Efficacy of trifluridine and tipiracil (TAS-102) versus placebo, with supportive care, in a randomized, controlled trial of patients with metastatic colorectal cancer from Spain: results of a subgroup analysis of the phase 3 RECOURSE trial

Significant response from fruquintinib plus anti-PD-1 immunotherapy for microsatellite stable metastatic colorectal cancer with liver and lung metastasis in the third line: case report

Background

There are limited treatment options available for patients with metastatic colorectal cancer (mCRC). About 95% of CRC patients have mismatch repair proficient/microsatellite stable (pMMR/MSS) tumors are virtually unresponsive to programmed cell death protein 1 (PD-1) antibody treatment. This report shows that a patient with pMMR/MSS mCRC achieved significant response and the longest progression-free survival (PFS) of 28 months currently reported from tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor receptor (VEGFR) family (VEGFR-1,2,3) (fruquintinib) plus anti-PD-1 immunotherapy in the third line, providing a new and promising treatment option for some MSS mCRC patients.

Case Description

This case details a 65-year-old male with CRC who was diagnosed with pT4aN2bM0, IIIC, and pMMR/MSS after curative surgery in August 2018. Subsequently, he received adjuvant chemotherapy [FOLFOX (folinic acid, fluorouracil, and oxaliplatin) for 5 cycles], first-line treatment (pelvic radiation plus capecitabine), and second-line treatment [TOMIRI (raltitrexed and irinotecan) plus cetuximab for 2 cycles]. Lung, liver, and pelvic cavity metastases worsened in October 2019. He began receiving the fruquintinib plus PD-1 inhibitor (FP) regimen as third-line treatment and after 3 cycles, the size of the lung lesions was significantly reduced and evaluated as partial response (PR), whereas the liver and pelvic cavity lesions remained stable. As of December 2021, he had received a total of 33 courses of FP regimen. In February 2022, liver metastases progressed. In brief, he achieved a long PFS of 28 months and an overall survival (OS) of 40 months from the third-line treatment. Additionally, the patient only experienced mild proteinuria after the combined treatment and tolerated well.

Conclusions

Fruquintinib combined with immunotherapy could exert good therapeutic effects with safety in MSS mCRC patients. And patients with lung metastasis may be the principal beneficiaries.

Tas-102 for Refractory Metastatic Colorectal Cancer: A Multicenter Retrospective Cohort Study

Trifluridine/tipiracil (TAS-102) is an oral chemotherapy approved for the treatment of metastatic colorectal cancer. The efficacy and tolerability of TAS-102 were shown in phase II-III clinical trials and in several real-life studies. The elderly and other special subgroups are underrepresented in published literature. We conducted a retrospective multicenter study to assess the effectiveness and safety of TAS-102 in consecutive patients with pretreated mCRC. In particular, we estimated the effectiveness and safety of TAS-102 in elderly patients (aged ≥70, ≥75 and ≥80 years) and in special subgroups, e.g., patients with concomitant heart disease. One hundred and sixty patients were enrolled. In particular, 71 patients (44%) were 70 years of age or older, 50 (31%) were 75 years of age or older, and 23 (14%) were 80 years of age or older. 19 patients (12%) had a concomitant chronic heart disease, three (2%) patients were HIV positive, and one (<1%) patient had a DPYD gene polymorphism. In 115 (72%) cases TAS-102 was administered as a third-line treatment. The median overall survival (OS) in the overall population was 8 months (95% confidence interval [CI], 6-9), while the median progression-free survival (PFS) was 3 months (95% CI, 3-4). No significant age-related reduction in effectiveness was observed in the subpopulations of elderly patients included. The toxicity profile was acceptable in both the whole and subgroups' population. Our study confirms the effectiveness and safety of TAS-102 in patients with pretreated mCRC, suggesting a similar risk-benefit profile in the elderly.

Clinical outcomes of chemotherapy-based therapies for previously treated advanced colorectal cancer: a systematic literature review and meta-analysis

PURPOSE

The purpose of this study was to evaluate clinical outcomes of standard therapies in previously treated, advanced colorectal cancer (CRC) patients.

