FOLFOXIRI plus bevacizumab as first-line treatment in BRAF mutant metastatic colorectal cancer.

BACKGROUND: BRAF V600E mutation plays a negative prognostic role in metastatic colorectal cancer (mCRC), leading to a median Progression Free Survival (PFS) of 4-6months with first-line conventional treatments. Our group recently reported in a retrospective exploratory analysis of a phase II trial that FOLFOXIRI (5-FU/LV+Oxaliplatin+Irinotecan) plus bevacizumab might allow to achieve remarkable results in terms of PFS and Overall Survival (OS) also in this poor-prognosis subgroup. The aim of this work was to prospectively validate our retrospective finding. PATIENTS AND METHODS: This phase II trial was designed to detect an increase in 6month-Progression Free Rate (6m-PFR) from 45% to 80% in a population of BRAF mutant mCRC patients treated with first-line FOLFOXIRI plus bevacizumab. Secondary end-points were PFS, OS, response rate (RR) and the analysis of outcome parameters in the pooled population consisting of both retrospectively and prospectively included patients. This trial is registered with ClinicalTrials.gov, number NCT01437618. RESULTS: Two-hundred-fourteen potentially eligible mCRC patients were screened for BRAF mutational status. Fifteen BRAF mutant patients (7%) were included in the validation cohort. At a median follow up of 25.7months, 6m-PFR was 73%. Median PFS and OS were 9.2 and 24.1months, respectively. In the pooled population, at a median follow up of 40.4months, 6m-PFR was 84%. Median PFS and OS were 11.8 and 24.1months, respectively. Overall RR and disease control rate were 72% and 88%, respectively. CONCLUSION: Lacking randomised trials in this specific molecular subgroup, FOLFOXIRI plus bevacizumab might be a reasonable option for the first-line treatment of BRAF mutant mCRC patients.

A dose finding and pharmacokinetic study of capecitabine in combination with oxaliplatin and irinotecan in metastatic colorectal cancer.

PURPOSE: The GONO-FOLFOXIRI regimen demonstrated higher activity and efficacy than FOLFIRI in metastatic colorectal cancer patients. The aim of this study was to determine the maximum tolerated dose of capecitabine, in substitution of 5-fluorouracil, combined with oxaliplatin and irinotecan and to evaluate the pharmacokinetics of the drugs. PATIENTS AND METHODS: We treated 15 patients with escalating doses of capecitabine (from day 1 to 7) and fixed doses of oxaliplatin (85 mg/m(2)) plus irinotecan (165 mg/m(2)) (both administered on day 1), repeated every 2 weeks. Pharmacokinetic analysis was performed on plasma samples collected at the first cycle of treatment. RESULTS: The maximum tolerated dose of capecitabine resulted 2,000 mg/m(2)/day, with diarrhea being the only dose-limiting toxicity. Large interpatient variability in the pharmacokinetic parameters of investigated drugs was observed. Results in terms of activity are promising. CONCLUSIONS: At the maximum tolerated dose of capecitabine of 2,000 mg/m(2)/day the combination is feasible with promising activity and deserves further investigations.

Adjuvant chemotherapy in the treatment of colon cancer: randomized multicenter trial of the Italian National Intergroup of Adjuvant Chemotherapy in Colon Cancer (INTACC).

BACKGROUND: To determine whether the addition of leucovorin to the combination 5-fluorouracil plus levamisole prolongs disease-free survival and overall survival in patients with radically resected colon cancer (Dukes' B(2-3) and C). PATIENTS AND METHODS: Patients (1703) were accrued between March 1992 and February 1995 in a large-scale clinical trial within five Italian cooperative groups. After stratification for center, patients were randomized as follows: arm A, 5-fluorouracil [450 mg/m(2) intravenous (i.v.) bolus on days 1-5] and levamisole (150 mg orally for 3 days, every 14 days for 6 months) versus arm B, 6-S-leucovorin (100 mg/m(2) i.v. bolus on days 1-5) followed by 5-fluorouracil (370 mg/m(2) i.v. bolus on days 1-5), plus levamisole (as arm A), every 4 weeks for six cycles. RESULTS: After a median follow-up of 6.4 years no significant difference was seen for either disease-free survival (58% versus 60%, not significant) or 5-year overall survival (68% versus 71%, not significant), respectively. Gastrointestinal toxicity (World Health Organization grade 3/4) was more frequent in arm B (8% versus 18%, not significant). CONCLUSIONS: In this trial the schedules used showed no statistically significant differences in terms of disease-free survival or overall survival in the treatment of colorectal cancer.

