Comparison of oral ftorafur and intravenous 5-fluorouracil in patients with advanced cancer of the stomach, colon or rectum

In this prospective randomized study the effect of oral Ftorafur was compared with that of intravenous 5-fluorouracil in patients with advanced adenocarcinoma of the stomach, colon or rectum. Forty-five patients were evaluable. The overall response rates were 26.9% in the 5-fluorouracil group, 26.7% in the Ftorafur group. The median duration of response was 6 months in both groups. Survival in the 5-fluorouracil group was slightly better than in the Ftorafur group, but the difference was not statistically significant. The myelosuppressive effect of 5-fluorouracil was significantly stronger than that of Ftorafur. Gastrointestinal side effects were more pronounced in the Ftorafur group, but the difference was not statistically significant.     

Ftorafur, adriamycin, cyclophosphamide and BCG in the treatment of metastatic breast cancer.

Ftorafur is a 5-fluorouracil analogue which is slowly metabolized to 5-FU, resulting in prolonged therapeutic levels of this latter drug. Ninety-one evaluable patients with metastatic breast cancer were treated with Ftorafur, Adriamycin, cyclophosphamide, and BCG (ACFTOR-BCG), in an attempt to increase the effectiveness of the program or decrease its myelosuppressive toxicity. The results of this trial were compared to those previously reported with the combination of 5-FU, Adriamycin, cyclophosphamide, and BCG (FAC-BCG). Overall objective response rates were 65% and 76% for ACFTOR-BCG and FAC-BCG, respectively. Durations of response were 12 months and 14 months for ACFTOR-BCG and FAC-BCG (p = 0.53). The median survival of responders was 22 and 23.9 months, respectively. Substantial toxicity was observed with Ftorafur: nausea and vomiting severe enough to cause weight loss was observed in a substantially higher fraction of the patients treated with this drug than with 5-FU. Other side-effects, which were not observed with the 5-FU combination, were somnolence, dizziness, personality changes, tremor, ataxia, and confusion. No differences in myelosuppressive toxicity were observed between the two combinations, and the incidence of infectious complications was identical. The combination of Ftorafur, Adriamycin, cyclophosphamide and BCG did not offer any advantages with respect to increased effectiveness or reduced toxicity over the FAC-BCG regimen in breast carcinoma.     

Experimental study on the carcinogenicity of the Cytostatic drug ftorafur (tegafur)

Long-term carcinogenicity of Ftorafur (Tegafur) was studied in rodents. Rats and mice were treated for one year per os with 40 (mice) and 60 (rat) mg/kg Ftorafur twice a week and were followed for their entire life. Analysis of the data provide no evidence for the carcinogenicity of Ftorafur in rodents. These findings are similar to other antimetabolite studies and contrasts with the carcinogenic alkylating agents.     

Biological and biochemical properties of the 2-hydroxyl metabolites of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea.

The lethal and bone marrow toxicity and antitumor activity of the cis- and trans-2-hydroxylated metabolites of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) have been correlated with their relative in vitro alkylating and carbamoylating activities. Both the isomers have considerably greater alkylating activity and shorter chemical half-lives than the parent compound and on a molar basis have greater antitumor activity against i.p. L1210 leukemia. However, in terms of molar doses resulting in the death of 10% of normal mice, the cis- and trans-2 isomers were 2- and 3-fold more toxic than was CCNU in normal mice. In comparing the antitumor activity produced by a maximum nonlethal dose for each compound, we found that the trans isomer had activity identical to that of CCNU (413 and 410% increased life span compared to control), and the cis isomer had considerably less (152%). Like chlorozotocin, both isomers possess low carbamoylating activity and increased water solubility, two features that have been considered possible contributors to the bone marrow-sparing character of chlorozotocin. However, in the murine model the human bone marrow colony formation (CFU-C) assay neither hydroxylated metabolite of CCNU was associated with reduced myelotoxicity.     

