Multicenter phase I study of irinotecan plus raltitrexed in patients with 5-fluorouracil-refractory advanced colorectal cancer.
Irinotecan and raltitrexed are active against advanced colorectal cancer, act through different mechanisms, and have non-overlapping toxicity profiles. In vitro studies have shown a schedule-dependent synergism between both drugs. The aim of this multicenter study was to determine the maximum tolerated dose (MTD) of this combination. Patients with 5-fluorouracil-refractory, advanced colorectal cancer were eligible. Dose escalation consisted of irinotecan (250-350 mg/m(2) as a 60-min infusion) in combination with a fixed dose of raltitrexed (3 mg/m(2) as a 15-min infusion, 1 h after irinotecan). Courses were repeated every 21 days. Three to 6 patients were to be included at each dose level. Dose limiting (NCI-CTC grade 3-4) toxicities (DLT) were assessed during the first 2 cycles. Thirteen patients were recruited (4, 3 and 6 in levels I, II and III, respectively). Main toxicity was diarrhea and asthenia, whereas myelotoxicity was mild. At level III, 2/6 patients experienced DLT (grade 4 diarrhea and neutropenia). The MTD was not reached, but further dose escalation was not attempted. Among 12 patients with measurable disease, 2 partial responses were observed for an overall response rate of 17%. The combination of single-agent full doses of irinotecan (350 mg/m(2)) and raltitrexed (3 mg/m(2)) in a 3-weekly schedule is feasible, with mild toxicity and a promising clinical activity. Diarrhea is the DLT, but it is not more common or severe than that described with irinotecan alone.
Medical Oncology Department of Hospital Universitario La Fe de Valencia, Valencia, Spain. aparicio_josurt@gva.es
Jorge
J
Aparicio
Ramón
R
de las Peñas
José María
JM
Vicent
Salvador
S
Garcerá
Cristina
C
Llorca
Inmaculada
I
Maestu
Ana L
AL
Yuste
Jordi
J
Farrés
D000368:Aged; D000964:Antimetabolites, Antineoplastic; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D000077146:Irinotecan; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011799:Quinazolines / Q000008:administration & dosage / Q000009:adverse effects; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects; D016896:Treatment Outcome
D000964:Antimetabolites, Antineoplastic; D011799:Quinazolines; D013876:Thiophenes; D000077146:Irinotecan; C068874:raltitrexed; D005472:Fluorouracil; D002166:Camptothecin