There is interest in improving the tumoricidal effects of preoperative radiotherapy for rectal carcinoma by studying new radiosensitizers. The safety and toxicity profile of these combination regimens needs rigorous clinical evaluation. The primary objective of this study was to evaluate the toxicity of combining bavituximab, an antibody that targets exposed phosphatidylserine, with capecitabine and radiation therapy.
Patients with stage II or III rectal adenocarcinoma were enrolled on a phase I study combining radiation therapy, capecitabine, and bavituximab. A standard 3+3 trial designed was used.
In general, bavituximab was safe and well tolerated in combination with radiation therapy and capecitabine in the treatment of rectal adenocarcinoma. One patient at the highest dose level experienced a grade III infusion reaction related to the bavituximab. One tumor demonstrated a complete pathologic response to the combination treatment.
Bavituximab is safe in combination with capecitabine and radiation therapy at the doses selected for the study. Further clinical investigation would be necessary to better define the efficacy of this combination.
Departments of *Radiation Oncology
‡Surgery, University of Texas Southwestern Medical Center, Dallas, TX
Present address: Grace Raja, MD, Central Arkansas Radiation Therapy Institute, Little Rock, AR.
Present address: Glen Balch, MD, Emory University School of Medicine, Atlanta, GA.
Bavituximab is investigational in the study of rectal cancer as part of the regimen described in this manuscript.
J.M.: clinical trial support from Peregrine Pharmaceuticals Inc. (as noted); clinical trial support from DFINE Inc; royalties from UpToDate Inc. J.A.: consultant for Edwards Lifesciences. M.S.B.: consulting/advisory roles for Bayer, Celgene, Ipsen; research funding from Merck, BMS, MedImmune, Five Prime Pharmaceuticals, Celgene, Mirna, and Precision Biologics; speaker for Ipsen; travel expenses from Mirna and Precision Biologics. The remaining authors declare no conflicts of interest.
Reprints: Jeffrey Meyer, MD, Department of Radiation Oncology, University of Texas Southwestern Medical Center, 5801 Forest Park Road, Dallas, TX 75390. E-mail: email@example.com.