METHODS

A systematic literature review was conducted in Embase, MEDLINE, and CENTRAL databases (January 2000-July 2021), annual oncology conferences (2019-2021), and clinicaltrials.gov to identify studies evaluating the use of licensed interventions in second-line or later settings. The primary outcome of interest was objective response rate (ORR) and secondary outcomes included progression-free survival (PFS) and overall survival (OS). ORR was pooled using the Freeman-Tukey double arcsine transformation. For survival outcomes, published Kaplan-Meier curves for OS and PFS were digitized to re-construct individual patient-level data and pooled following the methodology described by Combescure et al. (2014).

RESULTS

Twenty-three trials evaluating standard chemotherapies with or without targeted therapies across 4,791 advanced CRC patients contributed to our meta-analysis. In the second-line setting, the random effects pooled estimate of ORR was 22.4% (95% confidence interval (CI): 18.0, 27.1), median PFS was 7.0 months (95% CI: 6.4, 7.4), and median OS was 14.9 months (95% CI: 13.6, 16.1). In the third-line or later setting, the random effects pooled estimate of ORR was 1.7% (95% CI: 0.8, 2.7), median PFS was 2.3 months (95% CI: 2.0, 2.8), and median OS was 8.2 months (95% CI: 7.1, 9.1).

CONCLUSION

Standard treatments have limited efficacy in the second-line or later setting with worsening outcomes in later lines. Given the global burden of CRC, further research into novel and emerging therapeutic options following treatment failure is needed.

Acute inflammatory reaction during anti-angiogenesis therapy combined with immunotherapy as a possible indicator of the therapeutic effect: Three case reports and literature review

The posterior line treatment of unresectable advanced or metastatic gastrointestinal (GI) tumors has always been a challenging point. In particular, for patients with microsatellite stable (MSS)/mismatch repair proficient (pMMR) 0GI tumors, the difficulty of treatment is exacerbated due to their insensitivity to immune drugs. Accordingly, finding a new comprehensive therapy to improve the treatment effect is urgent. In this study, we report the treatment histories of three patients with MSS/pMMR GI tumors who achieved satisfactory effects by using a comprehensive treatment regimen of apatinib combined with camrelizumab and TAS-102 after the failure of first- or second-line regimens. The specific contents of the treatment plan were as follows: apatinib (500 mg/d) was administered orally for 10 days, followed by camrelizumab (200 mg, ivgtt, day 1, 14 days/cycle) and TAS-102 (20 mg, oral, days 1-21, 28 days/cycle). Apatinib (500 mg/d) was maintained during treatment. Subsequently, we discuss the possible mechanism of this combination and review the relevant literature, and introduce clinical trials on anti-angiogenesis therapy combined with immunotherapy.

A randomized phase II trial of hepatic arterial infusion of oxaliplatin plus raltitrexed versus oxaliplatin plus 5-fluorouracil for unresectable colorectal cancer liver metastases

Background

The purpose was to compare the efficacy and safety of hepatic arterial infusion (HAI) of oxaliplatin plus raltitrexed (TOMOX) to those of oxaliplatin plus 5-fluorouracil (FOLFOX) for unresectable colorectal cancer liver metastases (CRCLM).

Methods

Patients with unresectable CRCLM were randomly assigned to receive HAI of TOMOX or FOLFOX. The primary end points were progression-free survival (PFS) measured from the date of randomisation until the date of disease progression and objective response rate (ORR). The secondary end points were overall survival (OS) measured from the date of randomisation until the date of death from any cause, disease control rate (DCR), and adverse events.

Results

113 patients were randomly assigned. With a median follow-up of 39.5 months, the PFS was 5.8 months [95% CI, 4.838–6.762]) and 4.6 months [95% CI, 3.419–5.781; P = 0.840], and the median OS was 17.6 months [95% CI, 13.828–21.372] and 13.1 months [95% CI, 11.215–14.985; P = 0.178] for the FOLFOX and TOMOX arm, respectively. The ORR were 26.1% vs 22.4% and DCR were 80.4% vs 71.4% in the FOLFOX and TOMOX arms. The most common severe adverse event was elevation of liver enzymes and pain, which did not differ in the two arms.

