Oxaliplatin plus irinotecan and leucovorin-modulated 5-fluorouracil triplet regimen every other week: a dose-finding study in patients with advanced gastrointestinal malignancies.
BACKGROUND
Oxaliplatin (OXA) and irinotecan (IRI) are active drugs in first-line as well as second-line treatment of advanced colorectal cancer patients, their toxicity profiles are not overlapping, and both drugs have shown synergism with folinic acid-modulated 5-fluorouracil (5-FU). We planned this phase I study to define the dose-limiting toxicities (DLTs), the maximum tolerated doses (MTDs), and the recommended doses (RDs) for a triplet regimen including OXA plus IRI on day 1, and 6S-folinic acid (LFA) plus 5-FU on day 2, every 2 weeks.


METHODS
At least three patients had to be treated at each dose level, and the trial proceeded if no more than 33% of patients showed a DLT after the first cycle. Starting from OXA 85 mg/m(2) (over 2 h) and IRI 150 mg/m(2) (over 1 h), an alternated escalation was planned up to 110 mg/m(2) and 200 mg/m(2), respectively. Thereafter, a fixed dose of LFA, 250 mg/m(2) (as 2-h infusion), plus an escalating dose of 5-FU (from 650 to 800 mg/m(2) as an intravenous bolus) was added on day 2 to the previous dose level of OXA and IRI.


RESULTS
Forty-six patients, all but four affected by advanced colorectal primaries, entered this study. The MTDs for OXA and IRI given on the same day were 110 and 200 mg/m(2): these doses caused a DLT in three of six patients. The previous dose level (110 and 175 mg/m(2), respectively) on day 1 was safely followed on day 2 by LFA plus 5-FU up to 800 mg/m(2). Indeed, only one of three patients treated at this last level had a DLT. This cohort was then expanded including a total of 14 patients, and on the whole series five cases of DLT occurred: WHO grade 4 neutropenia (two patients), grade 3 or 4 diarrhoea (three patients). Cumulative toxicity was analysed in 43 patients for a total of 347 cycles: grade 4 neutropenia was detected in 13 patients (30%); it was not dose-related, nor was it exacerbated by the addition of modulated 5-FU. Febrile neutropenia occurred in four patients. Grade 3 or 4 diarrhoea was suffered by nine (21%) and five (12%) patients, respectively. Two complete and nine partial responses were reported on 40 evaluable patients (six patients were disease-free at study entry), giving a response rate of 27.5% (95% confidence interval 15% to 44%); nine of 18 (50%) assessable patients of the two last cohorts treated with the triplet regimen achieved a complete response (two patients) or a partial response (seven patients).


CONCLUSIONS
The RDs for this biweekly regimen were: OXA 110 mg/m(2) plus IRI 175 mg/m(2) on day 1, and LFA 250 mg/m(2) plus 5-FU 800 mg/m(2) on day 2. This regimen appeared active in pretreated gastrointestinal malignancies, and it is worthy of being evaluated in advanced colorectal carcinoma after failure of 5-FU-based adjuvant or palliative treatment.
Comella
P
P
Division of Medical Oncology A, National Tumour Institute, Naples, Italy. pcomella@sirio-oncology.it
Casaretti
R
R
De Rosa
V
V
Avallone
A
A
Izzo
F
F
Fiore
F
F
Lapenta
L
L
Comella
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000009:adverse effects*; D001707:Biopsy, Needle; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D006801:Humans; D007262:Infusions, Intravenous; D000077146:Irinotecan; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000008:administration & dosage / Q000009:adverse effects; D011379:Prognosis; D011725:Pyridines / Q000008:administration & dosage / Q000009:adverse effects; D016019:Survival Analysis; D016896:Treatment Outcome
D009944:Organoplatinum Compounds; D011725:Pyridines; C431073:oxiplatin; D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin