Lymphoma is treated using therapeutic combinations of PDX and gemcitabine by administering to a patient suffering from lymphoma a therapeutically effective amount of PDX in combination with a therapeutically effective amount of gemcitabine. The two agents can be administered together or in either order, although administration of PDX followed by gemcitabine is preferred. As in the case of MTX and Ara-C, synergism is observed, but the extent of the synergism is greater. Further, test results indicate that mechanism of action for combinations of PDX and Gem is different than for MTX and Ara-C, with more emphasis on induction of apoptosis.