Phase I study of TAS-102 and irinotecan combination therapy in Japanese patients with advanced colorectal cancer

Phase I study of trifluridine/tipiracil (TAS-102) plus irinotecan in combination with bevacizumab as a second-line therapy for patients with metastatic colorectal cancer

PURPOSE

This phase I trial is to determine the recommended dose of the TAS-102, irinotecan plus bevacizumab regimen and assess its safety and efficacy in patients with metastatic colorectal cancer refractory to fluoropyrimidine and oxaliplatin treatment.

METHODS

A 3 + 3 designed dose escalation was performed. Patients were administered TAS-102 (30-35 mg/m2 twice daily on days 1-5) and irinotecan (150-165 mg/m2 on day 1) combined with a fixed dose of bevacizumab (5 mg/kg on day 1) every two weeks. The primary endpoint was the determination of the recommended phase II dose.

RESULTS

Eighteen patients were enrolled: 6 at the Level 1 (TAS-102 30 mg/m2 twice daily, irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg), six at the Level 2 (TAS-102 35 mg/m2 twice daily, irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg), and six at the Level 3 (TAS-102 30 mg/m2 twice daily, irinotecan 165 mg/m2 plus bevacizumab 5 mg/kg). Five dose-limiting toxicities occurred: one observed at Level 1 (thrombocytopenia), two at Level 2 (neutropenia and diarrhea), and two at Level 3 (fatigue and neutropenia). The RP2D was established as TAS-102 30 mg/m2 twice daily and irinotecan 150 mg/m2 plus bevacizumab 5 mg/kg. The most frequent grade 3/4 treatment-related adverse events were neutropenia (33.3%), diarrhea (16.7%), and thrombocytopenia (11.1%). No treatment-related death occurred. Two patients (11.1%) experienced partial responses and 14 (77.8%) had stable disease.

CONCLUSION

The regimen of TAS-102, irinotecan, and bevacizumab is tolerable with antitumor activity for metastatic colorectal cancer patients refractory to first-line fluoropyrimidines and oxaliplatin treatment.

Clinical Phase I Study of TAS102/Irinotecan/Bevacizumab Combination Therapy in Japanese Patients With Unresectable Metastatic Colorectal Cancer (mCRC)

BACKGROUND

In this phase I study, we aimed to examine the safety of a triple combination (TAS-102/irinotecan/bevacizumab) therapy in patients with previously treated metastatic colorectal cancer (mCRC).

METHODS

In the TAS-102 dose-escalation phase, we determined dose-limiting toxicity (DLT), estimated the maximum tolerated dose (MTD), and determined the recommended dose (RD); in the expansion phase, we evaluated safety. The RD was administered in advance for 10 patients. The TAS-102 dose was increased to 25-35 mg/m2 and administered orally twice on days 1-5 and 8-12. Irinotecan (100 mg/m2) and bevacizumab (5 mg/m2) were administered on days 1 and 15 of the treatment, respectively.

RESULTS

Fifteen patients were enrolled in dose-escalation Levels 1-3, and ten in the expansion phase. A 30 mg/m2 TAS-102 dose at Level 2 was administered to three patients, with one presenting grade 4 neutropenia. A 35 mg/m2 TAS-102 dose at Level 3 was administered to five patients, with three patients presenting grade 4 neutropenia and grade 3 DLTs. We added three patients at Level 2 and set the MTD at 30 mg/m2, with no DLTs. The RD was fixed at 25 mg/m2, with no DLTs (N = 10) or treatment-related deaths. One patient showed complete response at Level 2, four presented partial response, and eleven individuals maintained stable disease for over four months. The median progression-free survival duration was 7.6 months, while the median overall survival period was 16.9 months.

CONCLUSION

The TAS-102/irinotecan/bevacizumab combination therapy was safe, effective, and well-tolerated in patients previously treated with mCRC.