Conclusion

HAI chemotherapy was effective for unresectable CRCLM. HAI of FOLFOX has similar efficacy to TOMOX, and HAI of TOMOX had shorter arterial infusion time.

Clinical Trial Registration

https://clinicaltrials.gov/, identifier NCT02557490.

TAS-102 Monotherapy and Combination Therapy with Bevacizumab for Metastatic Colorectal Cancer

Objective

To evaluate the effectiveness and safety of TAS-102 monotherapy and combination therapy with bevacizumab in the treatment of metastatic colorectal cancer.

Methods

The PubMed, Web of Science, MEDLINE, and Cochrane Library databases were searched for the literature on TAS-102 treatment of metastatic colorectal cancer. Extracted data include median overall survival (mOS), median progression-free survival (mPFS), and the incidence of adverse events for meta-analysis.

Results

Our study found that the mOS of patients treated with TAS-102 monotherapy was 6.95 (95% CI: 6.26-7.72) months and the mPFS was 2.53 (95% CI: 2.31-2.78) months. The mOS in patients treated by TAS-102 combined with bevacizumab was 10.41 (95% CI: 8.40-12.89) months, and the mPFS is 4.35 (95% CI: 3.05-6.20) months. In the control experiment, the patients' mOS and mPFS were improved. TAS-102+B vs. TAS-102 (OR = 0.41, 95% CI: 0.18-0.93; OR = 0.72, 95% CI: 0.63-0.83) and TAS-102 vs. placebo (OR = 0.44, 95% CI: 0.29-0.67; OR = 0.51, 95% CI: 0.42-0.62) were studied to actively prevent the occurrence of neutropenia, leukopenia, febrile neutropenia, anemia, and vomiting.

Conclusion

TAS-102 monotherapy and combination therapy with bevacizumab can significantly improve the survival of patients and prevent specific adverse events from happening.

Early Clinical Experience with Trifluridine/Tipiracil for Refractory Metastatic Colorectal Cancer: The ROS Study

Simple Summary

Trifluridine/tipiracil is an oral combination therapy currently approved as a salvage-line treatment in patients with metastatic colorectal cancer refractory to, or not, candidates for available therapies. However, there is no consensus on the specific factors that should be considered to select patients who benefit the most from trifluridine/tipiracil in clinical practice. The aim of our retrospective cohort study was to assess the early clinical experience with trifluridine/tipiracil in Spain and identify potential survival markers. Our findings endorse the real-life efficacy and safety of trifluridine/tipiracil for refractory metastatic colorectal cancer, as well as revealing the presence of ≤2 metastatic sites, absence of liver metastasis, alkaline phosphatase levels < 300 IU, trifluridine/tipiracil dose reductions, and neutrophil/lymphocyte ratio < 5 as survival markers. Combinations of these markers may help physicians to identify subsets of patients with refractory metastatic colorectal cancer that may benefit the most from trifluridine/tipiracil in their daily practice.

Abstract

Trifluridine/tipiracil is currently approved for metastatic colorectal cancer (mCRC) refractory to available therapies. However, there is no consensus on factors that predict treatment outcomes in daily practice. We assessed the early clinical experience with trifluridine/tipiracil in Spain and potential survival markers. This was a retrospective cohort study of mCRC patients who participated in the trifluridine/tipiracil early clinical experience programme in Spain. The primary outcome was overall survival (OS). Associations between OS and patient characteristics were assessed using multivariate Cox regression analyses. A total of 379 patients were included in the study. Trifluridine/tipiracil was administered for a median of 3.0 cycles and discontinued mainly due to disease progression (79.2%). The median OS was 7.9 months, with a 12-month OS rate of 30.5%. Cox analyses revealed that the following variables independently enhanced OS: ≤2 metastatic sites, no liver metastasis, alkaline phosphatase < 300 IU, trifluridine/tipiracil dose reductions, and neutrophil/lymphocyte ratio < 5. Grade ≥ 3 toxicities were reported in 141 (37.2%) patients, including mainly afebrile neutropaenia (23.2%), anaemia (12.1%), and thrombocytopaenia (5.3%). This study supports the real-life efficacy and safety of trifluridine/tipiracil for refractory mCRC and identifies tumour burden, liver metastasis, alkaline phosphatase, dose reductions, and neutrophil/lymphocyte ratio as survival markers.

