Anthracyclines.

Area of Science:

• Pharmacology and Toxicology
• Oncology Drug Safety
• Preclinical Research

Background:

• Anthracyclines like doxorubicin (DOXO), epirubicin (EPI), and idarubicin (IDA) are crucial in cancer therapy.
• Preclinical safety assessment is vital to understand their genotoxic and carcinogenic potential.
• Existing data on these endpoints for DOXO, EPI, and IDA require comprehensive review.

Purpose of the Study:

• To review genotoxicity and carcinogenicity data for DOXO, EPI, and IDA from preclinical safety studies.
• To evaluate the in vitro and in vivo genotoxic profiles of these anthracyclines.
• To assess long-term carcinogenicity in rats following single and multiple dose administrations.

Main Methods:

• Genotoxicity assays included bacterial gene mutation (Salmonella typhimurium), mammalian cell gene mutation (V79), and chromosome aberration tests (human lymphocytes in vitro, mouse bone marrow in vivo).
• Long-term carcinogenicity studies involved single and multiple intravenous (i.v.) dose administrations of DOXO, EPI, and IDA to rats of different ages and sexes.
• Animals were observed for 12 to 18 months post-dosing to monitor tumor development.

Main Results:

• Genotoxicity studies indicated activity in gene mutation assays (bacterial and mammalian) and chromosome aberration assays (in vitro and in vivo).
• Long-term rat studies identified mammary tumors, considered species-specific and not directly compound-related.
• Absence of tumor induction in typical target organs for DNA-reactive compounds suggests limited carcinogenic potential.

Conclusions:

• DOXO, EPI, and IDA exhibit genotoxic activity across various in vitro and in vivo assays.
• Despite genotoxicity, these anthracyclines did not demonstrate significant carcinogenicity in long-term rat studies.
• The observed genotoxicity does not appear to translate into neoplastic induction in standard carcinogenicity models.