Second-line treatment with oxaliplatin + raltitrexed in patients with advanced colorectal cancer failing fluoropyrimidine/leucovorin-based chemotherapy

Irinotecan plus raltitrexed as second-line treatment in locally advanced or metastatic colorectal cancer patients: a prospective open-label, single-arm, multi-center, phase II study

BACKGROUND

Colorectal cancer is the third most common cancer and the second leading cause of cancer death. There are limited therapeutic options for the treatment of locally advanced or metastatic colorectal cancers which fail first-line chemotherapy. Phase I/II studies showed that the combined application of the raltitrexed and irinotecan has significant synergistic effect and acceptable toxicity. However, most of these previous studies have relatively small sample size.

METHODS

This is a prospective open-label, single-arm, multi-center, Phase II trial. Brief inclusion criteria: patients were aged 18 to 75 years with locally advanced or metastatic colorectal cancer after failure of 5-FU and oxaliplatin therapy. Enrolled patients received raltitrexed (3 mg/m2, d1) and irinotecan (180 mg/m2, d1) each 21-day cycle until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival, and the secondary endpoints were disease control rate, objective response rate, overall survival and safety.

RESULTS

A total of 108 patients were enrolled between September 2016 and May 2020. The median age was 61 years, ECOG 1 score accounts for 67.6%, the rest were ECOG 0. A total of 502 cycles were completed, with an average of 4.6 cycles and a median of 4 cycles. 108 patients were evaluated, with an objective response rate of 17.6%, and disease control rate of 76.9%. The median follow-up time was 27 months (range:3.1-61.0 m) at data cut-off on March 2023. Median progression-free survival was 4.9 months (95% CI 4.1-5.7) and median overall survival was 13.1 months (95% CI 12.2-15.5). The most common adverse events that were elevated are alanine aminotransferase increased, aspartate aminotransferase increased, fatigue, diarrhoea, neutrocytopenia, thrombocytopenia, hypohemoglobin, and leukocytopenia. Most of the adverse events were Grade I/II, which were relieved after symptomatic treatment, and there were no treatment-related cardiotoxicities and deaths.

CONCLUSIONS

The combination of raltitrexed and irinotecan as second-line treatment for mCRC could be a reliable option after failure of standard 5-Fu-first-line chemotherapy in locally advanced or metastatic colorectal cancers, especially for patients with 5-FU intolerance (cardiac events or DPD deficiency patients).

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03053167, registration date was 14/2/2017.

First-line chemotherapy with raltitrexed in metastatic colorectal cancer: an Association des Gastro-entérologues Oncologues (AGEO) multicentre study

BACKGROUND

In case of contraindication or intolerance to fluoropyrimidines, raltitrexed is a validated alternative in metastatic colorectal cancer (mCRC), associated or not with oxaliplatin. Little is known about the outcomes of raltitrexed combined with irinotecan or targeted therapies.

METHODS

This retrospective multicentre study enroled mCRC patients treated with first-line raltitrexed-based chemotherapy. Treatment-related toxicities were recorded. Progression-free survival (PFS) and overall survival (OS) were calculated from treatment start.

RESULTS

75 patients were treated with raltitrexed alone, TOMOX, or TOMIRI with or without bevacizumab. Grade 3-4 adverse events were seen in 31% of patients, without significant difference between the different treatment schedules. amongst the 36 patients with a history of fluoropyrimidine-induced cardiac toxicity, none developed cardiovascular events on raltitrexed. Median PFS and OS were 10.6 (95% CI 8.2 - 13.1) and 27.4 months (95% CI 24.1-38.1), respectively. Considering the chemotherapy regimen, TOMOX was significantly associated with better PFS and OS compared to TOMIRI and raltitrexed alone.

CONCLUSIONS

In patients with mCRC not eligible for fluoropyrimidines, first-line raltitrexed-based chemotherapy had an acceptable safety profile. PFS and OS were consistent with usual survival data in mCRC, and significantly better in patients treated with TOMOX, independently of associated targeted therapies.

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.

Biweekly Raltitrexed Combined With Irinotecan as Second-Line Therapy for Patients With Metastatic Colorectal Cancer: A Phase II Trial

OBJECTIVE

Irinotecan-based doublet chemotherapy strategy was standard second-line backbone for patients with oxaliplatin-refractory metastatic colorectal cancer. The aim of this study was to evaluate tolerability and efficacy of raltitrexed combined with irinotecan biweekly administered as the second-line therapy for mCRC patients.

