieved in solid tumors by inducing vascular normalization and hypoxia correction with antiangiogenics. In a CT26 colon carcinoma syngeneic murine model, ME-344 in combination with regorafenib showed significantly reduced tumor growth compared to regorafenib alone (Navarro et al. Cell Reports. 2016;15:2705). A randomized phase 0/1 window of opportunity study in HER2-negative breast cancer showed significant decrease in the proliferation marker Ki67 in patients administered ME-344 plus bevacizumab vs. bevacizumab alone (Quintela-Fandino et al, Clin Cancer Res. 2020;26:35). The current study evaluates the safety and efficacy of ME-344 in combination with bevacizumab in refractory metastatic colorectal cancer, a clinical setting where continued antiangiogenic inhibition has established benefit. Prior phase 1-1b studies of ME-344 as a single agent and in combination have established the RP2D at 10 mg/kg when administered intravenously weekly. Methods: This is an open-label phase 1b study in patients ≥18 years old with metastatic colorectal cancer after failure of standard therapies, including fluoropyrimidine-, irinotecan-, and oxaliplatin-based regimens, anti-EGFR if RAS wild-type, PD/L-1-blocking antibody if MSI-H/dMMR, and BRAF-targeted therapy if BRAF V600E mutated. Other key eligibility criteria include measurable disease, ECOG performance status 0-1, adequate bone marrow, liver and renal function, no uncontrolled brain metastatic disease, no peripheral neuropathy grade ≥2, no uncontrolled hypertension or diabetes, and no increased hemorrhagic risk. Enrollment will proceed in 2 cohorts of 20 patients each. Cohort 1 will be administered ME-344 at 10 mg/kg on days 1, 8, and 15 of a 28-day cycle and bevacizumab 5 mg/kg on days 1 and 15. Cohort 2 will be administered ME-344 at 10 mg/kg and bevacizumab 5 mg/kg both on days 1 and 15 of a 28-day cycle. Treatment will continue until disease progression or intolerance. Tumor assessment is performed every 8 weeks for 6 months and then every 3 months using RECIST-1 criteria. The primary endpoint is 16-week PFS. Secondary endpoints are PFS, response rate, and safety. Correlative analysis will evaluate treatment-related metabolic response. The study is actively enrolling, funded by MEI Pharma, and registered under NCT02100007. Clinical trial information: NCT02100007 .

Clinical characterization and therapeutic outcomes of patients (pts) with colorectal cancer (CRC) harboring somatic BRCA1/2 mutations.

