TAS-102 plus bevacizumab for patients with metastatic colorectal cancer refractory to standard therapies (C-TASK FORCE): an investigator-initiated, open-label, single-arm, multicentre, phase 1/2 study

First-line trifluridine/tipiracil plus bevacizumab for unresectable metastatic colorectal cancer: SOLSTICE study design

Trifluridine/tipiracil (TT) is an orally administered combination of the thymidine-based nucleoside analogue trifluridine and the thymidine phosphorylase inhibitor tipiracil hydrochloride, which increases the bioavailability of cytotoxic trifluridine. Encouraging antitumor activity of first-line TT + bevacizumab (TT-B) has been observed in a Phase II study in patients with unresectable metastatic colorectal cancer ineligible for combination oxaliplatin- or irinotecan-based therapy. Here, we describe the design of SOLSTICE (NCT03869892), an open-label, Phase III trial in unresectable metastatic colorectal cancer patients who are not candidates for, or do not require, intensive therapy. The 854 patients were randomized 1:1 to receive first-line TT-B versus capecitabine + bevacizumab. The primary objective is to demonstrate superior progression-free survival with TT-B over capecitabine + bevacizumab. The first patient was enrolled in March 2019.

Retrospective cohort study of trifluridine/tipiracil (TAS-102) plus bevacizumab versus trifluridine/tipiracil monotherapy for metastatic colorectal cancer

Background

A previous phase I/II C-TASK FORCE study of trifluridine/tipiracil plus bevacizumab for patients with heavily pretreated metastatic colorectal cancer (mCRC) showed promising activity with an acceptable toxicity profile. This retrospective study aimed to investigate the safety and efficacy of trifluridine/tipiracil plus bevacizumab compared with trifluridine/tipiracil monotherapy in patients with heavily pretreated mCRC in clinical settings.

Methods

Records of patients with mCRC refractory to standard therapies who initiated trifluridine/tipiracil plus bevacizumab from January 2016 to March 2018 or trifluridine/tipiracil monotherapy from June 2014 to December 2015 were retrospectively reviewed at our institution.

Results

Totally, 60 patients received trifluridine/tipiracil plus bevacizumab and 66 received trifluridine/tipiracil monotherapy. All patients had previously received standard chemotherapy. Median progression-free survival (PFS) was 3.7 months [95% confidence interval (CI), 2.3–5.1] in the trifluridine/tipiracil plus bevacizumab group and 2.2 months (95% CI, 1.8–2.6) in the trifluridine/tipiracil monotherapy group [hazards ratio (HR) 0.69; 95% CI 0.48–0.99]. PFS rate at 16 weeks was 46.6% for the trifluridine/tipiracil plus bevacizumab group and 33.9% for the trifluridine/tipiracil monotherapy group. Although a relatively higher incidence of grade ≥ 3 neutropenia was observed in the trifluridine/tipiracil plus bevacizumab group than that in the other group (50.0% vs. 40.9%, p = 0.371), the incidence of febrile neutropenia was not high (3.3% vs. 7.8%, p = 0.444).

Conclusions

In real-world settings, trifluridine/tipiracil plus bevacizumab prolonged PFS and helped achieve higher 16-week PFS rate compared with trifluridine/tipiracil monotherapy in patients with heavily pretreated mCRC with manageable toxicities.

Trial registration

Retrospectively registered.

Bevacizumab in Combination with TAS-102 Improves Clinical Outcomes in Patients with Refractory Metastatic Colorectal Cancer: A Retrospective Study

Objective

TAS‐102 is effective for treating patients with metastatic colorectal cancer (mCRC). This study determined whether combining bevacizumab (Bmab) with TAS‐102 improves clinical outcomes in refractory mCRC.

Patients and Methods

We retrospectively analyzed data from Japanese patients with refractory mCRC who received TAS‐102 (35 mg/m², twice a day) with (T‐B group) or without Bmab (TAS‐102 monotherapy; T group) between July 2014 and December 2018. The primary endpoint was median overall survival (OS), and secondary endpoints were median time to treatment failure, overall response rate, and the incidence of adverse events. Clinical outcomes were compared using propensity score matched analysis.