Clinical evaluation of ftorafur (pyrimidine-deoxyribose n1-2'-furanidyl-5-fluorouracil).

Ftorafur, a possible sustained-release formulation of 5-fluorouracil, was administered to 27 patients with metastatic cancers. The majority of patients had adenocarcinoma, most of which (60%) arose from the gastrointestinal tract. Ftorafur was given i.v. at doses ranging from 1 to 3 g/sq m/day for 5 days, repeated every 2 to 3 weeks. Gastrointestinal (68%) and neurological (17%) toxicities were the most common side effects encountered in this study and became dose limiting at doses greater than 2 g/sq m/day for 5 days. Myelosuppression (7%) was infrequent. Other toxicities included weakness (20%), chills and fever (8%), and phlebitis (1%). Of 24 evaluable patients, 4 (17%) responded (1 complete and 3 partial remissions). Responses were seen in 1 of 8 carcinomas of the lung, 1 of 5 carcinomas of the stomach, 1 of 3 carcinomas of the colon, and 1 of 1 carcinoma of the jejunum. The duration of response ranged from 4 to 58 weeks. The results of this study resemble somewhat those obtained with the laborious 5-day continuous i.v. infusion of 5-fluorouracil. Daily doses of 2 g/sq m for 5 days, repeated every 3 weeks, produced significant antitumor effect and tolerable toxicity.     

Phase I-II study of ftorafur and methyl-CCNU in advanced colorectal cancer.

The combination of Ftorafur (NSC-148958) and methyl-CCNU (NSC-95441) was evaluated in 36 patients with advanced colorectal cancer. The principle toxicities encountered were myelosuppression, gastrointestinal, and neurological. There were no complete responses and only 5/34 (14.7%) patients achieved a partial response. Methyl-CCNU and Ftorafur does not appear to be an effective combination in advanced adenocarcinoma of the colon and rectum.     

Phase I study of ftorafur, an analog of 5-fluorouracil.

Ftorafur, a furanyl analog of 5-fluorouracil (5-FU), is reported to be five to six times less toxic and possibly more effective in cancer of the breast and colon than 5-FU. The drug was synthesized, formulated, and utilized in toxicologic studies, and then in 24 patients with advanced incurable malignancies. When Ftorafur is given by intravenous push, it results in immediate flushing, dizziness, nausea, retching, and in some cases transient hypotension. These immediate side effects are largely eliminated by administering the drug slowly by infusion. In patients, 60 mg/kg of Ftorafur given i.v. daily for up to 10 days resulted in mild toxicity. However, 80 mg/kg given i.v. daily for 7 days resulted in severe toxicity, with nausea, vomiting, stomatitis, leukopenia, and thrombocytopenia. These studies confirm those of the Russian investigators as to toxicity and dosage, even with a different method of administration more convenient for therapy. Phase II studies are presently being carried out to compare the effectiveness of Ftorafur and 5-FU.     