METHODS

The study was a prospective, single-center, non-randomized, open-label phase II clinical trial. Patients with mCRC after failure with oxaliplatin and fluoropyrimidine or its derivatives were enrolled. Irinotecan (180 mg/m2) and raltitrexed (2.5 mg/m2) were given intravenously on day 1. Cycles were repeated every 2 weeks. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included overall response rate (ORR), disease control rate (DCR), overall survival (OS), and adverse events (AEs).

RESULTS

Between December 2012 and October 2016, 33 and 35 patients enrolled were assessed for response and safety, respectively. The ORR was 8.6%, and the DCR was 71.4%. The median PFS was 4.5 months (95% CI 3.8-5.2). The median OS was 12.0 months (95% CI 8.5-15.5). Four patients received conversion therapy to no evidence of disease (NED), and 2 patients were still alive with beyond 24 months survival. The most common grade 3/4 AEs were anorexia (14.3%), vomiting (14.3%), nausea (11.4%), fatigue (8.6%), and leukopenia (8.6%). No one died from treatment-related events. The incidence and severity of toxicity were irrelevant to UGT1A1 status.

CONCLUSIONS

The combination of irinotecan with raltitrexed is an efficient, convenient, and acceptable toxic regimen for second-line treatment for mCRC patients.

Clinical efficacy of irinotecan plus raltitrexed chemotherapy in refractory esophageal squamous cell cancer

Our retrospective study assessed the efficacy and safety of irinotecan plus raltitrexed in esophageal squamous cell cancer (ESCC) patients who were previously treated with multiple systemic therapies. Between January 2016 and December 2018, records of 38 ESCC patients who underwent irinotecan plus raltitrexed chemotherapy after at least one line of chemotherapy were reviewed. Efficacy assessment was performed every two cycles according to the RECIST version 1.1. A total of 95 cycles of chemotherapy were administered, and the median course was 3 (range 2-6). There was no treatment-related death. Nine patients had partial response, 21 had stable disease and eight had progressive disease. The overall objective response rate was 23.68% (9/38) and the disease control rate was78.94% (30/38). After a median follow-up of 18.5 months, the median progression-free survival and overall survival were 105 and 221 days, respectively. There were five patients (13.15%) with grade 3/4 leukopenia, three patients (7.89%) with grade 3/4 neutropenia and one patient (2.63%) with grade 3/4 diarrhea. The combination of irinotecan plus raltitrexed was effective for pretreated ESCC patients. Further studies are needed to determine the optimal dose of the two drugs.

Oxaliplatin with Raltitrexed and Preoperative Radiotherapy in T3-T4 Extraperitoneal Rectal Cancer. A Dose Finding Study

Aims and background

The availability of new drugs offers the opportunity to improve the outcome of locally advanced rectal cancer. Raltitrexed and oxaliplatin are effective in advanced colorectal cancer with acceptable toxicity and can act as radiation enhancers as shown in phase 1-11 studies. The aim of the study was thus to determine the recommended dose of oxaliplatin concomitantly administered with raltitrexed and concurrent preoperative radiotherapy in patients with stage 11-111 extraperitoneal rectal cancer.

Methods

From September 2001 to September 2002, 18 consecutive patients with T3/T4 rectal cancer were treated at our Institution with preoperative chemoradiation followed by surgery after 6-8 weeks. Pelvic radiotherapy was delivered at a dose of 45 Gy in 25 fractions in 5 weeks followed by a 5.4 Gy boost at 1.8 Gy daily. Concomitant chemotherapy consisted of 3 mg/m2/iv of raltitrexed on days 1, 19, 38 of radiotherapy treatment with incremental doses of oxaliplatin according to dose finding rules (4 dose levels: 65, 85, 110, 130 mg/m2). Dose-limiting toxicity for oxaliplatin was defined as either grade 3-4 hematological or grade 3-4 gastrointestinal or neurological toxicity. We studied a minimum of 3 patients at each dose level.

Results

Three patients were treated at 65, 85, and 110 mg/m2/iv, respectively, while 9 patients were recruited at the last dose level. Neither grade 3-4 gastrointestinal nor neurological toxicity were documented. Dose-limiting toxicity was documented in 2/9 subjects at the 130 mg/m2 level consisting of grade 3 transient asymptomatic leukopenia. Thirteen patients developed transient increase of one or more liver enzymes (grade 3-4) and 2 patients developed grade 3 perineal dermatitis. All patients received the programmed dose of radiotherapy. The chemotherapy regimen was not completed in 4 cases due to grade 2 protracted leukopenia.

