Phase II study of S-1, a novel oral fluorophyrimidine derivative, in patients with metastatic colorectal carcinoma. S-1 Cooperative Colorectal Carcinoma Study Group

Impaired Consciousness Due to Hyperammonemia During S-1 Administration for Unresectable Pancreatic Cancer

A 71-year-old woman diagnosed with unresectable locally advanced pancreatic cancer was initially treated with gemcitabine and nab-paclitaxel as first-line therapy. The tumor exhibited no significant progression; however, after 12 cycles, the patient developed drug-induced interstitial pneumonia, leading to the discontinuation of gemcitabine and nab-paclitaxel therapy. Following recovery from pneumonia, S-1 therapy was initiated as second-line treatment. During S-1 therapy, she was hospitalized because of impaired consciousness and was subsequently diagnosed with hyperammonemia induced by S-1. Although rarely reported, S-1-induced hyperammonemia is potentially a significant adverse effect. Here, we herein report the case of a patient with pancreatic cancer.

Phase II study of SOXIRI (S-1/oxaliplatin/irinotecan) chemotherapy in patients with unresectable pancreatic ductal adenocarcinoma

BACKGROUND

To provide data on the safety and efficacy of a combination chemotherapy regimen consisting of S-1, oxaliplatin, and irinotecan (SOXIRI) as a first-line therapy in unresectable pancreatic ductal adenocarcinoma (UPDA) patients.

METHODS

Patients with UPDA and no prior treatment chemotherapy in the UPDA setting were enrolled. The primary endpoint was the objective response rate (ORR). Secondary endpoints were overall survival (OS), progression-free survival (PFS) and adverse events. Patients received 80 mg/m2 S-1 twice a day for 2 weeks in an alternate-day administration cycle, 85 mg/m2 oxaliplatin on Day 1, and 150 mg/m2 irinotecan on Day 1 of a 2-week cycle.

RESULTS

In these 62 enrolled patients, the ORR was 27.4 %, median OS was 12.1 months, and median PFS was 6.5 months. Major grade 3 or 4 toxicity included neutropenia (22.3 %), leucopenia (16.1 %), nausea (9.7 %), vomiting (9.7 %), thrombocytopenia (6.5 %), anorexia (8.5 %), anemia (4.8 %), and diarrhea (1.6 %). No treatment-related deaths occurred. In addition, the analysis of 32 patients suffering pain revealed that the rate of pain relief was 34.4 %.

CONCLUSION

SOXIRI might be a standard regimen with an acceptable toxicity profile and favorable efficacy for use as chemotherapy in patients with UPDA.

Efficacy and safety of SOXIRI versus mFOLFIRINOX in advanced pancreatic cancer

Background

Modified fluorouracil/leucovorin/irinotecan/oxaliplatin (FOLFIRINOX) regimen (mFOLFIRINOX), comprised of fluorouracil, leucovorin, irinotecan and oxaliplatin, is the first-line standard chemotherapy in patients with advanced pancreatic cancer. The S-1/oxaliplatin/irinotecan (SOXIRI) regimen has also been studied recently under similar conditions. This study compared its efficacy and safety.

Methods

All cases of locally advanced or metastatic pancreatic cancer treated with the SOXIRI or mFOLFIRINOX regimen in Sun Yat-sen University Cancer Centre from July 2012 to June 2021 were reviewed retrospectively. The data of patients who satisfied the inclusion criteria were compared between two cohorts, including overall survival (OS), progression-free survival (PFS), objective response rate, disease control rate and safety.

Results

A total of 198 patients were enrolled in the study, including 102 patients treated with SOXIRI and 96 patients treated with mFOLFIRINOX. There was no significant difference in OS [12.1 months versus 11.2 months, hazard ratio (HR) = 1.04, p = 0.81] or PFS (6.5 months versus 6.8 months, HR = 0.99, p = 0.96) between patients treated with SOXIRI and mFOLFIRINOX. In the subgroup analysis, patients with slightly elevated baseline total bilirubin (TBIL) or underweight patients before chemotherapy were more likely to have a longer OS or PFS from SOXIRI than from mFOLFIRINOX. In addition, the carbohydrate antigen (CA)19-9 decline was a good predictor for the efficacy and prognosis of both chemotherapy regimens. All grade adverse events were parallel in all kinds of toxicities except that anaemia was more common in the SOXIRI group than in the mFOLFIRINOX group (41.4% versus 24%, p = 0.03). The occurrence of any grade 3 to 4 toxicity was similar in the two groups.

Conclusions

For locally advanced or metastatic pancreatic cancer patients, the SOXIRI regimen had similar efficacy and controllable safety compared with the mFOLFIRINOX regimen.

Efficacy and safety of preoperative chemoradiotherapy with S-1 for advanced rectal cancer: a phase II study

Background

Preoperative chemoradiotherapy (CRT) for patients with rectal cancer is not yet established in Japan. We aimed to evaluate the efficacy and safety of preoperative CRT with S-1, a fixed-dose combination of tegafur, gimeracil, and oteracil potassium.

Materials and methods

We conducted a prospective, interventional, non-randomized single-center study. Radiotherapy was administered at a total dose of 45 Gy (1.8 Gy in 25 fractions) for five weeks. S-1 was administered orally for nine weeks (five weeks during and four weeks after radiotherapy) at a dose of 80 mg/m²/day. The endpoint was the pathological complete response (pCR) rate.

Results

Twenty-eight patients were finally enrolled. The following patient characteristics were recorded: clinical Stage (II: n = 12, III: n = 16), median age (66 years, range 40-77 years), male/female ratio (20/8), and lesion site (Ra-Rb:3/Rb:23/Rb-P:2). Preoperative treatment was completed in 27 patients (96%). Treatment abandonment occurred because of diarrhea. Grade 3 or higher adverse events were observed in one (4%) patient with two events. No serious adverse events occurred in the ≥ 70 years group. The response rate was 68% in all patients and 68% among elderly patients. Radical resection was achieved in all patients, including 19 (68%) who underwent sphincter-preserving surgery. The pCR rate was 11% (three patients). The five-year disease-free survival rate was 68%, and the overall survival rate was 82%. Local recurrence occurred in only one patient five years after surgery.

Conclusion

Preoperative CRT with S-1 alone may be a safe and acceptable regimen from the perspective of adverse events and oncological outcomes.

Trial registration

UMIN Clinical Trial Registry: UMIN000013598. Registered 1 April 2014, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recpt-no=R000015887.

Managing 5FU Cardiotoxicity in Colorectal Cancer Treatment

Fluorouracil (5FU) is the backbone chemotherapy agent in the treatment of colorectal cancer (CRC). Cardiotoxicity represents an uncommon but serious side effect of treatment with 5FU. Here, we review the current literature on 5FU-cardiotoxicity in the setting of CRC specifically, with a focus on data from the modern era of combination chemotherapy. Despite decades of study, there is little consensus on risk factors and biomarkers for 5FU-cardiotoxicity, nor how patients with CRC should be managed following a cardiotoxicity event. Given the elevated risk of recurrent cardiotoxicity on rechallenge, the use of alternative regimens that do not contain 5FU is a critical aspect of management. Data on the cardiotoxicity risk and efficacy of non-5FU regimens in CRC are therefore reviewed in detail.

