A prospective phase II study of raltitrexed combined with S-1 as salvage treatment for patients with refractory metastatic colorectal cancer

Aim

A third‐line chemotherapy regimen for metastatic colorectal cancer (mCRC) is not available in China. Studies have shown that raltitrexed or S‐1 has no complete cross‐resistance with fluorouracil (5‐FU). In this phase II study, we prospectively analyzed the efficacy and safety of raltitrexed combined with S‐1 (RS regimen) in the treatment of mCRC after the failure of conventional chemotherapy.

Methods

A total of 105 patients with mCRC with progression following treatment with 5‐FU, oxaliplatin, and irinotecan were enrolled between November 2015 and May 2019. Patients received intravenous infusion of raltitrexed (3 mg/m² from day 1 every 3 weeks) and oral S‐1 (80‐120 mg for 14 days every 3 weeks). Tumor evaluations were performed every two cycles according to the RECIST 1.1 guidelines.

Results

In the intention‐to‐treat patients, the objective response and disease control rates were 7.62% and 48.57%, respectively. The median progression‐free survival and median overall survival were 2.5 and 8.0 months, respectively. Common adverse events included neutropenia, anemia, thrombocytopenia, and nausea, while neutropenia, anemia, thrombocytopenia nausea, diarrhea, skin eruption, and oral ulceration had grade 3 or higher adverse events. Subgroup analysis revealed that primary site or gene mutation status had little influence on the RS regimen efficacy, while the baseline albumin level, 5‐FU administration in second‐line therapy, and number of previous treatment regimens affected the efficacy.

Conclusion

The RS regimen demonstrated favorable effects in patients with mCRC following failure of standard chemotherapy, and could be a new choice for third‐line treatment, and must be verified in future randomized clinical trials (Clinical trial: NCT02618356).

A multicenter phase II study of TAS-114 in combination with S-1 in patients with pretreated advanced gastric cancer (EPOC1604)

BACKGROUND

This is a phase 2 study aimed at evaluating the efficacy and safety of TAS-114, a novel deoxyuridine triphosphatase inhibitor, combined with S-1 in patients with advanced gastric cancer (AGC).

METHODS

Eligible patients had AGC with measurable lesions, according to the Response Evaluation Criteria in Solid Tumors (RECIST, v1.1), with two or more previous chemotherapy regimens including fluoropyrimidines, platinum agents, and taxanes or irinotecan. The primary endpoint was objective response rate (ORR) according to the RECIST, v1.1. Twenty-nine patients were required according to Simon's optimal two-stage design, with one-sided a = 5% and power = 80%. Threshold and expected ORRs were 5% and 25%. Patients received TAS-114 (400 mg/body, twice a day) and S-1 (30 mg/m², twice a day) for 14 days, followed by 7 days of rest in one 3-week cycle. Protein expression levels of dUTPase and BRCA1 in tumor samples were determined by immunohistochemistry.

RESULTS

Accrual was terminated in June 2018 because meeting the predefined efficacy criteria was considered difficult. ORR and disease control rate were 5.0% [95% confidence interval (CI), 0.1-24.9%] and 70.0% (95% CI, 45.7-88.1%), respectively, for all 20 patients enrolled. Median progression-free survival (PFS) and overall survival were 2.4 months (95% CI, 1.2-3.3 months) and 7.1 months (95% CI, 5.2-9.4 months), respectively. Median PFS in the groups with high and low dUTPase protein expression in the cytoplasm was 2.8 months (95% CI, 1.4-3.9) and 1.6 months (95% CI, 0.6-2.4), respectively [hazard ratio, 0.40 (95% CI, 0.16-1.04), log-rank test two-sided p = 0.047]. Grade 3 or higher treatment-related adverse events included anemia (20%), leucopenia (15%), neutropenia (10%), rash (10%), thrombocytopenia (5%), and lymphopenia (5%) CONCLUSIONS: TAS-114 with S-1 showed only modest antitumor activity with acceptable safety profiles for patients heavily pretreated with AGC.

