A phase II study of cetuximab/irinotecan in patients with heavily pretreated metastatic colorectal cancer: predictive value of early specific toxicities.
BACKGROUND
This study was designed to evaluate the predictive value of early specific toxicities on efficacy of weekly irinotecan/cetuximab administered as salvage therapy in patients with metastatic colorectal cancer (CRC) refractory to oxaliplatin and irinotecan.


METHODS
Seventy patients received a regimen composed of weekly irinotecan 125 mg/m2 as a 1-hour intravenous infusion and cetuximab 400 mg/m2 infused over 2 hours as the initial dose and 250 mg/m2 infused over 1 hour for subsequent administrations. A single treatment cycle was composed of 4 weekly irinotecan infusions followed by 2 weeks of rest. The predictive value of adverse events (AEs) attributable to cetuximab (rash) and major toxicities attributable to irinotecan (gastrointestinal [GI] and hematologic) were observed after the first cycle of treatment and, therefore, correlated to activity and efficacy of cetuximab and weekly irinotecan.


RESULTS
Sixty-six of 70 patients received >or= 1 cycle of chemotherapy and were therefore evaluable for response. Overall, toxicity observed was generally mild and manageable. According to an intent-to-treat analysis, a partial response was exhibited in 15.7% of patients, with a median progression-free survival (PFS) and median overall survival time of 4 months and 9 months, respectively. As expected, PFS (P = .01) and median survival (P = .04) correlated strongly with the presence and severity of the rash. Surprisingly, the presence of at least moderate hematologic and GI toxicity was associated with improved PFS (P = .03).


CONCLUSIONS
Our data suggest that irinotecan-induced AEs might predict a better outcome in advanced CRC. This finding would identify a different subset of patients-those likely to benefit from a renewed sensitivity to irinotecan induced by cetuximab.
Gamucci
Teresa
T
Department of Medical Oncology, S.S. Trinità Hospital of Sora, Frosinone, Italy.
Nelli
Fabrizio
F
Cianci
Giovanni
G
Grassi
Giulia
G
Moscetti
Luca
L
Sperduti
Isabella
I
Zeuli
Massimo
M
Cortesi
Enrico
E
D'Auria
Giuliana
G
Pollera
Camillo Francesco
CF
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D018450:Disease Progression; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D000077146:Irinotecan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011379:Prognosis; D013997:Time Factors; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000077146:Irinotecan; D000068818:Cetuximab; D002166:Camptothecin