Development of a Multicriteria Decision Analysis Framework for Evaluating and Positioning Oncologic Treatments in Clinical Practice

PURPOSE

Several frameworks have been developed to define and quantify the value of oncologic therapies and to support decision making; however, they define treatment value mainly in terms of clinical benefit. As part of its mission to improve oncologic care, the ECO Foundation (Excellence and Quality in Oncology) directed this pilot study aimed at developing a reflective multicriteria decision analysis (MCDA)-based framework for evaluating and positioning oncologic drugs in the clinical setting.

METHODS

The framework was developed following Evidence and Value: Impact on Decision-Making methodology, and literature was reviewed to identify relevant criteria. The selected criteria were then presented to a group of experts composed of 9 clinical oncologists who assessed each criterion for inclusion in the framework and suggested modifications in their definition and/or response scale. The framework was tested in 2 case studies (abemaciclib for advanced or metastatic hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer and TAS-102 for metastatic colorectal cancer) to validate the proposed framework; this was followed by a discussion of the results.

RESULTS

Eight of the 15 criteria presented to the experts were included in the framework: disease severity, unmet needs, comparative efficacy, comparative safety/tolerability, treatment intent, comparative treatment cost, comparative other medical costs, and quality of evidence. Framework validation in 2 drug cases resulted in similar value scores, although they were based on different contributing criteria and resulted in different clinical recommendations.

CONCLUSION

We developed and validated a reflective MCDA framework for the assessment and positioning of oncologic therapies in Spain. Additional work is needed to create a manual for practical decision making in the clinical setting.

Prognostic and Predictive Biomarkers in Patients with Metastatic Colorectal Cancer Receiving Regorafenib

Regorafenib is a tyrosine kinase inhibitor approved by the FDA for the treatment of patients with chemotherapy refractory metastatic colorectal cancer (mCRC). Regorafenib inhibits signaling through multiple receptors associated with angiogenesis, metastasis, and tumor immunity. Here, we report biomarker results from LCCC1029, a randomized, placebo-controlled, phase II trial of chemotherapy ± regorafenib in patients with second-line mCRC. A panel of 20 soluble protein biomarkers (termed the Angiome) was assessed in the plasma of 149 patients from the LCCC1029 trial both at baseline and along the treatment continuum. Baseline protein levels were analyzed for prognostic and predictive value for progression-free survival (PFS) and overall survival (OS). Changes in protein levels during treatment were analyzed for potential pharmacodynamic effects. Six markers (HGF, IL6, PlGF, VEGF-R1, OPN, and IL6R) were found to be prognostic for PFS. Nine markers (IL6, TIMP-1, PlGF, VCAM-1, ICAM-1, OPN, TSP-2, HGF, and VEGF-R1) were prognostic for OS. Higher baseline levels of OPN (P _intx = 0.0167), VCAM-1 (P _intx = 0.0216), and PDGF-AA (P _intx = 0.0435) appeared to predict for PFS benefit from regorafenib compared with placebo. VCAM-1 was also potentially predictive of OS benefit from regorafenib compared with placebo (P _intx = 0.0124). On-treatment changes of six markers reflected potential on-target effect of regorafenib. Consistent results were observed in an Italian cohort where 105 patients with late-stage mCRC received regorafenib monotherapy. The key findings of this study suggest that VCAM-1 may be a predictive biomarker for regorafenib benefit, while multiple protein markers may be prognostic of outcome in patients with mCRC.

Pharmacokinetics, Safety, and Preliminary Efficacy of Oral Trifluridine/Tipiracil in Chinese Patients with Solid Tumors: A Phase 1b, Open-Label Study

Purpose

Trifluridine/tipiracil (FTD/TPI) is approved in Japan, the United States (US), and Europe for metastatic colorectal cancer (mCRC) refractory to standard therapies. This Phase 1b open-label study focused on the pharmacokinetic (PK) and toxicity profiles of FTD/TPI in Chinese patients with solid tumors.