Bevacizumab, Irinotecan, and Biweekly Trifluridine/Tipiracil for Metastatic Colorectal Cancer: MODURATE, a Phase Ib Study

BACKGROUND

In this phase Ib study MODURATE, we optimized the dosing schedule and tested the efficacy and safety of trifluridine/tipiracil, irinotecan, and bevacizumab in patients with metastatic colorectal cancer with fluoropyrimidine and oxaliplatin treatment failure.

METHODS

We included a dose escalation (3 + 3 design) and an expansion cohort. Patients were administered trifluridine/tipiracil (25-35 mg/m2 twice daily, days 1-5), irinotecan (150-180 mg/m2, day 1), and bevacizumab (5 mg/kg, day 1) every 2 weeks. The recommended phase II dose (RP2D) in the dose escalation cohort was administered to at least 15 patients in both cohorts combined.

RESULTS

Twenty-eight patients were enrolled. Five dose-limiting toxicities were observed. RP2D was defined as trifluridine/tipiracil 35 mg/m2, irinotecan 150 mg/m2, and bevacizumab 5 mg/kg. Of 16 patients who received RP2D, 86% (14/16) experienced grade ≥3 neutropenia without febrile neutropenia. Dose reduction, delay, and discontinuation occurred in 94%, 94%, and 6% of patients, respectively. Three patients (19%) showed partial response and 5 had stable disease for >4 months, with a median progression-free and overall survival of 7.1 and 21.7 months, respectively.

CONCLUSION

Biweekly trifluridine/tipiracil, irinotecan, and bevacizumab administration may have moderate antitumor activity with high risk of severe myelotoxicity in previously treated patients with metastatic colorectal cancer [UMIN Clinical Trials Registry (UMIN000019828) and Japan Registry of Clinical Trials (jRCTs041180028)].

Study protocol of an open-label, single arm phase II trial investigating the efficacy and safety of Trifluridine/Tipiracil combined with irinotecan as a second line therapy in patients with cholangiocarcinoma (TRITICC)

BACKGROUND

The prognosis of patients with advanced biliary tract cancer (BTC) who have progressed on gemcitabine plus cisplatin is dismal. Trifluridine/tipiracil (FTD/TPI) and irinotecan have proven efficacy in different gastrointestinal malignancies. We therefore hypothesized that this combination might improve the therapeutic outcome in patients with BTC after failure of first line treatment.

METHODS

TRITICC is an interventional, prospective, open-label, non-randomised, exploratory, multicentre, single-arm phase IIA clinical trial done in 6 sites with expertise in managing biliary tract cancer across Germany. A total of 28 adult patients (aged ≥ 18 years) with histologically verified locally advanced or metastatic biliary tract cancer (including cholangiocarcinoma and gallbladder or ampullary carcinoma) with documented radiological disease progression to first-line gemcitabine based chemotherapy will be included to receive a combination of FTD/TPI plus irinotecan according to previously published protocols. Study treatment will be continued until disease progression according to RECIST 1.1 criteria or occurrence of unacceptable toxicity. The effect of FTD/TPI plus irinotecan on progression-free survival will be analyzed as primary endpoint. Safety (according to NCI-CTCAE), response rates and overall survival are secondary endpoints. In addition, a comprehensive translational research program is part of the study and might provide findings about predictive markers with regard to response, survival periods and resistance to treatment.

DISCUSSION

The aim of TRITICC is to evaluate the safety and efficacy of FTD/TPI plus irinotecan in patients with biliary tract cancer refractory to previous Gemcitabine based treatment.

TRIAL REGISTRATION

EudraCT 2018-002936-26; NCT04059562.