134 Background: Somatic BRCA1/2 mutations in BRCA-associated cancers increase therapeutic sensitivity to platinum-based chemotherapies and PARP inhibitors, but the implications of BRCA mutations in non- BRCA-associated cancers such as CRC is unknown and hypothesized to be shaped by tumor lineage. We thus conducted a retrospective analysis of outcomes with platinum-based chemotherapy and PARP inhibition in pts with CRC, where the estimated prevalence of BRCA1/2 alterations is 3-4%. Methods: Pts with blood or tissue next generation sequencing (NGS) positive for a somatic BRCA1/2 variant and a diagnosis of CRC were identified from a single institution database. The pathogenicity of each mutation was annotated using public genomic databases (e.g. ClinVar). Pt characteristics were compared using Fisher’s exact test. Log-rank test was used for comparison of survival distribution among groups. Results: 8,258 NGS reports with a BRCA1/2 alteration from 1760 cancer pts were identified of which 189 (11%) had a diagnosis of CRC. 54/189 CRC pts (29%) had ≥1 pathogenic BRCA1/2 variant, 19 pts (10%) had ≥1 benign variant, and 134 pts (69%) had 1 ≥ variant of unknown significance (VUS); 26 pts (14%) had more than one BRCA1/2 variant. Pts with ≥1 pathogenic mutation (n=54) were more likely to have an inactivating DNA polymerase epsilon (POLE) mutation versus pts with only benign/VUS BRCA1/2 variants (n=135) (20% vs 6%, p=0.004) while prevalence of microsatellite instability (MSI-H) (19% vs 13%, p=0.37) and Ras/Raf (53% vs 53%, p=1.00) were similar between groups. Median progression free survival (PFS) among 115 CRC pts (unselected for BRCA1/2 pathogenicity) who received an oxaliplatin-based regimen for advanced disease in the 1st line (n=52) was similar to the median PFS among pts who received an irinotecan-based regimen (n=63) (7.0 mths vs 7.0 mths, p=0.48). Median PFS with an oxaliplatin-based regimen in the 1st line among 52 pts with pathogenic BRCA1/2 variants (n=13) was 5.1 mths vs 7.4 mths among pts with benign/VUS BRCA1/2 variants (n=39) (p=0.398). There were no significant differences in median PFS among pts with a pathogenic vs benign/VUS BRCA1/2 variants when the analysis was restricted to pts with BRCA1/2 variants identified in tissue (p=0.76) and to pts without co-occurring driver mutations (Ras/Raf, MSI-H, and/or POLE) (p=0.1). Overall survival in patients with advanced disease was similar between pts with a pathogenic (n=52) vs benign/VUS (n=122) BRCA variants (37.1 mths vs 45.1 mths, p=0.14). 6 pts (4 with pathogenic BRCA1/2 and 3 with VUS) received a PARP inhibitor after a median of 3 lines of treatment and the best response was disease progression in 6 pts (100%). Conclusions: In the context of CRC, somatic BRCA1/2 mutations frequently co-occur with pathogenic POLE mutations, but do not appear to confer therapeutic benefit to platinum-based chemotherapy and PARP inhibitors.

HGCSG1801: A multicenter, prospective, phase II trial of second-line FOLFIRI plus aflibercept in patients with metastatic colorectal cancer (mCRC) refractory to anti-EGFR antibodies.

113 Background: Aflibercept (AFL) combined with FOLFIRI prolongs overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC) who failed a prior oxaliplatin-based regimen. However, there is limited evidence on the efficacy and safety of AFL plus FOLFIRI in RAS / BRAF wild type pts previously treated with anti-epidermal growth factor receptor (EGFR) agents. Therefore, we conducted a phase II trial evaluating the efficacy and safety of AFL plus FOLFIRI in Japanese pts with mCRC failing a prior oxaliplatin-based chemotherapy combined with an anti-EGFR agent. Methods: This was a prospective open-label phase II trial. AFL (4 mg/kg iv) followed by FOLFIRI (irinotecan 180 mg/m2, leucovorin 200 mg/m2 iv, bolus 5-FU 400 mg/m2 and infusional 5-FU 2400 mg/m2/46 h) was given every 2 weeks until progression or unacceptable toxicities. The primary endpoint was progression-free survival (PFS) rate at 6 months; secondary endpoints included OS, PFS, overall response rate (ORR), disease control rate (DCR), adverse events, and relative dose intensity (RDI) for each drug. Given a PFS rate threshold at 6 months of 38.9% and an expected PFS rate of 58.4% with AFL plus FOLFIRI, a sample size of 41 pts was required (two-sided alpha, 0.1; beta, 0.2). Analyses were conducted in the full analysis set (FAS) of pts satisfying eligibility criteria. Results: Forty-three patients were enrolled between November 2019 and October 2022, and 43 were analyzed (median age 68 years (range 27-80); male, 69.8%; ECOG PS 0/1, 72.1%/27.9%; left sided primary tumor, 90.7%). The primary endpoint was met: 6-month PFS rate was 58.7% (90%CI, 45.5%-71.9%). Median PFS and OS were 7.3 months (95%CI, 5.5-11.0 months) and 18.8 months (95%CI, 12.9-26.6 months), respectively. The ORR was 23.3 % (95%CI, 11.8-38.6%) and DCR was 88.4% (95%CI, 74.9- 96.1%). Mean RDI of AFL, irinotecan, bolus 5-FU and infusional 5-FU were 75.3% (SD, 26.2), 50.6% (SD, 12.5), 31.6% (SD, 26.6), and 58.7% (SD, 7.21), respectively. The main grade ≥3 adverse events included hypertension (62.8%), neutropenia (55.8%), leukopenia (25.6%), febrile neutropenia (11.6%), fatigue (9.3%), anorexia (9.3%), proteinuria (9.3%) and diarrhea (7.0%). No deaths and no new safety signals with a causal relation to the study treatment were observed. Conclusions: Results of this prospective phase II study suggest that AFL plus FOLFIRI shows a high response rate and a manageable safety profile in Japanese pts with mCRC who failed a first-line oxaliplatin-based plus anti-EGFR regimen. Clinical trial information: jRCTs011190006 .