Sequence effect of irinotecan and fluorouracil treatment on pharmacokinetics and toxicity in chemotherapy-naive metastatic colorectal cancer patients.

PURPOSE: To investigate the sequence effect of irinotecan and a 48-hour infusion of fluorouracil (5-FU) modulated by leucovorin (LV) on the plasma pharmacokinetics of irinotecan and its metabolites, the toxicity profile of this combination, and irinotecan's maximum-tolerated dose (MTD). PATIENTS AND METHODS: Thirty-three metastatic colorectal cancer patients were randomized to receive a 60-minute infusion of irinotecan before or after a 48-hour infusion of 5-FU modulated by LV. The reverse sequence was used after 21 days for the second cycle. 5-FU 3,500 mg/m2 was preceded by l-LV 250 mg/m2. Irinotecan 150 mg/m2 (starting dose) was administered to the first three patients. The dose was escalated by 50 mg/m2 in subsequent groups of three to six patients to determine the MTD for both sequences. Pharmacokinetic analysis of irinotecan and its metabolites was performed after each cycle. RESULTS: Toxicities were affected by the sequence of administration of irinotecan and 5-FU, with an improved tolerability for irinotecan followed by 5-FU. The irinotecan MTD was reached at 300 mg/m2 when irinotecan followed 5-FU and at 450 mg/m2 when it preceded 5-FU. In seven of 23 patients who received both sequences at identical irinotecan doses, the dose-limiting toxicity was observed only when irinotecan followed 5-FU. Pharmacokinetic analysis revealed that the administration sequence significantly affected the SN-38 area under the concentration-versus-time curve (AUC), which was 40.1% lower (P <.05) when irinotecan preceded 5-FU. CONCLUSION: The sequence of treatment with irinotecan and infusional 5-FU affects the tolerability of this combination. This can be explained in part by a reduced SN-38 AUC when irinotecan preceded infusional 5-FU. Well-defined 5-FU/irinotecan regimens are needed because the administration sequence or the interval between the agents might affect treatment tolerance and perhaps also activity.

5-fluorouracil administered as a 48-hour chronomodulated infusion in combination with leucovorin and cisplatin: a randomized phase II study in metastatic colorectal cancer.

OBJECTIVE: The primary objective of this trial was to determine the objective response of two regimens with CDDP administered every 2 weeks immediately before or after an 'optimal' 48-hour chronomodulated infusion of 5-fluorouracil (5-FU) modulated with leucovorin (LV) in metastatic colorectal cancer patients. Secondary endpoints were toxicity, 5-FU and its metabolites, plasma pharmacokinetics and progression-free and overall survival. METHODS: Metastatic colorectal cancer patients with measurable disease who were chemotherapy-naive or pretreated only with a 5-FU-bolus-based chemotherapy were eligible for this study. The study was designed as a randomized phase II clinical trial. RESULTS: Eighty-three patients were entered into the study. Forty-two were randomized to CDDP given before 5-FU and 41 to CDDP given after 5-FU. Patient characteristics were similar among the two groups. Toxicities were also similar among the two arms and the most frequent WHO grade III-IV toxicities were stomatitis (14%) and neutropenia (39-50%). Plasma pharmacokinetic profiles of 5-FU and 5-FUH2 were not significantly affected by the sequence of CDDP and 5-FU administration. Antitumor activity was similar in the two arms and was very promising both in pretreated patients (response rate 29%; 95% confidence interval 15-46%) and in chemotherapy-naive patients (response rate 56%, complete response 9%, 95% confidence interval 40-71%). Median survival of the patients with and without pretreatment was 12 and 16 months, respectively. CONCLUSIONS: These results do not suggest a sequence dependence of the synergism between CDDP and 5-FU. However, they challenge the need of oxaliplatin to improve 5-FU/LV activity in advanced colorectal cancer. In fact, our results with an 'optimal' 5-FU dose and scheduling are very similar to those obtained with oxaliplatin plus 5-FU/LV. However, only a randomized phase III study will be able to give an answer to the hypotheses raised by this study.

Oral doxifluridine in advanced hepatocellular carcinoma: A phase II study.