Estrogen Receptor Subtypes Elicit a Distinct Gene Expression Profile of Endothelial-Derived Factors Implicated in Atherosclerotic Plaque Vulnerability

In the presence of established atherosclerosis, estrogens are potentially harmful. MMP-2 and MMP-9, their inhibitors (TIMP-2 and TIMP-1), RANK, RANKL, OPG, MCP-1, lysyl oxidase (LOX), PDGF-β, and ADAMTS-4 play critical roles in plaque instability/rupture. We aimed to investigate (i) the effect of estradiol on the expression of the abovementioned molecules in endothelial cells, (ii) which type(s) of estrogen receptors mediate these effects, and (iii) the role of p21 in the estrogen-mediated regulation of the aforementioned factors. Human aortic endothelial cells (HAECs) were cultured with estradiol in the presence or absence of TNF-α. The expression of the aforementioned molecules was assessed by qRT-PCR and ELISA. Zymography was also performed. The experiments were repeated in either ERα- or ERβ-transfected HAECs and after silencing p21. HAECs expressed only the GPR-30 estrogen receptor. Estradiol, at low concentrations, decreased MMP-2 activity by 15-fold, increased LOX expression by 2-fold via GPR-30, and reduced MCP-1 expression by 3.5-fold via ERβ. The overexpression of ERα increased MCP-1 mRNA expression by 2.5-fold. In a low-grade inflammation state, lower concentrations of estradiol induced the mRNA expression of MCP-1 (3.4-fold) and MMP-9 (7.5-fold) and increased the activity of MMP-2 (1.7-fold) via GPR-30. Moreover, p21 silencing resulted in equivocal effects on the expression of the abovementioned molecules. Estradiol induced different effects regarding atherogenic plaque instability through different ERs. The balance of the expression of the various ER subtypes may play an important role in the paradoxical characterization of estrogens as both beneficial and harmful.

A phase 1b multicenter study of TAS-102 in combination with irinotecan in patients with advanced recurrent or unresectable gastric and gastroesophageal adenocarcinoma after at least one line of treatment with a fluoropyrimidine and platinum-containing regimen

TAS-102 is approved for treatment of refractory metastatic gastroesophageal carcinoma (mGEC). This study sought to determine whether the combination of TAS-102 with irinotecan (TASIRI) was safe and effective in previously treated mGEC. This was a single-arm phase 1b study for patients (pts) with mGEC previously treated with at least one line of fluoropyrimidine and platinum-containing regimen. TAS-102 was given at 25 mg/m² twice daily on days 1 to 5 with irinotecan 180 mg/m² on day 1 of a 14-day cycle. The primary endpoint was progression-free survival at 6 months ≥ 35% (PFS-6). 20 Pts were enrolled. The study met its primary endpoint. PFS-6 is 40% (95% CI 19.3-60.0). Median PFS and overall survival are 5.3 months and not reached, respectively. 17 of 20 pts had measurable disease by RECIST criteria. Of the 17, 13 had stable disease and 4 had progressive disease as best response (8 pts had tumor shrinkage < 30%). The disease control rate was 75%. In exploratory analyses, mutations in homologous recombination deficiency genes were associated with inferior PFS (P < 0.03). The most common any grade (G) treatment-related adverse events (TRAE) were nausea (n = 14, 70%), diarrhea (n = 9, 45%), and fatigue (n = 8, 40%). G3-4 TRAE in > 5% of pts were anemia (20%) and neutropenia (10%). 2 serious TRAE were reported: G4 febrile neutropenia (n = 1) and G3 hypotension (n = 1). There was no G5 TRAE. The combination of TASIRI showed encouraging clinical activity with a meaningful improvement in PFS-6 compared to historic controls.

Pharmacogenomics Testing in Phase I Oncology Clinical Trials: Constructive Criticism Is Warranted

Simple Summary

Phase I clinical trials are a cornerstone of pharmaceutical development in oncology. Many studies have now attempted to incorporate pharmacogenomics into phase I studies; however, many of these studies have fundamental flaws that that preclude interpretation and application of their findings. Study populations are often small and heterogeneous with multiple disease states, multiple dose levels, and prior therapies. Genetic testing typically includes few variants in candidate genes that do no encapsulate the full range of phenotypic variability in protein function. Moreover, a plurality of these studies do not present scientifically robust clinical or preclinical justification for undertaking pharmacogenomics studies. A significant amount of progress in understanding pharmacogenomic variability has occurred since pharmacogenomics approaches first began appearing in the literature. This progress can be immediately leveraged for the vast majority of Phase I studies. The purpose of this review is to summarize the current literature pertaining to Phase I incorporation of pharmacogenomics studies, analyze potential flaws in study design, and suggest approaches that can improve design of future scientific efforts.

