This randomized phase II trial studies how giving a drug called levocetirizine to patients
with colorectal cancer affects their tumor response to capecitabine and bevacizumab.
Capecitabine is a chemotherapy drug that blocks tumor growth by disrupting DNA and RNA
synthesis and repair (cell division and survival). Bevacizumab is a monoclonal antibody that
blocks the ability of tumors to grow and spread by inhibiting the growth of blood vessels
that feed them. Patients with colorectal cancer can develop a resistance to the effects of
bevacizumab. Levocetirizine may decrease tumor resistance to bevacizumab. Giving bevacizumab,
capecitabine, and levocetirizine dihydrochloride together may be an effective treatment for
refractory colorectal cancer.