Results

Data from 57 patients were analyzed (T‐B group: 21 patients, T group: 36 patients). Median OS was significantly longer in the T‐B group than the T group (14.4 months vs. 4.5 months, p < .001). Cox proportional hazard analysis showed that combination therapy with Bmab was significantly correlated with OS. Propensity score matched analysis confirmed that the median OS was significantly longer in the T‐B group than the T group (14.4 months vs. 6.1 months, p = .006) and that there was a significant correlation between Bmab and OS. The incidence of hypertension (grade ≥2) as an adverse event was significantly higher in the T‐B group than the T group (23.8% vs. 0.0%, p = .005), whereas other adverse events were comparable between the two groups.

Conclusion

Treatment with Bmab in combination with TAS‐102 is significantly associated with improved clinical outcomes in patients with mCRC refractory to standard therapies.

Implications for Practice

Combining bevacizumab (Bmab) with TAS‐102 significantly improved overall survival and several prognostic indicators in patients with metastatic colorectal cancer (mCRC) refractory to standard therapies, with manageable toxicities. Treatment with Bmab in combination with TAS‐102 is significantly associated with improved clinical outcomes in patients with mCRC.

To determine whether combined treatment with bevacizumab improves clinical outcomes, this retrospective study compared the efficacy and safety of treatment with or without bevacizumab in patients receiving TAS‐102 for metastatic colorectal cancer.

A Trial Protocol of Biweekly TAS-102 and Bevacizumab as Third-Line Chemotherapy for Advanced/Recurrent Colorectal Cancer: A Phase II Multicenter Clinical Trial (The TAS-CC4 Study)

Background: Treatment with TAS-102 has significantly improved the progression-free survival (PFS) and overall survival (OS) of patients with metastatic colorectal cancer (mCRC). Reportedly, the combination of TAS-102 plus bevacizumab extends the median PFS. The present study aimed to confirm the efficacy and safety of TAS-102 plus bevacizumab (biweekly administration) as third-line chemotherapy for patients with mCRC. Methods/Design: This is a single-arm, open-label, prospective, nonrandomized, multicenter phase II trial conducted in Japan. With a threshold and expected PFS of 2.1 and 3.5 months, respectively, the simulation results showed a sample size of 42 with α = 0.05 (both sides) for 90% power, based on the One-Arm Binomial test using the SWOG statistical tool. If the estimated dropout is 7%-8%, the target sample size is estimated to be 45. The TAS-CC4 study regimen comprised 28-day cycles with biweekly oral administration of TAS-102 (35 mg/m² twice daily on days 1-5 and 15-19 of every 28-day cycle) and bevacizumab (5.0 mg/kg on days 1 and 15). The primary end point is the PFS; secondary end points include response rate (RR), OS, grade ≥3 neutropenia, and genetic alterations (KRAS/BRAF mutations) in the circulating cell-free DNA. Discussion: The present study can contribute to the determination of the effective dosing interval of TAS-102 and bevacizumab in patients with mCRC and is thought to lead to prophylaxis of neutropenia and prolongation of the treatment period.

U3-1402, a Novel HER3-Targeting Antibody-Drug Conjugate, for the Treatment of Colorectal Cancer

HER3 is overexpressed in several cancers, including colorectal cancer. Although therapies with anti-HER3 antibodies have been investigated, significant clinical benefits have not been reported. U3-1402 is a novel HER3-antibody-drug conjugate (ADC) composed of the HER3 antibody patritumab and a novel topoisomerase I inhibitor, DX-8951 derivative (DXd). The sensitivity of DXd was evaluated by a growth inhibition assay. The antitumor activity of U3-1402 was evaluated in a murine xenograft model in which its effects on cells, with a range of HER3 expression levels, were compared with those of patritumab alone, irinotecan, control-ADC, and saline. In the growth inhibition assay, all colorectal cancer cell lines were sensitive to DXd. In the tumor xenograft model, significant tumor regression with U3-1402 was observed both in the DiFi cell line (high HER3 expression; KRAS wild type) and in SW620 (high HER3 expression; KRAS mutation), but no treatment effect was observed in Colo320DM (low HER3 expression). Notably, SW620 tumor growth was significantly suppressed with U3-1402 compared with the saline-treated group (P < 0.001) and showed greater activity compared with the irinotecan group. By contrast, patritumab alone, control-ADC, and saline did not significantly differ in tumor growth inhibition. The antitumor activity of U3-1402 was dependent on HER3 expression level, but not on KRAS mutation status. These results support further investigation of development strategies for U3-1402 in patients with HER3-expressing colorectal cancer.