Abstract

While over ten-thousand phase I studies are published in oncology, fewer than 1% of these studies stratify patients based on genetic variants that influence pharmacology. Pharmacogenetics-based patient stratification can improve the success of clinical trials by identifying responsive patients who have less potential to develop toxicity; however, the scientific limits imposed by phase I study designs reduce the potential for these studies to make conclusions. We compiled all phase I studies in oncology with pharmacogenetics endpoints (n = 84), evaluating toxicity (n = 42), response or PFS (n = 32), and pharmacokinetics (n = 40). Most of these studies focus on a limited number of agent classes: Topoisomerase inhibitors, antimetabolites, and anti-angiogenesis agents. Eight genotype-directed phase I studies were identified. Phase I studies consist of homogeneous populations with a variety of comorbidities, prior therapies, racial backgrounds, and other factors that confound statistical analysis of pharmacogenetics. Taken together, phase I studies analyzed herein treated small numbers of patients (median, 95% CI = 28, 24–31), evaluated few variants that are known to change phenotype, and provided little justification of pharmacogenetics hypotheses. Future studies should account for these factors during study design to optimize the success of phase I studies and to answer important scientific questions.

TAS-102: A resurrected novel Fluoropyrimidine with expanding role in the treatment of gastrointestinal malignancies

TAS-102 is an orally administered fixed-dose formulation consisting of trifluorothymidine (TFT), a fluoropyrimidine antimetabolite, and tipiracil (TPI), an inhibitor of thymidine phosphorylase (TP) that prevents rapid degradation of TFT and ensures its bioavailability. The novelty of TAS-102 lies in its antitumor activity against 5-fluorouracil (5-FU) resistant tumors, demonstrated both in the in vitro models and xenografts. The cytotoxic activity of TFT relies primarily on extensive incorporation of the TFT metabolite into the cellular DNA inducing DNA dysfunction and cell death. In contrast, 5-fluorouracil (5-FU) interferes with DNA biosynthesis by inhibiting thymidylate synthase(TS), which partly explains the absence of cross-resistance between TAS-102 and 5-FU. TAS-102 is currently approved in the third-line setting for patients with metastatic colorectal and gastric cancer based on phase III randomized clinical trial data confirming an overall survival benefit with TAS-102. The preliminary data from recently reported studies suggest a potential expanding role of TAS-102 in a variety of gastrointestinal (GI) cancers. The current article presents an overview of the pharmacology, clinical development of TAS-102, and its emerging role in the treatment of GI cancers. In addition, we discussed the rationale underlying the ongoing clinical trials investigating various combinations of TAS-102 with other anticancer agents, including targeted therapies, in a wide range of GI tumors.

Trifluridine/tipiracil for the treatment of metastatic gastric cancer

Introduction: Trifluridine/tipiracil is a novel oral cytotoxic chemotherapy consisting of a thymidine-based nucleoside analog, trifluridine, and a thymidine phosphorylase inhibitor, tipiracil. Trifluridine/tipiracil was approved for the treatment of metastatic colorectal cancer refractory to standard therapies. A phase II trial in Japan demonstrated that this therapy has antitumor activity and is tolerated by patients with advanced gastric cancer (AGC); as a result, the phase III TAGS trial (Trifluridine/tipiracil versus placebo in patients with heavily pretreated metastatic gastric cancer) was initiated.Area covered: Trifluridine/tipiracil has proved effective for heavily pretreated AGC and has thus been approved for use in the United States in February 2019, Japan in August 2019 and the European Union in September 2019. Detail of the phase III TAGS trial is discussed in this review.Expert opinion: Trifluridine/tipiracil after at least two previous courses of systemic chemotherapy improved rates of survival of gastric cancer; thus it has become one of the treatment options in affected patients. Currently, several clinical trials of trifluridine/tipiracil in combination with other anticancer agents such as ramucirumab (an anti-vascular endothelial growth factor receptor 2 monoclonal antibody) for patients with AGC are ongoing.