Hepatocellular carcinoma (HCC) remains one of the most common neoplasms in the world. Doxifluridine is an oral fluoropyrimidine derivative activated to 5-fluorouracil by uridine phosphorylase which is more expressed in malignant cells. Therefore, we conducted a phase II study to evaluate the activity of oral doxifluridine in patients with advanced hepatocellular carcinoma. Twenty-five advanced hepatocellular carcinoma patients entered the study; doxifluridine was given orally at the initial daily total dose of 2,250 mg for 4 consecutive days every week. All patients are evaluable for toxicity: these included mainly grade 1-2 (WHO) diarrhea, stomatitis, nausea and vomiting; 4 patients (16%) experienced grade 3-4 diarrhea. Twenty-four patients are evaluable for response and 1 complete and 3 partial responses have been observed (response rat 17%, 95% confidence interval: 5-37). Oral doxifluridine at the dose and schedule we used, although having only modest activity in advanced HCC, may represent an alternative to other frequently used chemotherapeutic agents, because of its favorable toxicity profile and its simple route of administration.

Infusions of fluorouracil and leucovorin: effects of the timing and semi-intermittency of drug delivery.

Preclinical and clinical studies have demonstrated that the circadian modulation of 5-FU delivery may reduce toxicities and improve antitumor activity. However, the relative importance of the timing of 5-FU delivery has not been clinically addressed. The aims of this study were to determine the toxicities, the maximum tolerable doses and the activity of a regimen with 5-fluorouracil (5-FU) and leucovorin (LV) administered as a 14-day continuous infusion according to a flat or three different chronomodulated rhythms in patients with metastatic gastrointestinal carcinomas. A total of 113 patients entered the study and their characteristics were comparable among the four groups. Toxicities included mainly stomatitis and diarrhea, and a reduced toxicity was observed in all the three chronogroups that allowed the delivery of higher dose intensities. Response rates were not significantly different among the four groups. These results suggest that a reduction in 5-FU+LV toxicity and an increase in 5-FU dose intensity can be obtained by a nonsinusoidally circadian modulated infusion. However, the reduction in toxicity observed seems to be dependent mainly on the quasi-intermittency and not on the timing of 5-FU+LV delivery.

Suramin in combination with weekly epirubicin for patients with advanced hormone-refractory prostate carcinoma.

BACKGROUND: Suramin and epirubicin are both active agents in the treatment of patients with hormone-refractory advanced prostate carcinoma, with demonstrated antitumor synergism in vitro on human prostate carcinoma cells and different dose-limiting toxicities. The authors conducted this Phase II study to determine the feasibility, toxicity, and antitumor activity of suramin in combination with epirubicin. METHODS: Only patients with hormone-independent advanced prostate carcinoma who had progressive disease after the last therapeutic maneuver they had undergone, including antiandrogen withdrawal, entered the study. Suramin was administered initially as a 6-day continuous infusion for 10 consecutive weeks and then for 6 days every 28 days for a maximum of 6 months. Doses were determined by a computer-assisted dosing system that used Bayesian pharmacokinetics to maintain suramin plasma concentrations of 200-250 microg/mL. Cortisone acetate 25 mg, administered at 8 a.m. and 8 p.m. daily, was begun 4 weeks after the initiation of suramin therapy. Epirubicin 25 mg/m2 was given as a weekly intravenous bolus beginning on Day 1 and was continued for a maximum of 6 months. RESULTS: Twenty-six patients entered the study. Toxicities mainly included World Health Organization Grade 1-2 nausea, fatigue, anorexia, neutropenia, peripheral neuropathy, creatinine elevation, proteinuria, and prolonged prothrombin time, whereas Grade 3 toxicities were uncommon. Among 11 patients with measurable disease, 3 (27%) demonstrated an objective response. Among 24 patients evaluated for prostate specific antigen (PSA) response, 8 (33%; 95% confidence interval 16-55%) had a > or =50% decrease in PSA levels, which lasted a median of 32 (range, 8-52) weeks. Median progression free and overall survival were both 8 months. CONCLUSIONS: The combination of suramin and epirubicin used in the current study is feasible, is associated with moderate toxicities, and has antitumor activity in advanced hormone-refractory prostate carcinoma. However, the results obtained with this combination do not represent major improvements in the treatment of patients with this disease, compared with suramin or epirubicin alone or other available treatments.