A systematic review of salvage therapy to patients with metastatic colorectal cancer previously treated with fluorouracil, oxaliplatin and irinotecan +/- targeted therapy

Oxaliplatin, irinotecan and 5-fluorouracil in combination with or without targeted therapies are well-documented treatment options for first- and second-line treatments of metastatic colorectal cancer. However, there are much less data on the beneficial effect on systemic therapy in the third-line setting. We therefore performed a systematic review of the current literature on third or later lines of treatment to patients with metastatic colorectal cancer after the use of approved drugs or combinations.

METHODS

A computer-based literature search was carried out using Pubmed and data reported at international meetings. Original studies reporting ≥15 patients who had previously received 5-fluorouracil, oxaliplatin and irinotecan were included. Furthermore, patients with KRAS wild type tumours should had received EGFR-directed therapy.

RESULTS

Conventional chemotherapeutic agents as capecitabine, mitomycin C, and gemcitabine have limited or no activity. Retreatment with oxaliplatin might be an option in selected patients. In addition, rechallenge with EGFR-directed therapy might be a valuable strategy. Data also suggest that angiogenetic drugs may postpone further progression and prolong survival. Lately, regorafinib has been approved. In conclusion, our current knowledge is based on many retrospective studies, some phase II studies and very few randomized clinical trials. Further prospective phase III trials comparing an investigational drug or combination with best supportive care in third- or later lines of treatment in metastatic colorectal cancer are highly warranted. Identification of predictive biomarkers and improvement of our understanding of molecular mechanisms is crucial.

Intestinal iron homeostasis and colon tumorigenesis

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.

Abrogation of the accelerated blood clearance phenomenon by SOXL regimen: promise for clinical application

We recently proposed an S-1 combined with oxaliplatin (SOXL) regimen, a combination treatment consisting of oral metronomic S-1 dosing and intravenous administration of oxaliplatin (l-OHP) containing PEGylated liposomes, which showed potent antitumor activity in vivo. PEGylated liposomes induce what is referred to as the "accelerated blood clearance (ABC) phenomenon" upon repeated administration and consequently lose their long-circulating characteristics. This phenomenon seems to pose an impediment for the clinical application and use of PEGylated liposomal formulations. In the present study, l-OHP-containing PEGylated liposomes in the SOXL regimen significantly attenuated the ABC phenomenon in a dose-dependent manner through suppression of the anti-PEG IgM response, which allowed an enhanced hepatic uptake of subsequently injected test PEGylated liposomes. In tumor-bearing mice, the abrogation of the ABC phenomenon restored intratumor accumulation of subsequently injected PEGylated liposomes. Consequently, the therapeutic efficacy of the SOXL regimen over the combination of the free form of the drugs was credited not only with the selective delivery of drugs to the tumor tissue but also with ensuring an adequate accumulation of subsequent doses within the tumor tissue. The SOXL regimen we proposed may hold promise as a safe and effective treatment regimen for advanced colorectal cancer.

Metastatic colorectal cancer: current treatment and future options for improved survival. Medical approach--present status

BACKGROUND

Metastatic colorectal cancer has a poor prognosis, and the majority of patients are left with palliative measures. The development seen using medical treatments are reviewed.

MATERIAL AND METHODS

A systematic approach to the literature-based evidence of effects from palliative chemotherapy and targeted drugs was aimed at.

RESULTS

The continuous improvements during the past 20-25 years have been documented in several large conclusive trials. At the end of the 1980s, the evidence that chemotherapy should be used at all was very limited, whereas presently most patients can be offered three lines of chemotherapy with or without a targeted drug based upon good scientific evidence. Median survival in trials has gradually improved from about 6 months to above 24 months in the most recent trials. Survival in the populations has, however, not improved to the same extent. Several important issues remain to be solved, such as the best sequence of treatments, what regimens to use in various situations, when to start and when to stop if a response is seen, whether cure may be possible in a small subset of patients, and socioeconomic issues. Integration of surgery and other local methods have further improved outcome for some individuals, but must be fine-tuned.