Phase I study of DFP-11207, a novel oral fluoropyrimidine with reasonable AUC and low Cmax and improved tolerability, in patients with solid tumors

5-fluorouracil (5-FU) and 5-FU derivatives, such as capecitabine, UFT, and S-1, are the mainstay of chemotherapy treatment for gastrointestinal cancers, and other solid tumors. Compared with other cytotoxic chemotherapies, these drugs generally have a favorable safety profile, but hematologic and gastrointestinal toxicities remain common. DFP-11207 is a novel oral cytotoxic agent that combines a 5-FU pro-drug with a reversible DPD inhibitor and a potent inhibitor of OPRT, resulting in enhanced pharmacological activity of 5-FU with decreased gastrointestinal and myelosuppressive toxicities. In this Phase I study (NCT02171221), DFP-11207 was administered orally daily, in doses escalating from 40 mg/m2/day to 400 mg/m2/day in patients with esophageal, colorectal, gastric, pancreatic or gallbladder cancer (n = 23). It was determined that DFP-11207 at the dose of 330 mg/m2/day administered every 12 hours was well-tolerated with mild myelosuppressive and gastrointestinal toxicities. The pharmacokinetic analysis determined that the 5-FU levels were in the therapeutic range at this dose. In addition, fasted or fed states had no influence on the 5-FU levels (patients serving as their own controls). Among 21 efficacy evaluable patients, 7 patients had stable disease (33.3%), of which two had prolonged stable disease of >6 months duration. DFP-11207 can be explored as monotherapy or easily substitute 5-FU, capecitabine, or S-1 in combination regimens.

A case of primary ovarian signet-ring cell carcinoma treated with S-1/CDDP therapy

BACKGROUND

Primary ovarian signet-ring cell carcinoma is extremely rare, with only five recent case reports. Almost all reported cases of ovarian signet-ring cell carcinoma have been treated with TC therapy and none have reported regarding the use of S-1/CDDP therapy. We report a case of primary ovarian signet-ring cell carcinoma treated postoperatively with S-1/CDDP therapy.

CASE PRESENTATION

We describe a 55-year-old woman diagnosed with stage IB primary ovarian signet-ring cell carcinoma that was treated with S-1/CDDP therapy. Preoperative transvaginal ultrasonography and contrast-enhanced computed tomography (CT) revealed a solid tumor measuring 10 cm in diameter in the pelvis. The tumor marker levels were as follows: CA125, 41.6 U/mL; CA19-9, < 2.0 U/mL; and CEA, 2.2 ng/mL. Ovarian cancer was suspected, and total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were performed. The left ovary was enlarged to greater than fist-sized, and there was a small amount of clear yellow ascites. Histological examination of the left ovary led to the diagnosis of signet-ring cell carcinoma. Histological examination of the right ovary also showed the presence of a signet-ring cell carcinoma. After surgery, upper and lower gastrointestinal endoscopy and positron-emission tomography-CT were performed to search for a possible primary lesion, but none was found. The patient was diagnosed with primary ovarian signet-ring cell carcinoma with FIGO Stage IB (PT1b, NX, M0). As postoperative adjuvant chemotherapy, S-1/CDDP therapy (S-1120 mg/day/body × 14 days, CDDP 50 mg/m2 day 8, q 21 days) was administered for six cycles. There was no recurrence 27 months after the initial treatment.

CONCLUSIONS

We considered S-1/CDDP therapy was effective for primary ovarian signet-ring cell carcinoma. This is the first case report of primary ovarian signet-ring cell carcinoma treated with S-1/CDDP therapy in the world.

A Study of the S-1 or Capecitabine as First-line Regimen in Patients with Metastatic Colorectal Cancer: A Real World Study

Objectives: To compare the 2-year overall survival (OS) rate and safety between patients using S-1 and capecitabine in the first-treatment of metastatic colorectal cancer in the real clinical setting. Methods: In this retrospective cohort study, patients satisfying the following criteria were identified from 10 centers in China. The 2-year OS rate and safety were assessed. The propensity score matching (PSM) was used to control basic characteristics of the two groups to balance the processing bias and confoundings. Results: A total of 1367 patients were identified, 824 patients accepted capecitabine and 546 patients accepted S-1. After PSM, 533 eligible patients were included in each group without statistical significance in age, sex, BMI, KPS score and comorbidities. The 2-year OS rate between two groups was without significant statistical difference (61.9% vs. 62.9%, p=0.4295). The subgroup analysis showed that the 2-year OS rate had no significant difference between men and women, younger and older than 60 years old, different metastatic sites, different chemotherapy courses between S-1 and capecitabine groups. The hematological adverse events were all without statistical difference between two groups, but the incidence of diarrhea (16.4% vs. 23.6%, p=0.0018) and hand-foot syndrome (28.7% vs. 46.7%, p<0.001) in S-1 group were lower than those in the capecitabine group. Conclusions: Compared to capecitabine, S-1 had a similar 2-year OS rate but had a lower incidence of adverse events in the real clinical setting. So, S-1 could be a good choice in the first-treatment of patients with metastatic colorectal cancer in China.

Phase II study of S-1 on alternate days plus bevacizumab in patients aged ≥ 75 years with metastatic colorectal cancer (J-SAVER)

BACKGROUND

Alternate-day administration of S-1 is thought to reduce toxicities. This phase II study evaluated S-1 on alternate days combined with bevacizumab as first-line treatment for elderly patients with metastatic colorectal cancer.

PATIENTS AND METHODS

Eligible patients had histologically proven colorectal adenocarcinoma, measurable metastatic lesions, age ≥ 75 years, Eastern Cooperative Oncology Group performance status ≤ 1, no previous chemotherapy, and refused oxaliplatin- or irinotecan-containing regimens. Patients received 40 mg, 50 mg, or 60 mg (body surface area ≤ 1.25 m², > 1.25 to ≤ 1.50 m², or > 1.50 m², respectively) of S-1 twice orally on Sunday, Monday, Wednesday, and Friday every week. Bevacizumab (7.5 mg/kg) was administered every 3 weeks. The primary endpoint was progression-free survival.

RESULTS

Of 54 enrolled patients, 50 patients were evaluated for efficacy and 53 for safety. The median age was 79 years (range 75-88 years). The median progression-free survival was 8.1 months (95% confidence interval (CI) 6.7-9.5 months). The median overall survival was 23.1 months (95% CI 17.4-28.8 months). The response rate was 44% (95% CI 30.2-57.8%), and the disease control rate was 88% (95% CI 79.0-97.0%). Grade 3 or higher hematologic, non-hematologic, and bevacizumab-related adverse events occurred in 9%, 11%, and 25% of patients, respectively. The most common grade 3 and 4 treatment-related adverse events were hypertension (11%), nausea (6%), fatigue (6%), anemia (6%), and proteinuria (6%). Only 6 patients discontinued treatment due to adverse events.

CONCLUSION

S-1 on alternate days combined with bevacizumab showed better tolerability and comparable survival compared with the results of similar studies.

Phase II Study of the Triple Combination Chemotherapy of SOXIRI (S-1/Oxaliplatin/Irinotecan) in Patients with Unresectable Pancreatic Ductal Adenocarcinoma

LESSONS LEARNED

The triple combination chemotherapy of SOXIRI (S-1/oxaliplatin/irinotecan) in patients with unresectable pancreatic ductal adenocarcinoma was an effective treatment that appeared to be better tolerated than the widely used FOLFIRINOX regimen.SOXIRI regimen may provide an alternative approach for advanced pancreatic cancer.

BACKGROUND

In our previous phase I study, we determined the recommended dose of a biweekly S-1, oxaliplatin, and irinotecan (SOXIRI) regimen in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). This phase II study was conducted to assess the safety and clinical efficacy in patients with unresectable PDAC.