Protracted continuous infusion of 5-fluorouracil and low-dose leucovorin in patients with metastatic colorectal cancer resistant to 5-fluorouracil bolus-based chemotherapy: a phase II study.

Continuous-infusion (c.i.) 5-fluorouracil (5-FU) can overcome resistance to bolus 5-FU, and leucovorin (LV) enhances the cytotoxic effects of 5-FU, mainly when the duration of exposure to the latter is prolonged. The main objective of this study was therefore to determine the activity of a prolonged infusion schedule of 5-FU + LV in patients with metastatic colorectal cancer resistant to a 5-FU bolus-based chemotherapy. Only patients with metastatic measurable disease in progression during or within 2 months of the end of a 5-FU bolus +/- LV-based chemotherapy were eligible for the study. 5-FU and l-LV were given as a 14-day c.i. every 28 days, the 5-FU dose being 200 mg/m2 per day and the l-LV dose being 5 mg/m2 per day. A total of 59 patients entered the study, of which 48 were resistant to 5-FU + LV and 11, to 5-FU + levamisole. Treatment was well tolerated, and WHO grade 3-4 toxicities were uncommon (11% of patients developed stomatitis and 7%, diarrhea). According to an intent-to-treat analysis, 10 of 59 patients obtained an objective response (1 complete response, 9 partial responses), for an objective response rate of 16% (95% confidence interval 8-25%). The median progression-free survival and overall survival were 4 and 9 months, respectively. The protracted 5-FU + LV c.i. schedule used in the present study is a well-tolerated and moderately active regimen in metastatic colorectal cancer patients resistant to 5-FU bolus +/- LV. Only randomized studies can determine whether this palliative treatment has advantages in comparison with other second-line therapies such as 5-FU c.i. without LV, irinotecan, or oxaliplatin.

Suramin in combination with 5-fluorouracil (5-FU) and leucovorin (LV) in metastatic colorectal cancer patients resistant to 5-FU+LV-based chemotherapy.

AIMS AND BACKGROUND: Suramin has been shown to be of interest as a potential new anticancer agent because of its capacity to inhibit the binding of several growth factors to their receptors and to inhibit the growth of cancer cells in vitro. Since multi-autocrine loops involving growth factors which are antagonized by suramin have been demonstrated in colorectal cancer, we previously evaluated the activity of suramin in patients with advanced colorectal cancer. Interestingly, in this study three patients who had received 5-FU+LV after suramin, although heavily pretreated with fluoropyrimidines, obtained an objective response. This observation was intriguing as it might have been that suramin had changed the biology of the tumor, making it sensitive to 5-FU+LV. We therefore conducted the present study to investigate the possibility that suramin might overcome the resistance to 5-FU+LV. METHODS AND STUDY DESIGN: Only colorectal cancer patients with metastatic and progressive disease during 5-FU+LV-based chemotherapy were eligible for this study. Suramin was administered for eight weeks at doses determined by means of a computer-assisted dosing algorithm that used Bayesian pharmacokinetics to maintain suramin plasma concentrations of 200-250 microg/ml. 5-FU was administered weekly at a dosis of 450 mg/m2 halfway through a two-hour infusion of I-LV 250 mg/m2 starting one week after the initiation of suramin for a maximum of 26 weeks. RESULTS: Treatment was relatively well tolerated, but no objective responses were observed after the accrual of 13 patients in the first stage of the trial. Consequently, the trial was interrupted according to the initial two-stage sampling design. CONCLUSIONS: The present study does not support the hypothesis that suramin might overcome resistance to 5-FU+LV and its use in colorectal cancer is not recommended.

Maximum tolerable doses of intravenous zidovudine in combination with 5-fluorouracil and leucovorin in metastatic colorectal cancer patients. Clinical evidence of significant antitumor activity and enhancement of zidovudine-induced DNA single strand breaks in peripheral nuclear blood cells.

