Evolution of acute lymphoblastic leukemia in mice treated with carrier-bound methotrexate and levamisole

The cytotoxic and antitumoral activities of free or bound to bovine serum albumin (BSA) methotrexate (MTX) and the influence of levamisole (LMS) on these were assayed on murine leukemia. Whereas the in vitro cytotoxic action of MTX was reduced by its conjugation to BSA, in vivo a single dose of 15 mg/kg MTX, which lacked therapeutic effect on tumor-bearing mice, increased the mean survival time (MST) of the animals when given as MTX-BSA. Levamisole slightly increased the MST of the tumor-bearing animals when administered as a 10 mg/kg single dose 7 days after the tumor inoculation. We were unable to achieve synergism between LMS and MTX-BSA when measuring MST and the tumor growth evolution.