Genotoxicity of 1- and 2-nitropropane in the rat

2-Nitropropane (2-NP) is a rat liver carcinogen, whilst the 1-isomer is non-carcinogenic in rodents. Although DNA repair tests in the rat liver discriminated clearly between the carcinogenic and the non-carcinogenic isomer, uniformly negative results have been published for the mouse bone marrow micronucleus test (BMMN test) with both isomers. Therefore, the latter assay did not discriminate between the carcinogenic and the non-carcinogenic isomer. To investigate whether this is due to endpoint specificity or organospecificity of 2-NP, studies were carried out in the rat in which micronucleus induction (bone marrow and liver) and unscheduled DNA synthesis (UDS) induction (liver) were measured after oral treatment with either nitropropane isomer. 2-NP induced UDS in the liver whilst the 1-isomer was negative, thus confirming the published studies. In the BMMN test, occasional small increases in the incidence of micronuclei were found for both compounds, but results were interpreted as negative after considering the control background data and the lack of reproducibility. By contrast, the liver micronucleus test revealed a clastogenic effect of 2-NP in the liver. This indicates that 2-NP induces chromosome aberrations as well as DNA repair in vivo, but it seems to act organospecifically. For 1-NP a slightly increased incidence of micronuclei was found in the liver, which was accompanied by a markedly increased mitotic index. It therefore remains questionable as to whether this increased micronucleus frequency for 1-NP is an indicator of a clastogenic effect, or whether it is caused by an increased cell proliferation induced by 1-NP. Consequently, it is too early to conclude whether the liver micronucleus assay is able to discriminate between the carcinogenic and non-carcinogenic isomer. However, the results provide further evidence that bone marrow assays are insufficient for the detection of all genotoxic carcinogens in vivo. This indicates the need for analysing a second tissue, particularly when negative bone marrow results have been obtained with in vitro genotoxins.     

Oral Ftorafur Versus Intravenous 5-Fluorouracil: A comparative study in patients with colorectal cancer

The toxicities of ora] Ftorafur (1 g/m²/day 1-21) and intravenous 5-fluorouracil (5-FU) (500 mg/m²/day 1-5) were compared in a prospective randomized study in patients with colorectal cancer. The treatment courses were repeated every 6th week. Leu-copenia was more common after 5-FU. Leucocyte nadir in connection with first treatment cycle was on average seen on day 15 in patients receiving 5-FU and on day 28 in patients receiving Ftorafur. Significantly more patients on 5-FU developed stomatitis. There was no difference in the number of patients with diarrhea or nausea/vomiting. Median survival and response rates were not significantly different after the two treatment schedules.     

Hydroxylated metabolies of R,S-1-(tetrahydro-2-furanyl)-5-fluorouracil (Ftorafur) in rats and rabbits.

Two hydroxylated metabolies (M1 and M2) have been isolated from rabbit urine after administration of Ftorafur (FT). The structures of 3'-OH-FT and 4'-OH-FT were assigned to M1 and M2, respectively. A reverse-phase high performance liquid chromatography assay was developed for jeasuring FT, M1, M2, and 5-fluorouracil (FU) plasma levels. M1, M2, and FU were present in rabbit and rat plasma in greatly varying concentrations after FT administration. Pharmacokinetic studies suggest that FU formation proceeds via metabolic intermediate(s) and that the extent of FT activation is variable. A horse liver thymidine phosphorylase ,reparation capable of catalyzing the conversion of beta-ribo-2'-deoxy-5-fluorouracil to FU was inactive against FT and M1. However, 20% of M2 was converted to FU by this enzume, which suggests that the urinary metabolite M2 consisted of a mixture of enantiomers with 20% present in the natural beta-D configuration. The stereochemistry of M1 remains unknown. Hydroxylation of FT to beta-D-4'-OH-FT and subsequent cleavage to FU by thymidine phosphorylase represents one possible activation mechanism of FT to FU. ,owever, lack of correlation between plasma levels of M2 and FU indicates that this mode of metabolic activation may account for only part of the overall activation of FT in vivo.     

Modelling of ftorafur and 5-fluorouracil pharmacokinetics following oral UFT administration. A population study in 30 patients with advanced breast cancer

