Randomized phase II study of irinotecan plus mitomycin C vs. oxaliplatin plus mitomycin C in patients with advanced fluoropyrimidine/leucovorin-pretreated colorectal cancer.
BACKGROUND
Irinotecan and oxaliplatin are two new agents with promising activity in advanced colorectal cancer. Based on preclinical and clinical evidence that both drugs might act synergistically with mitomycin C, a randomized study using a 'pick the winner' design was undertaken to determine the effectiveness and tolerance of these two combination schedules in patients with fluoropyrimidine/leucovorin-pretreated advanced colorectal cancer.


METHODS
Sixty-four patients with metastatic colorectal cancer, who progressed while receiving or within 6 months after discontinuing palliative chemotherapy with fluoropyrimidines/leucovorin were enrolled onto this study. They were randomly assigned to treatment with irinotecan 120 mg/m2 on days 1 + 15 plus mitomycin C 8 mg/m2 on day 1 (arm A) or oxaliplatin 85 mg/M2 on days 1 + 15 plus mitomycin C 8 mg/m2 on day 1 (arm B). In both treatment arms, courses were repeated every 4 weeks.


RESULTS
The objective response rate in arm A is 7/33 (21.2%; 95% confidence interval, 9.0-38.9%) as compared to 5/31 in arm B (16.1%; 95% CI, 5.5-34.7%). Stable disease was noted in 48.5 vs. 45.2%, whereas the tumor progressed in 30.3 vs. 38.7%, respectively. Similar to the recorded response activities, the difference of the two combination regimens in terms of median time to progression (7.0 vs. 5.2 months) and overall survival (12.0 vs. 11.2 months) was only minor and clincally insignificant. The tolerance of treatment was acceptable in both arms, though severe adverse reactions requiring dose reductions (30 vs. 16%) and treatment delays (22 vs. 13% of courses) were more commonly noted with irinotecan/mitomycin C. The most common toxicities in arm A were neutropenia (85%; WHO grade 3/4 in 33%), thrombocytopenia (52%), diarrhea (45%), emesis (52%) and alopecia (92%). In arm B, common toxicities included neutropenia (68%; grade 3/4 in 13%), thrombocytopenia (81%), emesis (52%), and peripheral neutropathy (48%).


CONCLUSIONS
Both mitomycin C combination regimens seem to provide an acceptable therapeutic index in patients with fluoropyrimidine/leucovorin-pretreated metastatic colorectal cancer. In view of the increasing need for a broader chemotherapeutic armentarium for second-line therapy of this common malignant disease, both regimens may be worthwhile to undergo further clinical investigation.
Scheithauer
Werner
W
Department of Internal Medicine I, Vienna University Medical School, Austria.
Kornek
Gabriela V
GV
Brugger
Stefan
S
Ullrich-Pur
Herbert
H
Valencak
Julia
J
Raderer
Markus
M
Fiebiger
Wolfgang
W
Kovats
Erwin
E
Lang
Fritz
F
Depisch
Dieter
D
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000556:secondary; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011446:Prospective Studies; D016879:Salvage Therapy; D016896:Treatment Outcome
D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D016685:Mitomycin; D000077146:Irinotecan; D002955:Leucovorin; D002166:Camptothecin