Caelyx

Caelyx is a brand name for pegylated liposomal doxorubicin (PLD), a liposome-encapsulated form of the anticancer antibiotic doxorubicin. The pegylated liposomes extend circulation time in the bloodstream and alter tissue distribution, which can increase drug accumulation in tumors while reducing peak exposure to healthy tissues.

Pharmacology and mechanism of action: Doxorubicin intercalates into DNA and inhibits topoisomerase II, disrupting cancer cell replication. Encapsulation in PEGylated liposomes changes pharmacokinetics, leading to a longer systemic half-life and a different tissue distribution profile. This formulation is designed to reduce some of the noncancerous tissue toxicity associated with conventional doxorubicin, particularly cardiotoxicity, though cumulative exposure to doxorubicin remains a concern.

Indications and usage: Caelyx is used in the treatment of several cancers, with regional approvals varying. It is commonly prescribed for ovarian cancer, Kaposi’s sarcoma, and breast cancer, especially in patients who have previously received other therapies or in certain combination regimens. Dosing schedules are determined by regional labeling and patient factors, and regimens are adjusted for toxicity, organ function, and treatment response.

Adverse effects: Notable side effects include hand-foot syndrome (palmar-plantar erythrodysesthesia), fatigue, mucositis, nausea, and cytopenias. Infusion-related reactions can occur. While the formulation lowers some risks of acute cardiotoxicity compared with conventional doxorubicin, monitoring of cardiac function remains important, particularly with cumulative exposure.

Administration and safety: Caelyx is given by intravenous infusion in a clinical setting. Pregnancy should be avoided if possible, and patients should follow healthcare provider guidance on monitoring, dosing, and supportive care.