Bevacizumab, oxaliplatin, and capecitabine with radiation therapy in rectal cancer: Phase I trial results.
OBJECTIVE
The overexpression of vascular endothelial growth factor (VEGF) is associated with poor outcomes in colorectal cancer patients. Bevacizumab, a VEGF inhibitor, enhances the effects of chemotherapy and radiation therapy on tumor cytotoxicity in preclinical models, including colorectal cancer. A Phase I trial was undertaken to evaluate the combination of bevacizumab, capecitabine, oxaliplatin, and radiation therapy in patients with rectal cancer.


METHODS
Patients with pathologically confirmed adenocarcinoma of the rectum were eligible. Pretreatment staging included computerized tomography, endoscopic ultrasound, and surgical evaluation. Patients received 50.4 Gy of external beam radiation therapy (EBRT) to the tumor in 28 fractions. Capecitabine, oxaliplatin, and bevacizumab were administered concurrently with radiation therapy. After EBRT completion, patients were restaged and evaluated for surgery. Primary endpoints included the determination of dose-limiting toxicity and a recommended Phase II dose, non dose-limiting toxicity, and preliminary radiographic and pathologic response rates.


RESULTS
Eleven patients were enrolled. All were evaluable for toxicity and efficacy. Dose level 2 was associated with unacceptable toxicity (primarily diarrhea). Dose level 1 had an acceptable toxicity profile. The recommended Phase II dose in our study was bevacizumab 15 mg/kg Day 1 + 10 mg/kg Days 8 and 22, oxaliplatin 50 mg/m2 weekly, and capecitabine 625 mg/m2 bid during radiation days. Six patients had clinical responses. Two patients had a pathologic complete response, and 3 had microscopic disease only. One patient experienced a postoperative abscess, one a syncopal episode during adjuvant chemotherapy, and one a subclinical myocardial infarction during adjuvant chemotherapy.


CONCLUSIONS
The combination of bevacizumab, capecitabine, oxaliplatin, and radiation therapy in rectal cancer was tolerable, with encouraging response rates. Further investigation with this regimen is being pursued in a Phase II setting.
Czito
Brian G
BG
Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA. czito001@mc.duke.edu
Bendell
Johanna C
JC
Willett
Christopher G
CG
Morse
Michael A
MA
Blobe
Gerard C
GC
Tyler
Douglas S
DS
Thomas
John
J
Ludwig
Kirk A
KA
Mantyh
Christopher R
CR
Ashton
Jill
J
Yu
Daohai
D
Hurwitz
Herbert I
HI
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D000068258:Bevacizumab; D000069287:Capecitabine; D003131:Combined Modality Therapy / Q000009:adverse effects; D003841:Deoxycytidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D003967:Diarrhea / Q000209:etiology; D005221:Fatigue / Q000209:etiology; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D006801:Humans; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000008:administration & dosage / Q000009:adverse effects; D000077150:Oxaliplatin; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D003841:Deoxycytidine; D000068258:Bevacizumab; D000069287:Capecitabine; D005472:Fluorouracil