METHODS

Patients with previously untreated metastatic and locally advanced PDAC were enrolled. The primary endpoint was response rate (RR). Secondary endpoints were adverse events (AEs), progression-free survival (PFS), and overall survival (OS). Patients received 80 mg/m² of S-1 twice a day for 2 weeks in alternate-day administration, 150 mg/m² of irinotecan on day 1, and 85 mg/m² of oxaliplatin on day 1 of a 2-week cycle.

RESULTS

Thirty-five enrolled patients received a median of six (range: 2-15) treatment cycles. The RR was 22.8% (95% confidence interval [CI]: 10.4-40.1); median OS, 17.7 months (95% CI: 9.8-22.0); and median PFS, 7.4 months (95% CI: 4.2-8.4). Furthermore, the median OS in patients with distant metastasis was 10.1 months, whereas that in patients with locally advanced PDAC was 22.6 months. Major grade 3 or 4 toxicity included neutropenia (54%), anemia (17%), febrile neutropenia (11%), anorexia (9%), diarrhea (9%), and nausea (9%). There were no treatment-related deaths.

CONCLUSION

SOXIRI is considered a promising and well-tolerated regimen in patients with unresectable PDAC.

A Phase II study of S-1 plus oral leucovorin in heavily treated metastatic colorectal cancer patients

Purpose

Fewer treatment options are available for refractory metastatic colorectal cancer (mCRC). In early trials, S-1 monotherapy was effective for mCRC patients after chemotherapy failure and its combination with oral leucovorin therapy offers promising results in untreated mCRC. Hence, we conduct a Phase II trial to assess the efficacy of S-1 plus oral leucovorin (SL) in refractory mCRC that progressed after multiple prior standard therapies.

Methods

In this open-label, single-arm study, we enrolled the refractory mCRC patients who received fluoropyrimidine, oxaliplatin, and irinotecan treatment and at least one targeted therapy previously. The doses of SL were 40–60 and 30 mg twice daily separately. They were administered for 7 days in a 2-week cycle. Treatment was continued until disease progression.

Results

Of the 41 enrolled patients, 36 patients were evaluable with 61.1% disease control rate. The median progression-free survival and overall survival were 2.55 and 7.63 months, respectively. Regression change in tumor size stayed 10%–20% in five patients (13.9%) through 18 weeks after treatment, and two patients continued free from tumor progression at 30 and 42 weeks. Compared with moderate heavily pretreated mCRC patient subgroup (≤4 prior regimens), the severe heavily pretreated subgroup (≥5 prior regimens) showed similar disease control rate and survival benefit. Grade 3 or higher toxicities were documented only in 11 patients (26.8%).

Conclusion

SL shows potential as a salvage regimen in refractory mCRC patients especially in the severe heavily pretreated setting and is well tolerated in these patients.

Neoadjuvant S-1 with concurrent radiotherapy followed by surgery for borderline resectable pancreatic cancer: study protocol for an open-label, multicentre, prospective phase II trial (JASPAC05)

INTRODUCTION

Borderline resectable pancreatic cancer (BRPC) can involve the portal vein, superior mesenteric vein, superior mesenteric artery, coeliac axis or hepatic artery, and has a high probability of positive surgical margins and poor prognosis after resection. Neoadjuvant chemoradiation is expected to provide substantial local control and prolong survival in patients with BRPC.

METHODS AND ANALYSIS

This open-label, multicentre, prospective phase II trial will assess S-1 with concurrent radiotherapy as preoperative treatment for BRPC. Participants will receive S-1 (40 mg/m2 twice daily) and concurrent radiotherapy (50.4 Gy in 28 fractions), with restaging and surgery after 3-8 weeks. Recruitment will be for a 36-month period with a minimum 24-month follow-up. The primary endpoint is the R0 resection rate for BRPC confirmed with central review. The secondary endpoints are overall survival, disease-free survival, response rate to neoadjuvant chemoradiation, pathological response rate, 2-year survival rate, surgical morbidity rate and acute and late toxicity rates. Objectives include quantifying the number of participants per year to evaluate whether randomised trials can be performed for this rare tumour.

ETHICS AND DISSEMINATION

This trial has been approved by the National Cancer Center Institutional Review Board. Written informed consent will be obtained from all participants. Serious adverse events will be reported to the safety desk of the trial, the Data and Safety Monitoring Board and trial sites. Trial results will be submitted for peer-reviewed publication.

TRIAL REGISTRATION NUMBER

Pre-results, UMIN000009172.

Phase II study of S-1 plus leucovorin in patients with metastatic colorectal cancer: Regimen of 1 week on, 1 week off

A phase II study of S‐1 plus leucovorin (LV) given in a 4‐week schedule (2 weeks’ administration followed by 2 weeks’ rest) for patients with untreated metastatic colorectal cancer (mCRC) showed that the combination was effective, but grade 3 toxicities (diarrhea, stomatitis and anorexia) occurred at a relatively high rate. In this phase II study, we evaluated the efficacy and safety of a 2‐week schedule of S‐1 plus LV. Patients with mCRC received oral S‐1 (40–60 mg) and LV (25 mg) twice daily for 1 week, followed by 1 week's rest. Treatment was repeated until disease progression or unacceptable toxicity. The primary endpoint was response rate. The pharmacokinetics of S‐1 and LV in Chinese patients were evaluated on day 1 of the first cycle. Seventy‐three patients were enrolled in Japan and China. Of 71 eligible patients, the response rate was 53.5%, and the disease control rate was 83.1%. Median progression‐free survival and median overall survival were 6.5 and 24.3 months, respectively. The incidences of grade 3 toxicities were diarrhea 8.3%, stomatitis 8.3%, anorexia 2.8% and neutropenia 9.7%. There were no treatment‐related deaths. The pharmacokinetics profiles of S‐1 plus LV in Chinese patients were similar to those in Japanese patients. This 2‐week schedule of S‐1 plus LV showed good efficacy and better tolerability than the 4‐week schedule. This therapy will be the base regimen for mCRC to be added by other cytotoxic or molecular‐targeted drugs. The optimized treatment schedule for S‐1 plus LV was 1 week on and 1 week off.

Multicenter, randomized, open-label Phase II study comparing S-1 alternate-day oral therapy with the standard daily regimen as a first-line treatment in patients with unresectable advanced pancreatic cancer

PURPOSE

Non-inferiority for overall survival (OS) following alternate-day treatment with the oral anticancer drug S-1 compared with standard daily treatment was assessed in Japanese patients with unresectable advanced pancreatic cancer in a multicenter, randomized, phase II study. This trial was registered at the UMIN Clinical Trials Registry (no. 000008604).

METHODS

Chemotherapy-naïve patients with locally advanced or metastatic pancreatic cancer were randomly assigned 2:1 to treatment with alternate-day (twice daily on alternate days from days 1 through 42 of a 42-day cycle) or daily (twice daily on days 1 through 28 of a 42-day cycle) treatment with S-1. The primary endpoint was OS. Secondary endpoints were progression-free survival (PFS), time to treatment failure, response rate, quality of life assessments, and safety.

RESULTS

A total of 190 patients were enrolled, of which 185 were included in the final analysis (alternate-day: 121; daily: 64). Median OS was 9.4 for the alternate-day group and 10.4 months for the daily group [hazard ratio (HR), 1.19; 95% credible interval, 0.86 to 1.64], indicating that non-inferiority of alternate-day treatment to daily treatment was not demonstrated. Median PFS was 3.0 for the alternate-day group and 4.2 months for the daily group (HR, 1.65; 95% credible interval, 1.20-2.29). The incidence of anorexia, fatigue, neutrophils, pigmentation, and pneumonitis was lower in alternate-day treatment compared with daily treatment.

