In vitro antitumor activity of a new platinum complex, cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3 -dioxolane]platinum(II) (SKI 2053R), against human lung and stomach cancer cell lines

The in vitro antitumor activity of a new platinum complex, cis-malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3- dioxolane]platinum(II) (SKI 2053R, NSC D644591), cisplatin (CDDP) and carboplatin (CBDCA) was determined against two human lung cancer (PC-9 and PC-14) and two human stomach cancer (MKN-45 and KATO III) cell lines by human tumor clonogenic assay. The activity of SKI 2053R was compared with those of CDDP and CBDCA in terms of relative antitumor activity (RAA, peak plasma concentration/IC₅₀). Mean IC₅₀ values (μg/ml) of SKI 2053R, CDDP and CBDCA were 6.4 ± 0.8, 1.8 ± 0.7 and 20.6 ± 12.2, respectively. The RAAs of SKI 2053R, CDDP and CBDCA were 1.6 ± 0.4, 2.0 ± 0.8 and 1.2 ± 0.6, respectively. The differences in these values were not statistically significant. The results, demonstrating that antitumor activity, of SKI 2053R is similar to those of CDDP and CBDCA, suggest that SKI 2053R is an interesting candidate for further development as a new anticancer drug.