Chlormethine Other names: HN2 Mustine Embikhin Mechlorethamine

Chlormethine is a bifunctional alkylating agent that inhibits rapidly proliferating cells.

Patients who received chlormethine in Study 201 had no measurable concentrations of chlormethine in blood collected 1, 3 and 6 hours post-application on Day 1, and at the first month visit.

Similarly, patients who received chlormethine gel 0.04% in a follow-up study (Study 202) had no measurable concentrations of chlormethine or its degradation product (half-mustard) in blood collected 1 hour post-application on Day 1 or after 2, 4, or 6 months of treatment.

Chlormethine was shown to be genotoxic in bacterial, plant, and mammalian cells. Chlormethine was carcinogenic in rat and mouse carcinogenicity studies after subcutaneous and intravenous administration.

Dermal application of chlormethine to mice at a dose of 15 mg/kg for up to 33 weeks resulted in skin tumours (squamous cell carcinomas and skin papilloma). There were no reports of systemic tumours after topical administration of chlormethine.

Intravenously administered chlormethine impaired male fertility in rats at a daily dose of ≥0.25 mg/kg for 2 weeks. No dedicated animal studies on the effects of chlormethine on female fertility have been reported in the literature.

Chlormethine caused foetal malformations in mice and rats when given as single injections of 1–2.5 mg/kg. Other findings in animals included embryo-lethality and growth retardation when administered as a single injection.