Methods

Patients with definitive histologically or cytologically confirmed advanced/metastatic solid tumors refractory to standard treatments were enrolled. FTD/TPI (35 mg/m²) was administered orally twice daily for five consecutive days, followed by a 2-day recovery. Treatment was repeated for five consecutive days, followed by a 16-day recovery. The primary objective was to assess PK characteristics of FTD, 5-trifluoromethyl-2,4 (1H,3H)-pyrimidinedione (FTY; an inactive form of FTD), and TPI, calculated from plasma concentrations. Additionally, these PK values were compared with those from similar Phase 1 studies in patients from Japan and the US, using Tukey–Kramer’s honestly significant difference (HSD) multiple comparison tests. Safety and preliminary efficacy of FTD/TPI were assessed.

Results

Fifteen patients (12 males, three females) were enrolled, most with CRC (87%). Geometric mean analysis showed that maximum plasma concentration (C_max) of FTD increased after multiple administration (from day 1 [3019.5 ng/mL] to day 12 [3693.1 ng/mL]), and the exposure (AUC_0-t) increased 2.4-fold (day 1:7796.6 ng/mL•h; day 12:18,181.3 ng/mL•h). There was no meaningful change in the exposure to FTY and TPI throughout the study. HSD tests showed comparable PK for FTD, FTY, and TPI between Chinese and Japanese patients, and comparable exposure to FTD between Chinese and US patients. Eight patients (53.3%) experienced Grade 3 treatment-emergent adverse events, most frequently anemia and fatigue (13.3%, two events each). Median progression-free survival was 1.9 months.

Conclusion

FTD/TPI had an acceptable safety and efficacy profile and PK characteristics were comparable between Chinese, Japanese, and US patients, suggesting that this treatment may be suitable for Chinese patients with refractory mCRC.

Trial Registration

This trial was registered at clinicaltrials.gov as NCT02261532.

The underreporting of phase III chemo-therapeutic clinical trial data of older patients with cancer: A systematic review

PURPOSE

Inspired by the American Society of Clinical Oncology's recommendations to strengthen the evidence base for older adults with cancer, the purpose of this systematic review is to identify the reporting of treatment efficacy and adverse events specific to older adults with cancer in Phase III chemo-therapeutic clinical trials. This review also investigates the frequency with which these data points were reported in the literature to identify gaps in reporting and opportunities to expand the knowledge base on clinical outcomes for older adults with cancer.

METHODS

Chemo-therapeutic clinical trial data published from July 1, 2016 to June 30, 2017 was reviewed. Manuscripts (n = 929) were identified based on keyword searches of EMBASE and PubMed. After removal of duplicates (n = 116) and articles that did not meet this study's inclusion criteria (n = 654), 159 articles were identified for review.

RESULTS

Reviewed papers were published in 36 different scientific journals and included twenty-five different cancer types. Of the 159 articles, 117 (73.6%) reported age-specific medians and 75 (47.2%) included stratifications of data by age. Treatment efficacy was reported in 96.2% of the articles with 39.9% reporting effectiveness of treatment by age. Reporting of adverse events was included in 84.9% of the articles with only 8.9% reporting these events stratified by age.

CONCLUSION

Results suggest inadequate reporting of treatment efficacy and adverse events as well as basic descriptive statistics about the age distribution of study subjects. Conscious efforts are needed to address these deficiencies at every level of planning and conducting clinical trials as wells as reporting outcomes stratified by age. Ultimately, standardized reporting could lead to improved treatment decisions and outcomes for older adults with cancer.

CD276-Positive Circulating Endothelial Cells Do Not Predict Response to Systemic Therapy in Advanced Colorectal Cancer

CD276 can discriminate between tumor derived and normal CECs (circulating endothelial cells). We evaluated whether CD276⁺CEC is a clinically relevant biomarker to predict response to palliative systemic therapy in patients with metastatic colorectal cancer (mCRC). Samples were prospectively collected from patients with mCRC enrolled in the ORCHESTRA trial (NCT01792934). At baseline and after three cycles of 5-fluorouracil/leucovorin and oxaliplatin ± bevacizumab, CECs were measured by flowcytometry (CD34⁺CD45^negCD146⁺DNA⁺; and CD276⁺). A clinically relevant cut-off value of (CD276⁺)CECs was determined as 100% sensitivity (and 80% specificity in 95% confidence interval) identifying patients with progressive disease within 6 months. There were 182 baseline samples and 133 follow up samples available for analysis. CEC and CD276⁺CEC counts significantly increased during treatment from 48 to 90 CEC/4 mL (p = 0.00) and from 14 to 33 CD276⁺CEC/4 mL (p = 0.00) at baseline and at first evaluation, respectively. CEC and CD276⁺CEC counts were not predictive for poor response (area under the curve (AUC) 0.53 for CEC and AUC 0.52 for CD276⁺CEC). Despite numerical changes during therapy, CEC and CD276⁺CEC counts do not adequately predict poor response to first line palliative systemic therapy in patients with mCRC.