PURPOSE: The pharmacokinetics of ftorafur, 5-fluorouracil (5FU) and uracil were investigated in order to built a population pharmacokinetic model for the anticancer drug UFT, administered with leucovorin and vinorelbine. METHODS: A total of 31 patients with metastatic breast cancer were treated with escalating oral doses of UFT (300 to 500 mg per day) plus leucovorin (90 mg per day) in combination with intravenous vinorelbine (15 to 25 mg/m(2)). Concentration-time data were obtained on days 1, 8, 15 and 21 of cycle 1. RESULTS: Of the 31 patients treated, 30 were available for the pharmacokinetic analysis. Ftorafur, 5FU and uracil appeared rapidly in plasma and showed large interpatient variations. Ftorafur concentrations were higher than those of 5FU and uracil. AUC significantly increased between day 1, and days 8, 15 and 21. Ftorafur C(max) and AUC values were proportional to UFT dose, whereas C(max) and AUC values of 5FU and uracil were not linearly related to UFT dose. The pharmacokinetics of ftorafur were ascribed to a two-compartment open model in which 5FU was produced from the central compartment. The absorption and exponential distribution rate constants were assumed equal. The effect of uracil on 5FU elimination was straightforward, since no reasonable curve-fitting could be obtained for 5FU data when this covariate was not taken into account. The uracil concentration inducing a 50% reduction in 5FU elimination was 2.67 micro mol.l(-1). This result confirms the important role played by uracil as a competitive inhibitor of 5FU catabolism. CONCLUSION: A pharmacokinetic model for ftorafur and 5FU was developed and should be useful to further study drug interactions and establish dosing guidelines.     

Pharmacokinetics of leucovorin (D,L-5-formyltetrahydrofolate) after intravenous injection and constant intravenous infusion

The pharmacokinetics of the active and inactive diastereoisomers of leucovorin and its active metabolite, 5-methyltetrahydrofolate (5-CH3-THF) were studied after iv injection of leucovorin in normal human subjects at a dose of 28 mg/m2, and in patients given 500 mg/m2 daily by constant iv infusion for a 5.5 day period. In both studies the plasma half-life (t1/2) of the active isomer, L-formyltetrahydrofolate (CHO-THF), was only 32 to 35 minutes, whereas the inactive isomer, D-CHO-THF had a plasma t 1/2 of 352 to 485 minutes. During constant infusion, the plasma levels reached plateaus of 2.33 and 37.5 microM for L-CHO-THF and D-CHO-THF, respectively. The inactive isomer was cleared from plasma only by urinary excretion of the unchanged drug. The active isomer was also excreted unchanged in the urine but in addition was extensively metabolized to the active metabolite L-5-CH3-THF. The active metabolite achieved a plasma level of 4.85 microM during constant infusion and appeared to have a longer t 1/2 after constant infusion than was observed after iv injection. Furthermore a larger apparent volume of distribution (Vd) of 5-CH3-THF was obtained in the constant infusion study. These findings suggest that constant iv infusion of large doses of leucovorin can considerably expand the intracellular pools of active folate. The consequence of the extensive accumulation of the inactive isomer, D-CHO-THF, is not known. However, the small Vd of D-CHO-THF suggests that it does not extensively accumulate in tissues.     

Mutagenicity of the enantiomers of the diastereomeric bay-region benzo(c)phenanthrene 3,4-diol-1,2-epoxides in bacterial and mammalian cells

The mutagenic activities of the enantiomers of the pair of diastereomeric bay-region benzo(c)phenanthrene 3,4-diol-1,2-epoxides were evaluated in histidine-dependent strains of Salmonella typhimurium and in an 8-azaguanine-sensitive Chinese hamster cell line. In strains TA 98 and TA 100 of S. typhimurium, the range in mutagenic activity observed for the four optically active isomers was less than 4- and 2-fold, respectively. The diol-epoxide with (1S,2R,3R,4S) absolute configuration and the benzylic hydroxyl group trans to the epoxide oxygen [(+)-diol epoxide-2] was the most active isomer in both strains. The enantiomeric (-)-diol-epoxide-2 isomer, with (1R,2S,3S,4R) absolute configuration identical to that of the exceptionally tumorigenic (+)-diol-epoxide-2 isomers of benzo(a)pyrene, benz(a)anthracene, and chrysene, was the least active isomer in strain TA 98 (27%) and the second most active isomer in strain TA 100 (90%). In Chinese hamster V79 cells (-)-diol-epoxide-2 was the most active of the four benzo(c)phenanthrene isomers, and a 4- to 5-fold range in mutagenic activity was observed. The differences in mutagenic activity between the four bay-region diol-epoxide isomers of benzo(c)phenanthrene in the three test systems are relatively small when compared with results from similar studies with optically active bay-region diol-epoxide isomers of three other polycyclic aromatic hydrocarbons, and may be explicable, in part, by a tendency of the hydroxyl groups of benzo(c)phenanthrene diol-epoxides to adopt comparable pseudodiequatorial conformations.     