BACKGROUND: Experimental studies have demonstrated that 5-fluorouracil (5-FU) enhances zidovudine (AZT)-induced DNA strand breaks and cytotoxicity. Phase I studies have demonstrated that the maximum tolerable dose (MTD) of AZT is 8000 mg/sqm when administered i.v. over two hours after weekly 5-FU + l-leucovorin (LV), and that this combination has promising antitumor activity. The purpose of this study was therefore to evaluate the antitumor activity of weekly bolus 5-FU + LV + AZT, administered at its MTD, and to determine whether 5-FU enhances AZT-induced DNA strand breaks in blood nuclear cells. PATIENTS AND METHODS: Twenty-nine chemotherapy-naïve metastatic colorectal cancer patients with measurable disease entered the study to evaluate the activity of a weekly 5-FU 500 mg/m2 i.v. bolus + LV 250 mg/m2 i.v. two-hour infusion + AZT 8000 mg/m2 i.v. two-hour infusion. In 10 different patients, who during three different weeks received 5-FU + LV, AZT and 5-FU + LV + AZT, DNA strand breaks in blood nuclear cells were determined by a fluorescent analysis of DNA unwinding. RESULTS: Treatment was generally well tolerated and WHO grades III-IV toxicities, consisting mostly of diarrhea (17%), were uncommon. One patient died of severe diarrhea with consequent hypokalemia and cardiac arrhythmia. All patients were considered evaluable for response, and 3 (10%) complete and 10 (35%) partial responses were observed, for an objective response rate of 45% (95% confidence limit interval 26%-64%). Both 5-FU + LV and AZT decreased the percentage of double stranded DNA in nuclear blood cells. The greatest effect was observed with 5-FU + LV + AZT, which reduced the percentage of double stranded DNA to 50% and 36% after 24 and 48 hours, respectively, and this interaction between 5-FU + LV and AZT was found to be cumulative. CONCLUSIONS: These studies demonstrate that the present dose and schedule of AZT in combination with 5-FU + LV has significant activity in metastatic colorectal cancer and that the combination of 5-FU + LV with AZT increases the amount of DNA damage. Therefore, AZT in combination with 5-FU + LV warrants further study in colorectal cancer.

Postoperative adjuvant chemoradiotherapy for rectal cancer: analysis of acute and chronic toxicity.

AIMS AND BACKGROUND: The aim of the study was to evaluate acute and chronic toxicity of combined postoperative standard radiation therapy to the pelvis and 5-fluorouracil plus levamisole in resectable rectal cancer. METHODS: Between July 1990 and September 1993, 58 patients with histologically confirmed adenocarcinoma of the rectum entered the prospective study. The schedule consisted of 5-fluorouracil, 450 mg/m2 i.v. for 5 days, and from day 28 5-fluorouracil, 450 mg/m2 i.v. weekly for 24 weeks, plus levamisole given orally at the dose of 150 mg every day for 3 days every 2 weeks for 6 months; radiotherapy (180 cGy/day) 5 days a week for a total dose of 45 Gy was administered from day 28. RESULTS: After the first cycle of chemotherapy (before radiotherapy), overall toxicity was mild. During chemoradiotherapy, dose-limiting toxicity was grade 3 diarrhea and proctitis, for which the combined treatment was interrupted for more than 7 cumulative days in 28 patients. During the 24 weeks of weekly 5-fluorouracil (after radiotherapy), no severe toxicity was reported. Three-year survival and progression-free survival were 65% and 50-55%, respectively. CONCLUSIONS: Although adjuvant chemoradiotherapy is usually feasible, in our study toxicity was severe in a substantial proportion of patients, probably due to the schedule applied. We are evaluating the feasibility and toxicity of a combined treatment which includes 5-fluorouracil in continuous chronomodulated infusion during radiotherapy.

Phase II study of oral doxifluridine in elderly patients with advanced non-small-cell lung cancer.

Elderly patients with advanced non-small-cell lung cancer (NSCLC) are usually excluded from most clinical trials because of the toxicity associated with chemotherapy. About 50% of the new cases of lung cancer occur in patients older than 65 years. Doxifluridine is a fluoropyrimidine derivate which can be administered orally with very low toxicities. This phase II study evaluates the toxicity and activity of a home therapy with oral doxifluridine in elderly advanced NSCLC patients. Thirty-three advanced NSCLC patients, aged 70 years or more, entered the study; median ECOG performance status was 1 (0-2) and 22 patients (66.6%) had metastatic disease. Doxifluridine was given orally in three divided doses, for a total daily dose of 2,250 mg, for 4 consecutive days every week. The treatment was well tolerated; five patients (15%) experienced a grade 3 diarrhea which required doxifluridine dose reduction to 1,500 mg daily. Thirty-one patients are evaluable for response; four partial responses (12.9%) have been observed (95% confidence limit interval 3.6-29.8%); 17 patients (54.8%) had a stabilization of the disease. This study demonstrates that a home therapy with oral doxifluridine in elderly NSCLC patients is feasible and well tolerated and should encourage further studies.

