Abstract

Twenty-three compounds were tested for their effectiveness in increasing the survival time of mice with leukemia P1534. The previously reported (7) activity of the Vinca alkaloids, vincristine and vinblastine, against leukemia P1534 was confirmed. 2-Chloro-4',4''-di-2-imidazolin-2-ylterephthalanilide, 5-fluorouracil, and 5-fluorodeoxyuridi e also displayed a high degree of effectiveness. A vincristineresistant variant of leukemia P1534 was cross-resistant to 2-chloro-4',4''-di-2-imidazolin-2-ylterephthalanilide. 1 Presented in part at the 54th annual meeting of the American Association for Cancer Research, Toronto, Canada, 1963. 2 This study was supported by Contract No. PH-43-62-182 from the Cancer Chemotherapy National Service Center, National Institutes of Health, and Grant No. Ca-03192-07S1, National Cancer Institute, National Institutes of Health, Public Health Service, U. S. Department of Health, Education, and Welfare. 3 Visiting Fulbright Scholar at the National Cancer Institute. Current address, Polish Academy of Sciences, Gdansk, Poland. 4 Drug Evaluation Branch, Cancer Chemotherapy National Service Center, National Cancer Institute. Formerly Biochemical Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland. 5 Division of Experimental Chemotherapy, Sloan-Kettering Institute for Cancer Research, New York, N. Y.