22. Patients who are pregnant (positive pregnancy test) or nursing. Use of effective means of contraception (men and women) in subjects of child-bearing potential. To date, no fetal studies in animals or humans have been performed. The possibility of harm to a fetus is likely. Bevacizumab specifically inhibits VEGF, which is responsible for formation of new blood vessels during development, and antibodies can cross the placenta. Therefore, bevacizumab should not be administered to pregnant women.