Conclusions

The maximum tolerated dose of oxaliplatin was not reached at the maximum dose level (IV); 130 mg/m2 can therefore be defined as the recommended dose. The combination of oxaliplatin with raltitrexed and radiotherapy can be considered feasible and well tolerated.

Raltitrexed plus Oxaliplatin in the Treatment of Metastatic Colorectal Cancer

Aims and background

As raltitrexed and oxaliplatin (L-OHP) are both effective in the treatment of colorectal cancer but have different mechanisms of action, we studied the antitumoral activity and safety of their combined use in patients with advanced colorectal cancer.

Methods

A 15-min intravenous infusion of raltitrexed (2.5 mg/m2) and a 180-min infusion of oxaliplatin (100 mg/m2) were administered on day 1 every three weeks for a maximum of six cycles.

Results

The study involved 51 patients (27 males and 24 females) with a median age of 65 years (range, 43-78); 28 were aged ≥65 years. The primary tumor site was the colon in 35 patients and the rectum in 16. Thirty-four patients had received prior chemotherapy: 20 as adjuvant treatment and 14 as pretreatment. The most frequent metastatic sites were liver (18 cases), lung (10 cases), liver + lung (8 cases) and lymph nodes (3 cases). Twenty-four patients completed the entire treatment plan. The most common toxicities were transaminitis (16 patients, grade 3-4), diarrhea (six patients, grade 3), nausea/vomiting (one patient, grade 4), and asthenia (one patient, grade 3). The treatment was stopped in one patient because of prolonged grade 4 transaminitis. The adverse event profile was similar in the patients aged >65 years and <65 years. Complete responses were observed in 2 patients, partial responses in 12, stable disease in 23, and progression in 8.

Conclusions

The results of the study suggest that the raltitrexed plus oxaliplatin regimen is feasible and clinically active in advanced colorectal cancer.

A systematic review of raltitrexed-based first-line chemotherapy in advanced colorectal cancer

Raltitrexed is a thymidylate synthase inhibitor belonging to the antimetabolite class of cytotoxic drugs. It is also effective in colorectal cancer (CRC) both as a single agent and in combination with other drugs, in particular in those patients with cardiologic risk factors or previous cardiotoxicity. The efficacy of first-line raltitrexed-based chemotherapy containing oxaliplatin (TOMOX) and irinotecan (TOMIRI) was investigated in this systematic review. Studies that enrolled advanced CRC patients for first-line therapy with TOMOX/TOMIRI combinations were identified using electronic databases (Pubmed, SCOPUS, Web of Science, EMBASE, and the Cochrane Library). A systematic analysis was carried out using Comprehensive Meta Analysis (version 2.2.064) software to calculate the pooled response rate and 95% confidence limits. The median pooled overall survival and progression-free survival were also calculated. Results for TOMOX and TOMIRI studies were compared using the two-sided Student's t-test. We tested for significant heterogeneity using Cochran's χ-test and I index. Twelve studies published between 2001 and 2012 were eligible for this analysis and a total of 735 patients were enrolled in these studies. The overall response rate was 40% (95% confidence interval 34-46%): 43.9% for TOMOX and 34.1% for TOMIRI arms. The weighted median overall survival and progression-free survival times were 14.6 and 6.7 months, respectively. Neutropenia and liver toxicity were more frequent with TOMOX, whereas neutropenia and diarrhea were more frequent with TOMIRI. However, compared with historical FOLFOX and FOLFIRI trials, raltitrexed-based doublets are associated with less neutropenia and gastrointestinal toxicity and uncommon cardiotoxicity. TOMOX and TOMIRI doublets are active as first-line chemotherapy for advanced CRC and seem useful in particular when the use of 5-fluorouracil is contraindicated for cardiac comorbidity.

Targeting thymidylate synthase in colorectal cancer: critical re-evaluation and emerging therapeutic role of raltitrexed

INTRODUCTION

5-fluorouracil continues to be the cornerstone of treatment for colorectal cancer. Although fluoropyrimidines are generally considered as well-tolerated drugs, severe toxicities can be a major clinical problem, and the recommended prolonged infusion of 5-fluorouracil provokes discomfort in patients. Raltitrexed (Tomudex), a quinazoline analogue of folinic acid, is a selective and direct thymidylate synthase (TS) inhibitor with a convenient 3-weekly schedule of administration.

