The toxicologic evaluation of marcellomycin--an antineoplastic anthracycline antibiotic

Dose-related toxicologic effects of marcellomycin, an antineoplastic anthracycline antibiotic, were observed in single-dose studies in mice iv (43.05-67.65 mg/m2) and dogs iv (41.0-90.2 mg/m2), and in multiple-dose studies in dogs iv (9.8-29.6 mg/m2 2X/week for 6 weeks) and rats sc (9 weekly doses at 26.2-72.2 mg/m2). Toxicity was primarily manifested by suppression of myeloid tissue, especially the erythrocytic and thrombocytic series, and lymphoid tissues. Initially a neutrophilic leukocytosis was observed in dogs and rats, which was considered possibly to be due to mobilization of the marginal and bone marrow neutrophil pools. In dogs, this was followed by a marked, dose-related neutropenia; and, in rats that died, there was marked depletion of bone marrow cells. Other toxicities observed included enteropathy, severe subcutaneous serofibrinous inflammatory edema and necrosis at injection sites, prostate and seminal vesicle atrophy, uterine hypoplasia, testicular and pancreatic degeneration, thyroid follicular proliferation and hemorrhage in various organs. In general, these toxicities were reversible in surviving animals during recovery periods. Significant cardiotoxicity was not demonstrated.