Structure and activity of specific inhibitors of thymidine phosphorylase to potentiate the function of antitumor 2'-deoxyribonucleosides

The OCT2/MATE1 Interaction Between Trifluridine, Metformin and Cimetidine: A Crossover Pharmacokinetic Study

BACKGROUND AND OBJECTIVES

Trifluridine/tipiracil, registered for the treatment of patients with metastatic gastric and colorectal cancer, is a substrate and inhibitor for the organic cation transporter 2 (OCT2) and the multidrug and toxin extrusion protein 1 (MATE1), which raises the potential for drug-drug interactions with other OCT2/MATE1 modulators. Therefore, we prospectively examined the effect of an OCT2/MATE1 inhibitor (cimetidine) and substrate (metformin) on the pharmacokinetics of trifluridine.

METHODS

In this three-phase crossover study, patients with metastatic colorectal or gastric cancer were sequentially treated with trifluridine/tipiracil alone (phase A), trifluridine/tipiracil concomitant with metformin (phase B) and trifluridine/tipiracil concomitant with cimetidine (phase C). The primary endpoint was the relative difference in exposure of trifluridine assessed by the area under the curve from timepoint zero to infinity. A > 30% change in exposure was considered clinically relevant. A p-value of < 0.025 was considered significant because of a Bonferroni correction.

RESULTS

Eighteen patients were included in the analysis. Metformin did not significantly alter the exposure to trifluridine (- 12.6%; 97.5% confidence interval - 25.0, 1.8; p = 0.045). Cimetidine did alter the exposure to trifluridine significantly (+ 18.0%; 97.5% confidence interval 4.5, 33.3; p = 0.004), but this increase did not meet our threshold for clinical relevance. Metformin trough concentrations were not influenced by trifluridine/tipiracil.

CONCLUSIONS

Our result suggests that the OCT2/MATE1 modulators cimetidine and metformin can be co-administered with trifluridine/tipiracil without clinically relevant effects on drug exposure.

CLINICAL TRIAL REGISTRATION

NL8067 (registered 04-10-2019).

The emerging emetogenicity of trifluridine/tipiracil (TAS‑102) from patient self-reporting: a multicenter, prospective, observational study

BACKGROUND

Trifluridine/tipiracil (TAS-102) is an oral anticancer drug with adequate efficacy in unresectable colorectal cancer, but frequently also induces chemotherapy-induced nausea and vomiting (CINV). To investigate the occurrence of CINV and antiemetic therapy in patients with colorectal cancer treated with TAS-102 (JASCC-CINV 2001).

METHODS

We conducted a multicenter, prospective, observational study in patients with colorectal cancer who received TAS-102 without dose reduction for the first time. Primary endpoint was the incidence of vomiting during the overall period. Secondary endpoints were the incidence of nausea, significant nausea, anorexia, other adverse events (constipation, diarrhea, insomnia, fatigue, dysgeusia) and patient satisfaction. Patient diaries were used for primary and secondary endpoints. All adverse events were subjectively assessed using PRO-CTCAE ver 1.0. and CTCAE ver 5.0.

RESULTS

Data from 100 of the 119 enrolled patients were analyzed. The incidence of vomiting, nausea, and significant nausea was 13%, 67%, and 36%, respectively. The incidence of vomiting in patients with and without prophylactic antiemetic therapy were 20.8% and 10.5%, respectively. Prophylactic antiemetics were given to 24% of patients, of whom 70% received D2 antagonists. Multivariate Cox proportional hazards analysis showed that experience of CINV in previous treatment tended to be associated with vomiting (hazard ratio [HR]: 7.13, 95% confidence interval [CI]: 0.87-58.5, P = 0.07), whereas prophylactic antiemetic administration was not (HR: 1.61, 95 CI: 0.50-5.21, P = 0.43). With regard to patient satisfaction, the proportion of patients who were "very satisfied," "satisfied," "slightly satisfied" or "somewhat satisfied" was 81.8%.

CONCLUSIONS

The low incidence of vomiting and high patient satisfaction suggest that TAS-102 does not require the use of uniform prophylactic antiemetic treatments. However, patients with the experience of CINV in previous treatment might require prophylactic antiemetic treatment.

Simultaneous determination of tipiracil, trifluridine and its metabolite 5-trifluoromethyluracil in human plasma using segmented polarity LC-MS/MS: A fully validated assay with clinical application

Trifluridine (FTD) and tipiracil (TPI) hydrochloride tablets (TAS-102) were used for the treatment of patients with metastatic rectal cancer that was resistant to conventional chemotherapy drugs. In this study, a rapid and sensitive liquid chromatography-tandem mass spectrometry method was developed and fully validated for the simultaneous determination of TPI, FTD, and the metabolite 5-trifluoromethyluracil (FTY) of FTD in human plasma. The plasma samples were prepared by protein precipitation. The chromatography separation was performed using ACE Excel 3 AQ (100 × 2.1 mm i.d., 1.7 µm, ACE, England) column protected by a security guard cartridge (4.0 × 2.0 mm i.d., 5 µm, Phenomenex, USA) with a gradient elution of 0.05% acetic acid in water and methanol at a flow rate of 0.35 mL/min. The MS/MS analysis was performed by using multiple reaction monitoring with the segmented polarity (positive for TPI: m/z 243.1→183.0, and negative for FTD: m/z 295.1→252.0 and FTY: m/z 178.9→158.9) electrospray ionization mode. The segmented polarity mode was designed to achieve two advantages: better sensitivity and simultaneous determination of the analytes with different ion polarities. The calibration ranges were as follows: 1.00-250 ng/ for TPI, 8.00-8000 ng/mL for FTD and 5.00-1250 ng/mL for FTY. The selectivity, accuracy, precision, matrix effect, recovery, carryover, dilution integrity and stability test results meet ICH acceptance criteria. The method was evaluated using the RGB model and successfully applied to a clinical study in patients with solid tumors. For TPI, FTD and FTY, the maximum plasma concentration was 137-147 ng/mL, 6160-6240 ng/mL and 724-725 ng/mL, respectively; the plasma elimination half-life was 1.69-1.78 h, 1.70 h, and 3.09-3.14 h, respectively, after an oral administration of 60 mg TAS-102.

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 mitigates codon-specific effects of trifluridine/tipiracil on efficacy outcome parameters in metastatic colorectal cancer

BACKGROUND

Molecular informed therapy changed treatment patterns of metastatic colorectal cancer (mCRC). Recently KRAS G12, the most prevalent RAS mutation in mCRC, was investigated to be a negative predictive marker for the efficacy of trifluridine/tipiracil (FTD/TPI). Whether this proposed selectivity remains when FTD/TPI is combined with bevacizumab remains elusive. We aimed to describe the efficacy of FTD/TPI + bevacizumab depending on the RAS mutational status in a real-world population.

PATIENTS AND METHODS

Patients from five different cancer centers in Austria who received FTD/TPI + bevacizumab in any treatment line having available information on their molecular profile were eligible. Data were retrospectively collected by chart review. Survival data were compared using log-rank test. Multivariate Cox regression models included several established covariates.