CONCLUSION

S-1 for advanced pancreatic cancer should be taken daily as recommended, based on the decreased OS and PFS and marginal improvement in safety observed in the alternate-day group.

S-1 monotherapy in a patient with cholangiolocellular carcinoma: A case report

A 71-year-old man with alcoholic cirrhosis was found to have multiple hypervascular lesions in the liver on enhanced computed tomography. An ultrasound-guided biopsy of the lesion was performed. Immunohistochemical analysis for hepatocyte paraffin 1 expression was negative; cytokeratin (CK) 7, CK19, epithelial cell adhesion molecule and epithelial membrane antigens were positive; mucicarmine staining was negative. The tumor was thus histologically diagnosed as cholangiolocellular carcinoma (CoCC). The tumor was inoperable due to the associated advanced liver disease. In addition, the patient preferred systemic chemotherapy using only orally administered agents. Thus, S-1 monotherapy was recommended. S-1 was initially administered orally at a dose of 80 mg/day. Although the levels of tumor marker (prothrombin induced by vitamin K absence/antagonist-II and carbohydrate antigen 19-9) levels were marginally elevated, their values did not change over the entire course. The patient achieved a partial response according to the Response Evaluation Criteria In Solid Tumors (RECIST) and modified RECIST 1 year after chemotherapy initiation. In conclusion, S-1 monotherapy exhibited promising efficacy against unresectable CoCC.

Efficacy and safety of oxaliplatin, bevacizumab and oral S-1 for advanced recurrent colorectal cancer

The aim of this study was to evaluate the efficacy and safety of co-administration of oral S-1 and oxaliplatin (SOX) in combination with bevacizumab (bev) in patients with advanced recurrent colorectal cancer. A retrospective study of 36 patients with advanced recurrent colorectal cancer was performed, of whom 27 received first-line and 9 received second-line SOX+bev chemotherapy between 2010 and 2013 at the Hachioji Digestive Disease Hospital (Hachioji, Japan). The SOX+bev regimen consisted of administration of intravenous oxaliplatin (85 mg/m²) on days 1 and 14, bevacizumab (5 mg/kg) on day 1, and co-administration of oral S-1 twice daily on days 1-14. The drug regimen was repeated every 4 weeks. SOX+bev treatment was associated with a response rate of 45.2%, a disease control rate of 71%, and a median progression-free survival (PFS) and overall survival (OS) of 9.9 and 21.9 months, respectively. Patients who received first-line chemotherapy benefited from treatment in terms of prolonged PFS (13.8 months) and OS (28.2 months). Grade 3/4 adverse events were infrequent and included anaemia, thrombocytopenia, anorexia, diarrhea, sensory neuropathy, increased aspartate aminotransferase level and skin rash. In conclusion, SOX+bev therapy was found to be feasible and safe for patients with advanced and recurrent colorectal cancer.

Phase I Clinical Study of Irinotecan Plus S-1 in Patients With Advanced or Recurrent Cervical Cancer Previously Treated With Platinum-Based Chemotherapy

OBJECTIVES

This study aimed to determine the maximum tolerated dose and acute dose-limiting toxicities (DLTs) of intravenous irinotecan plus oral S-1 in patients with advanced or recurrent uterine cervical cancer.

METHODS

Irinotecan was administered intravenously over the course of 90 minutes on day 1, and S-1 was given orally in 2 divided doses from days 1 to 14 of a 21-day cycle. The dose of S-1 was escalated in a stepwise fashion from 40 (level 1) to 60 mg/m (level 2) and then 80 mg/m (level 3), whereas the dosage of irinotecan remained the same (150 mg/m). The primary end point for the escalation study was acute DLT that occurred within 2 cycles of chemotherapy.

RESULTS

Twelve patients were enrolled and treated over 3 dose levels. Their median age was 47 years (range, 28-48 years). At level 1, one episode of grade 3 anemia and a grade 3 fatigue were observed, but no DLT developed. At level 2, the first patient experienced febrile neutropenia, which was considered to be a DLT. To evaluate the toxicity of this dose level, 5 more patients were evaluated. However, no DLT developed in these patients. At level 3, although grade 1 to 2 hematological and nonhematological toxicities developed, no DLT occurred.

CONCLUSIONS

In women with advanced or recurrent cervical cancer previously treated with platinum-based chemotherapy, S-1 plus irinotecan in a triweekly setting is a reasonable treatment regimen with an acceptable toxicity profile. The recommended doses of S-1 and irinotecan for this regimen are 80 and 150 mg/m, respectively.

Phase 1 study on S-1 and oxaliplatin therapy as an adjuvant after hepatectomy for colorectal liver metastases

of Background Data The effectiveness of adjuvant chemotherapy in patients with stage II/III colorectal cancer has been confirmed in various studies. However, no adjuvant chemotherapy for colorectal liver metastasis (CLM) classified to stage IV has been established. Objectives We conducted a phase 1 study of S-1 and oxaliplatin to determine the recommended dose (RD) in patients with CLM as adjuvant therapy in two institutes. Methods S-1 and oxaliplatin were administered from day 1 to day 14 of a 3-week cycle as a 2-h infusion every 3 weeks, respectively. The initial doses of S-1 and oxaliplatin were fixed to 80 mg/m(2) and 100 mg/m(2), respectively (level 1). We scheduled in the protocol a dose change of S-1 and oxaliplatin to level 2 (S-1: 80 mg/m(2) and oxaliplatin: 130 mg/m(2)) or level 0 (S-1: 65 mg/m(2) and oxaliplatin: 100 mg/m(2)) depending on the incidence of dose-limiting toxicity (DLT) at level 1 in six patients. Results Because DLT occurred in one among the initial six patients at level 1, the doses were increased to level 2 in the next six patients. At level 2, grade 3 leukopenia and neutropenia occurred in one (16.7 %) and two (33.3 %) patients, respectively, in the absence of non-hematological event. Because no DLT occurred at level 2, we suggest that the RD can be set to the level 2 dose. The median number of cycles delivered at RD was 8. The mean relative dose intensity of S-1 and oxaliplatin at RD was 0.90 and 0.63, respectively. Conclusion In a patient undergoing hepatectomy for CLM, 80 mg/m(2) of S-1 and 130 mg/m(2) of oxaliplatin are recommended as adjuvant therapy. A further study is required to confirm the efficacy and safety of this regimen on a larger scale.

Adjuvant chemotherapy for colon cancer: the difference between Japanese and western strategies

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer in the western world and also in Japan. The key factors in curing CRC are early detection, surgery and adequate adjuvant chemotherapy if needed.

AREAS COVERED

Based on the results of following pivotal adjuvant trials, FOLFOX or XELOX are considered standard adjuvant chemotherapy for patients with stage III colon cancer in the western countries. On the other hand, 5-FU based monotherapies showed favorable results as adjuvant chemotherapy in Japan providing comparable results to doublet strategies in the western countries. There are two key factors that could provide better outcome: D3 lymph node dissection (LND) and thorough pathological examinations.

EXPERT OPINION

I believe that oxaliplatin based adjuvant chemotherapy may not be suitable for at least substage IIIA patients who underwent D3 surgery and were diagnosed by thorough pathological examinations for the following two reasons: toxicities and strongly stage-dependent added benefit of oxaliplatin in overall survival. We are awaiting the final results of three Japanese ongoing trials focusing on oxaliplatin based adjuvant chemotherapy. These results will hopefully help us create and implement global guidelines for truly standardizing the management of colon cancer prevalent all over the world, and help physicians recommend the treatment strategy available to each patient.