CONCLUSIONS

Progress has been rapid in advanced colorectal cancer. This is likely a result of well-designed trials in collaboration between academy and industry, showing a great interest in the disease. A multi-professional approach and future collaborations may hopefully introduce new treatment concepts, further improving outcome.

Combination therapy with metronomic S-1 dosing and oxaliplatin-containing PEG-coated cationic liposomes in a murine colorectal tumor model: synergy or antagonism?

Combination therapy with 2 or more drugs with different mechanisms of action has been considered a promising strategy for the effective treatment of advanced and metastatic cancers. However, the rational design of combination therapy represents a potential prerequisite for its effectiveness. Recently, we showed that the combination of oral metronomic S-1 dosing with oxaliplatin (l-OHP)-containing PEG-coated "neutral" liposomes exerted excellent antitumor activity. In addition, we recently designed a PEG-coated "cationic" liposome for dual-targeting delivery of l-OHP to tumor endothelial cells and tumor cells in a solid tumor. This targeted liposomal l-OHP formulation showed efficient antitumor activity in a murine tumor model, compared with l-OHP-containing PEG-coated "neutral" liposomes. In the present study, we investigated the issue of whether metronomic S-1 dosing with l-OHP-containing PEG-coated "cationic" liposomes creates synergy. Unfortunately, metronomic S-1 dosing resulted in impaired delivery of PEG-coated "cationic" liposomes into tumor tissue, presumably by decreasing the binding sites on tumor blood vessels available for the liposomes. The anticipated cytotoxic synergistic effect of the combination treatment was not achieved. Instead, the combination treatment showed lower antitumor efficacy than l-OHP-containing PEG-coated "cationic" liposomes alone. These results suggest that the combined treatment of S-1 and l-OHP-containing PEG-coated "cationic" liposomes seems to be antagonistic rather than synergistic.

Combination chemotherapy with S-1 plus cisplatin for gastric cancer that recurs after adjuvant chemotherapy with S-1: multi-institutional retrospective analysis

BACKGROUND

It is unclear whether S-1 plus cisplatin is effective for patients with recurrent gastric cancer after adjuvant S-1 chemotherapy.

METHODS

We retrospectively evaluated the efficacy of S-1 plus cisplatin in patients whose gastric cancer recurred after adjuvant S-1 chemotherapy.

RESULTS

In the 52 patients evaluated, the median duration of adjuvant S-1 chemotherapy was 8.1 months, and the median recurrence-free interval (RFI) since the last administration of adjuvant S-1 was 6.4 months. Among the 36 patients with measurable lesions, 7 achieved a complete or partial response, and 13 were evaluated as having stable disease, for an overall response rate of 19.4% and a disease control rate of 55.6%. For all patients, the median progression-free survival (PFS) was 4.8 months, and the median overall survival (OS) was 12.2 months. Compared with patients with an RFI of <6 months (n = 25), patients with an RFI of ≥6 months (n = 27) had a significantly higher response rate (5.0 vs. 37.5%, respectively), longer PFS (2.3 vs. 6.2 months, respectively), and longer overall survival (7.3 vs. 16.6 months, respectively). According to a multivariate Cox model including performance status (PS) and reason for discontinuation of adjuvant S-1, an RFI of 6 months was still significantly associated with PFS and OS.

CONCLUSIONS

S-1 plus cisplatin is effective for patients with gastric cancer that recurs after adjuvant S-1 chemotherapy, especially for those with an RFI of ≥6 months.

Hepatic arterial infusion of 5-fluorouracil for patients with liver metastases from colorectal cancer refractory to standard systemic chemotherapy: a multicenter, retrospective analysis

INTRODUCTION

This retrospective study evaluated the safety and efficacy of hepatic arterial infusion chemotherapy (HAIC) with 5-fluorouracil (5-FU) for patients with liver metastases from colorectal cancer refractory to standard systemic chemotherapy.