RESULTS

One hundred and twenty-three patients with mCRC were included in this study. Median overall survival (OS) was highly similar in the RAS wild type (WT) [9.63 months (95% confidence interval [CI] 8.055-13.775 months)] and the RAS mutant cohorts [8.78 months (95% CI 8.055-11.014 months)], which was confirmed in a multivariable model adjusting for potential confounders; hazard ratio (HR): 1.05 (95% CI 0.618-1.785; P = 0.857). In addition, no effect of KRAS G12 status on patient outcome was observed. In detail, OS was 8.88 months (95% CI 7.332-12.921 months) in patients with KRAS G12 mutation, compared to 9.47 months (95% CI 8.088-11.375 months) in patients with RAS WT/no-KRAS G12 disease [HR: 0.822 (95% CI 0.527-1.282; P = 0.387)].

CONCLUSION

This real-world study indicates that the efficacy of FTD/TPI + bevacizumab is independent of RAS mutational status and that bevacizumab may therefore mitigate the potentially limited efficacy of FTD/TPI monotherapy in the KRAS G12-mutated population.

TK-1, TP, Ang-2, and Tie-2 mRNA expression in plasma-derived microvesicles of chemo-refractory metastatic colorectal cancer patients

BACKGROUND

Trifluridine/tipiracil and regorafenib are indicated for metastatic colorectal cancer (mCRC) patients' refractory to standard chemotherapy. No prognostic or predictive biomarkers are available for these agents.

METHODS

We assessed messenger ribonucleic acid (mRNA) expression of four biomarkers implicated in the mechanism of action of trifluridine/tipiracil (TK-1 and TP) and regorafenib (Ang-2 and Tie-2) in baseline plasma-derived microvesicles of chemo-refractory mCRC patients treated with these agents (trifluridine/tipiracil cohort and regorafenib cohort), to explore their prognostic and predictive role.

RESULTS

Baseline characteristics of the two cohorts were not different. Ang-2 mRNA was not detectable. Only TK-1 expression measured as a continuous variable was associated with progression-free survival (HR=1.09, 95%CI: 0.99-1.21; p=0.07) and overall survival (HR=1.11, 95%CI: 1.00-1.22; p=0.04), confirmed at multivariate analysis for progression-free survival (p=0.02) with a positive trend for overall survival (p=0.08). Baseline mRNA levels of TK-1, TP and Tie-2 were not predictive of trifluridine/tipiracil and regorafenib benefit.

CONCLUSION

Baseline mRNA levels of TK-1, TP and Tie-2 on plasma-derived microvesicles were not predictive of trifluridine/tipiracil and regorafenib benefit. Future studies should analyze the early modulation of these biomarkers to assess their potential predictive role.

Comparison of the efficacy and safety of third-line treatments for metastatic colorectal cancer: a systematic review and network meta-analysis

Background

The objective of this study is to evaluate the efficacy and safety of different third-line treatment regimens for metastatic colorectal cancer (mCRC) through a comprehensive analysis and network meta-analysis (NMA). Additionally, the study aims to provide guidance on selecting appropriate third-line systemic treatment regimens for patients with mCRC.

Methods

We conducted a search of the PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials databases from January 1, 2005, to May 20, 2023, to include phase II/III randomized clinical trials (RCTs) of third-line treatments for mCRC. The primary outcome assessed in the NMA was median overall survival (mOS), and other outcomes included median progression-free survival (mPFS), disease control rate (DCR), and grade 3 or higher adverse events (≥3AEs).

Results

Ultimately, nine phase II/III RCTs involving five treatment regimens were included in this study. Trifluridine/tipiracil (TAS-102) plus bevacizumab (hazard ratio [HR] 0.41, 95% credible interval [CrI] 0.32-0.52) was found to be the most effective treatment for mOS compared to best supportive care (BSC). TAS-102 plus bevacizumab also significantly improved mPFS compared to BSC (HR 0.20, 95% CrI 0.16-0.25). In terms of adverse events (AEs), TAS-102 (RR 0.52, 95% CrI 0.35-0.74) had a lower incidence of ≥3AEs compared to fruquintinib, but fruquintinib (RR 1.79, 95% CrI 1.10-3.11) showed better improvement in DCR than TAS-102. Subgroup analysis using the Bayesian surface under the cumulative ranking curve (SUCRA) ranked the regimens based on the OS benefit. The results indicated that TAS-102 plus bevacizumab ranked first across age, gender, Eastern Cooperative Oncology Group performance status (ECOG PS), and time from initial diagnosis of metastatic disease to randomization.

Conclusion

TAS-102, fruquintinib, TAS-102 plus bevacizumab, the regorafenib standard dose regimen (regorafenib), and the regorafenib dose-escalation regimen (regorafenib 80+) all demonstrated improved OS and PFS compared to BSC in mCRC patients. However, TAS-102 plus bevacizumab may be the optimal choice for third-line treatment in mCRC patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php, CRD42023434929.

Prognostic factors in refractory metastatic colorectal cancer patients treated with Trifluridine/Tipiracil

PURPOSE

The systemic treatment options for metastatic colorectal cancer (mCRC) are unsatisfactory, and the disease recurs despite the use of numerous medications and their combinations. Trifluridine/Tipiracil is a relatively new drug used in refractory mCRC. Little is known about its real-world effectiveness and prognostic and predictive factors. Therefore, this study aimed to develop a prognostic model for refractory mCRC treated with Trifluridine/Tipiracil.

METHODS

We retrospectively evaluated the data from 163 patients who had received Trifluridine/Tipiracil as a third or fourth line of treatment for refractory mCRC.

RESULTS

After starting Trifluridine/Tipiracil, 21.5% of patients survived one year, and the median overall survival after Trifluridine/Tipiracil initiation was 251 days (SD: 17.855; 95%CI: 216-286). Median progression-free survival after Trifluridine/Tipiracil initiation was 56 days (SD: 4.826; 95%CI 47-65). Moreover, the median overall survival from diagnosis was 1333 days (SD: 82.84; 95%CI: 1170-1495). In forward stepwise multivariate Cox regression analysis, initial radical treatment (HR = 0.552, 95% CI 0.372-0.819, p < 0.003), the number of cycles of first-line chemotherapy (HR = 0.978, 95% CI 0.961-0.995, p < 0.011), the number of cycles of second-line chemotherapy (HR = 0.955, 95% CI 0.931-0.98, p < 0.011), BRAF mutation (HR = 3.016, 95% CI = 1.207-7.537, p = 0.018), and hypertension (HR = 0.64, 95% CI = 0.44-0.931, p = 0.02) were all associated with survival after Trifluridine/Tipiracil initiation. Our model and model-based nomogram displayed an AUC of 0.623 for one-year survival estimation in the testing cohort. The C-index for the prediction nomogram was 0.632.

CONCLUSION

We have developed a prognostic model for refractory mCRC treated with Trifluridine/Tipiracil based on five variables. Moreover, we reported a nomogram which could be used by oncologists in clinic visits on a daily basis.

Long-Term Progression-Free Survival of a Pre-Treated Patient with Metastatic Colorectal Cancer Receiving Trifluridine/Tipiracil

Trifluridine/tipiracil is approved for the use in later or last-line setting in previously treated metastatic colorectal cancer (mCRC) patients who progressed on standard anti-tumor drugs including 5-fluorouracil (5-FU), irinotecan, oxaliplatin, anti-VEGF and anti-EGFR antibodies, or who are not considered candidates for those standard therapies. In this report, we describe a 67-year-old male patient with KRAS-mutated mCRC and metachronous liver and lung metastasis who failed prior 5-FU- and irinotecan-containing regimens, but then showed long-term disease control for 31 months on single-agent trifluridine/tipiracil given as second-line treatment. According to our experience, trifluridine/tipiracil is a feasible and effective treatment option in earlier but not necessarily last-line therapy in mCRC patients who are not considered candidates for doublet or triplet chemotherapy. Besides its efficacy, it is associated with maintained quality of life and a manageable toxicity profile. Considering increasing age of mCRC patients and their wish for maintaining an independent lifestyle, further research on the use of trifluridine/tipiracil in earlier lines of systemic mCRC therapy is warranted.