5-FU induced cardiotoxicity: case series and review of the literature

Background

5-Fluorouracil (5-FU) is an antimetabolite chemotherapy used for a variety of solid tumors. It has the potential to cause a wide spectrum of cardiotoxicity, ranging from asymptomatic electrocardiographic changes to cardiomyopathy and subsequent cardiac failure. Main body of the abstract: We present two descriptive cases of new-onset severe cardiomyopathy induced by 5-FU followed by a review of the literature.

Conclusion

Our case series emphasizes the importance of early recognition of this rare complication and prompt cessation of 5-FU, as cardiac dysfunction in this context is potentially reversible.

Trifluridine/Tipiracil (TAS-102) for refractory metastatic colorectal cancer in clinical practice: a feasible alternative for patients with good performance status

INTRODUCTION

Our aim was to assess efficacy and safety and prognostic factors associated with TAS-102 in clinical practice.

METHOD

Retrospective, multicenter, and observational study including patients with advanced refractory colorectal cancer who started TAS-102 between March 2016 and August 2018. The primary end point was overall survival (OS). Secondary end points included progression-free survival, toxicity and analyze prognostic factors present at the beginning of TAS-102.

RESULT

84 patients were evaluable. The median OS was 8.30 (95% CI 6.23-9.87) months and PFS was 2.62 (95% CI 2.36-3.05) months. In multivariate analysis, ECOG 0 and reduced dose combined with more cycles were associated with better prognosis. Patients with an ECOG > 0 had worse prognosis (HR 3.34, 95% CI 1.09-10.27, p = 0.035). 95.2% experienced some type of adverse effect and 45.2% had grade ≥ 3 toxicities.

CONCLUSION

Results suggest reconsidering TAS-102 in patients with ECOG > 0, something that should be investigated in prospective randomized clinical trials.

Feasibility and effectiveness of trifluridine/tipiracil in metastatic colorectal cancer: real-life data from The Netherlands

Background

The RECOURSE trial showed clinical efficacy for trifluridine/tipiracil for refractory metastatic colorectal cancer patients. We assessed the feasibility and effectiveness of trifluridine/tipiracil in daily clinical practice in The Netherlands.

Methods

Medical records of patients from 17 centers treated in the trifluridine/tipiracil compassionate use program were reviewed and checked for RECOURSE eligibility criteria. Baseline characteristics, safety, and survival times were compared, and prespecified baseline characteristics were tested in multivariate analyses for prognostic significance on overall survival (OS).

Results

A total of 136 patients with a median age of 62 years were analyzed. Forty-three patients (32%) did not meet the RECOURSE eligibility criteria for not having received all prior standard treatments (n = 35, 26%) and/or ECOG performance status (PS) 2 (n = 12, 9%). The most common grade ≥3 toxicities were neutropenia (n = 44, 32%), leukopenia (n = 8, 6%), anemia (n = 7, 5%), and fatigue (n = 7, 5%). Median progression-free survival (PFS) and median OS were 2.1 (95% CI, 1.8–2.3) and 5.4 months (95% CI, 4.0–6.9), respectively. Patients with ECOG PS 2 had a worse median OS (3.2 months) compared to patients with ECOG PS 0–1 (5.9 months). ECOG PS, KRAS-mutation status, white blood cell count, serum lactate dehydrogenase, and alkaline phosphatase were prognostic factors for OS.

Conclusions

Our data show that treatment with trifluridine/tipiracil in daily clinical practice is feasible and safe. Differences in patient characteristics between our population and the RECOURSE study population should be taken into account in the interpretation of survival data. Our results argue against the use of trifluridine/tipiracil in patients with ECOG PS 2.

