Vorasidenib

An oral dual inhibitor of the mutant IDH1 and IDH2 enzymes with brain penetration, approved by the FDA for the treatment of adult and paediatric patients aged 12 years and over with grade 2 astrocytoma or oligodendroglioma harbouring a susceptible IDH1 or IDH2 mutation, following surgery. It is administered orally at a dose of 40 mg daily.

As of the last update, no published data on its excretion into breast milk were available.

Its pharmacokinetic properties (very large volume of distribution, moderately high molecular weight, and high percentage of protein binding) make excretion into breast milk difficult, but its high lipophilicity and very long half-life would facilitate it.

Possible adverse reactions include gastroenteritis, fatigue and abnormal liver enzymes. ^{(FDA 2024)}

During cancer treatment, breastfeeding must be discontinued due to potentially serious side effects for the infant. Chemotherapy does not affect milk production either during or after treatment.

Its very long half-life (T½ 10 days) indicates a period of between 50 and 70 days for plasma levels of the drug to become clinically insignificant.

Given the substantial evidence regarding the benefits of breastfeeding for infants’ development and mothers’ health, it is advisable to assess the risk-benefit balance of any maternal treatment, including chemotherapy, by providing individual advice to each mother who wishes to continue breastfeeding. ^{(Koren 2013)}