Clinical Effect of the C-Reactive Protein to Serum Albumin Ratio in Patients with Metastatic Gastric or Gastroesophageal Junction Cancer Treated with Trifluridine/Tipiracil

Trifluridine/tipiracil (FTD/TPI) is an oral anticancer agent used as a third- or later-line treatment for patients with metastatic gastric cancer/gastroesophageal junction cancer (mGC/GEJC). The C-reactive protein-to-serum albumin ratio (CAR) is an inflammation-based prognostic marker in gastric cancer. This retrospective study evaluated CAR's clinical significance as a prognostic factor in 64 patients with mGC/GEJC administered FTD/TPI as a third- or later-line therapy. Patients were categorized into high- and low-CAR groups based on pre-treatment blood data. This study evaluated associations between CAR and overall survival (OS), progression-free survival (PFS), clinicopathological features, treatment efficacy, and adverse events. The high-CAR group had significantly worse Eastern Cooperative Oncology Group performance status, a higher prevalence of patients administered with a single course of FTD/TPI, and a higher rate of patients not administered chemotherapy after FTD/TPI therapy than the low-CAR group. Median OS and PFS were significantly poorer in the high-CAR group than in the low-CAR group (113 vs. 399 days; p < 0.001 and 39 vs. 112 days; p < 0.001, respectively). In multivariate analysis, high CAR was an independent prognostic factor for OS and PFS. The overall response rate was not significantly different between the high- and low-CAR groups. Regarding adverse events, the high-CAR group had a significantly lower incidence of neutropenia and a higher incidence of fatigue than the low-CAR group. Therefore, CAR may be a potentially useful prognostic factor for patients with mGC/GEJC treated with FTD/TPI as third- or later-line chemotherapy.

Lineage of drug discovery research on fluorinated pyrimidines: chronicle of the achievements accomplished by Professor Setsuro Fujii

Prof. Setsuro Fujii achieved significant results in the field of drug discovery research in Japan. He developed nine well-known drugs: FT, UFT, S-1 and FTD/TPI are anticancer drugs, while cetraxate hydrochloride, camostat mesilate, nafamostat mesilate, gabexate mesilate and pravastatin sodium are therapeutic drugs for various other diseases. He delivered hope to patients with various diseases across the world to improve their condition. Even now, drug discovery research based on Dr. Fujii's ideas is continuing.

Depletion of plasma thymidine results in growth retardation and mitochondrial myopathy in mice overexpressing human thymidine phosphorylase

Plasma thymidine levels in rodents are higher than in other mammals including humans, possibly due to a different pattern and lower level of thymidine phosphorylase expression. Here, we generated a novel knock-in (KI) mouse line with high systemic expression of human thymidine phosphorylase to investigate this difference in nucleotide metabolism in rodents. The KI mice showed growth retardation around weaning and died by 4 weeks of age with a decrease in plasma thymidine level compared with the litter-control WT mice. These phenotypes were completely or partially rescued by administration of the thymidine phosphorylase inhibitor 5-chloro-6-(2-iminopyrrolidin-1-yl) methyl-2,4(1H,3H)-pyrimidinedione hydrochloride or thymidine, respectively. Interestingly, when thymidine phosphorylase inhibitor administration was discontinued in adult animals, KI mice showed deteriorated grip strength and locomotor activity, decreased bodyweight, and subsequent hind-limb paralysis. Upon histological analyses, we observed axonal degeneration in the spinal cord, muscular atrophy with morphologically abnormal mitochondria in quadriceps, retinal degeneration, and abnormality in the exocrine pancreas. Moreover, we detected mitochondrial DNA depletion in multiple tissues of KI mice. These results indicate that the KI mouse represents a new animal model for mitochondrial diseases and should be applicable for the study of differences in nucleotide metabolism between humans and mice.

The evolving strategies for the management of patients with metastatic gastric cancer: A narrative review and expert opinion

Gastric cancer (GC) is recognized as one of the most common deadly malignancies worldwide and about 40-50% of patients present at diagnosis with an unresectable disease due to a locally advanced or already metastatic condition. Recently, therapeutic options for management of metastatic GC (mGC) have been approved allowing a potential improvement of patient cancer treatment response and also an establishment of a continuum of care for this aggressive disease. This report is the result of a literature review by an expert panel. The aim of this document is to provide evidence, wherever it is lacking, to provide expert opinion directed at strategic management of mGC, and in particular aspect at practical management where appropriate guidelines are not available. Treatment landscape with new therapeutic strategies for third line and beyond, role of imaging, prognostic factors, symptoms, and markers as well as the importance of multidisciplinary approach particularly the nutritional aspects are discussed.

Pooled safety analysis from phase III studies of trifluridine/tipiracil in patients with metastatic gastric or gastroesophageal junction cancer and metastatic colorectal cancer

BACKGROUND

Trifluridine/tipiracil (FTD/TPI) showed clinical benefit, including improved survival and manageable safety in previously treated patients with metastatic colorectal (mCRC) or gastric/gastroesophageal junction (mGC/GEJC) cancer in the phase III RECOURSE and TAGS trials, respectively. A pooled analysis was conducted to further characterize FTD/TPI safety, including management of haematologic toxicities and use in patients with renal or hepatic impairment.

PATIENTS AND METHODS

Adults with ≥2 prior regimens for advanced mGC/GEJC or mCRC were randomized (2 : 1) to FTD/TPI [35 mg/m² twice daily days 1-5 and 8-12 (28-day cycle); same dosage in both trials] or placebo plus best supportive care. Adverse events (AEs) were summarized in the safety population (patients who received ≥1 dose) and analysed by renal/hepatic function.

RESULTS

TAGS and RECOURSE included 335 and 533 FTD/TPI-treated and 168 and 265 placebo-treated patients, respectively. Overall safety of FTD/TPI was similar in TAGS and RECOURSE. Haematologic (neutropenia, anaemia) and gastrointestinal (nausea, diarrhoea) AEs were most commonly observed. Laboratory-assessed grade 3-4 neutropenia occurred in 37% (TAGS)/38% (RECOURSE) of FTD/TPI-treated patients (median onset: 29 days/55 days), and 96% (TAGS)/97% (RECOURSE) of cases resolved regardless of renal/hepatic function. Supportive medications for neutropenia were received by 17% (TAGS) and 9% (RECOURSE); febrile neutropenia was reported in 2% and 4%, respectively. Overall grade ≥3 AEs were more frequent in patients with moderate renal impairment [81% (TAGS); 85% (RECOURSE)] versus normal renal function (74%; 67%); anaemia and neutropenia were more common in patients with renal impairment. FTD/TPI safety (including haematologic AEs) was consistent across patients with normal and mildly impaired hepatic function.

CONCLUSIONS

These results support FTD/TPI as a well-tolerated treatment in patients with mGC/GEJC or mCRC, with a consistent safety profile. Safety was largely similar in patients with normal or mildly impaired renal/hepatic function; however, patients with renal impairment should be monitored for haematologic toxicities.