Phase I Study of Trifluridine/Tipiracil Plus Irinotecan and Bevacizumab in Advanced Gastrointestinal Tumors

PURPOSE

This two-part phase Ib trial determined the maximum tolerated dose (MTD) of the combination of trifluridine/tipiracil (FTD/TPI) and irinotecan in patients with advanced gastrointestinal tumors, and evaluated the safety, pharmacokinetics, and antitumor activity of the FTD/TPI, irinotecan, and bevacizumab triplet combination in previously treated metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

Dose escalation (3+3 design) in advanced gastrointestinal tumors was followed by expansion in mCRC. During dose escalation, patients received FTD/TPI (20-35 mg/m² twice daily; days 1-5 of a 14-day cycle) and irinotecan (120-180 mg/m²; day 1). During expansion, the MTD of FTD/TPI and irinotecan plus bevacizumab (5 mg/kg; day 1) was administered.

RESULTS

Fifty patients (26 across six dose-escalation cohorts and 24 in the expansion phase) were enrolled. Two dose-limiting toxicities (fatigue and neutropenia) were observed in the dose-escalation phase, and MTD was defined as FTD/TPI 25 mg/m² twice daily plus irinotecan 180 mg/m². In the expansion phase, 83% (20/24) experienced any-cause grade ≥3 adverse events (AEs) with the triplet combination, most frequently neutropenia (42%), leukopenia (25%), and diarrhea (12%). AEs of any-cause led to dosing interruptions, modifications, and discontinuations in 29%, 17%, and 4% of patients, respectively. No treatment-related deaths occurred. Three patients (12%) experienced partial responses and 16 (67%) patients had stable disease lasting >4 months. The median progression-free survival was 7.9 months (95% confidence interval, 5.1-13.4 months).

CONCLUSIONS

Tolerability and activity observed in this phase I trial support further investigation of the FTD/TPI-irinotecan-bevacizumab combination in previously treated mCRC.

Phase II Trial of Trifluridine/Tipiracil in Patients with Advanced, Refractory Biliary Tract Carcinoma

LESSONS LEARNED

Trifluridine/tipiracil (FTD/TPI) shows promising antitumor activity in heavily pretreated patients with advanced biliary tract carcinoma, including patients with 5-fluorouracil refractory tumors. FTD/TPI has an acceptable safety profile and should be studied further in patients with advanced biliary tract carcinoma after progression on standard first-line therapy.

BACKGROUND

Patients with advanced biliary tract carcinoma (BTC) refractory to first-line therapy lack an established second-line option. Trifluridine/tipiracil (FTD/TPI) has activity in both fluoropyrimidine-sensitive and -resistant tumors, which led us to conduct a single arm phase II trial to evaluate the safety and efficacy of FTD/TPI for patients previously treated for advanced BTC.

METHODS

Patients with advanced BTC previously treated with at least one line of chemotherapy were enrolled and treated with FTD/TPI until disease progression or unacceptable toxicity. The primary endpoint target was to have at least 6 patients who were progression free and alive at 16 weeks among 25 evaluable patients. Secondary endpoints included overall survival (OS), overall response rate (ORR), progression-free survival (PFS), and toxicity.

RESULTS

Of 27 evaluable patients, 59.3% received at least three prior lines of therapy, and 81.5% had previous exposure to fluoropyrimidine. Eight (32%, 95% confidence interval [CI], 14.9%-53.5%) patients were progression free at 16 weeks in the primary analysis population (n = 25), which met the predefined efficacy criteria. Median PFS and OS were 3.8 (95% CI, 2-5.8 months) and 6.1 (95% CI, 4.4-11.4 months) months, respectively. No objective responses were seen. There were no unexpected safety signals noted.

