Antibiotic MX 2

Antibiotic MX 2 is an orally active antibiotic. Antibiotic MX 2 inhibits growth of drug-sensitive and multidrug-resistant murine and human tumor cells, and prolongs lifespan of tumor-bearing mice. Antibiotic MX 2 exhibits antitumor activity against human tumor xenografts, including gastric adenocarcinomas, non-small-cell lung carcinomas, and mammary adenocarcinomas. Antibiotic MX 2 is effective against sublines of P388 leukemia resistant to Adriamycin or acclacinomycin A in vivo as well as in vitro. Antibiotic MX 2 can be used for the research of L1210 leukemia, Lewis lung carcinoma, colon adenocarcinomas 26 and 38, gastric adenocarcinoma, non-small-cell lung carcinoma, mammary adenocarcinoma, drug-resistant P388 leukemia (P388/ADM, P388/ACR, P388/MMC)^[1]. In Vitro:Antibiotic MX 2 (Graded nM concentrations; 72 h) potently inhibits the growth of sensitive P388 leukemia cells with an IC₅₀ of 8.5 nM, and drug-resistant P388 sublines (P388/ADM, P388/ACR, P388/MMC) show minimal cross-resistance to the compound^[1]. In Vivo:Antibiotic MX 2 (0.44-5 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 produces a maximum ILS of 270% and cures 3/6 mice at 3.33 mg/kg in female CD2F₁ mice bearing i.p.-inoculated L1210 leukemia^[1].
Antibiotic MX 2 (0.375-3 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 produces a maximum ILS of 240% at 1.5 mg/kg and cures 6/7 mice at 3 mg/kg in female CD2F₁ mice bearing i.v.-inoculated L1210 leukemia^[1].
Antibiotic MX 2 (0.375-3 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 achieves a maximum tumor growth inhibition with a T/C of 4% at 3 mg/kg in female BD2F₁ mice bearing s.c.-implanted Lewis lung carcinoma^[1].
Antibiotic MX 2 (1.33-3 mg/kg; i.v.; Days 1, 8, 15, 22) administered i.v. on Days 1, 8, 15, and 22 achieves a maximum tumor growth inhibition with a T/C of 15% and maximum ILS of 54% at 3 mg/kg, curing 2/10 mice in female CD2F₁ mice bearing s.c.-implanted colon adenocarcinoma 26^[1].
Antibiotic MX 2 (0.5-4 mg/kg; i.v.; Days 1, 8, 15, 22) administered i.v. on Days 1, 8, 15, and 22 achieves a maximum tumor growth inhibition with a T/C of 1% at 4 mg/kg and maximum ILS of 48% at 2, 3, and 4 mg/kg, with 5/6 survivors at 3 mg/kg in female BD2F₁ mice bearing s.c.-inoculated colon adenocarcinoma 38^[1].
Antibiotic MX 2 (2 mg/kg; i.v.; every 4 days; 3 total doses) administered at 2 mg/kg i.v. every 4 days for 3 total doses is effective (T/C ≤50% with statistical significance) against 3/4 gastric adenocarcinomas, 1/2 non-small-cell lung carcinomas, and 2/2 mammary adenocarcinomas, including a marked effect against MX-1 mammary adenocarcinoma, in female BALB/c-nu/nu athymic nude mice bearing human tumor xenografts^[1].
Antibiotic MX 2 (0.38-1.48 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 produces a maximum ILS of 87% at 1.48 mg/kg in female CD2F₁ mice bearing i.p.-inoculated ADM-resistant P388/ADM leukemia^[1].
Antibiotic MX 2 (0.48-2.5 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 produces a maximum ILS of 94% at 2.5 mg/kg in female CD2F₁ mice bearing i.p.-inoculated ACR-resistant P388/ACR leukemia^[1].
Antibiotic MX 2 (1.25-2.5 mg/kg; i.v.; Days 1, 5, 9) administered i.v. on Days 1, 5, and 9 produces a maximum ILS of 86% at 2.5 mg/kg in female CD2F₁ mice bearing i.p.-inoculated MMC-resistant P388/MMC leukemia^[1].