AREAS COVERED

In this review, through critical insight into the mechanism of action and main clinical experiences, the authors suggest the necessity to reconsider raltitrexed as a valuable anticancer drug and as a suitable option for colorectal cancer. The authors highlight its emerging therapeutic role in clinical practice for patients with fluoropyrimidine-induced cardiotoxicity or a significant history of cardiac disease.

EXPERT OPINION

This review discusses if TS could still be a relevant target for colorectal cancer in the era of molecular therapy and if raltitrexed should still be considered a drug with a life-threatening toxicity. Furthermore, this review discusses the principal combination clinical experiences of raltitrexed and its emerging therapeutic role in clinical practice as a suitable option for colorectal cancer patients with fluoropyrimidine-induced cardiotoxicity or a significant history of cardiac disease.

Alternative treatment options in colorectal cancer patients with 5-fluorouracil- or capecitabine-induced cardiotoxicity

Most chemotherapy regimens in colorectal cancer treatment are 5-fluorouracil (5-FU)/leucovorin or capecitabine-based. Cardiotoxicity is a less common but potentially lethal complication of 5-FU or capecitabine treatment, and some physicians might be unfamiliar with treatment alternatives. Rechallenging should be avoided because it carries a high risk of recurrence of the cardiac symptoms and prophylactic treatment is not always protective. Possible alternative treatment options to be considered are to replace the oral capecitabine or intravenous 5-FU by a 5-FU bolus regimen, by uracil-tegafur or tegafur/gimeracil/oteracil, both oral fluoropyrimidines combining a 5-FU prodrug with a dihydropyrimidine dehydrogenase (DPD) inhibitor, or by raltitrexed, a thymidilate synthase inhibitor whose metabolism is independent of DPD. Patients with advanced colorectal cancer and fluoropyrimidine-induced cardiotoxicity can be treated with other non-fluoropyrimidine related chemotherapy, either as a single agent, combined, or in combination with biological agents. In this report we discuss the different alternative treatment options.

A randomized phase II study to compare oxaliplatin plus 5-fluorouracil and leucovorin (FOLFOX4) versus oxaliplatin plus raltitrexed (TOMOX) as first-line chemotherapy for advanced colorectal cancer

INTRODUCTION

The aim of this study was to compare TOMOX versus FOLFOX4 as first-line treatment of advanced colorectal cancer (CRC).

MATERIALS AND METHODS

191 chemotherapy-naïve patients were randomized to receive TOMOX or FOLFOX4. Patients were evaluated every 3 months and chemotherapy was continued until disease progression or unacceptable toxicity. Overall response rate was the primary endpoint.

RESULTS

183 patients were included in the intent-to-treat analysis (92 TOMOX and 91 FOLFOX4). Overall response rate was 45.6 and 36.3 % (p = 0.003) for TOMOX and FOLFOX4, respectively. No statistically significant differences were observed in overall survival (15.6 and 17.2 months; p = 0.475); progression-free survival (7.7 and 8.7 months; p = 0.292), and response duration (6.4 and 7.6 months; p = 0.372) for TOMOX and FOLFOX4, respectively. Grades 3 and 4 neutropenia (p < 0.0001) and leukopenia (p = 0.028) were more common with the FOLFOX4 regimen, while hepatic disorders and asthenia were higher in TOMOX group (p = ns). There were two treatment-related deaths in the FOLFOX4 arm and one in the TOMOX arm. Quality of life analysis based on the SF-36 revealed differences between the two regimens for physical and mental composite scores after 6 weeks, and for body pain and emotional role functioning after 6 and 12 weeks; all of these favored the FOLFOX4 arm (p ≤ 0.05).

CONCLUSIONS

TOMOX and FOLFOX4 seem to have similar efficacy and are well tolerated in the first-line treatment for advanced CRC with different profiles of toxicity. The convenient TOMOX regimen may offer an alternative to fluoropyrimidine-based regimens.

