Animal Studies on Lurbinectedin's Effects
Lurbinectedin's preclinical data show reproductive toxicity in animals. In rats, intravenous doses at or above 0.4 mg/m² (about 1/6 the human dose of 3.2 mg/m²) caused embryo-fetal lethality, reduced fetal weight, and skeletal abnormalities like delayed ossification. No maternal toxicity occurred at these levels. Similar effects appeared in rabbits at higher doses relative to humans. These findings indicate potential harm to developing fetuses, leading to FDA pregnancy category Not Assigned with warnings against use in pregnancy.[1][2]
Human Data and Clinical Trials
No adequate human studies exist on lurbinectedin's safety in pregnancy. Clinical trials for Zepzelca (lurbinectedin) excluded pregnant or breastfeeding women, with no reported inadvertent exposures documented in trial data. Post-marketing surveillance has not yielded pregnancy-specific safety evidence.[1][2]
Regulatory Warnings and Recommendations
The Zepzelca label states it can cause fetal harm based on animal data, advising pregnancy avoidance. Women of reproductive potential must use effective contraception during treatment and for 6 months after the last dose. Males with pregnant partners should use condoms. A pregnancy exposure registry (1-888-840-3617) collects data on outcomes. It's unknown if lurbinecteddin passes into breast milk; breastfeeding is not recommended during treatment and for 2 weeks after.[1][2]
What Happens with Accidental Exposure?
Limited real-world cases exist due to the drug's recent approval (2020) and oncology use. Animal data predict risks like miscarriage or birth defects, but human outcomes remain unstudied. Providers should report exposures to the registry for emerging data. No evidence supports safety; discontinuation and counseling are standard.[1]
Sources
[1]: Zepzelca (lurbinectedin) Prescribing Information
[2]: Drugs.com - Lurbinectedin Use During Pregnancy