Induction chemotherapy with carboplatin and ftorafur in advanced head and neck cancer. A randomized study.

From 1987 to 1989, 42 patients with locally advanced squamous cell carcinoma of the head and neck (Stages III-IV, Mo) were randomized to receive radiotherapy (Group A) or three courses of induction chemotherapy followed by radiotherapy (Group B). There were 36 evaluable patients, 17 in Group A and 19 in Group B. The radiotherapy regimen was the same for both groups, 66-74 Gy total tumor doses with standard fractionation scheme of 2 Gy/day. The chemotherapy regimen was a combination of carboplatin 400 mg/m2 by intravenous bolus injection on day 1, and Ftorafur 1,000 mg/m2 orally once a day for 14 days. Cycles were given every 4 weeks. The complete response rate in Group A was 65%; in group B it was 31.5% after induction chemotherapy and 84% after radiotherapy. The 42-month actuarial overall survival rates were 34% for Group A and 47% for Group B (P = NS). Patients from both groups with a complete response had a significantly longer survival time than those with a partial response (P less than 0.001). No significant differences in disease-free survival were found between the two treated groups. The chemotherapy regimen was well tolerated, with moderate hematologic and gastrointestinal toxicity. Increased in radiation toxicity by chemotherapy was not observed.     

Chemoimmunotherapy with or without oophorectomy in premenopausal patients with advanced breast cancer.

Ninety-eight premenopausal patients with stage IV breast cancer were treated with chemoimmunotherapy alone, or with combination oophorectomy-chemoimmunotherapy either simultaneously (chemoimmunotherapy within four weeks of oophorectomy) or sequentially (delayed chemoimmunotherapy until evidence of progressive disease or no response to oophorectomy). The chemoimmunotherapy consisted of a three-drug combination of Adriamycin, cyclophosphamide, and 5-fluorouracil or Ftorafur; immunotherapy consisted of either oral levamisole, BCG by scarification, or a combination of both. Forty patients underwent simultaneous oophorectomy-chemoimmunotherapy, with a response rate of 85% and a median duration of response of 25 months. Response rate of 69% and a median duration of response of 16.6 months was observed with the 29 patients who received sequential oophorectomy-chemoimmunotherapy. Another 29 patients were treated with chemoimmunotherapy alone and achieved a response rate of 87% and a median duration of response of 11.8 months. Though there were no significant differences in the response rate, patients treated with chemoimmunotherapy alone had a significantly shorter median duration of response (P less than 0.05). This would suggest that oophorectomy in combination with chemoimmunotherapy is the most favorable treatment modality for premenopausal patients with advanced metastatic breast cancer.     

Immunobiology and therapeutic manipulation of heterotransplanted Nb rat prostatic adenocarcinoma