Enrichment of circulating helper-T (Th) and unswitched memory-B (NSwM-B) cell populations and responsiveness to immune checkpoint blockade (ICB) in microsatellite-stable (MSS)/mismatch repair-proficient (pMMR) colorectal cancer (CRC).

150 Background: The anti-tumor activity of ICB in MSS/pMMR-CRC is limited. However, recent studies have highlighted the possibility of inducing ICB responsiveness by oxaliplatin-based chemotherapy. The understanding of underlying mechanisms and identification of rational biomarkers are major focus areas in immuno-oncology. Methods: Patients with previously untreated, unresectable abdominal metastases from MSS/pMMR-CRC were randomly assigned to the oxaliplatin-based standard Nordic FLOX regimen (control arm) or 2 FLOX cycles followed by 2 ICB (nivolumab) cycles in a repeat sequential schedule (experimental arm). Radiologic response assessment was done every 8 weeks, and the study arms reached identical primary endpoint – median progression-free survival (PFS) 9.3 months. Experimental-arm patients at one study center had peripheral blood mononuclear cells (PBMC) prepared at study entry (V1), after the initial 2 FLOX cycles (V3), and after the succeeding 2 nivolumab cycles (V5). The PBMC were incubated with 19 cell-surface antibodies and analyzed by mass cytometry. Patients were categorized in PFS &gt;9.3 months (improved; n = 7) or PFS &lt;9.3 months (shortened; n = 6). Live cell clusters were identified by hierarchically applying automated 1D gates to the available lineage markers. After gating, all cells were assigned to soft clusters according to phenotypes. The cluster sizes were used to compute the differential abundance of immune-cell populations and a Peacock test assessed multivariate changes between the improved and shortened PFS groups. Results: Circulating CD4+ (Th) cells and CD27+IgD+ (NSwM-B) cells were concurrently enriched in the improved PFS group. After the initial 2 FLOX cycles (V3), median increase (from V1) was 2.89% (of lymphocyte count) for Th cells and 0.54% (of leukocyte count) for NSwM-B cells (p &lt; 0.001). Continued responses occurred over the succeeding 2 nivolumab cycles (until V5) with median increase of 1.19% for Th cells and 0.19% for NSwM-B cells (p &lt; 0.001). The association between the immune-cell alterations and PFS was validated by categorizing the cases in above or below the median increase in Th and NSwM-B cell populations from V1 to V5. The high-increase group achieved median PFS 15.0 months (95% CI, 10.8-19.2) compared to 4.0 months (95% CI, 1.9-22.1) for the low-increase group (log-rank; p = 0.002). Conclusions: This unsupervised analysis of high-dimensional PBMC data from a limited case number revealed that circulating Th and NSwM-B cell populations may mediate ICB responsiveness invoked by short-course oxaliplatin-based chemotherapy in patients with abdominal metastases from MSS/pMMR-CRC. Owing to weaknesses of such a post-hoc analysis, further studies are needed to confirm the generalizability of these findings. Clinical trial information: NCT003388190 .

The efficacy of chemotherapy for colorectal cancer with early recurrence after adjuvant chemotherapy.