CONCLUSION

FTD/TPI demonstrated promising antitumor activity, with acceptable toxicity, in heavily pretreated patients with advanced BTC.

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.

Emerging combination therapies for metastatic colorectal cancer - impact of trifluridine/tipiracil

Patients with metastatic colorectal cancer (mCRC) are surviving longer now than ever before, but mortality rates are still high and more effective therapies are clearly needed. For patients with disease that is refractory to fluoropyrimidines, oxaliplatin, irinotecan, and biologic agents targeting the vascular endothelial growth factor and epidermal growth factor receptor pathways, novel treatment options trifluridine/tipiracil (TAS-102) and regorafenib can be effective disease stabilizers. However, objective clinical responses are rare and toxicities are manageable but common. In order to tackle poor clinical responses to TAS-102, there is an ongoing effort to effectively combine this drug with other agents, particularly those targeting angiogenesis. Certain subpopulations appear to benefit more than others from TAS-102; those that benefit often have underlying genetic defects in DNA repair pathways and/or develop neutropenia. In this review, we focus on the role of TAS-102 in the treatment of mCRC, including its use in combination with other agents, potential predictive biomarkers of response to TAS-102, and possible future directions.

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.

Regorafenib Versus Trifluridine/Tipiracil for Refractory Metastatic Colorectal Cancer: A Retrospective Comparison

BACKGROUND

Regorafenib and trifluridine/tipiracil (TAS-102) both prolong survival for patients with refractory metastatic colorectal cancer. However, it is unclear which drug should be administered first.

MATERIALS AND METHODS

We retrospectively evaluated the data from patients who had received regorafenib or TAS-102 at 2 institutions from May 2013 to March 2015. The inclusion criteria were disease refractory or intolerant to fluoropyrimidines, oxaliplatin, irinotecan, anti-vascular endothelial growth factor antibodies, and anti-epidermal growth factor receptor (EGFR) antibodies (if KRAS exon 2 wild-type), and no previous treatment with regorafenib or TAS-102.

RESULTS

A total of 146 and 54 patients received regorafenib and TAS-102, respectively. The baseline characteristics were similar between the 2 groups, except for a history of irinotecan and anti-EGFR therapy and high alkaline phosphatase levels. The median progression-free survival and overall survival were 2.1 months and 6.7 months, respectively, with regorafenib and 2.1 months and 6.5 months, respectively, with TAS-102 (progression-free survival hazard ratio 1.20, P = .27; overall survival hazard ratio, 1.01, P = .97). The analysis of overall survival for patients after the approval of TAS-102 in Japan was similar to the overall survival for the entire population. The frequency of hand-foot syndrome and increased aspartate aminotransferase, alanine aminotransferase, and bilirubin levels was higher and the frequency of neutropenia, leukopenia, anemia, nausea, and febrile neutropenia was lower with regorafenib than with TAS-102. No remarkable differences were found in the efficacy and safety of TAS-102 between patients with and without previous regorafenib and vice versa.

CONCLUSION

Regorafenib and TAS-102 had similar efficacy but resulted in different toxicities, which could guide the agent choice.

Chemotherapy induced neutropenia at 1-month mark is a predictor of overall survival in patients receiving TAS-102 for refractory metastatic colorectal cancer: a cohort study

Background

TAS-102 (trifluridine and tipiracil hydrochloride; a novel combination oral nucleoside anti-tumor agent) has recently received regulatory approval for patients with refractory metastatic colorectal cancer (mCRC). Internal review of data at a single-institution showed a trend towards better overall survival (OS) for patients who experienced chemotherapy-induced neutropenia at 1-month (CIN-1-month). To explore this finding further, a cohort study was designed based on outcome data from three centers in United States and one from Japan.