Summary Nb rat prostatic adenocarcinomas, previously induced by the administration of testosterone and estrogen, have been serially studied as heterotransplants into congenitally athymic (nude) mice and into groups of Nb rats. This animal system has been used to evaluate the chemotherapeutic efficacy of 5-fluorouracil and Ftorafur. The use of both species was to determine if there would be any significant difference in relative tumor growth in nude mice which lack functional T cells as opposed to intact Nb rats. The autonomous tumor, 102 Pr, is the subject of the thesis presented herein. One donor Nb rat bearing 102 Pr prostatic adenocarcinoma served as the donor for this experiment. The nude mice and Nb rats received the transplant on the same date and were subjected to the chemotherapies outlined above and were treated after there was sufficient increase in tumor volume from the 2 mm³ wedge to assure growth and neovascularity (>60 mm³). Statistically significant data was presented revealing 5-fluorouracil to be efficacious in the treatment of these tumors. Also presented is data revealing differences in growth versus time in the respective recipient animal hosts. It is suggested herein that this combination animal model system could be used for screening potential cytotoxic chemotherapeutic agents.Support for this research was funded by the University of California Cancer Research Coordinating Committee Grant #78D10 awarded to Dr. Drago, and the National Cancer Institute Grant #20816 awarded to Dr. Gershwin, who is the recipient of the U.S. Public Health Service Research Career Development Award AI00193     

A phase II trial of ftorafur: adriamycin and mitomycin-C (FAM II) in advanced gastric adenocarcinoma.

Fifteen patients with advanced gastric cancer were treated with the combination of Ftorafur, Adriamycin and mitomycin-C (FAM II). Three patients showed partial responses, in five the disease remained stable for at least 3 months and seven showed progression while on treatment. All responding patients showed survival in excess of 12 months. Hematologic toxicity was of only moderate severity. Median white count nadir was 3500 cells/mm3 and median platelet nadir was 187,000 cells/mm3. Four patients had white count nadirs from 2000--2500 cells/mm3 and three had nadirs from 500--1500 cells/mm3; also there were four with platelet nadirs less than 100,000/mm3. However, no drug-related infections occurred and no platelet transfusions were required. The major non-hematologic toxicities of the regimen were nausea, vomiting, dizziness, vertigo, and rhinorrhea. These toxicities were limiting and resulted in termination of the trial because of poor patient acceptance and the failure of the combination to exhibit a therapeutic advantage over the similar combination (FAM) that employed weekly 5-fluorouracil in place of Ftorafur.     

UFT-induced haemolytic anaemia

A case of haemolytic anaemia in a patient under treatment with UFT for metastatic colon cancer is reported. Haemolytic anaemia has previously been associated with many other chemotherapeutic agents, but not with UFT, an oral anticancer agent combining tegafur (Ftorafur, a prodrug of 5-fluorouracil) and uracil.     

LFP方案双途径化疗治疗胃肠道肿瘤的临床观察

[目的]探讨腔内化疗配合全身化疗治疗晚期胃肠道恶性肿瘤的临床疗效。[方法]将术后腹腔转移或失去手术时机的晚期胃肠道癌随机分为治疗组和对照组。治疗组亚叶酸钙(CF)、呋喃氟尿嘧啶(FT 207)、顺铂(PDD)联用 ,行腹腔联合静脉化疗 ,对照组行CF、FT 207、PDD联用单纯静脉化疗 ,两组化疗药物总剂量相同。[结果]治疗组有效率为66.67 % ,1年生存率为60 % ;对照组有效率为40.54% ,1年生存率为35 % ,统计学差异明显(P<0.05) ,而治疗组不良反应明显轻于对照组(P<0.01)。[结论]LFP方案腹腔联合静脉化疗是治疗晚期胃肠道恶性肿瘤的有效方法 ,较单纯静脉化疗毒副作用明显减轻 ,有效率及1年生存率有所提高。     

左旋咪唑与呋喃氟脲嘧啶伍用对小鼠抗肿瘤及免疫功能的影响

本文采用呋喃氟脲嘧啶(FT-207)与增效减毒剂左旋咪唑(LMS)伍用来提高FT-207的疗效。结果伍用对小鼠S-180肉瘤的抑制作用与LMS的剂量有关,以低剂量的LMS(1mg/kg)抑瘤最佳,并能拮抗FT-207所致小鼠白细胞下降,增加小鼠胸腺和脾脏重量,促进小鼠腹腔内巨噬细胞吞噬功能,提高小鼠脾脏中NK细胞活性。