Tolerability and toxicological profile of pixantrone (Pixuvri®) in juvenile mice. Comparative study with doxorubicin

•Pixantrone dimaleate or doxorubicin was given IP to mice on PND 10, 13, 17, 35, 39 and 42.•All pixantrone animals survived, doxorubicin induced 50% mortality.•Recoverable bone marrow toxicity and irreversible toxicity to thymus and reproductive organs were seen with both drugs.•Minimal cardiotoxicity in pixantrone males at PND 96 and reduced heart weight with doxorubicin on PND 42 were recorded. The tolerability of pixantrone dimaleate (Pixuvri®), an aza-anthracenedione for non-Hodgkin lymphoma, was assessed in juvenile mice after intraperitoneal injection. Twenty animals/sex/dose received pixantrone 15 or 27mg/kg/day on Post-Natal-Days (PND) 10, 13, 17, 20, 35, 39 and 42 in comparison with doxorubicin, 3mg/kg/day. Animals were sacrificed on PND 42, 73 and 96. All pixantrone animals survived, while doxorubicin induced 52.5% mortality and the surviving animals were sacrificed early due to severe toxicity. Recoverable bone marrow toxicity (pixantrone), and toxicity to thymus and reproductive organs (pixantrone, doxorubicin) were observed without nephro- or hepatotoxicity. Pixantrone was measurable in plasma up to 2h (occasionally 6h) post-dose. At PND 42, mean Cmax and AUC values increased proportionally with dose, without gender difference or accumulation. Pixantrone showed minimal cardiotoxicity in males and negligible in females at PND 96. Doxorubicin induced significant heart weight reduction at PND 42, however early sacrifice impeded further cardiac assessments.