Methods

CIN-1-month after starting TAS-102 was defined by the Common Terminology Criteria for Adverse Events (CTCAE), version 4.03 as a neutrophil count decrease of ≥ grade 2 (absolute neutrophil count < 1500/mm³). Patients had confirmed mCRC that was refractory to standard therapies. Patient demographics and clinical characteristics were compared between patients with CIN-1-month (CIN-1-month positive) versus those who did not have CIN-1-month (CIN-1-month negative); with the median progression-free survival (PFS) and OS were calculated using the Kaplan-Meier method, and differences evaluated using the Log-rank test.

Results

Our cohort study had a total of 149 patients with data regarding their neutrophil assessment at 1-month mark. Patients who developed ≥ grade 2 CIN-1-month had a both longer PFS (median 3.0 months versus 2.4 months; Log-rank P-value = 0.01), as well as OS (14.0 versus 5.6 months; Log-rank P-value < 0.0001). Only CIN-1-month (adjusted HR: 0.21 (95 % CI: 0.11–0.38) and higher baseline CEA levels (adjusted HR: 2.00 (95 % CI: 1.22–3.35) were noted to be independent predictors of OS. Furthermore, the CIN-1-month was noted to be a statistically significantly predictor of OS over a wide range of cutoffs.

Conclusions

Our observations are novel and hypothesis generating. Neutropenia after starting TAS-102 was associated with better prognosis in patients with refractory mCRC. It can be postulated that the dosage of TAS-102 potentially may need to be increased to achieve better outcomes in patients not experiencing any neutropenia. Further pharmacologic investigations should help elucidate these issues.

TAS-102, the first "cardio-gentle" fluoropyrimidine in the colorectal cancer landscape?

Background

Cardiotoxicity in the form of cardiac arrhythmia, myocardial infarction, and angina-like symptoms are not rare complications of fluoropyrimidines as 5-Fluorouracil (5FU) and capecitabine.

Discussion

Tas-102, a novel oral fluoropyrimidine, was recently approved by FDA for the treatment of advanced and refractory colorectal cancer. Its unique mechanism of action doesn’t seem linked with cardiotoxicity in clinical trials reported so far.

Summary

TAS 102 may represent one of the drugs of choice for patients with advanced colorectal cancer with cardiac disease. This intriguing and clinically relevant issue is briefly examined.

TAS-102 for Treatment of Advanced Colorectal Cancers That Are No Longer Responding to Other Therapies

TAS-102 is a novel oral formulation of trifluridine (TFT) and tipiracil hydrochloride (TPI), a thymidine phosphorylase inhibitor. TFT was originally synthesized in the 1960s and is a nucleoside analogue that impedes DNA synthesis by inhibition of thymidylate synthase. TFT's main mechanism of action, however, seems to be its incorporation into DNA, which distinguishes TFT from current well-known antimetabolites like 5-fluorouracil (5-FU). The rapid degradation of TFT brought initial clinical development to a halt, but TFT reentered clinical trials when addition of a TPI was found to improve the bioavailability of TFT. The combined TFT-TPI formulation was tested in patients with treatment-refractory metastatic colorectal cancer in the randomized phase III RECOURSE study. Compared with placebo, TAS-102 was associated with an overall survival (OS) and progression-free survival (PFS) benefit and a 32% reduction in risk of death [median OS, 7.1 (95% CI, 6.5-7.8) vs. 5.3 months (95% CI, 4.6-6.0); median PFS, 2.0 (95% CI, 1.9-2.1) vs. 1.7 months (95% CI, 1.7-1.8); HR for death, 0.68 (95% CI, 0.58-0.81, P < 0.001)]. Based on the results of this pivotal trial and supported by results from an earlier phase II study, TAS-102 recently gained FDA approval. This article reviews the development of TAS-102 and its therapeutic value for the proposed indication. Clin Cancer Res; 22(12); 2835-9. ©2016 AACR.