Funding

Johannes J.M. Kwakman received an unrestricted research grant from Servier.

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.

Pharmacogenomics of Targeted Agents for Personalization of Colorectal Cancer Treatment

The use of targeted agents in the treatment of metastatic colorectal cancer (CRC) has improved patient outcomes. Anti-epidermal growth factor receptor (anti-EGFR) agents (cetuximab and panitumumab) and antiangiogenic molecules (bevacizumab, regorafeninb, ramucirumab, and aflibercept) have been successfully integrated into clinical practice. Other drugs have been designed to target additional deregulated pathways in CRC, such as MAPK (mitogen-activated protein kinase)/PI3K-AKT (phosphatidylinositol-3-kinase-AKT serine/threonine kinase)/mTOR (mammalian target of rapamycin), HER-2 and 3 ( human epidermal growth factor receptor-2 and -3), and BRAF. A major issue with targeted treatment is early identification of patients with primary or secondary drug resistance. Pharmacogenomic research has demonstrated its value in this field, highlighting some tumor mutations that could discriminate responders from non-responders. The tumor genetic profile of the RAS/RAF pathway is needed before treatment with anti-EGFR agents; mutations in EGFR pathway genes have also been explored in relation to antiangiogenic molecules although further data are required prior to their integration into clinical practice. The introduction of immunotherapy has paved the way for a new generation of predictive markers, including genome-wide assessment of the tumor landscape. Furthermore, the development of next generation sequencing technology and non-invasive approaches to analyze circulating tumor DNA will make real-time monitoring of the tumor pharmacogenomic markers possible in the clinical routine, rendering precision medicine available to every patient.

Adherence, Dosing, and Managing Toxicities With Trifluridine/Tipiracil (TAS-102)

Trifluridine/tipiracil (TAS-102) is a new oral combination therapy approved by the US Food and Drug Administration for the treatment of patients with metastatic colorectal cancer who are refractory to or intolerant of standard chemotherapy. This agent consists of a thymidine-based nucleoside analogue (trifluridine) and a thymidine phosphorylase inhibitor (tipiracil), which is included to reduce the degradative breakdown of trifluridine. In the phase III Randomized, double-blind, phase III Study of TAS-102 plus best supportive care [BSC] versus placebo plus BSC in patients with metastatic colorectal cancer [CRC] refractory to standard chemotherapies (RECOURSE) trial, trifluridine/tipiracil showed significant improvement in overall survival compared with placebo. Trifluridine/tipiracil is administered at a 35 mg/m2 dose orally twice daily in a 28-day cycle consisting of 5 treatment days/2 rest days for 2 weeks followed by a rest period of 2 weeks. Because trifluridine/tipiracil is a completely oral chemotherapy regimen, patient adherence to treatment is an important consideration. It is also critical to have strategies in place for managing toxicities, because side effects might have a negative effect on patient adherence. The most frequent adverse events reported in patients with metastatic colorectal cancer receiving trifluridine/tipiracil in the phase III RECOURSE trial were myelosuppression, nausea/vomiting, diarrhea, decreased appetite, and fatigue. In this review we aim to provide clinicians with practical recommendations for facilitating patient adherence to oral chemotherapy, managing trifluridine/tipiracil dosing, and address the most common adverse events in patients who receive trifluridine/tipiracil therapy.

Human pyrimidine nucleotide biosynthesis as a target for antiviral chemotherapy

The development of broad-spectrum, host-acting antiviral therapies remains an important but elusive goal in anti-infective drug discovery. To replicate efficiently, viruses not only depend on their hosts for an adequate supply of pyrimidine nucleotides, but also up-regulate pyrimidine nucleotide biosynthesis in infected cells. In this review, we outline our understanding of mammalian de novo and salvage metabolic pathways for pyrimidine nucleotide biosynthesis. The available spectrum of experimental and FDA-approved drugs that modulate individual steps in these metabolic pathways is also summarized. The logic of a host-acting combination antiviral therapy comprised of inhibitors of dihydroorotate dehydrogenase and uridine/cytidine kinase is discussed.