A prospective feasibility study to evaluate neoadjuvant-synchronous S-1 with radiotherapy for locally advanced rectal cancer: A multicentre phase II trial

Treatment results of locally advanced rectal cancer without preoperative chemoradiotherapy (CRT) in Japan do not differ from those of Western countries. Preoperative CRT with new anticancer agents may decrease local recurrence rate and prevent distant metastases, thus improving survival. We conducted a trial to evaluate feasibility of neoadjuvant CRT using S-1 in patients with locally advanced rectal cancer. A multi-institutional (17 specialized centres), interventional, phase II trial was conducted from April 2009 to August 2011. Patients fulfilling the following requirements before neoadjuvant CRT were included: histologically proven rectal carcinoma; tumour in the upper or lower rectum; cancer classified as T3-4 N0-3 M0. Neoadjuvant CRT with S-1 (80 mg/m²/day on days 1-5, 8-12, 22-26, and 29-33) and irradiation (total 45 Gy/25 fr, 1.8 Gy/day, on days 1-5, 8-12, 15-19, 22-26, and 29-33) was performed. Total mesorectal excision with D3 lymphadenectomy was performed during weeks 4 and 8 after completion of neoadjuvant CRT. The primary endpoint was completion rate of neoadjuvant CRT. Secondary endpoints were response rate to neoadjuvant CRT, short-term clinical outcomes, curative resection rate, and pathologic response (grade 2/3). Of the 37 patients included, 86.5% completed neoadjuvant CRT (95% CI, 75.5-97.5%), and 10.8% (4) experienced an adverse event (grade 3/4). Response rate (RECIST 1.0) was 56.8% (95% CI, 40.8-72.7%), and pathologic response rate was 48.6% (95% CI, 32.5-64.8%). This study demonstrated that neoadjuvant-synchronous S-1+radiotherapy for locally advanced rectal cancer was feasible in terms of pathologic response and adverse events. Registration number: UMIN-CTR, No. C003396.

Phase II study of oxaliplatin combined with S-1 and leucovorin (SOL) for Chinese patients with metastatic colorectal cancer

BACKGROUND

Fluoropyrimidine and oxaliplatin are widely used for patients with colorectal cancer. This phase II study was conducted to evaluate the efficacy and safety of the combination of S-1, oxaliplatin, and leucovorin (SOL) in the treatment of Chinese patients with metastatic colorectal cancer (mCRC).

METHODS

Eligible patients with untreated mCRC from four hospitals in China received intravenous oxaliplatin (85 mg/m(2)) on day 1, oral S-1 twice daily (80-120 mg per day) on day 1-7, and leucovorin twice daily (50 mg per day) simultaneously with S-1, every 2 weeks.

RESULTS AND DISCUSSION

Forty patients were enrolled in our study. In total, 296 cycles of SOL were administered. The overall response rate was 50.0%. At a median follow-up of 27 months, progression-free survival and overall survival were 7.0 months (95% confidence interval [CI] 6.0-10.6 months) and 22.2 months (95% CI 15.1-29.3 months), respectively. The most common grade 3/4 non-hematological adverse events were diarrhea (n = 8, 20.0%), nausea (n = 3, 7.5%), and vomiting (n = 3, 7.5%). The most common grade 3/4 hematological toxicities were thrombocytopenia (n = 3, 7.5%), neutropenia (n = 1, 2.5%), and abnormal alanine transaminase/aspartate transaminase levels (n = 1, 2.5%). There was one treatment-related death.

CONCLUSIONS

The data indicate that the SOL regimen is effective and moderately tolerated in Chinese patients with mCRC.

TRIAL REGISTRATION

CLINICAL TRIAL INFORMATION

ChiCTR-TNRC-100000838.

Evaluation of Thymidylate Synthase Expression in Prostate Cancer

Thymidylate synthase (TS), a key enzyme in DNA synthesis, is over-expressed in a variety of cancer cells. 5-Fluorouracil, an anticancer agent clinically used against various cancers, including prostate cancer, inhibits DNA synthesis by binding TS. In this study, we investigated expression of TS in prostate cancer and its prognostic significance. Seventy-five prostatic tissue specimens were obtained from patients who had undergone prostate biopsy for diagnosis of prostate cancer. We analyzed the cancerous tissue specimens for TS expression using immunohistochemistry. TS expression was significantly increased in patients with bone metastasis. No relationship was found between expression of TS and the other clinicopathological findings. Because TS expression could be used as a prognostic parameter in patients with prostate cancer, an accurate prediction of prognosis might help to select patients for more intensive surgical, hormonal, or chemotherapeutic approaches, including 5-fluorouracil. Additional prospective studies are warranted to define the role of TS in selecting patients for adjuvant therapy for prostate cancer.

A Muti-center, Randomized Phase II Study of Oxaliplatin and S-1 versus Capecitabine and Oxaliplatin in Patients with Metastatic Colorectal Cancer

Background: Capecitabine plus oxaliplatin (XELOX) is considered one of the primary chemotherapy regimens for patients with metastatic colorectal cancer (CRC). Oxaliplatin plus S-1 (OS) has also demonstrated significant efficacy in CRC. We performed this randomized phase II study to evaluate the efficacy and toxicity of XELOX versus OS as first-line chemotherapy in patients with metastatic CRC.

Methods: Patients were assigned randomly to receive either OS or XELOX chemotherapy. Oxaliplatin was administered intravenously to all patients at a dose of 130 mg/m² on day 1. Patients received either S-1 (40 mg/m²) or capecitabine (1,000 mg/m²), twice a day for 2 weeks, followed by a 1-week rest.

Results: Forty-two patients were assigned to the OS arm and 44 to the XELOX arm. The overall response rate was 33.3% (95% CI, 18.8-47.2) in the OS arm and 40.9% (95% CI, 25.5-54.4) in the XELOX arm (P = 0.230). The disease control rate was significantly higher in the OS arm than the XELOX arm [92.9% (95% CI, 83.7-100) versus 77.3% (95% CI, 64.5-89.4), P = 0.044]. With a median follow up of 17.9 months, the median progression-free survival was 6.1 months in the OS arm and 7.4 months in the XELOX arm, respectively (P = 0. 599). The median survival time was 18.7 months in the OS arm and 20.1 months in the XELOX arm (P = 0.340). The most common grade 3/4 hematologic toxicity was thrombocytopenia in both arms (19.0% for OS and 28.6% for XELOX). Grade 3/4 neutropenia was observed more frequently in the XELOX arm than the OS arm (16.7% vs. 2.4%, P = 0.026).

Conclusion: Both OS and XELOX were effective and well tolerated in patients with metastatic CRC. Our results indicate that the combination of oxaliplatin and S-1 is a possible additional therapeutic strategy for such patients.

A meta-analysis of safety and efficacy on first-line S-1 therapy in cancer patients

BACKGROUND

The incidence of grade 3/4 adverse effects due to S-1 therapy and the efficacy of S-1-based therapy vs. S-1 monotherapy have not been well described. We conducted an updated meta-analysis to evaluate this problem.

METHODS

We searched the electronic databases, including PubMed, Embase, and Cochrane database to investigate the effects of phase 2 and 3 prospective clinical trials on first-line S-1 therapy in cancer patients. Data from included studies were pooled using Stata version 12.0.