Combination chemotherapy with TAS-102 plus bevacizumab in salvage-line treatment of metastatic colorectal cancer: A single-center, retrospective study examining the prognostic value of the modified Glasgow Prognostic Score in salvage-line therapy of metastatic colorectal cancer

The combination regimen of TAS-102, a novel oral nucleoside antitumor agent containing trifluridine and tipiracil hydrochloride, with bevacizumab (C-TASK FORCE), a selective monoclonal antibody inhibitor of vascular endothelial growth factor-A, as salvage-line therapy for metastatic colorectal cancer (mCRC) was established based on its high clinical effectiveness. The aim of the present study was to evaluate the prognostic accuracy of the modified Glasgow Prognostic Score (mGPS) in patients receiving TAS-102 plus bevacizumab. The study included 17 patients (12 men and 5 women, mean age 60.4±13.4 years) with unresectable mCRC who were confirmed to have wild-type or mutant RAS genes. The patients received salvage-line treatment with TAS-102 plus bevacizumab at the Surgical Oncology Department of Gifu University School of Medicine between March 2016 and August 2018. The study population was heavily pretreated; the majority of the patients (71%) had received ≥4 prior regimens and, in addition to fluoropyrimidine, irinotecan and oxaliplatin, all had received bevacizumab (100%) and either cetuximab or panitumumab (47%). The RAS status was wild-type in 9 (53%) and mutant in 8 (47%) patients. The primary tumor locations included the right-sided colon in 5 patients (29%; cecum in 2 and transverse colon in 3 cases) and left-sided colorectum in 12 patients [71%; sigmoid colon in 4, rectosigmoid (Rs) in 4, and rectum above/below the peritoneal reflection (Ra/b) in 4 cases]. Metastatic sites included the liver in 15 (88%), lung in 13 (76%), lymph nodes in 7 (41%), and peritoneal dissemination in 5 (24%) patients. The number of metastatic sites was 1 in 3 (18%) and >2 in 14 (82%) patients. Their first staging imaging scans (after 2 cycles of therapy) were available for review in all 17 patients. At first evaluation, 5 (29%) patients had progressive disease (PD), 12 (71%) had stable disease, and none had a partial response to TAS-102 plus bevacizumab. The median overall survival (OS) of 14.1 months and progression-free survival (PFS) of 6.8 months were comparable to the 11.2 and 5.6 months, respectively, in the C-TASK FORCE study. Upon considering three groups, namely mGPS 0, mGPS 1 and mGPS 2, the median PFS times were significantly different (mGPS 0 vs. mGPS 2, P=0.02; and mGPS 1 vs. mGPS 2, P=0.06). The median PFS times in the mGPS 0, 1 and 2 groups were 12.1, 4.8 and 2.3 months, respectively. Median OS was also significantly different (mGPS 0 vs. mGPS 2, P=0.01; and mGPS 1 vs. mGPS 2, P=0.04). The median OS times in the mGPS 0, 1 and 2 groups were 14.0, not reached, and 2 months, respectively. The present study demonstrated the efficacy and safety of the TAS-102 plus bevacizumab combination as salvage-line treatment. This combination therapy (the TAS-102 plus bevacizumab) has obtained valid results with PFS OS as well as C-TASK.FORCE study. The results of the present study also confirmed the prognostic accuracy of mGPS in salvage-line treatment of patients with mCRC.

Selecting treatment options in refractory metastatic colorectal cancer

Survival of patients with metastatic colorectal cancer (mCRC) has significantly improved in the last decade. Survival gains are not driven by advances in first-line therapy but by incremental additional effects of subsequent treatment lines. To maximize outcomes, patients should receive all active agents. Identification of patient subgroups is increasing individualization of treatment. Novel oral agents, such as regorafenib and TAS-102, as well as promising immunotherapeutic agents have offered salvage treatment options for refractory mCRC. Although most therapeutic developments for mCRC in the chemorefractory setting focuses on new targets and/or more potent agents, reconsideration of established targets has gained importance with the growth of a rational pharmacogenomic approach to drug development, such as HER2. The authors describe treatment options for patients with refractory colon cancer following first- and second-line therapy.