Irinotecan, oxaliplatin and raltitrexed for the treatment of advanced colorectal cancer

Out of every 17-18 individuals in the US, one develops colorectal cancer (CRC) in their lifetime. Of individuals diagnosed with CRC, > 50% present or develop metastatic disease, which, if untreated, is associated with 6-9 months median survival. Although surgical resection is the primary treatment modality for CRC, chemotherapy is the mainstay of treatment for metastatic or unresectable disease. For nearly three decades, 5-fluorouracil (5-FU) has been the chemotherapy of choice for treatment of CRC. However, the response rates to single 5-FU therapy have been suboptimal with an objective tumour response of 10-20%. Attempts have been made to improve the efficacy of 5-FU by either schedule alteration (protracted infusion versus intravenous push) or biochemical modulation with leucovorin (LV). Continuous infusion induced more tumour regression and prolonged the time-to-disease progression with some significant impact on survival (11.3 versus 12.1 months; p < 0.04). 5-FU/LV resulted in a significant increase in overall response rates and in the prolongation of disease-free survival in the adjuvant setting, although severe toxicities represent a major clinical problem. The last 10 years have seen the addition of several new agents such as irinotecan, oxaliplatin, raltitrexed, bevacizumab and cetuximab. The prognosis has significantly improved with the addition of these agents, with median survivals now > 20 months. This review paper focuses on irinotecan, oxaliplatin and raltitrexed when used alone and in combination.

Side effects during chemotherapy predict tumour response in advanced colorectal cancer

To investigate whether a relationship between chemotherapy-associated adverse events and treatment efficacy exists, we have analysed the toxicity, objective response and survival data of 303 patients with advanced colorectal cancer. Patients were divided into two groups: the first with beneficial effect (I, n=245), and the second with progressive disease (II, n=58). Differences in terms of incidence rates, type and severity of adverse events were analysed with univariate and multivariate models. The median number of side effects in group I was 6 vs 4 in group II (OR=1.342; P=0.0001). An inverse correlation between disease control and treatment tolerance was confirmed when side effects were analysed according to severity and type of treatment-associated toxicities (haematological: P=0.0005 vs nonhaematological P=0.0001). When median survival was analysed according to the number of adverse events, it was 10 (95% CI, 3–7), 16 (14–18), and 18 (16–20) months in case of 0–1, 2–5, and ⩾6 adverse events, respectively (P=0.01). In conclusion, the results of this analysis suggest that occurrence of side effects during chemotherapy in advanced colorectal cancer is an independent and reliable prognostic indicator for response and survival.

Chemoradiation with raltitrexed and oxaliplatin in preoperative treatment of stage II-III resectable rectal cancer: Phase I and II studies

PURPOSE

Two separate studies were conducted, the first to evaluate the maximal tolerated dose and the second the efficacy of raltitrexed plus oxaliplatin in conjunction with preoperative chemoradiation in patients with resectable T3 rectal carcinoma.

METHODS AND MATERIALS

A total of 48 patients received radiotherapy (50 Gy) administered to the posterior pelvis 5 d/wk for 5 weeks. Combination raltitrexed (3 mg/m(2)) and oxaliplatin (60 to 130 mg/m(2)) was administered on Days 1, 19, and 38.

RESULTS

The recommended dose of oxaliplatin is 130 mg/m(2) (maximal tolerated dose not reached). No patients developed Grade 4 acute toxicity. Grade 3 acute toxicity occurred in 9 patients (18.7%). It was hematologic in 1 patient and GI in 1 patient; 7 patients had an asymptomatic increase of transaminase. Surgery was performed in 47 (98%) of 48 patients. Of the 47 patients, 42 underwent sphincter-saving surgery; in 19, the tumor at diagnosis was located <30 mm from the anorectal ring. Chemoradiation in combination with raltitrexed and oxaliplatin produced high rates of tumor response. The overall tumor downstaging rate was 73% for T and N stages. A complete pathologic tumor response (pT0) or microscopic tumor foci (pTmic) was observed in 28 patients. The tumor regression grade (TRG), using the Mandard scoring system, was TRG1 in 16 patients (43.2%), TRG2 in 12 (32.4%), TRG3 in 12 (32.4%), TRG4 in 6 (16.2%), and TRG5 in 1 patient (2.7%).

CONCLUSION

Raltitrexed plus oxaliplatin combined with pelvic radiotherapy was effective and well tolerated in patients with resectable T3 rectal carcinoma.

Raltitrexed plus weekly oxaliplatin as first-line chemotherapy in metastatic colorectal cancer: a multicenter non-randomized phase ii study

AIM

The primary aims of this study were activity and toxicity evaluation of a new raltitrexed and oxaliplatin-based regimen, as a first-line chemotherapy, in patients with metastatic colorectal cancer (MCC). Survival evaluation was considered a secondary endpoint.