Trifluridine/tipiracil as a therapeutic option in real life setting of metastatic colorectal cancer: An efficacy and safety analysis

Background: In the phase III RECOURSE trial, the orally administered combination trifluridine/tipiracil (FTD/TPI) demonstrated a survival benefit and an acceptable safety profile, earning approval as a third-line therapy in metastatic colorectal cancer (mCRC). This study aimed to assess the efficacy and safety of FTD/TPI in daily clinical practice in Romanian population.

Methods: A single-center, retrospective, and observational study analyzed patients with mCRC that received chemotherapy with trifluridine/tipiracil between May 2019 and May 2022 at the Oncology Institute Prof. Dr. Ion Chiricuță in Cluj-Napoca, Romania. Study endpoints included safety, and median progression-free survival (PFS).

Results: In this Romanian cohort (n = 50) the most common treatment-emergent adverse event was haematological toxicity (76%): anemia (50%), leucopenia (38%), neutropenia (34%), and thrombocytopenia (30%), followed by fatigue (60%), and abdominal pain (18%). Overall, the median progression-free survival was 3.85 months (95% CI: 3.1–4.6 months). PFS was significantly correlated with the number of FTD/TPI administrations and prior surgery.

Conclusion: Our study corroborated the previously described safety profile for FTD/TPI in the third-line setting, and demonstrated relatively superior mPFS.

Influence of precedent drug on the subsequent therapy in the sequence of trifluridine/tipiracil with/out bevacizumab and regorafenib for unresectable or recurrent colorectal cancer

Background

Trifluridine/tipiracil (TFTD), with or without bevacizumab (Bev), and regorafenib are salvage chemotherapy options for metastatic colorectal cancer (mCRC). Here, we examined the influence of precedent drug on the efficacy of subsequent drug.

Method

The subjects were patients with mCRC who received salvage chemotherapy with TFTD (with/without Bev) followed by regorafenib (TFTD→Rego group/TFTD+Bev→Rego group), or reverse sequence (Rego→TFTD group) at the National Cancer Center Hospital between November 2013 and December 2020. The overall survival (OS), progression-free survival (PFS), disease control rate (DCR), tumor growth rate (TGR), and tumor growth kinetics (TGK) in the first evaluation were assessed in the three groups.

Results

A total of 69 patients, including 27 in the TFTD→Rego group, 13 in the TFTD+Bev→Rego group, and 29 in the Rego→TFTD group, were identified. There were no significant differences in the OS among the three groups, and in the PFS and DCR between the precedent and subsequent therapies in any of the groups. The median TGR (%/month) and TGK (mm/month) in the precedent→subsequent therapy were 50.9→32.7 (p = 0.044) and 8.76→7.79 in the TFTD→Rego group, 25.4→36.1 and 7.49→9.92 in the TFTD+Bev→Rego group, and 40.8→24.4 (p = 0.027) and 8.02→7.20 in the Rego→TFTD group, respectively.

Conclusion

In crossover use of TFTD with/without Bev and regorafenib, both agents showed similar efficacy in terms of the conventional parameters, but the differences observed in the TGR and TGK might suggest some influence of prior regorafenib treatment on the efficacy of subsequent TFTD therapy, and vice versa.

Targeting nucleotide metabolism: a promising approach to enhance cancer immunotherapy

Targeting nucleotide metabolism can not only inhibit tumor initiation and progression but also exert serious side effects. With in-depth studies of nucleotide metabolism, our understanding of nucleotide metabolism in tumors has revealed their non-proliferative effects on immune escape, indicating the potential effectiveness of nucleotide antimetabolites for enhancing immunotherapy. A growing body of evidence now supports the concept that targeting nucleotide metabolism can increase the antitumor immune response by (1) activating host immune systems via maintaining the concentrations of several important metabolites, such as adenosine and ATP, (2) promoting immunogenicity caused by increased mutability and genomic instability by disrupting the purine and pyrimidine pool, and (3) releasing nucleoside analogs via microbes to regulate immunity. Therapeutic approaches targeting nucleotide metabolism combined with immunotherapy have achieved exciting success in preclinical animal models. Here, we review how dysregulated nucleotide metabolism can promote tumor growth and interact with the host immune system, and we provide future insights into targeting nucleotide metabolism for immunotherapeutic treatment of various malignancies.

Prophylactic use of pegfilgrastim enables the management of severe neutropenia without dose delays in patients with metastatic colorectal cancer treated with TAS‑102 plus bevacizumab

Combined treatment with bevacizumab and trifluridine/tipiracil (TAS-102) leads to an increased chance of survival in patients with refractory metastatic colorectal cancer (mCRC); however, this treatment is associated with an increased frequency of severe neutropenia (number of neutrophils <1,000), which should ideally be managed without dose delays. The present study provided a retrospective review of 35 patients with mCRC, and aimed to elucidate the benefits of prophylactic pegfilgrastim for the treatment of severe neutropenia. Patients received TAS-102 (35 mg/m²) orally twice daily on days 1-5 and 8-12 of each 28-day treatment cycle, along with intravenous bevacizumab (5 mg/kg) on days 1 and 15. Moreover, the patients received 3.6 mg pegfilgrastim on day 15 of each cycle. The incidence of adverse events (AEs), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS) were assessed. In the first and subsequent cycles, 23 and 12 patients, respectively, received pegfilgrastim. The most common AE experienced was grade 3/4 neutropenia (8 patients; 22.9%). Among these 8 patients, 6 (17.1%) and 3 (8.6%) exhibited neutropenia prior to receiving pegfilgrastim or following discontinuation of pegfilgrastim administration, respectively. Moreover, 1 individual among these 8 patients (2.9%) demonstrated grade 3 neutropenia both prior to receiving pegfilgrastim and following discontinuation of pegfilgrastim. A total of 2 patients (5.7%) exhibited grade 3 bone pain, which prevented sustainable administration of pegfilgrastim and resulted in grade 3 neutropenia. Dose delays and dose reduction of TAS-102 due to neutropenia were required in 5 (14.3%) and 2 (5.7%) patients, respectively, during the treatment period. None of the patients exhibited severe neutropenia during chemotherapy after pegfilgrastim administration, thereby preventing dose delays and dose reduction of TAS-102. The relative dose intensity was 96.8% (65.0-100.0%), and the DCR was 54.3%. The median PFS and median OS were 4.4 and 14.9 months, respectively. In conclusion, prophylactic pegfilgrastim may facilitate the management of severe neutropenia without dose delays in patients with mCRC treated with TAS-102 plus bevacizumab.

Efficacy, safety and quality-of-life data from patients with pre-treated metastatic colorectal cancer receiving trifluridine/tipiracil: results of the TALLISUR trial

Introduction

Trifluridine/tipiracil (FTD/TPI) improved both overall and progression-free survival (OS, PFS) of patients with pre-treated metastatic colorectal cancer (mCRC) in the pivotal phase III RECOURSE trial. However, health-related quality of life (HRQoL) was not assessed directly. To this end and to generate post-authorisation data, the TALLISUR trial was conducted.

Methods

In this prospective, multi-centre, Germany-wide, phase IV study, patients with pre-treated mCRC were given the choice to receive either FTD/TPI or best supportive care (BSC). A validated questionnaire, EORTC QLQ-C30, was employed to assess HRQoL. Secondary endpoints included OS, PFS and safety.

