Pegaspargase

Pegaspargase is the union of a variant of asparaginase (colaspase) with polyethylene glycol of molecular weight 5,000 daltons with a longer half-life than asparaginase.
Like asparaginase, pegaspargase is an enzyme that breaks down the plasma amino acid L-asparagine, preventing the growth of malignant cells of leukemia that, unlike normal cells, can not synthesize it.
Indicated in the treatment of acute lymphoblastic leukemia since the neonatal period.
Intravenous or intramuscular administration every 14 days.

At the date of last update, we did not find published data on its excretion in breast milk.

Its high molecular weight makes excretion in breast milk very unlikely.
Its low oral bioavailability hinders the passage to infant plasma from breast milk ingested since, by its protein nature, it degrades in the gastrointestinal tract, not absorbed, except in premature and immediate neonatal period in which there may be greater permeability intestinal.

It is known from Pharmacokinetics that after 3 elimination half-lives (T½) 87.5% of the drug is eliminated from the organism; after 4 T½ the 94%, after 5 T½ the 96.9%, after 6 T½ the 98.4% and after 7 T½ the 99%. From 7 T½ the plasmatic concentrations of drug in the organism are negligible. In general, a period of at least five half-lives can be considered a safe waiting period for breastfeeding again (Anderson 2016).

Assuming it can pass into breast milk and taking as reference the longest published T½ of all active metabolites (EMA 2018), these 5 T½ would correspond to 30 days. Due to the important adverse effects, it would be advisable to wait 7 T½, which would correspond to 42 days. Meanwhile, withdraw and discard milk from the breast regularly. The continued and long cycles make it very difficult to continue breastfeeding.

When it is possible to do so, the milk detections of each patient to determine the total elimination of the drug would be the best indicator to resume breastfeeding between two cycles of chemotherapy.

During breast cancer treatment, breastfeeding must be interrupted due to potentially serious side effects for the infant. Chemotherapy does not affect milk production during or after treatment.
Abrupt weaning can be psychologically traumatic for both the mother and the infant (Pistilli 2013). If the mother wishes, the production of milk can be maintained by regular extraction of the breast, being able to recover lactation in the periods in which no significant traces of the drug remain in the milk (Anderson 2016) or at the end of the treatment (Pistilli 2013).

Women undergoing chemotherapy during pregnancy have lower rates of breastfeeding due to difficulties in breastfeeding (Stopenski 2017), needing more support to achieve it.

Given the great evidence that exists on the benefits of breastfeeding for the development of babies and the health of mothers, it is advisable to evaluate the risk-benefit of any maternal treatment, including chemotherapy, individually advising each mother that wishes to continue with breastfeeding (Koren 2013).

• Asparaginase (High Risk probable)
• Maternal Cancer (High Risk probable)

Alternatives

• Asparaginase (High Risk probable)