Pan-Asian adapted ESMO consensus guidelines for the management of patients with metastatic colorectal cancer: a JSMO-ESMO initiative endorsed by CSCO, KACO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) consensus guidelines for the treatment of patients with metastatic colorectal cancer (mCRC) was published in 2016, identifying both a more strategic approach to the administration of the available systemic therapy choices, and a greater emphasis on the use of ablative techniques, including surgery. At the 2016 ESMO Asia Meeting, in December 2016, it was decided by both ESMO and the Japanese Society of Medical Oncology (JSMO) to convene a special guidelines meeting, endorsed by both ESMO and JSMO, immediately after the JSMO 2017 Annual Meeting. The aim was to adapt the ESMO consensus guidelines to take into account the ethnic differences relating to the toxicity as well as other aspects of certain systemic treatments in patients of Asian ethnicity. These guidelines represent the consensus opinions reached by experts in the treatment of patients with mCRC identified by the Presidents of the oncological societies of Japan (JSMO), China (Chinese Society of Clinical Oncology), Korea (Korean Association for Clinical Oncology), Malaysia (Malaysian Oncological Society), Singapore (Singapore Society of Oncology) and Taiwan (Taiwan Oncology Society). The voting was based on scientific evidence and was independent of both the current treatment practices and the drug availability and reimbursement situations in the individual participating Asian countries.

Two Cases of Long-Term Control of Metastatic Colorectal Cancer via FTD/TPI plus Bevacizumab in Elderly Patients

With advances in new cytotoxic drugs and molecular-targeted drugs, the prognosis of patients with metastatic colorectal cancer (mCRC) has improved. However, physicians often hesitate to administer intensive standard regimens to elderly patients with mCRC. Recently, first-line regimens that are effective in and well-tolerated by patients who are not eligible for intensive chemotherapy have been established. However, the therapeutic strategies to adopt after the failure of first-line treatment for patients who are not eligible for intensive chemotherapy remain unclear. We herein report two cases of long-term control of mCRC via FTD/TPI+bevacizumab (Bmab) as second- or third-line treatment in elderly patients without severe adverse events. In case 1, first-line treatment with Tegafur-Uracil, which is a prodrug of 5-FU, caused disease progression in a short period after the initiation of chemotherapy. In case 2, intensive first-line treatment caused severe adverse events, and treatment was discontinued. However, in both cases, disease control was obtained for a long time without severe adverse events by subsequent treatment with FTD/TPI+Bmab. The success in these present cases indicates that FTD/TPI+Bmab as a second- or third-line treatment is a therapeutic option for elderly patients with mCRC who are not eligible for intensive chemotherapy, even after failure of treatment with 5-FU.

Third- or Later-line Therapy for Metastatic Colorectal Cancer: Reviewing Best Practice

An increasing number of patients with metastatic colorectal cancer (mCRC) are able to receive 3 or more lines of therapy. Treatments in this setting can include regorafenib (an oral multikinase inhibitor), trifluridine/tipiracil hydrochloride (TAS-102), antibodies that target epidermal growth factor receptor for patients with RAS wild-type tumors (if no prior exposure), and, where approved, anti-programmed cell death protein 1 inhibitors for patients with microsatellite instability-high mCRC. Although guidelines describe the available treatment options, few insights are provided to guide selection and sequencing. In this article, we share expert opinion from diverse geographic regions, to offer guidance for best practice when selecting and managing third-line treatment for mCRC. Various factors, including performance status, age, and tumor sidedness, can be used to guide treatment selection. Biomarkers, such as RAS, BRAF, and microsatellite instability, can be useful for treatment stratification. Management of adverse events, to maintain quality of life, is a key consideration and is crucial to best practice in this setting. Common toxicities associated with third-line treatments are hand-foot skin reaction, fatigue, diarrhea, and cytopenias. Patients who receive third-line and later-line treatments should be monitored for these events, especially during the first 2 cycles. Dose modifications can also be used to manage toxicities and to minimize the effect on quality of life, while maximizing treatment benefit. Clinical trials of emerging agents, new treatment combinations, and novel therapies continue the efforts to improve outcomes for patients with mCRC. Sharing expert opinions on best practice for treatment selection and management can ultimately improve outcomes for patients with mCRC.

Safety and Efficacy of Trifluridine-Tipiracil Hydrochloride Oral Combination (TAS-102) in Patients with Unresectable Colorectal Cancer

AIM

To retrospectively examine efficacy and safety of oral combination of trifluridine and tipiracil hydrochloride (TAS-102) as the second-line therapeutic agent for unresectable colorectal cancer.