PATIENTS AND METHODS

Forty-four patients were enrolled into this phase II trial. Treatment consisted of raltitrexed 3 mg/m2 iv on d 1 and oxaliplatin 70 mg/m2 iv on d 1 and d 8 every 3 wk.

RESULTS

Twenty patients (45.5%) achieved a response [95% confidence interval (CI): 30.1% to 54.1%], 18 (40.9%) had stable disease, and only 6 (13.6%) developed progressive disease. After a median follow-up time of 14.7 mo (range 6.3-18.6 mo), the median time to disease progression was 6 mo (range 2.0-16.7) (95% CI: 4.4-7.6) and the overall survival was 14.8 mo (range 3-23) (95% CI: 11.2-18.4). Neutropenia was the most common hematological side effect, while transient AST/ALT increase, neurotoxicity, asthenia, and diarrhea were the most common nonhematological side effects.

CONCLUSIONS

Our data confirmed that oxaliplatin administered weekly plus raltitrexed is an active combination in newly diagnosed patients with advanced colorectal carcinoma that merits further investigation versus the classic schedule in a randomized, phase III trial.

Oxaliplatin: a review of its use in combination therapy for advanced metastatic colorectal cancer

Oxaliplatin (Eloxatin) is the only platinum compound to show clinical activity in colorectal cancer. The efficacy of a combination of oxaliplatin with various schedules of fluorouracil (5-FU)/folinic acid (FA) as first- or second-line treatment for advanced metastatic colorectal cancer has been investigated in large phase III trials. FOLFOX4 (an oxaliplatin/5-FU/FA regimen) as first-line therapy (n = 795) was superior to irinotecan/5-FU/FA (IFL). Response rates were 45% vs 31%, and median progression-free survival duration was 8.7 vs 6.9 months. The survival advantage shown by FOLFOX4 over the irinotecan combination (median survival duration 19.5 vs 14.8 months) may be confounded by differences in post-study treatment but equivalent efficacy is supported by another phase III trial of oxaliplatin and irinotecan combinations. As first-line therapy, oxaliplatin added to various 5-FU/FA regimens more than doubled the response rates from 16-22.6% to 48.3-53% and the median duration of progression-free survival was significantly longer with oxaliplatin/5-FU/FA than 5-FU/FA alone (7.9-9 versus 5.3-6.2 months, respectively). In disease resistant to irinotecan-based therapies, the oxaliplatin (FOLFOX4) regimen had superior efficacy to 5-FU/FA alone in a pivotal phase III trial (n = 816). Response rates and median durations of progression-free survival were 9.6% vs 0.7% and 5.6 vs 2.6 months, respectively. An oxaliplatin-induced cumulative peripheral sensory neuropathy (evident when total dose reaches approximate, equals 800 mg/m(2)) is dose limiting. The most frequently occurring grade 3 or 4 toxicities in oxaliplatin/5-FU/FA-recipients were neutropenia (up to 48%) and neurological toxicities (up to 18%). Gastrointestinal effects (diarrhoea [ approximate, equals 12%], nausea, vomiting, or mucositis/stomatitis [up to 6%]) are manageable. Withdrawals from oxaliplatin treatment were due to neuropathy (up to 10%), diarrhoea and/or vomiting (1%) or cutaneous toxicity (1%).

CONCLUSION

As first-line therapy for metastatic colorectal cancer, oxaliplatin with 5-FU/FA consistently improves response rates and progression-free survival compared with various regimens of 5-FU/FA alone. The significant survival advantage shown by oxaliplatin/5-FU/FA (FOLFOX4) compared with first-line therapy with irinotecan/5-FU/FA (IFL) is encouraging but may require further confirmation. Oxaliplatin/5-FU/FA produces a significantly higher response rate and longer progression-free survival than 5-FU/FA in patients failing irinotecan-based therapies, and as such is also a useful second-line treatment. Although cumulative neurotoxicity is dose limiting, oxaliplatin has a manageable tolerability profile. Oxaliplatin as first- or second-line therapy is a valuable addition to the limited, but expanding, armamentarium of cytotoxic agents useful in advanced metastatic colorectal cancer.

Palliative treatment of patients with colorectal cancer

BACKGROUND

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

MATERIAL AND METHODS

A systematic approach to the literature-based evidence was aimed at.