Results

Of 194 eligible patients, 185 decided to receive FTD/TPI and 9 to receive BSC. The low number of patients in the BSC-arm did not allow statistically meaningful analyses. On the other hand, treatment with FTD/TPI was associated with maintained HRQoL. Median OS was 6.9 months [95% confidence interval (CI) 6.1-8.2 months] and median PFS was 2.5 months (95% CI 2.1-2.9 months). The most frequent treatment-emergent adverse events were neutropenia (27.6%) and anaemia (22.7%). Febrile neutropenia occurred in 1.1%.

Conclusions

Treatment of patients suffering from pre-treated mCRC with FTD/TPI was associated not only with prolonged survival and delayed progression but also with maintained HRQoL.

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First patient-reported HRQoL and post-authorisation efficacy and safety data from German mCRC patients receiving FTD/TPI.

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Results were consistent with results of pivotal phase III and other studies.

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FTD/TPI prolonged survival and delayed progression with manageable toxicity profile.

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Treatment with FTD/TPI was associated with maintained HRQoL.

Trifluridine/tipiracil in the treatment of gastric cancer

Trifluridine/tipiracil is a compound drug, approved in 2015 by the Food and Drug Administration, and in 2016 by the European Medicines Agency, for the treatment of chemorefractory metastatic colorectal cancers, after the phase 3 RECOURSE trial demonstrated significant benefit. Another phase 3 trial (TAGS) showed significant improvement of overall survival and progression-free survival in refractory gastric cancer and gastroesophageal junction cancer, leading to further approval from the FDA on February 2019, followed by Japan in August 2019 and the European Union in September 2019. As promising results have already been observed in the chemorefractory gastric and gastroesophageal-junction cancers, ongoing trials are assessing the use of trifluridine/tipiracil with other standard of care agents, aiming to further improve the survival rate of these patients.

Polycyclic nitrogen heterocycles as potential thymidine phosphorylase inhibitors: synthesis, biological evaluation, and molecular docking study

New polycyclic heterocycles were synthesised and evaluated as potential inhibitors of thymidine phosphorylase (TP). Inspired by the pharmacophoric pyrimidinedione core of the natural substrate, four series have been designed in order to interact with large empty pockets of the active site: pyrimidoquinoline-2,4-diones (series A), pyrimidinedione linked to a pyrroloquinoline-1,3-diones (series B and C), the polycyclic heterocycle has been replaced by a pyrimidopyridopyrrolidinetetraone (series D). In each series, the tricyclic nitrogen heterocyclic moiety has been synthesised by a one-pot multicomponent reaction. Compared to 7-DX used as control, 2d, 2l, 2p (series A), 28a (series D), and the open intermediate 30 showed modest to good activities. A kinetic study confirmed that the most active compounds 2d, 2p are competitive inhibitors. Molecular docking analysis confirmed the interaction of these new compounds at the active binding site of TP and highlighted a plausible specific interaction in a pocket that had not yet been explored.

Initial experience of TAS-102 chemotherapy in Australian patients with Chemo-refractory metastatic colorectal cancer

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.

Evaluation of Thymidine Phosphorylase Inhibitors in Glioblastoma and Their Capacity for Temozolomide Potentiation

A number of studies have shown high levels of thymidine phosphorylase (TP) expression in glioblastoma (GBM), with trace or undetectable TP levels in normal developed brain tissue. TP catalyzes the reversible phosphorolysis of thymidine to thymine and 2-deoxyribose-1-phosphate, maintaining nucleoside homeostasis for efficient DNA replication and cell division. The TP-mediated catabolism of thymidine is responsible for multiple protumor processes and can support angiogenesis, glycation of proteins, and alternative metabolism. In this study, we examined the effect of TP inhibition in GBM using the known nanomolar TP inhibitors 5-chloro-6-[1-(2'-iminopyrrolidin-1'-yl)methyl]uracil (TPI) and the analogous 6-[(2'-aminoimidazol-1'-yl)methyl]uracils. Although these TP inhibitors did not demonstrate any appreciable cytotoxicity in GBM cell lines as single agents, they did enhance the cytotoxicity of temozolomide (TMZ). This pontetiated action of TMZ by TP inhibition may be due to limiting the availability of thymine for DNA repair and replication. These studies support that TP inhibitors could be used as chemosensitizing agents in GBM to improve the efficacy of TMZ.

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.

Post-marketing surveillance study of trifluridine/tipiracil in patients with metastatic colorectal cancer

BACKGROUND

The novel oral nucleoside antineoplastic agent trifluridine/tipiracil was approved for metastatic colorectal cancer in Japan in March 2014. In this post-marketing surveillance study, we investigated the safety and efficacy of trifluridine/tipiracil in a real-world setting, particularly haematological drug reactions classified according to the baseline renal and hepatic functions.

METHODS

We investigated patients with metastatic colorectal cancer who received trifluridine/tipiracil during the first four treatment cycles prospectively. The patients typically received 35 mg/m2 trifluridine/tipiracil twice daily on days 1-5 and 8-12 every 28 days. The primary objective was to assess the safety of trifluridine/tipiracil, but its efficacy was also evaluated.

RESULTS

Between July 2014 and June 2016, 860 patients were enrolled in the study, and the safety and efficacy of trifluridine/tipiracil were evaluated in 823 patients. Adverse drug reactions occurred in 89.7% of the patients. The most common adverse drug reactions were decreased white blood cell count (67.0%) and neutrophil count (63.9%). Haematological drug reactions of grade ≥3 were observed in 41.7% of the patients with normal renal function; 50.3, 65.6 and 78.9% of the patients had mild, moderate and severe renal impairments, respectively. Hepatic impairment was not associated with a higher incidence of haematological drug reactions. The median overall survival was 8.4 months, with a 1-year survival rate of 33.7%.

CONCLUSION

This post-marketing surveillance study further confirmed the safety and tolerability profile of trifluridine/tipiracil observed in a clinical study setting.

Targeting thymidine phosphorylase inhibition in human colorectal cancer xenografts

Human thymidine phosphorylase (hTP) is overexpressed in several solid tumors and is commonly associated with aggressiveness and unfavorable prognosis. 6-(((1,3-Dihydroxypropan-2-yl)amino)methyl)-5-iodopyrimidine-2,4(1H,3H)-dione (CPBMF-223) is a noncompetitive hTP inhibitor, which has been described as a tumor angiogenesis inhibitor. The present study investigated the effects of CPBMF-223 in a xenograft tumor induced by human colorectal carcinoma cells (HCT-116). Additionally, CPBMF-223 capacity to reduce cell migration, its toxicological profile, and pharmacokinetic characteristics, were also evaluated. The intraperitoneal treatment with CPBMF-223 markedly prevented the relative tumor growth with an efficacy similar to that observed for 5-fluorouracil. Interestingly, number of vessels were significantly decreased in the treated groups. Moreover, CPBMF-223 significantly reduced the migration of cell line HCT-116. In the Ames assay and in an acute oral toxicity test, the molecule did not alter any evaluated parameter. Using the zebrafish toxicity model, cardiac and locomotor parameters were slightly changed. Regarding the pharmacokinetics profile, CPBMF-223 showed clearance of 9.42 L/h/kg after intravenous administration, oral bioavailability of 13.5%, and a half-life of 0.75 h. Our findings shed new light on the role of hTP in colorectal cancer induced by HCT-116 cell in mice, pointing out CPBMF-223 as, hopefully, a promising drug candidate.

