Effect of 1,3,3,5,5-pentaziridino-1-thia-2,4,6-triaza-3,5-diphosphorine-1-oxide, a new antitumor agent with inorganic ring, on various experimental tumors.

Abstract

1,3,3,5,5-Pentaziridino-1-thia-2,4,6-triaza-3,5-diphosphorin-1-oxide (SOAZ), a new antitumor agent, was evaluated for antitumor activity against various mouse and rat tumor systems. The optimal treatment regimens of SOAZ (i.p.) gave 262 and 134% increase in life span (ILS) in mice with P388 [mouse] leukemia and L1210 [mouse] leukemia implanted i.p., respectively, and 239% ILS in rats with [rat] Yoshida sarcoma of which 86% survived for 60 days after i.p. tumor implantation. The compound showed a definite activity against [mouse] Lewis lung carcinoma implanted i.v. The compound also exhibited 80-100% inhibition of local tumor growth in all 4 experimental tumor systems. In contrast to cyclophosphamide, SOAZ was active against B16 [mouse] melanoma and Meth A [mouse fibrosarcoma], and demonstrated high activity against a subline of L1210 leukmemia resistant to cyclophosphamide.