Atrasentan

Strong or moderate CYP3A inducers: Avoid concomitant use. ( 7.1 ) OATP1B1/1B3 inhibitors: Avoid concomitant use. ( 7.1 )

7.1 Effect of Other Drugs on VANRAFIA Strong or Moderate CYP3A Inducers Avoid concomitant use with a strong or moderate CYP3A inducer. Atrasentan is a CYP3A substrate [see Clinical Pharmacology (12.3)] . Concomitant use with a strong and moderate CYP3A inducer is expected to decrease atrasentan exposure [see Clinical Pharmacology (12.3)] , which may reduce VANRAFIA efficacy. OATP1B1/1B3 Inhibitors Avoid concomitant use with organic anion transporting polypeptides 1B1/1B3 (OATP1B1/1B3) inhibitors. Atrasentan is a OATP1B1/1B3 substrate [see Clinical Pharmacology (12.3)] .

Concomitant use with a OATP1B1/1B3 inhibitor increases atrasentan exposure [see Clinical Pharmacology (12.3)] , which may increase the risk of VANRAFIA adverse reactions.

8.1 Pregnancy Risk Summary Based on data from animal reproductive toxicity studies, VANRAFIA may cause fetal harm, including birth defects and fetal death, when administered to a pregnant patient and is contraindicated during pregnancy [see Contraindications (4.1)] . There are no available data on VANRAFIA use in pregnancy to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Available data from published literature and post-marketing surveillance over decades of use with products in the same pharmacologic class (ERA) have not identified an increased risk of major birth defects.

However, these data are limited and do not establish the presence or absence of a drug-associated risk of major birth defects. Methodological limitations of these post marketing reports and published literature include lack of a control group; limited information regarding dose, duration, and timing of exposure; and missing data. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal endothelin receptor antagonist use.

In animal reproduction studies, oral administration of atrasentan to pregnant rats and rabbits throughout organogenesis at doses that were below the maximum recommended human dose (MRHD) based on area under the curve (AUC) caused teratogenic effects in rats and rabbits (see Data) . Advise pregnant patients of the potential risk to the fetus [see Contraindications (4.1)] . The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S.

general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data In embryo-fetal development studies in pregnant rats and rabbits, teratogenicity and/or embryo-fetal toxicity were observed. In pregnant rats, oral administration of atrasentan throughout organogenesis at doses of 0.1, 0.3, 1.0, and 3.0 mg/kg/day resulted in developmental abnormalities primarily including the ear, lower jaw, or skull in all treated groups with detectable plasma exposures to atrasentan. The no adverse effect level of atrasentan plasma exposure was not determined.

In pregnant rabbits, oral administration of atrasentan throughout organogenesis at doses of 0.1, 0.3, 1.0 and 3.0 mg/kg/day resulted in visceral malformations including deformities in the cardiovascular system…