Pyran copolymer as an effective adjuvant to chemotherapy against a murine leukemia and solid tumor.

Pyran (divinyl ether-maleic anhydride) copolymer (NSC 46015) is a polyanion with interferon-inducing and macrophage-stimulating properties, and therefore it has been studied as a possible antitumor agent. Extensive studies using pyran as an adjuvant to chemotherapy against the LSTRA murine leukemia and the Lewis lung carcinoma were performed. Pyran was effective over a dose range of 0.1 to 100 mg/kg/day. Single and multiple dose schedules were both capable of producing significant numbers of cures or increasing life-span, but pyran was ineffective if used without remission inducing chemotherapy. Various molecular weights of pyran copolymer were compared against NSC 46015 for adjuvant activity as well. In general, NSC 46015 tended to be the most efficacious, but all the pyran sizes that were tested possessed significant activity.