Idelalisib

The Basics

What is Idelalisib?

Treatment of relapsed chronic lymphocytic leukemia (CLL).

Brand names for Idelalisib

Zydelig

How Idelalisib is classified

Antineoplastic Agents, Enzyme Inhibitors, Protein Kinase Inhibitors, Signal Transduction Inhibitors

Idelalisib During Pregnancy

Idelalisib pregnancy category

Category Not AssignedNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Idelalisib while pregnant

Based on findings in animal studies (see Data) and the mechanism of action [see CLINICAL PHARMACOLOGY], Zydelig may cause fetal harm when administered to a pregnant woman. There are no available data in pregnant women to inform the drug-associated risk. In animal reproduction studies, administration of idelalisib to pregnant rats during organogenesis resulted in decreased fetal weight and congenital malformations in rats at maternal exposures (AUC) 12 times those reported in patients at the recommended dose of 150 mg twice daily (see Data). All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The background risk of major birth defects and miscarriage for the indicated population is unknown. However, the background risk of major birth defects is 2-4% and of miscarriage is 15-20% of clinically recognized pregnancies in the U.S. general population. Data Animal Data In an embryo-fetal development study in rats, pregnant animals receiving oral doses of idelalisib during the period of organogenesis (implantation to closure of the hard palate), embryo-fetal toxicities were observed at the mid- and high-doses that also resulted in maternal toxicity, based on reductions in maternal body weight gain. Adverse findings at idelalisib doses ‚â• 75 mg/kg/day included decreased fetal weights, external malformations (short tail), and skeletal variations (delayed ossification and/or unossification of the skull, vertebrae, and sternebrae). Additional findings were observed at 150 mg/kg/day dose of idelalisib and included urogenital blood loss, complete resorption, increased post-implantation loss, and malformations (vertebral agenesis with anury, hydrocephaly, and microphthalmia/anophthalmia). The dose of 75 and 150 mg/kg/day of idelalisib in rats resulted in exposures (AUC) of approximately 12 and 30 times, respectively, the human exposure at the recommended dose of 150 mg twice daily.

Taking Idelalisib While Breastfeeding

What are recommendations for lactation if you're taking Idelalisib?

No information is available on the clinical use of idelalisib during breastfeeding. Because idelalisib is more than 84% bound to plasma proteins, the amount in milk is likely to be low. It is sometimes given in combination with rituximab, which may increase the risk to the infant. The manufacturer recommends that breastfeeding be discontinued during idelalisib therapy and for at least 1 month after the last dose.

Maternal / infant drug levels

No information is available on the clinical use of idelalisib during breastfeeding. Because idelalisib is more than 84% bound to plasma proteins, the amount in milk is likely to be low. It is sometimes given in combination with rituximab, which may increase the risk to the infant. The manufacturer recommends that breastfeeding be discontinued during idelalisib therapy and for at least 1 month after the last dose.

Possible effects of Idelalisib on milk supply

Relevant published information was not found as of the revision date.

Possible alternatives to Idelalisib

None listed