Oral drugs in the treatment of metastatic colorectal cancer

Colorectal cancer (CRC) is one of the most common forms of cancer, with an estimated 1.36 million new cases and almost 700,000 deaths annually. Approximately 21% of patients with CRC have metastatic disease at diagnosis. The objective of this article is to review the literature on the efficacy and safety of oral drugs available for the treatment of metastatic colorectal cancer (mCRC). Several such drugs have been developed, and fluoropyrimidines are the backbone of chemotherapy in this indication. They exert their antitumour activity by disrupting the synthesis and function of DNA and RNA. Oral fluoropyrimidines include prodrugs capecitabine, tegafur, eniluracil/5-fluorouracil, tegafur/uracil, tegafur/gimeracil/oteracil and trifluridine/tipiracil (FTD/TPI). Oral drugs offer several advantages over injectable formulations, including convenience, flexibility, avoidance of injection-related adverse events (AEs) and, in some circumstances, lower costs. However, oral drugs may not be suitable for patients with gastrointestinal obstruction or malabsorption, they may result in reduced treatment adherence and should not be co-administered with drugs that interfere with absorption or hepatic metabolism. Oral fluoropyrimidines such as capecitabine, as monotherapy or in combination with oxaliplatin, irinotecan or bevacizumab, are as effective as intravenous 5-fluorouracil (5-FU) in first-line treatment of mCRC. Other oral fluoropyrimidines, such as FTD/TPI, are effective in patients with mCRC who are refractory, intolerant or ineligible for 5-FU. In addition, oral fluoropyrimidines are used in adjuvant treatment of mCRC. Regorafenib is an oral multikinase inhibitor used in patients in whom several previous lines of therapy have failed. Frequent AEs associated with oral drugs used in the treatment of CRC include hand-foot syndrome and gastrointestinal and haematological toxicities.

Fused and Substituted Pyrimidine Derivatives as Profound Anti-Cancer Agents

The rationale behind drug design is the strategic utilization of heterocyclic fragments with specific physicochemical properties to form molecular targeted agents. Among the heterocyclic molecules, pyrimidine has proved to be a privileged pharmacophore for various biological cancer targets. The anti-cancer potential of small molecules with fused and substituted pyrimidines can be enhanced through bioisosteric replacements and altering their ADME parameters. Although several small molecules are used in cancer chemotherapy, oncology therapeutics has various limitations, especially in their routes of administration and their concurrent side effects. Such pernicious effects may be overcome, via selective biological targeting. In this review, the biological targets, to inhibit cancer, have been discussed. The structural activity relationship of fused and substituted pyrimidines was studied. Eco-friendly synthetic approaches for pyrimidine derivatives have also been discussed. This review will give an insight to scientists and researchers of medicinal chemistry discipline to design small molecules having a pyrimidine scaffold with high anti-cancer potential.

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.

Safety and activity of trifluridine/tipiracil and ramucirumab in previously treated advanced gastric cancer: an open-label, single-arm, phase 2 trial

BACKGROUND

Findings of preclinical and clinical trials in colorectal cancer have shown promising antitumour effects of the co-formulation trifluridine/tipiracil and VEGF inhibition. We aimed to investigate the safety and activity of trifluridine/tipiracil and ramucirumab for previously treated advanced gastric cancer.

METHODS

We did an open-label, single-arm, two-cohort, phase 2 study at eight centres in Japan. We enrolled patients with unresectable advanced gastric cancer or gastro-oesophageal junction adenocarcinoma. Cohort A included patients previously treated with one line of chemotherapy without ramucirumab and cohort B included patients previously treated with two to four lines of chemotherapy, including ramucirumab. Patients received trifluridine/tipiracil (35 mg/m2) orally twice daily on days 1-5 and days 8-12 of each 28-day treatment cycle, plus intravenous ramucirumab (8 mg/kg) on days 1 and 15. The primary endpoint was the disease control rate, assessed by investigators and defined as the proportion of patients with a confirmed best overall response, according to Response Evaluation Criteria in Solid Tumors version 1.1. This trial is registered on JapicCTI (JapicCTI-194596) and is ongoing but not recruiting.

FINDINGS

Between April 8 and Oct 11, 2019, 64 patients were enrolled and included in the safety and activity analyses, 33 in cohort A and 31 in cohort B. In cohort A, the disease control rate was 85% (95% CI 68-95; 28 of 33 patients) and in cohort B it was 77% (59-90; 24 of 31 patients). Common treatment-related adverse events of grade 3 or worse were neutrophil count decreased (27 [82%] in cohort A and 23 [74%] in cohort B), white blood cell count decreased (eight [24%] and seven [23%]), and platelet count decreased (eight [24%] and four [13%]). Serious treatment-related adverse events were recorded in three patients in cohort A (fatigue and neutrophil count decreased; large intestine perforation; and febrile neutropenia, platelet count decreased, and anaemia). No patients in cohort B had a serious treatment-related adverse event, and no treatment-related deaths were reported in either cohort.

INTERPRETATION

Trifluridine/tipiracil and ramucirumab showed an acceptable safety profile and clinical activity in patients with previously treated advanced gastric cancer regardless of previous ramucirumab exposure.

FUNDING

Taiho Pharmaceutical and Eli Lilly.

Appropriateness of trifluridine/tipiracil in the clinical practice of third-line therapy in metastatic colorectal cancer

Aim: To help to remove misperception of an appropriate position of trifluridine/tipiracil (FTD/TPI) in the treatment of metastatic colorectal cancer. Materials & methods: The RAND Corporation/UCLA Appropriateness Method was used by a panel of Italian experts to develop recommendations concerning daily practice with FTD/TPI. Forty-three clinical scenarios were discussed in two rounds and the resulting statements were rated as appropriate, uncertain or inappropriate, according to the median score. Results: Several topics were dealt with, covering the profile of eligible patients, therapeutic options beyond the second line, the practice of treatment with FTD/TPI, evaluation and efficacy and toxicity, as well as costs and compliance. Conclusion: FTD/TPI is an important therapeutic resource in refractory metastatic colorectal cancer that combines manageability and safety.

Efficacy of Combination Chemotherapy Using a Novel Oral Chemotherapeutic Agent, FTD/TPI, with Ramucirumab Murine Version DC101 in a Mouse Syngeneic Cancer Transplantation Model

Trifluridine/tipiracil (FTD/TPI) (a.k.a. TAS-102) is a combination drug for metastatic colorectal cancer (CRC) and severely pretreated metastatic gastric/gastroesophageal junction (GEJ) cancers, comprising FTD, a thymidine-based antineoplastic nucleoside analog, and TPI, which enhances FTD bioavailability. Herein, in KRAS mutant murine colorectal cancer CT26 syngeneic models, we investigate whether combination therapy with DC101 (a surrogate ramucirumab antibody, rat antimouse vascular endothelial growth factor receptor (VEGFR)-2 monoclonal antibody (mAb)) improves FTD/TPI efficacy. Tumor growth inhibition (TGI) on day 15 was 38.0% and 30.6% upon DC101 monotherapy and FTD/TPI monotherapy respectively, and 60.3% upon combination therapy. Tumor volume was significantly lower (p < 0.001) upon combination treatment than upon FTD/TPI or DC101 monotherapy, indicating the additive effects of FTD/TPI and DC101. DNA-incorporated FTD levels on Day 8 were significantly higher in combination therapy with FTD/TPI (for 5 consecutive days) and DC101 (on alternate days for 7days) than in FTD/TPI monotherapy. Furthermore, vascular endothelial cell-specific marker CD31 was downregulated in DC101-treated tumors on day 8. These results indicate that combination therapy with FTD/TPI and DC101 is a promising treatment alternative regardless of KRAS mutations.