43 Background: Adjuvant chemotherapy is the standard treatment for patients with stage III colorectal cancer (CRC) underwent surgery.However, the efficacy of chemotherapy for early recurrence after adjuvant chemotherapy remains unclear. This study aimed to assess the efficacy of chemotherapy for CRC with early recurrence during or after adjuvant chemotherapy. Methods: We retrospectively reviewed CRC patients who underwent surgery at 3 institutions between 2016 and 2021. The inclusion criteria were as follows: ECOG performance status was 0 or 1, histology was adenocarcinoma, patients who received adjuvant chemotherapy following surgical resection, early recurrence during or within 12 months after adjuvant chemotherapy and no prior treatment for CRC after early recurrence. The interval from the last administration of adjuvant chemotherapy to recurrence was defined as the recurrence-free interval (RFI). Overall survival (OS), progression-free survival (PFS), objective response rates (ORR), and disease control rate (DCR) were assessed according to the RFI. Results: Of 448 patients, 32 patients were eligible. Median age was 57 years (range 26–79), 14 patients (44%) were male and ECOG performance status 0 / 1 was 29 (91%) / 3 (9%). RAS wild-type / mutant was 12 (38%) / 20 (62%) and right / left as sidedness was 21 (66%) / 11 (34%). Regarding adjuvant chemotherapy, 4 patients (12%) received single-agent therapy, while 28 patients (88%) received combination therapy with two agents. Palliative chemotherapy after early recurrence included Oxaliplatin-based regimens in 13 patients (41%), irinotecan-based regimens in another 13 patients (41%), and other regimens in 6 patients (18%). For all patients, the median PFS and OS were 10.4 months and 43.0 months, respectively. The ORR and DCR were 34.4% and 75.0%, respectively. When patients were divided into RFI &lt; 6 months and RFI ≥ 6 months, the ORR was superior in the RFI ≥ 6 months group to RFI &lt; 6 months group (56 % vs. 26%). The PFS (median 10.4 months vs. 17.8 months, HR 0.92; 95% Cl 0.36-2.38, p = 0.87) and OS (median 31.3 months vs. 43.0 months, HR 0.97; 95% Cl 0.31-3.08, p = 0.97) did not differ between the RFI &lt; 6 months group and the RFI ≥ 6 months group. Multivariate analysis for OS indicated a trend toward a poor prognosis in the RFI &lt; 6 months group compared to the RFI ≥ 6 months group (HR 1.78; 95% CI 0.35-8.98, p = 0.48). Conclusions: In patients with CRC experienced early recurrence, the RFI &lt; 6 months group had a trend of poor efficacy compared to the RFI of ≥ 6 months group.

Adjuvant oxaliplatin-based chemotherapy comparing observation alone after radical resection of metachronous metastases of colorectal cancer: interim analysis

Introduction. Despite the registered standard treatment option for patients who underwent radical resection for metachronous metastases of colorectal cancer (CRC), the feasibility of adjuvant chemotherapy (ACT) for all patients seems controversial. Due to studies demonstrating improved disease-free survival rates with postoperative chemotherapy vs observation, it would seem that there is reasonable expectation of improved overall survival (OS) rates, which, however, were not statistically different between groups. This article presents the interim results of our own study.Aim. To analyse the efficacy of ACT vs dynamic observation in patients who underwent surgery for metachronous metastases of colorectal cancer.Materials and methods. It was a prospective-retrospective, non-randomized, non-inferiority study. A total of 120 patients were recruited between June 2008 and September 2022. The ACT group included 71 patients. All patients received only oxaliplatin-based chemotherapy regimens; the dynamic observation group included 49 patients.Results. The interim analysis showed that the median disease-free survival (mDFS) in the ACT group (n = 71) was 20.9 months (13.7–28.3) vs 24.4 months in the dynamic observation group (n = 49) (11.1–37.7), HR: 0.76 (95% CI: 0.45–1.29), p = 0.29. Two-year disease-free survival (DFS) rates were 46.6% in the post-surgery chemotherapy (CT) group (n = 50) and 55.5% in the experimental group (n = 31), HR: 0.69 (95% CI: 0.39–1.2), p = 0.21.Conclusion. ACT has not improved the long-term treatment outcomes in patients who underwent radical resection for metachronous metastases of CRC.