RESULTS

Twenty eight studies were included. First-line S-1 monotherapy showed low incidence of grade 3/4 adverse effects. And the highest rate grade 3/4 hematological event was neutropenia [7%, 95% confidence interval (CI): 5-8%]; the highest rate grade 3/4 non-hematological event was anorexia (7%, 95% CI: 6-9%). Longer overall survival (OS) time and progression-free survival (PFS) time was exhibited in S-1-based therapy, compared with S-1 monotherapy [hazard ratio (HR) 0.836, 95% CI: 0.761-0.911, P=0.000, and HR 0.650, 95% CI: 0.540-0.759, P=0.000, respectively]. However, the incidence of grade 3/4 adverse effects was also higher in S-1-based therapy than S-1 monotherapy in cancer patients, with relative risk (RR) of neutropenia and anorexia were respectively 4.62 (95% CI: 2.92-7.30) and 1.46 (95% CI: 0.84-2.55).

CONCLUSIONS

S-1 monotherapy was demonstrated with low incidence of high grade adverse effects, therefore it is well tolerated for majority cancer patients; S-1-based therapy significantly improved OS and PFS compared with S-1 monotherapy, with an increased risk of high grade adverse effects.

Phase I trial of combination chemotherapy with gemcitabine, cisplatin, and S-1 in patients with advanced biliary tract cancer

AIM: To evaluate the dose-limiting toxicities (DLTs) and determine the maximum-tolerated dose (MTD) and recommended dose (RD) of combination chemotherapy with gemcitabine, cisplatin and S-1 which is an oral fluoropyrimidine pro-drug in patients with advanced biliary tract cancer.

METHODS: Patients with histologically or cytologically confirmed unresectable or recurrent biliary tract cancer were enrolled. The planned dose levels of gemcitabine (mg/m²), cisplatin (mg/m²), and S-1 (mg/m² per day) were as follows: level -1, 800/20/60; level 0, 800/25/60; level 1, 1000/25/60; and level 2, 1000/25/80. In each cycle, gemcitabine and cisplatin were administered intravenously on days 1 and 15, and S-1 was administered orally twice daily on days 1 to 7 and days 15 to 21, every 4 wk.

RESULTS: Twelve patients were enrolled, and level 0 was chosen as the starting dose. None of the first three patients had DLTs at level 0, and the dose was escalated to level 1. One of six patients had DLTs (grade 4 febrile neutropenia, leucopenia, and neutropenia; grade 3 thrombocytopenia) at level 1. We then proceeded to level 2. None of three patients had DLTs during the first cycle. Although the MTD was not determined, level 2 was designated at the RD for a subsequent phase II study.

CONCLUSION: The RD was defined as gemcitabine 1000 mg/m² (days 1, 15), cisplatin 25 mg/m² (days 1, 15), and S-1 80 mg/m² per day (days 1-7, 15-21), every 4 weeks. A phase II study is planned to evaluate the effectiveness of combination chemotherapy with gemcitabine, cisplatin, and S-1 in advanced biliary tract cancer.

The SOFT trial: a Phase III study of the dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine S-1 and oxaliplatin (SOX) plus bevacizumab as first-line chemotherapy for metastatic colorectal cancer

ABSTRACT 

A combination of oxaliplatin, leucovorin and 5-fluorouracil (FOLFOX) plus bevacizumab has been widely used for the first-line chemotherapy of metastatic colorectal cancer (mCRC). S-1 is an oral fluoropyrimidine preparation that combines tegafur, a prodrug of 5-fluorouracil, with two modulators. Several studies of combination chemotherapy with oxaliplatin plus S-1 (SOX) conducted in Asia have reported promising efficacy and safety in patients with mCRC, suggesting the potential to replace mFOLFOX6. The SOFT trial (JapicCTI-090699) was a randomized Phase III trial designed to evaluate the noninferiority of SOX plus bevacizumab to mFOLFOX6 plus bevacizumab in patients with mCRC. This review summarizes the drug concept of S-1 and the results of clinical trials of S-1 and SOX in CRC and presents an overview of the SOFT trial.

Combination chemotherapy with bevacizumab and S-1 for elderly patients with metastatic colorectal cancer (BASIC trial)

BACKGROUND

Chemotherapeutic regimens for elderly patients with metastatic colorectal cancer (mCRC), such as bevacizumab combined with 5-fluorouracil (5-FU) and leucovorin, often exclude oxaliplatin and irinotecan owing to the risk of toxicity. However, treatment with infusional 5-fluorouracil and leucovorin requires percutaneous port-catheter placement and other precautions, causing unnecessary stress for patients as well as healthcare workers.

METHODS

We conducted a phase II study to evaluate the efficacy and safety of bevacizumab plus S-1 in elderly patients with previously untreated mCRC. Bevacizumab was given intravenously every two weeks, and S-1 was administered orally on days 1-28 of a 42-day cycle. The primary end-point was progression-free survival (PFS). The secondary end-points were time to treatment failure, response rate (RR), overall survival (OS), treatment completion status and safety.

RESULTS

From October 2007 through March 2010, 56 patients were enroled. The median PFS was 9.9months, the median OS was 25.0months, and the RR was 57%. The main adverse events of grade 3 or higher were hypertension (11%), diarrhoea (9%) and neutropenia (7%).

CONCLUSION

Our results suggest that combination chemotherapy with S-1 and bevacizumab can be administered safely and continuously on an outpatient basis and is therapeutically effective in elderly patients with mCRC.

A Phase II Trial of Combined Chemotherapy with Oral S-1 and 24-Hour Infusions of Irinotecan plus Bevacizumab in Patients with Metastatic Colorectal Cancer

OBJECTIVES

Protracted low-dose infusion of irinotecan has been suggested to enhance antitumor activity. A phase II study was conducted to evaluate the safety and efficacy of oral S-1 combined with 24-hour infusion of irinotecan and intravenous bevacizumab for metastatic colorectal cancer (MCRC).

METHODS

The subjects were 79 patients with MCRC; 57 were chemotherapy naïve. Irinotecan (125 mg/m(2)) was administered as a 24-hour infusion on days 1 and 15, S-1 (80 mg/m(2)) was administered orally on days 1-14, and bevacizumab (5.0 mg/kg) was given on days 1 and 15. The treatment was repeated every 4 weeks.

RESULTS

Median follow-up was 20.0 months, and the mean number of cycles was 7. The overall response rate was 79.7% (95% CI, 69.2-88.0), 86.0% (95% CI, 74.2-93.7) for first-line and 63.6% (95% CI, 40.7-82.8) for second-line treatment. The median progression-free survival was 16.4 months (95% CI, 13.9-21.0) for first-line and 9.4 months (95% CI, 4.9-16.5) for second-line treatment. The median overall survival was not reached. Grade 3-4 toxicities were neutropenia (43%), leukopenia (20.3%), anorexia (19.0%), and diarrhea (10.1%). Toxicity was tolerable.

CONCLUSIONS

Combination chemotherapy with oral S-1 and biweekly 24-hour infusions of irinotecan plus bevacizumab appears to be highly active and well tolerated both as first-line and second-line chemotherapy for MCRC.

Efficacy of S-1 in colorectal cancer

INTRODUCTION

S-1 is an oral fluoropyrimidine that consists of tegafur, 5-chloro-2, 4-dihydroxypyridine and potassium oxonate. It has been developed as a prodrug of 5-fluorouracil with the goal of improving therapeutic efficacy and tolerability.