PATIENT AND METHODS

Treatment outcomes of 17 patients who had received TAS-102 at our Institution from January 2015 to January 2017 were analyzed. The indications for second-line TAS-102 treatment were intolerance to other multi-drug combination (four patients) or patient refusal of the standard second-line therapy (13 patients).

RESULTS

Among 17 patients who received TAS-102 as second-line therapy, partial response was observed in two (12%) and stable disease in two (12%). Outcomes of TAS-102 given as second-line therapy were: median overall survival of 5 months, response rate of 12% and disease control of 24%. Overall, no adverse events other than neutropenia were noted.

CONCLUSION

Our findings suggest a beneficial role of TAS-102 in second-line therapy for unresectable colorectal carcinoma.

Efficacy and safety of TAS-102 in refractory metastatic colorectal cancer: a meta-analysis

Background

TAS-102 has been applied to metastatic colorectal cancer (mCRC) patients who had received at least two prior regimens of standard chemotherapy. This meta-analysis is designed to assess the efficacy and safety of TAS-102 in patients with mCRC.

Methods

We searched randomized controlled trials (RCTs) through PubMed, Embase, Web of Science and Cochrane clinical trial databases and clinicaltrial.gov from database initiation to March 2018. The overall survival (OS), progression-free survival (PFS), disease control rate (DCR) and incidence of adverse events were summarized with the use of hazard ratio (HR) or risk ratio (RR).

Results

Three RCTs with 1318 patients were included. Results showed that TAS-102 significantly improved OS (HR 0.70, 95% confidence interval [CI] 0.62-0.79) and PFS (HR 0.46, 95% CI 0.40-0.52) in patients who were intolerant or refractory to fluoropyrimidine, irinotecan and oxaliplatin. The pooled odds ratio of DCR was 4.15 (95% CI 3.18-5.43). Notably, there were significant OS benefits both in patients with KRAS mutation (HR 0.76, 95% CI 0.63-0.92) and those with wild-type KRAS (HR 0.66, 95% CI 0.55-0.79). These benefits were also observed in patients with different numbers of metastatic sites. However, patients with >18 months since the diagnosis of first metastases seemed to have better OS (HR 0.65, 95% CI 0.55-0.77). The most common toxicities associated with TAS-102 were neutropenia (RR 116.51, 95% CI 23.51-577.33), leucopenia (RR 67.70, 95% CI 13.63-336.29), anemia (RR 4.28, 95% CI 2.70-6.79) and diarrhea (RR 5.10, 95% CI 1.40-18.61).

Conclusion

TAS-102 significantly improves OS, PFS and DCR in refractory mCRC patients with tolerable toxicity. Meanwhile, the OS benefits have nothing to do with KRAS status and the number of metastatic sites.

Rationale and design of the TRUSTY study: a randomised, multicentre, open-label phase II/III study of trifluridine/tipiracil plus bevacizumab versus irinotecan, fluoropyrimidine plus bevacizumab as second-line treatment in patients with metastatic colorectal cancer progressive during or following first-line oxaliplatin-based chemotherapy

Background

Trifluridine/tipiracil is an oral agent approved for the treatment of patients with metastatic colorectal cancer (mCRC). Trifluridine is an antineoplastic thymidine analogue, and tipiracil improves its bioavailability. A phase I/II C-TASK FORCE study of trifluridine/tipiracil plus bevacizumab for patients with refractory mCRC demonstrated promising efficacy results with mild toxicity profile. It is important that quality of life be preserved in patients with mCRC without compromising their prognosis. Here, we outline the TRiflUridine/tipiracil in Second-line sTudY phase II/III study (JapicCTI-173618), designed to demonstrate non-inferiority in overall survival of trifluridine/tipiracil plus bevacizumab compared with irinotecan, fluoropyrimidine and bevacizumab combination regimens as second-line treatment in patients with mCRC.

Patients and methods

Eligible patients have confirmed unresectable advanced or recurrent colorectal adenocarcinoma and have failed to respond to first-line oxaliplatin-based chemotherapy. A total of 524 patients are to be randomly assigned (1:1 ratio) to trifluridine/tipiracil plus bevacizumab or irinotecan, fluoropyrimidine and bevacizumab and stratified according to RAS status (wild type vs mutant). The primary endpoint of the phase II part is disease control rate with trifluridine/tipiracil plus bevacizumab therapy. Secondary endpoints are response rate and safety with trifluridine/tipiracil plus bevacizumab therapy. In the phase III part, the primary endpoint is overall survival, and secondary endpoints include quality of life, progression-free survival, response rate, disease control rate, safety, time to treatment failure, time to post-study treatment failure and the proportion of patients receiving post-study treatment. The first patient was enrolled in October 2017 and the study is anticipated to be completed in 2022.