Trifluridine/tipiracil in combination with local therapy may be a favorable option for refractory metastatic colorectal cancer patients: A case report

RATIONALE

Currently, the 5-year survival rate remains poor for patients with metastatic colorectal cancer (mCRC), and the purpose of therapy is to prolong survival while maintaining the quality of life. Trifluridine/tipiracil, an oral drug combining trifluorothymidine and a thymidine phosphorylase inhibitor, is indicated as salvage therapy for mCRC patients who have progressed after all available regimens. Combination of local treatments with systemic therapy such as trifluridine/tipiracil represents an apt management strategy for mCRC patients.

PATIENT CONCERNS

A 72-year-old man diagnosed with stage IV rectal adenocarcinoma (KRAS mutation) with peritoneal carcinomatosis and liver metastases developed resistance to 2 lines of treatment (bevacizumab/irinotecan/S-1 and bevacizumab/oxaliplatin/HDFL [high-dose 24-hour infusion of 5-fluorouracil and leucovorin regimen]) within 5 months.

DIAGNOSIS

Refractory stage IV rectal adenocarcinoma.

INTERVENTIONS

Systemic treatment of trifluridine/tipiracil has been given for approximately 15 months in addition to radiotherapy, Yttrium-90 radioembolization, and trans-arterial chemoembolization for peritoneal and liver metastases.

OUTCOMES

After 15 months, the patient was still taking trifluridine/tipiracil for disease control with a good quality of life.

LESSONS

Trifluridine/tipiracil plus other appropriate local therapy may significantly prolong patients survival with a satisfactory quality of life for patients with refractory mCRC. The favorable safety profile of trifluridine/tipiracil renders it a suitable option to be combined with other local therapies for metastatic lesions.

TAS-102 in metastatic colorectal cancer (mCRC): efficacy, tolerability, and quality of life in heavily pretreated elderly patients: a real-life study

BACKGROUND

TAS-102 is an oral monotherapy, combining trifluridine and tipiracil hydrochloride, indicated for the treatment of pretreated metastatic colorectal cancer (mCRC). The aim of this real-life study is to evaluate the efficacy and safety of TAS-102 in heavily pretreated elderly patients with mCRC whose disease has progressed with standard therapies.

METHODS

In this retrospective observational study, we enrolled 50 elderly patients >70 years of age (median age 78 years) with a diagnosis of mCRC who were previously treated or were not considered candidates for treatment with other available therapies. Patients aged >70 years with advanced colorectal cancer and with an ECOG performance status of grade 0 (n=18) or grade 1 (n=32) were included. Overall survival and progression-free survival were the primary endpoints, whereas objective response rate, tolerability, and quality of life were the secondary endpoints.

RESULTS

Treatment with TAS-102 appeared to be well tolerated and side effects were generally mild, achieving disease control and a benefit on quality of life. The median overall survival was 6.7 (95% CI 5.7-11.3) and the median progression-free survival was 2.1 months (95% CI 1.2-3.2), estimated using the Kaplan-Meier method.

CONCLUSION

TAS-102 represents a manageable and effective therapeutic opportunity and appeared to be well tolerated with generally mild side effects in elderly patients with mCRC who were heavily pretreated with standard therapies.

Comparative Cost-utility Analysis of Regorafenib and Trifluridine/Tipiracil in The Treatment of Metastatic Colorectal Cancer in Japan

PURPOSE

This study evaluated the cost utility of regorafenib and trifluridine/tipiracil (T/T) compared with that of best supportive care (BSC) in the treatment of patients with metastatic colorectal cancer previously treated with, or not considered candidates for, available therapies, including fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapies; anti-vascular endothelial growth factor agents; and anti-epidermal growth factor receptor agents, in Japan.

METHODS

Efficacy data, utility values, and costs were extracted from published studies. The cost and effectiveness of regorafenib and of T/T were compared with those of BSC and examined between the 2 agents over a 5-year time horizon using a partitioned survival analysis. The health outcomes were life-years (LYs) and quality-adjusted life-years (QALYs) gained. The costs were year-2018 revisions to the drug prices and medical fees. The uncertainty and robustness of the model were verified by 1-way sensitivity analysis, probability sensitivity analysis, and scenario analysis compared with different clinical studies. A 2% per-annum discount was applied to expenses and QALYs. The willingness-to-pay threshold used was 5 million Japanese yen (JPY).

FINDINGS

Regorafenib and T/T had incremental costs of 11,898,982 JPY (107,781 US dollars [USD]) and 5,000,141 JPY (45,291 USD), incremental effects of 0.249 QALYs (0.280 LYs) and 0.344 QALYs (0.421 LYs), and incremental cost-effectiveness ratios of 47,773,791 JPY (432,734 USD) and 14,550,577 JPY (131,799 USD) per QALY, respectively. Results of sensitivity analyses all exceeded the willingness-to-pay threshold of 15 million JPY. In the comparison of the 2 agents, T/T was a dominant alternative over regorafenib.

IMPLICATIONS

As a third-line or later treatment of metastatic colorectal cancer in Japan, T/T is cost-effective compared with BSC, whereas regorafenib is not. It is necessary to adjust the price of regorafenib based on the results of this analysis, with the improvement of clinical parameters such as survival time and adverse events.

TAS-102 in gastric cancer: Development and perspectives of a new biochemically modulated fluroropyrimidine drug combination

TAS-102 is a preconstituted drug combination comprising an oral fluoropyrimidine (trifluridine, TFT) and a potent inhibitor of thymidine phosphorylase (tipiracil hydrochloride, TPI). TFT/TPI has recently received Food and Drug Administration (FDA) approval also for the treatment of gastric cancer after at least two lines of chemotherapy. The approval was based on a large phase 3 trial (TAGS), in which TAS-102 showed a 31 % decrease in the risk of death compared with placebo. Here, we review the pharmacological properties, clinical development and potential future directions of TAS-102 in gastric cancer.

Synthetic Lethality with Trifluridine/Tipiracil and Checkpoint Kinase 1 Inhibitor for Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a disease characterized by a high mutation rate of the TP53 gene, which plays pivotal roles in the DNA damage response (DDR) and is regulated by checkpoint kinase (CHK) 2. CHK1 is another key DDR-related protein, and its selective inhibition is suggested to be particularly sensitive to TP53-mutated cancers, because a loss of both pathways (CHK1 and/or CHK2-p53) is lethal due to the serious impairment of DDR. Such a therapeutic strategy is termed synthetic lethality. Here, we propose a novel therapeutic strategy based on synthetic lethality combining trifluridine/tipiracil and prexasertib (CHK1 inhibitor) as a treatment for ESCC. Trifluridine is a key component of the antitumor drug combination with trifluridine/tipiracil (an inhibitor of trifluridine degradation), also known as TAS-102. In this study, we demonstrate that trifluridine increases CHK1 phosphorylation in ESCC cells combined with a reduction of the S-phase ratio as well as the induction of ssDNA damage. Because CHK1 phosphorylation is considered to be induced as DDR for trifluridine-mediated DNA damage, we examined the effects of CHK1 inhibition on trifluridine treatment. Consequently, CHK1 inhibition by short hairpin RNA or treatment with the CHK1 inhibitor, prexasertib, markedly enhanced trifluridine-mediated DNA damage, represented by an increase of γH2AX expression. Moreover, the combination of trifluridine/tipiracil and CHK1 inhibition significantly suppressed tumor growth of ESCC-derived xenograft tumors. Furthermore, the combination of trifluridine and prexasertib enhanced radiosensitivity both in vitro and in vivo Thus, the combination of trifluridine/tipiracil and a CHK1 inhibitor exhibits effective antitumor effects, suggesting a novel therapeutic strategy for ESCC.