Prognostic Impact of Primary Tumor Sidedness in Stage III Colorectal Cancer: Real-World Evidence from a Brazilian Cohort

BackgroundPrimary tumor sidedness (PTS) is an independent prognostic factor in patients with metastatic colorectal cancer (CRC), with a worse prognosis for right-sided tumors. There are limited data on the prognostic impact of PTS in stage III CRC. The main objective of this study was to analyze the prognostic impact of PTS in stage III CRC. Patients and MethodsA retrospective and uni-institutional cohort study was performed in an oncology reference center. Patients with stage III CRC treated with a 5-fluorouracil and oxaliplatin-based chemotherapy regimen (mFLOX regimen) from October 2007 to February 2013 were included. The primary outcome was the probability of overall survival (OS) at 5 years stratified by PTS. Secondary outcomes were the probability of disease-free survival (DFS) at 5 years and an analysis of the prognostic impact of clinical and molecular biomarkers. Kaplan‒Meier curves were used, and Cox models were used to evaluate prognostic factors associated with OS and DFS. ResultsOverall, 265 patients were evaluated. Transverse colon tumors, multicentric tumors, and undetermined primary subsites were excluded, resulting in 234 patients classified according to PTS: 95 with right sidedness (40.6%) and 139 with left sidedness (59.4%). The median follow-up time was 66 months [interquartile range (IQR): 39-81]. The 5-year OS probabilities for right-sided and left-sided tumors were 67% (95% CI: 58%-77%) and 82% (75%-89%), respectively [hazard ratio (HR): 2.02, 95% CI: 1.18-3.46; P = .010]. The 5-year probabilities of DFS for right-sided and left-sided tumors were 58% (49%-69%) and 65% (58%-74%), respectively (HR: 1.29, 0.84-1.97; P = 0.248). ConclusionThese data suggest that there may be a worse prognosis (inferior OS at 5 years) for resected right-sided stage III CRC patients treated in the real world. However, these data need to be confirmed by prospective studies with a larger number of participants.

Predictive Model of Oxaliplatin-induced Liver Injury Based on Artificial Neural Network and Logistic Regression.

Identifying potential high-risk groups of oxaliplatin-induced liver injury (OILI) is valuable, but tools are lacking. So artificial neural network (ANN) and logistic regression (LR) models will be developed to predict the risk of OILI. The medical information of patients treated with oxaliplatin between May and November 2016 at 10 hospitals was collected prospectively. We used the updated Roussel Uclaf causality assessment method (RUCAM) to identify cases of OILI and summarized the patient and medication characteristics. Furthermore, the ANN and LR models for predicting the risk of OILI were developed and evaluated. The incidence of OILI was 3.65%. The median RUCAM score with interquartile range was 6 (4, 9). The ANN model performed similarly to the LR model in sensitivity, specificity, and accuracy. In discrimination, the area under the curve of the ANN model was larger (0.920>0.833, p=0.019). In calibration, the ANN model was slightly improved. The important predictors of both models overlapped partially, including age, chemotherapy regimens and cycles, single and total dose of OXA, glucocorticoid drugs, and antihistamine drugs. When the discriminative and calibration ability was given priority, the ANN model outperformed the LR model in predicting the risk of OILI. Other chemotherapy drugs in oxaliplatin-based chemotherapy regimens could have different degrees of impact on OILI. We suspected that OILI may be idiosyncratic, and chemotherapy dose factors may be weakly correlated. Decision making on prophylactic medications needs to be carefully considered, and the actual preventive effect needed to be supported by more evidence.