AREAS COVERED

This review aims to provide an evidence-based update of clinical trials that have investigated the clinical efficacy, adverse-event profile, dosage and administration of S-1, given alone or in combination with conventional chemotherapeutics and new target-oriented drugs, in the management of colorectal cancer (CRC). Additionally, differences in the tolerability and pharmacokinetics of S-1 between Caucasians and Asians have been described. Finally, the therapeutic efficacy of S-1 regarding metastatic CRC or postoperative CRC has been discussed. Available data have stimulated further research, including Phase III trials for the treatment of advanced CRC.

EXPERT OPINION

Treatment using S-1 combined with oxaliplatin (± bevacizumab) and irinotecan has achieved promising results in terms of feasibility, safety and effectiveness. Furthermore, S-1 is an acceptable treatment as adjuvant chemotherapy for colon cancer.

Safety and pharmacokinetics of S-1 in a recurrent colon cancer patient with chronic myeloid leukemia treated with dasatinib: a case report

PURPOSE

The safety of S-1 in recurrent colorectal cancer patients with chronic myeloid leukemia (CML) treated with dasatinib has not been established. We evaluated the safety and pharmacokinetics of S-1 in a recurrent colon cancer patient with CML treated with dasatinib.

PATIENT

A 70-year-old man had undergone surgery three times for sigmoid colon cancer and recurrence. Systemic chemotherapy with S-1 plus oxaliplatin plus bevacizumab as a clinical trial had already been administered because of metastatic colon cancer. The patient's medical history was CML, and he had been receiving dasatinib treatment (100 mg once daily). Based on the diagnosis of unresectable and multiple metastases, S-1 monotherapy was started. S-1 (120 mg/day) was taken for 28 consecutive days, followed by a 14-day rest. Blood samples were obtained before and after the first administration of S-1. The plasma pharmacokinetics of S-1 were comparable to a pharmacokinetics study of S-1.

RESULTS

The area under the plasma concentration-time curve (AUC0-8) of tegafur (FT), 5-chloro-2, 4-dihydroxypyridine (CDHP), oxonate (Oxo), and 5-fluorouracil (5-FU) was 4,309.2, 716.3, 86.8, and 492.75 ng h/mL, respectively, after S-1 administration. The pharmacokinetics of FT, CDHP, Oxo, and 5-FU after treatment with S-1 were not significantly different from a phase I pharmacokinetics study of S-1. During treatment with S-1 and dasatinib, CML relapse and serious myelosuppression were not observed.

CONCLUSIONS

Our report suggests that S-1 is an important treatment option for recurrent colorectal cancer in patients with CML treated with dasatinib.

Thymidine phosphorylase mRNA expression may be a predictor of response to post-operative adjuvant chemotherapy with S-1 in patients with stage III colorectal cancer

The aim of the present study was to investigate markers in surgically resected specimens of colorectal cancer that can be used to predict the response to chemotherapy. The mRNA expression levels of enzymes involved in 5-fluorouracil (5-FU) metabolism and folate metabolism were measured in formalin-fixed, paraffin-embedded tumor sections obtained from the primary tumors of 54 patients with resected stage II or III colorectal cancer who received S-1 for one year. The 5-FU metabolizing enzymes studied were thymidylate synthase, dihydropyrimidine dehydrogenase and thymidine phosphorylase (TP). The folate metabolizing enzymes studied were folypolyglutamate synthetase, γ-glutamyl hydrolase and dihydrofolate reductase. The associations between the mRNA expression levels of these enzymes and clinical variables were investigated. Tumors were classified as exhibiting high or low expression as compared with the median mRNA expression level of each metabolizing enzyme defined as the cutoff value. The associations between the high and low expression levels of each enzyme and disease-free survival (DFS) were analyzed with the use of Kaplan-Meier curves and the log-rank test. DFS was not significantly associated with the relative mRNA expression level of any metabolizing enzyme in the study group as a whole, but there was a trend toward longer DFS in patients with high TP expression (P=0.066). In patients with stage III colorectal cancer, high TP expression was associated with significantly improved outcomes compared with low TP expression (P=0.039). These results indicate that the mRNA expression of TP, a metabolizing enzyme of 5-FU, is a significant predictor of response to post-operative chemotherapy with S-1 in patients with stage III colorectal cancer.

Phase I/II trial of irinotecan and S-1 combination chemotherapy as a second-line treatment for advanced colorectal cancer

BACKGROUND

This study attempted to determine the therapeutic dosage of irinotecan and S-1 (IRIS) as a second-line treatment for colorectal cancer (CRC).

METHODS

S-1 was administered on days 1-14 of a 28-day cycle. Irinotecan was administered on days 1 and 15. The irinotecan dose was then escalated to determine the maximum-tolerated dose and the recommended dose at a fixed dosage of S-1 (80 or 65 mg·m(-2)·day(-1)). The S-1 dose was reduced to 65 mg·m(-2)·day(-1) when dose-limiting toxicities were observed at 80 mg·m(-2)· day(-1) and the irinotecan dose was increased.

RESULTS

The recommended dose was 65 mg/m(2) for S-1 and 75 mg/m(2) for irinotecan. Twenty-one patients were treated at the recommended dose. The overall response rate was 28.6%.

CONCLUSION

This modified IRIS regimen is considered effective with acceptable toxicities for advanced CRC resistant to treatment with 5-fluorouracil/leucovorin or uracil and tegafur/leucovorin.

Role of aflibercept in the treatment of advanced colorectal cancer

SUMMARY Colorectal cancer is the third most common cancer in men, representing 10% of cases, and the second most common cancer in women, representing 9.4% of cases, worldwide. It is estimated that 50–60% of patients will develop metastases during the course of their disease, while 15–25% will present with synchronous metastatic lesions, reducing the probability of 5-year survival to 12%. Colon cancer represents the fourth most common cause of death from cancer worldwide and the second most common cause in developed countries. First-line therapy of advanced or metastatic colorectal carcinoma (mCRC) usually consists of the administration of oxaliplatin or irinotecan in combination with leucovorin and 5-fluorouracil. In the first- or second-line settings, monoclonal antibodies can be added to chemotherapy. Bevacizumab (anti-VEGF monoclonal antibody) is utilized with fluoropyrimidine-containing regimens in combination with oxaliplatin or irinotecan. Cetuximab can be administered in combination with irinotecan or as a single agent in patients who have wild-type KRAS. Panitumumab has also been approved for third-line single-agent therapy in KRAS wild-type patients and recently in first- and second-line therapy in combination with chemotherapy. There are no standard second-line treatments of mCRC specifically used in combination with FOLFIRI, and no drugs have been approved for patients with prior bevacizumab treatment. Aflibercept is a new angiogenesis inhibitor with a unique mechanism of action. Aflibercept is a recombinant fusion protein consisting of VEGF-binding portions from extracellular domains of the human VEGFR1 and 2 fused to the Fc portion of human IgG1. Aflibercept acts as a soluble decoy receptor that binds to VEGF-A with higher affinity than its native receptors, as well as the related ligands PIGF and VEGF-B. Aflibercept interferes with the biological actions of VEGF by ‘trapping’ VEGF and preventing it from interacting with its receptors on endothelial cells, blocking the activation of VEGFRs and the subsequent proliferation of endothelial cells; this results in inhibition of the growth of new vessels. The role of aflibercept in the management of mCRC was studied in the VELOUR trial, which showed that its addition to the FOLFIRI regimen resulted in a survival benefit, giving a statistically significant log-rank test with p = 0.0032 (hazard ratio: 0.817; 95.34% CI: 0.713–0.937). This benefit was supported by subgroup and sensitivity analyses, the increased median progression-free survival, and improved response rates observed in the aflibercept arm. Aflibercept toxicity is acceptable, manageable and within the established range of other VEGF inhibitors.