Treatment of metastatic renal cell carcinoma with constant-rate floxuridine infusion plus recombinant alpha 2b-interferon.

BACKGROUND: Floxuridine (FUDR) and alpha-interferon (IFN) are active agents in advanced renal cell carcinoma, with different dose-limiting toxic effects and antitumor synergism in experimental models. The main purpose of this phase II study was to assess the activity and toxic effects of a combination of FUDR and alpha 2b-IFN in metastatic renal cell carcinoma. PATIENTS AND METHODS: Metastatic renal cell carcinoma patients with measurable disease entered the study. FUDR was administered as a constant-rate continuous infusion for 14 days every 28 days at a starting daily dose of 0.1 mg/kg and with dose escalations of 0.025 mg/kg/day at each subsequent cycle if WHO > or = 2 toxicity had not occurred. IFN-alpha 2b 10 x 10(6) I.U. was administered intramuscularly 3 times per week. RESULTS: Forty-two patients entered the study and a total of 272 cycles of FUDR + alpha 2b-IFN were administered. In 41 evaluable patients WHO grade III-IV toxic effects included nausea and vomiting (22%), diarrhea (32%), stomatitis (12%), fatigue (27%) and anorexia (12%). It was possible to increase the initial FUDR does in 21 (50%) patients; the median FUDR dose intensity was 0.35 mg/kg/week (range 0.18-0.54). Among 39 evaluable patients, 3 (7.5%) complete and 10 (25.5%) partial responses were observed (response rate 33%, 95% confidence interval (CI) 19%-50%) which lasted a median of 13 months (5.5-40+). Responses also occurred in liver (2), in patients pretreated with systemic therapy (5) and in patients who had other unfavourable prognostic characteristics (7). Median progression-free and survival times were 9 and 16 months, respectively. CONCLUSIONS: In this study FUDR + alpha 2b-IFN demonstrated interesting activity in metastatic renal cell carcinoma, showing promise also in patients with unfavourable prognostic characteristics. The antitumor activity of FUDR and alpha 2b-IFN seems to be cumulative, but cumulative toxicity is also observed. These results require confirmation in randomised trials.

Intravenous azidothymidine with fluorouracil and leucovorin: a phase I-II study in previously untreated metastatic colorectal cancer patients.

PURPOSE: To determine the plasma pharmacokinetics and the maximum-tolerated dose (MTD) of intravenous (IV) azidothymidine (AZT) administered 90 to 120 minutes after fluorouracil (5-FU) and leucovorin and to preliminarily evaluate the antitumor activity of this combination in metastatic colorectal cancer. PATIENTS AND METHODS: 5-FU 500 mg/m2 IV bolus was administered once a week in the middle of a 2-hour infusion of leucovorin; AZT was given as a 90 to 120-minute IV infusion 60 minutes after 5-FU. Initial AZT dose was 0.5 g/m2, and it was escalated in successive cohorts of three patients by 0.5 to 2 g/m2. RESULTS: Thirty-five chemotherapy-naive metastatic colorectal cancer patients were entered onto the study, and AZT doses ranged from 0.5 to 10 g/m2. The peak AZT plasma concentration increased from 21.9 to 995.6 micromol/L. The area under the concentration/time curve (AUC) also showed a progressive, but not linear increase from 40.34 to 3,108 h x micromol/L. The most relevant toxicity was diarrhea, which was severe in six patients (17%). Toxicities were not AZT-dose-related, except fpr hypotension, which occurred in patients treated at AZT doses > or = 7 g/m2 and became dose-limiting for AZT 10 g/m2. Among 34 assessable patients, 15 objective responses were observed (44%; 95% confidence interval 27 to 62), lasting a median of 44 weeks; five (15%) were complete. CONCLUSION: AZT doses > or = 6 g/m2 administered IV over 90 to 120 minutes produce maximum plasma concentration and AUC similar to those previously reached in murine tumor models. Dose-limiting toxicity is hypotension, which occurs at AZT 10 g/m2. The recommended AZT dose for further studies is 8 g/m2. The combination of 5-FU plus leucovorin plus AZT is feasible with acceptable toxicities, and has promising activity in metastatic colorectal cancer.