RESULTS

The continuous improvements during the past 13-15 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 two lines of chemotherapy based upon good scientific evidence. Median survival has gradually improved from below 6 months to above 18 months in some recent trials. 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, and whether cure may be possible in a small subset of patients.

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. Future collaborations may hopefully introduce new treatment concepts, further improving outcome.

Prospects for colorectal cancer treatment: oral chemotherapy and targeted biotherapy

Since the 1990s, the emergence of new drugs has modified the prognosis of metastatic colorectal cancer. This malignant disease has largely benefited from the development of new drugs and new therapeutic concepts, such as oral chemotherapy or targeted biotherapy. Although a significant improvement in survival has been reached with these new therapeutic approaches, the optimal strategy remains to be defined, particularly the best sequence of drug administration. This review will focus upon new anticancer drugs, some of them with original mechanism of action, and steps towards the goal of better understanding and anticipating new treatments in colorectal carcinoma.

[Raltitrexed and oxaliplatin in colorectal cancer: in vitro and in vivo study of a synergistic cytostatic combination]

AIM

To evaluate the efficacy of combined raltitrexed and oxaliplatin in vitro using 4 colorectal cell-lines and subsequently in vivo in 36 patients with advanced colorectal cancer failing palliative 5-fluorouracil/leucovorin-based chemotherapy. In the preclinical phase of this study, the efficacy of oxaliplatin and of raltitrexed as well as of 5-FU alone and in combination was evaluated in 4 different human colorectalcarcinoma cell-lines with the MTT-test (Microculture Tetrazolium Assay). In the clinical phase 36 patients with metastatic colorectal cancer, who progressed while receiving or within 6 months after withholding palliative chemotherapy with 5-FU/leucovorin +/- irinotecan were enrolled in this study. Treatment consisted of oxaliplatin 130 mg/m2 and raltitrexed 3.0 mg/m2 both given on day 1 every 3 weeks for a total of 8 courses unless prior evidence of progressive disease. A supraadditive effect was found for the experimental combination of oxalipatin and raltitrexed in 3/4 of cell lines. In the clinical phase the overall response rate was 33.3% for all 36 evaluable patients. Seventeen additional patients (47.2%) had stable disease, and only 7 (19.5%) progressed. The median progression-free survival was 6.5 months (range, 1.2 to 14.0). After a median follow-up time of 12 months, 23 patients (63.8%) are still alive. The tolerance of treatment was acceptable with only 8/36 (22%) experiencing grade 3 or 4 neutropenia. Grade 3 nonhematologic adverse reactions included peripheral sensory neuropathy in 3, asthenia in 1, diarrhea in 2, and clinically insignificant increase in serum transaminases in 2 patients, respectively. Our data suggest that the combination of oxaliplatin and raltitrexed has not only in vitro, but also in vivo in patients with progressive fluoropyrimidine/leucovorine +/- irinotecan pretreated colorectal cancer antitumor activity. Because of its favorable toxicity profile and its convenient 3-weekly outpatient administration schedule, further evaluation of this regimen seems warranted.

Raltitrexed plus oxaliplatin as first-line chemotherapy in metastatic colorectal carcinoma: a multicentric phase II trial

For advanced colorectal carcinoma, two new drugs, raltitrexed (TOM) and oxaliplatin (L-OHP), have recently shown interesting results. Preclinical and clinical studies suggest that this combination, because of its favorable toxicity profile, high response rate and convenient schedule of administration, can be administered successfully in this disease. In our phase II study, 37 non pre-treated patients with metastatic colorectal carcinoma were treated with TOM (3 mg/m(2)) and L-OHP (130 mg/m(2)) every 3 weeks. In total, 222 cycles were administered; all patients received at least 2 cycles (median 6, range 2-8). There were two complete and 14 partial responses for an overall response rate of 43% (95% CI 27-69%). The median time to response was 2.5 months (range 2-4) and the median duration was 10.3 months (range 5-18). Twelve of the 23 (52%) patients with symptomatic colorectal cancer were classified as clinical benefit responders for at least 4 weeks during the study period. Treatment was well tolerated, and both acute, essentially hematologic, and cumulative hepatic and neurologic toxicities were manageable and reversible. Response rate and toxic effects observed during this study warrant additional studies comparing this TOM-L-OHP regimen with CPT-11 and/or capacitebine-containing regimens in metastatic colorectal carcinoma.