PATIENTS AND METHODS

Fifty-five patients who had shown disease progression during the prior standard systemic chemotherapy with oxaliplatin, irinotecan, and 5-FU were enrolled. The treatment was weekly HAIC with 5-FU 1000 mg/m2/5 hours through an indwelling catheter-port system.

RESULTS

No major adverse reaction was observed other than grade 3 leukocytopenia (3.6%) and hyperbilirubinemia (1.8%). The overall response rate and disease control rate were 18.2% and 70.9%, respectively. The median progression-free survival and median overall survival (OS) were 2.8 months, and 6.7 months, respectively. The initial sites of disease progression were liver in 14, other than liver in 27, and both in 6. Multivariate analysis identified Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 1 and number of extrahepatic metastatic sites (NMS) ≤ 1 as favorable prognostic factors for OS (hazard ratio [HR], 8.277; 95% CI, 3.60-19.0; P = .000 for ECOG PS; and HR, 2.456; 95% CI, 1.30-4.61; P = .005 for NMS).

CONCLUSION

HAIC with 5-FU may be a safe and effective treatment for patients with colorectal liver metastases refractory to standard systemic chemotherapy.

Regimen selection for first-line FOLFIRI and FOLFOX based on UGT1A1 genotype and physical background is feasible in Japanese patients with advanced colorectal cancer

OBJECTIVE

We examined the feasibility of regimen selection for first-line irinotecan, 5-fluorouracil and leucovorin or oxaliplatin, 5-fluorouracil and leucovorin in Japanese patients with advanced colorectal cancer based on UDP-glucuronosyltransferase 1A1 genotype as well as physical status of patients related to diarrhea.

METHODS

As first-line irinotecan, 5-fluorouracil and leucovorin is a little bit superior to oxaliplatin, 5-fluorouracil and leucovorin with respect to efficacy and toxicity, patients without risk factors of irinotecan-induced toxicity were first assigned to irinotecan, 5-fluorouracil and leucovorin. Patients with UDP-glucuronosyltransferase 1A1 28/ 28, 6/ 6, 28/ 6 or 28/ 27 and those with ascites, peritoneal dissemination or diarrhea first received oxaliplatin, 5-fluorouracil and leucovorin to avoid the irinotecan-induced neutropenia and diarrhea, respectively. We retrospectively evaluated the feasibility of this strategy by assessing toxicity and total progression-free survival in first- and subsequent second-line therapies in all patients studied.

RESULTS

In the first-line irinotecan, 5-fluorouracil and leucovorin (n = 61), Grade 4 neutropenia, febrile neutropenia and Grade 3 diarrhea occurred in 8.2, 3.3 and 3.3% of patients, respectively. In the first-line oxaliplatin, 5-fluorouracil and leucovorin (n = 26), Grade 4 neutropenia, febrile neutropenia, Grade 3 thrombocytopenia and Grade 3 neuropathy were observed in 11.5, 3.8, 3.8 and 7.7% of patients, respectively. In the second-line oxaliplatin, 5-fluorouracil and leucovorin (n = 38), Grade 3 diarrhea occurred in 2.6% of patients. In the second-line irinotecan monotherapy (n = 11), Grade 4 or febrile neutropenia occurred in 18% of patients and Grade 3 diarrhea in 9.1% of patients. In second-line S-1 (n = 9), Grade 3 anemia occurred in 2 patients. Median total progression-free survival in all 87 patients was 11.5 months.

CONCLUSIONS

Present regimen selection strategy would be feasible, since it causes less toxicity and similar efficacy comparing to previous studies. Determination of appropriate reduced dose in the second-line irinotecan monotherapy or other standard second-line therapy for patients with high-risk to irinotecan-induced toxicity might make this strategy more effective.