Suramin in patients with metastatic colorectal cancer pretreated with fluoropyrimidine-based chemotherapy. A phase II study.

BACKGROUND: The results of conventional chemotherapy in metastatic colorectal cancer are discouraging, making it a logical target for new treatment approaches a necessary consideration. Suramin is a polysulfonated naphthylurea that binds to several cellular growth factors and has in vitro activity against human colorectal cancer cells. Therefore, this Phase II study of patients with metastatic colorectal cancer was conducted to evaluate its clinical activity. METHODS: Suramin was administered as a 6-day continuous infusion every week for 8 consecutive weeks by using a computer-assisted dosing of Bayesan pharmacokinetics to maintain suramin plasma concentrations of 200-250 micrograms/ml. Twenty patients with metastatic colorectal cancer who were not responsive or in progression within 6 months after completing fluoropyrimidine-based chemotherapy entered the study. RESULTS: Toxicities included mostly Grade 1 and 2 fatigue, nausea and vomiting, peripheral neurotoxicity, creatinine elevation, and proteinuria. No objective responses were observed, but three of three patients who received 5-fluorouracil plus folinic acid after suramin achieved a partial response. CONCLUSIONS: These results indicate that suramin is inactive in patients with metastatic colorectal cancer pretreated with fluoropyrimidines. Pretreatment with suramin may have changed the biology of the tumor, sensitizing it to fluoropyrimidines. Studies to investigate this possibility are in progress.

Oral doxifluridine in elderly patients with metastatic colorectal cancer: a multicenter phase II study.

BACKGROUND: Cancer chemotherapy in elderly patients is an important and under-researched area. Doxifluridine is a fluoropyrimidine derivative and is activated to 5-fluorouracil by uridine phosphorylase, which is more highly expressed in malignant cells. Because of the high bioavailability and low toxicity of oral doxifluridine we conducted this phase II trial to evaluate the feasibility, toxicity and activity of a home therapy with oral doxifluridine in elderly metastatic colorectal cancer patients. PATIENTS AND METHODS: Forty-three elderly metastatic colorectal cancer patients entered the study: their median ECOG performance status was 1 (0-2) and median age 74 years (69-83), the predominant site of metastasis was liver and all but one of the patients had received no previous chemotherapy. Doxifluridine was given orally at the initial daily total dose of 2250 mg for 4 consecutive days every week. The daily dose was reduced to 1500 mg if toxicities greater than grade 2 (WHO) occurred. RESULTS: Forty-two patients are evaluable for toxicity: treatment was well tolerated, with the most common side effect being diarrhea, severe in 7 (17%) patients (6 grade 3 and 1 grade 4). Thirty-six patients are evaluable for response and 2 complete and 3 partial responses have been observed (response rate 14%; 95% confidence limit interval 5%-29%). CONCLUSIONS: This study demonstrates that a home therapy with oral doxifluridine in elderly advanced colorectal cancer patients is feasible, with a relatively low rate of toxicity, and has moderate activity, comparable to that of intravenous 5-fluorouracil. Therefore, this treatment may be considered for the management of advanced colorectal cancer in the elderly.

Synergistic antiproliferative activity of suramin and alpha 2A-interferon against human colorectal adenocarcinoma cell lines: in vitro studies.

Suramin, a polysulphonated naphthylurea proven to be an effective anticancer agent against selected tumours, and alpha 2A-interferon (alpha 2A-IFN) were investigated for their combined effects on HCT-8, HCT-15, CL-D, SW-480 and SW-620 human colorectal adenocarcinoma cell lines. All lines were sensitive to clinically achievable concentrations of suramin in a dose-dependent manner, while alpha 2A-IFN alone induced only a modest reduction of cell growth. Concomitant treatment with suramin and alpha 2A-IFN resulted in a synergistic inhibition of cell viability in each cell line at all doses tested. However, when suramin and alpha 2A-IFN were administered sequentially, inhibition of cell viability was clearly dependent on the timing of treatment schedule, with maximum effect obtained when alpha 2A-IFN was administered prior to suramin. In contrast, pretreatment with suramin was markedly inferior to the former one. In conclusion, suramin and alpha 2A-IFN exert a synergistic effect on human colorectal cell proliferation in vitro at clinically achievable concentrations. This observation may have clinical relevance although the mechanisms of interaction remain to be elucidated.