Multicenter non-randomized phase II study of raltitrexed (Tomudex) and oxaliplatin in non-pretreated metastatic colorectal cancer patients

BACKGROUND

This multicenter, phase II, open-label study evaluated the antitumor efficacy and safety of oxaliplatin and raltitrexed (Tomudex) in non-pretreated advanced colorectal cancer patients.

PATIENTS AND METHODS

Seventy-one patients received oxaliplatin 130 mg/m(2) and raltitrexed 3 mg/m(2) intravenously on an outpatient basis every 3 weeks. All patients had histologically proven metastatic colorectal adenocarcinoma, performance status <or=2 and good baseline organ function. Most (56%) had only one disease site. All patients were assessed for safety, and 66 of 69 eligible patients were assessed for response.

RESULTS

A total of 404 cycles were administered, with a median of six cycles per patient (range 1-12 cycles). Relative dose intensities were 0.98 and 0.98 for oxaliplatin and raltitrexed, respectively. The most common grade 3-4 toxicities (National Cancer Institute Common Toxicity Criteria) among treated patients were as follows: neutropenia (21 patients, 30%), asthenia (eight, 11%), diarrhea (12, 17%), liver function test abnormalities (24, 34%), nausea (nine, 13%) and vomiting (nine, 13%). Two treatment-related deaths occurred (hematotoxicity in one patient and gastrointestinal toxicity in the other) and two further deaths were possibly related to treatment (hepatic dysfunction in one patient and neuropathy in the other). Thirty-seven objective responses (one complete) were obtained [objective response rate 54%; 95% confidence interval (CI) 42% to 65%] in eligible patients. The median response duration was 8.5 months (95% CI 6.7-12.2 months), while median progression-free and overall survival among eligible patients were 6.2 (95% CI 5.1-6.9 months) and 14.6 months (95% CI 11.0-18.9 months), respectively.

CONCLUSIONS

The present study confirms the feasibility of the raltitrexed plus oxaliplatin combination and its activity in non-pretreated advanced colorectal cancer patients.

Oxaliplatin plus raltitrexed and leucovorin-modulated 5-fluorouracil i.v. bolus: a salvage regimen for colorectal cancer patients

The aim of the present study was to define the activity and tolerability of a triplet regimen including oxaliplatin 130 mg x m(-2) (2 h i.v. infusion) and raltitrexed 3.0 mg x m(-2) (15 min i.v. infusion) given on day 1, followed by levo-folinic acid 250 mg x m(-2) (2 h i.v. infusion) and 5-fluorouracil 1050 mg x m(-2) i.v. bolus on day 2, every 2 weeks, in pretreated colorectal cancer patients. From April 1999 to December 2000, 50 patients were enrolled: 26 were males and 24 females, their median age was 63 (range, 43-79) years; ECOG performance status was 0 in 26 patients, > or =1 in 24 patients; 26 patients had received previous adjuvant chemotherapy, 40 patients had been exposed to one or two lines of palliative chemotherapy (including irinotecan in 31 cases); 18 patients were considered chemo-refractory. A total of 288 cycles were administered, with a median number of 6 (range 1-12) courses per patient. A complete response was obtained in three patients, and a partial response in nine patients, giving a major response rate of 24% (95% confidence interval, 13-38%), while 15 further patients showed a stable disease, for an overall control of tumour growth in 60% of patients. Three complete responses and three partial responses were obtained in patients pretreated with irinotecan (response rate, 19%); among refractory patients, three achieved partial responses (response rate, 13%). After a median follow-up of 18 (range, 10-30) months, 40 patients showed a progression of disease: the growth modulation index ranged between 0.2 and 2.5: it was > or =1.33 (showing a significant delay of tumour growth) in 16 (40%) patients. Actuarial median progression-free survival time was 7.6 months, and median survival time was 13.6 months: estimated probability of survival was 55% at 1 year. Main severe toxicity was neutropenia: World Health Organisation grade 4 affected 32% of patients; non-haematological toxicity was mild: World Health Organisation grade 3 diarrhoea was complained of by 8%, and grade 3 stomatitis by 4% of patients; neurotoxicity (according to Lévi scale) was scored as grade 3 in 8% of patients. In conclusion, this regimen was manageable and active as salvage treatment of advanced colorectal cancer patients; it showed incomplete cross-resistance with irinotecan-based treatments, and proved to delay the progression of disease in a relevant proportion of treated patients.