What abnormalities may lurbinectedin cause in pregnancy?

What animal studies show about lurbinectedin's effects in pregnancy

Lurbinectedin, sold as Zepzelca, caused embryo-fetal toxicity and death in rats and rabbits at doses below human equivalents. In rats, it led to decreased body weight, skeletal variations (e.g., incomplete ossification), and reduced ossification. Rabbits showed total litter loss at all doses tested.[1][2]

Why it's classified as pregnancy category unknown with risks

No human data exists on lurbinectedin use in pregnancy. It's assigned Risk Summary Category 4 by the FDA, indicating positive evidence of human fetal risk from animal studies or limited data, with no evidence of benefits outweighing risks. It may cause fetal harm based on its mechanism (DNA-binding agent disrupting cell division).[1][2]

Contraception and fertility warnings for patients

Women of reproductive potential must use effective contraception during treatment and for 6 months after the last dose. Men with partners of reproductive potential should use contraception during treatment and for 4 months after. Lurbinectedin impairs fertility in animal models; human fertility effects are unknown.[1][2]

What to do if exposed during pregnancy

Verify pregnancy status before starting. If exposure occurs, apprise patients of potential fetal hazards. No specific antidote exists; report to Zepzelca Pregnancy Exposure Registry (1-888-438-4239) or FDA MedWatch for monitoring.[1][2]

Related reproductive risks patients ask about

• Breastfeeding: Do not breastfeed during treatment and for 2 weeks after last dose; present in milk in animal studies.
  
• Male-mediated effects: Unknown risk to partner pregnancies from semen.
  
• Fertility preservation: Consider options before starting, as ovarian function may be impaired.[1][2]
  
  Sources
  [1]: Zepzelca Prescribing Information (FDA)
  [2]: Drugs.com - Lurbinectedin Use in Pregnancy