Phase I study of nedaplatin prior to S-1 in patients with locally advanced head and neck squamous cell carcinoma

BACKGROUND

We previously reported on the regimen of S-1 plus nedaplatin (NDP), with S-1 was administered orally for 14 days and NDP intravenously on day 8. The maximum tolerated dose (MTD) of NDP was determined to be 90 mg/m². The main toxicities were neutropenia and thrombocytopenia. This result was tolerated, but we believe there is a more effective and tolerable regimen. Thus, we investigated the S-1 regimen administered orally for 14 days, and NDP intravenously on day 1 in patients with locally advanced head and neck squamous cell carcinoma.

PATIENTS AND METHODS

Oral administration of S-1 (days 1-14) and intravenous NDP (day 1) were tested for patients with advance head and neck cancer in a phase I setting. The dose of S-1 was fixed and the dose of NDP was escalated from 70 mg/m², with an increase of 10 mg/m² per step, to find the MTD.

RESULTS

A total of 15 patients were registered. The MTD of NDP was determined to be 100 mg/m². The main toxicities were neutropenia and thrombocytopenia. The response rate (RR) was 57.1%.

CONCLUSIONS

The recommended dose of NDP for a phase II study was determined to be 100 mg/m². We concluded that our regimen was well tolerated and that the RR was acceptable.

Phase I clinical and pharmacokinetic/pharmacogenetic study of a triplet regimen of S-1/irinotecan/oxaliplatin in patients with metastatic colorectal or gastric cancer

PURPOSE

We conducted a phase I study of S-1 combined with irinotecan and oxaliplatin (TIROX) to determine the maximum-tolerated dose (MTD) and recommended dose (RD) and to assess its safety, pharmacokinetics, pharmacogenetics, and preliminary efficacy in patients with metastatic colorectal cancer (MCRC) or metastatic gastric cancer (MGC).

METHODS

Patients received escalating doses of S-1 (30-40 mg/m² b.i.d.) orally on days 1-14, an escalating dose of intravenous irinotecan (120-150 mg/m²) on day 1, and a fixed dose of intravenous oxaliplatin (85 mg/m²) on day 1 every 3 weeks.

RESULTS

Twenty-three patients (10 MCRC, 13 MGC; 13 chemonaive, 10 previously treated for metastatic disease) were treated across six dose levels. Because only one patient experienced a dose-limiting toxicity of grade 3 anorexia at the highest dose level (S-1 40 mg/m² b.i.d., irinotecan 150 mg/m², and oxaliplatin 85 mg/m²) (n = 8), the MTD was not obtained, and this level was established as the RD. With a median of 10 cycles per patient, the most common grade 3 or 4 adverse events included neutropenia (43 %), diarrhea (13 %), and nausea (13 %). In 22 efficacy-evaluable patients, the objective tumor response rate was 59.1 % (75 % for both MCRC and MGC in the first-line setting) and the disease control rate was 100 %. The exploratory pharmacokinetic/pharmacogenetic study showed that CYP2A6 variants (*4, *7, *9) are associated with a lower metabolic ratio of S-1 (exposure ratio of 5-fluorouracil to tegafur).

CONCLUSIONS

The new triplet TIROX regimen has shown promising antitumor activity and a favorable toxicity profile in patients with MCRC and MGC.

A phase II study of cisplatin /S-1 in patients with carcinomas of unknown primary site

BACKGROUND

Carcinomas of unknown primary site (CUPs) are heterogeneous tumors associated with a poor prognosis. This phase II trial was designed to evaluate the efficacy and safety of a novel combination chemotherapy of S-1 and cisplatin (CDDP) in patients with CUP.

PATIENTS AND METHODS

Patients with previously untreated CUPs were eligible for this trial. The treatment schedule consisted of oral S-1 (40 mg/m(2)) twice a day on days 1-21, and intravenous CDDP (60 mg/m(2)) on day 8. This schedule was repeated every 5 weeks.

RESULTS

A total of 46 patients were enrolled. The overall response rate and the disease control rate were 41.3% and 80.4%, respectively. The median overall survival time was 17.4 months. Grade 3/4 neutropenia, thrombocytopenia, and febrile neutropenia occurred in 28.3%, 13.0%, and 2.2% of the patients, respectively.

CONCLUSION

CDDP plus S-1 combination chemotherapy is well tolerated and active first-line empiric therapies for patients with CUP.

Phase I study of oral S-1 and concurrent radiotherapy in patients with head and neck cancer

This study investigated the maximum tolerated dose (MTD) of S-1 with concurrent radiotherapy in patients with head and neck cancer, based on the frequency of dose-limiting toxicities (DLT). S-1 was administered orally at escalating doses from 40 mg/m(2) b.i.d. on the days of delivering radiotherapy, which was given at a total dose of 64-70 Gy in 32-35 fractions over 6-7 weeks. A total of 12 patients (3 patients at 40 mg/m(2), 6 patients at 60 mg/m(2), and 3 patients at 80 mg/m(2)) were enrolled in this trial. At the dose of 80 mg/m(2), two of the three patients developed DLT (Grade 3 anorexia and rhabdomyolysis) due to S-1, so the MTD was determined to be 80 mg/m(2). Among the 12 enrolled patients, 9 (75%) showed a complete response and 3 (25%) showed a partial response. The overall response rate was 100%. The recommended dose of S-1 with concurrent radiotherapy is 60 mg/m(2).

Multicenter Phase II Study of a New Effective S-1 and Irinotecan Combination Schedule in Patients with Unresectable Metastatic or Recurrent Colorectal Cancer

INTRODUCTION

This multicenter phase II study determined the efficacy and safety of new daily oral S-1 and weekly irinotecan (CPT-11) combination schedule in patients with previously untreated advanced or recurrent colorectal cancer.

PATIENTS AND METHODS

Patients received first-line chemotherapy comprising S-1 80 mg/m(2)/day given on days 3 to 7, 10 to 14, and 17 to 21 and 60 mg/m(2) CPT-11 administered intravenously on days 1, 8, and 15 of a 28-day cycle.

RESULTS

A total of 45 eligible patients were enrolled in this study. The overall response rate was 48.9%. Median progression-free survival and median overall survival was 8.1 months and 20.9 months, respectively. The rates of grade 3 or 4 toxicity were as follows: neutropenia, 8.9%; anemia, 4.4%; anorexia, 6.7%; and diarrhea, 6.7%.

CONCLUSIONS

This new S-1 and irinotecan combination schedule appeared to be an effective, well-tolerated, and convenient regimen in patients with advanced colorectal cancer as compared with conventional regimens such as FOLFIRI and IRIS.

Complete Response of Para-Aortic and Lateral Pelvic Lymph Node Recurrence of Rectal Cancer Treated to S-1 Monotherapy

This report presents a case of para-aortic and lateral pelvic lymph node recurrence of rectal cancer that showed complete response to S-1 monotherapy. A 69-year-old man underwent low anterior resection for rectal cancer in 2007. Para-aortic lymph and right lateral pelvic lymph node recurrence occurred in 2008. He received a fluorouracil/folinic acid plus oxaliplatin regimen; however, G4 neutropenia and G3 fatigue were experienced. We started S-1 monotherapy as a salvage treatment. Abdominal computed tomography did not reveal any para-aortic and lateral pelvic lymph nodes recurrence after 10 cycles of S-1 monotherapy. Hence, response in this case was classified as a complete response. No recurrence was noted 36 months after the complete response. S-1 monotherapy is likely to be effective in treating patients with metastatic colorectal cancer who do not respond to standard combination chemotherapy.