Clinical trial registration

JapicCTI-173618 (JapicCTI).

Trifluridine/tipiracil: an emerging strategy for the management of gastrointestinal cancers

Fluoropyrimidines are currently the backbone of treatment for gastrointestinal (GI) cancers but development of resistance to these agents remains a major problem. Trifluridine/tipiracil is an oral chemotherapeutic agent recently approved for third-line treatment of chemorefractory metastatic colorectal cancer. This article reviews the clinical value of trifluridine/tipiracil as a monotherapy, including recent trials in GI cancers, and the potential benefit of combining it with other agents in patients with GI cancers, including the preclinical rationale for combination therapy and recently completed and ongoing clinical trials. Data gathered so far suggest that trifluridine/tipiracil has the potential to form the chemotherapeutic backbone in the continuum of care for GI cancers in the future.

Update in Systemic and Targeted Therapies in Gastrointestinal Oncology

Progress has been made in the treatment of gastrointestinal cancers through advances in systemic therapies, surgical interventions, and radiation therapy. At the Multi-Disciplinary Patient Care in Gastrointestinal Oncology conference, the faculty members of the Penn State Health Milton S. Hershey Medical Center presented a variety of topics that focused on this sub-specialty. This conference paper highlights the new development in systemic treatment of various malignant diseases in the digestive system. Results of the recent clinical trials that investigated the clinical efficacy of pegylated hyaluronidase, napabucasin, and L-asparaginase in pancreatic carcinoma are presented. The use of peri-operative chemotherapy comprised of 5-fluorouracil or capecitabine, leucovorin, oxaliplatin, and docetaxel (FLOT), and immunotherapy including pembrolizumab, nivolumab, and ipilimumab in gastroesophageal carcinoma are discussed. Data from clinical trials that investigated the targeted therapeutics including nivolumab, ramucirumab, lenvatinib, and BLU-554 are reported. The role of adjuvant capecitabine in resected biliary tract carcinoma (BTC) and nab-paclitaxel in combination with gemcitabine and cisplatin in advanced BTC are presented. In colorectal carcinoma, the efficacy of nivolumab, adjuvant FOLFOX or CAPOX, irinotecan/cetuximab/vemurafenib, and trifluridine/tipiracil/bevacizumab, is examined. In summary, some of the above systemic therapies have become or are expected to become new standard of care, while the others demonstrate the potential of becoming new treatment options.

Patient-derived organoids model treatment response of metastatic gastrointestinal cancers

Patient-derived organoids (PDOs) have recently emerged as robust preclinical models; however, their potential to predict clinical outcomes in patients has remained unclear. We report on a living biobank of PDOs from metastatic, heavily pretreated colorectal and gastroesophageal cancer patients recruited in phase 1/2 clinical trials. Phenotypic and genotypic profiling of PDOs showed a high degree of similarity to the original patient tumors. Molecular profiling of tumor organoids was matched to drug-screening results, suggesting that PDOs could complement existing approaches in defining cancer vulnerabilities and improving treatment responses. We compared responses to anticancer agents ex vivo in organoids and PDO-based orthotopic mouse tumor xenograft models with the responses of the patients in clinical trials. Our data suggest that PDOs can recapitulate patient responses in the clinic and could be implemented in personalized medicine programs.

Profile of trifluridine/tipiracil hydrochloride in the treatment of metastatic colorectal cancer: efficacy, safety, and place in therapy

TAS-102, with its robust survival efficacy and feasible toxicity, is one of the standard salvage-line treatments for patients with metastatic colorectal cancer (mCRC). No definitive data are available to determine which drug should be administered first during salvage-line treatment. Therefore, it is imperative that we establish the sequence of administration by considering drug toxicity profiles based on patient characteristics, such as age, performance status, comorbidities, tolerability to previous treatments, and patient preferences. The identification of predictive biomarkers in response to TAS-102 or its toxicity is urgently needed for better patient selection. Moreover, to strengthen efficacy or relieve toxicity, combinations with other agents, which could potentially emerge as standard treatment regimens, have been investigated and compared to existing active regimens for mCRC.