Detection of trifluridine in tumors of patients with metastatic colorectal cancer treated with trifluridine/tipiracil

PURPOSE

Trifluridine (FTD) is the active component of the nucleoside chemotherapeutic drug trifluridine/tipiracil (FTD/TPI), which is approved worldwide for the treatment of patients with metastatic gastrointestinal cancer. FTD exerts cytotoxic effects via its incorporation into DNA, but FTD has not been detected in the tumor specimens of patients. The purpose of this study was to detect FTD in tumors resected from metastatic colorectal cancer (mCRC) patients who were administered FTD/TPI. Another purpose was to investigate the turnover rate of FTD in tumors and bone marrow in a mouse model.

METHODS

Tumors and normal tissue specimens were obtained from mCRC patients who were administered FTD/TPI or placebo at Kyushu University Hospital. Tumors and bone marrow were resected from mice with peritoneal dissemination treated with FTD/TPI. To detect and quantitate FTD incorporated into DNA, immunohistochemical staining of paraffin-embedded specimens (IHC-p staining) and slot-blot analysis of DNA purified from these tissues were performed using an anti-BrdU antibody. IHC-p staining of proliferation and apoptosis markers was also performed.

RESULTS

FTD was detected in metastatic tumors obtained from mCRC patients who were administered FTD/TPI, but who had discontinued the treatment several weeks before surgery. In a peritoneal dissemination mouse model, FTD was still detected in tumors 13 days after the cessation of FTD/TPI treatment, but had disappeared from bone marrow within 6 days.

CONCLUSION

These results indicate that FTD persists longer in tumors than in bone marrow, which may cause a sustained antitumor effect with tolerable hematotoxicity.

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.

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.

Theoretical analyses and experimental validation of the effects caused by the fluorinated substituent modification of DNA

Halogen-modified nucleic acid molecules, such as trifluorothymidine (FTD) and 5-fluorouracil, are widely used in medical science and clinical site. These compounds have a very similar nucleobase structure. It is reported that both of these compounds could be incorporated into DNA. The incorporation of FTD produces highly anti-tumor effect. However, it is not known whether to occur a significant effect by the incorporation of 5-fluorouracil. Nobody knows why such a difference will occur. To understand the reason why there is large differences between trifluorothymidine and 5-fluorouracil, we have performed the molecular dynamics simulations and molecular orbital calculations. Although the active interaction energy between Halogen-modified nucleic acids or and complementary adenine was increased, in only FTD incorporated DNA, more strongly dispersion force interactions with an adjacent base were detected in many thermodynamic DNA conformations. As the results, the conformational changes occur even if it is in internal body temperature. Then the break of hydrogen bonding between FTD and complementary adenine base occur more frequently. The double helix structural destabilization of DNA with FTD is resulted from autoagglutination caused by the bonding via halogen orbitals such as halogen bonding and the general van der Waals interactions such as CH–\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rm{\pi }}$$\end{document}π, lone pair (LP)–\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rm{\pi }}$$\end{document}π, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rm{\pi }}$$\end{document}π–\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rm{\pi }}$$\end{document}π interactions. Therefore, it is strongly speculated that such structural changes caused by trifluoromethyl group is important for the anti-tumor effect of FTD alone.

New bioanalytical microemulsion Electrokinetic chromatography method for the simultaneous determination of Trifluridine with its metabolites and Tipiracil in rat plasma: Application to pharmacokinetic studies

A Microemulsion Electrokinetic Chromatography method coupled with diode array detector (MEEKC-DAD) was developed for the first time and found to be efficient, sensitive, and selective for the simultaneous analysis of Trifluridine (FTD), and its metabolites 5-(trifluoromethyl) uracil (FTY) and 5-carboxy-2'-deoxyuridine (5CDU), and Tipiracil (TIP) in rat plasma. Sample pre-treatment involved a simple protein precipitation from plasma using acetonitrile. The separation was achieved using a fused silica capillary (65 cm total length, 55 cm effective length and 50 µm i.d.) and a microemulsion solution consisted of 1.66% sodium dodecyl sulfate (SDS), 0.91% heptane, 6.61% 1-butanol, and 90.72% borate buffer (20 mM, pH 9.5). Electrophoretic separation was carried out at 20 °C and 20 kV. The samples were injected for 40 s at 20 mbar and detected simultaneously at 205 nm. The electrophoretic parameters indicated that the developed MEEKC-DAD method permitted complete resolution of the analytes within 13 min. The developed method was fully validated according to the FDA guidelines for bioanalytical method validation. The method was linear in the range 200-4000 ng/ml for FTD, FTY, 5CDU, and 100-1000 ng/ml for TIP. The intra/inter-day accuracy and precisions were ≤4% for all drugs. Extraction recovery and stability were also assessed and were within acceptable range. After being validated, the method was applied for the determination of the studied drugs in plasma samples collected from rats injected intraperitoneally with a combination of FTD and TIP. The results obtained were used to study the pharmacokinetics of FTD with its metabolite and TIP in rat plasma.

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.

CD44/CD133-Positive Colorectal Cancer Stem Cells are Sensitive to Trifluridine Exposure

Cancer stem cells (CSCs) are involved in metastatic colorectal cancer recurrence, but no effective therapy targeting these cells is currently available. Because trifluridine (FTD)/tipiracil therapy is used for refractory colorectal cancer, we sought to determine whether FTD is effective against CSC-like cells. CD44⁺CD133⁺ high-expressing and other populations of human DLD-1 colon cancer cells were separately isolated through fluorescence-activated cell sorting. The sphere-forming activity of each population and the anti-sphere-forming effects of FTD and fluorouracil (5-FU) on CD44⁺CD133⁺ cells were then measured. CD44⁺CD133⁺ DLD-1 cells formed substantially more spheres than other cells. Moreover, treating CD44⁺CD133⁺ DLD-1 cells with subtoxic concentrations of FTD (1 µM) inhibited sphere formation, and this was superior to the effect of subtoxic concentrations (1 µM) of 5-FU. The associated inhibition rates for FTD and 5-FU were 58.2% and 26.1%, respectively. Further, CD44⁺CD133⁺ DLD-1 cells expressed higher levels of thymidine kinase 1, which is responsible for FTD phosphorylation, than DLD-1 cells, and FTD was incorporated into the DNA of CD44⁺CD133⁺ DLD-1 cells. Thus, our data show that FTD treatment is effective against CSC-like cells and might be applied as CSC-targeting chemotherapy for tumor subtypes with high CD44 and CD133 expression.