h a strong CYP3A inducer decreased lorlatinib plasma concentrations, which may decrease the efficacy of LORBRENA. The effect of concomitant use of LORBRENA with a moderate CYP3A inducer on lorlatinib plasma concentrations has not been studied.
Severe hepatotoxicity occurred in healthy subjects receiving LORBRENA with rifampin, a strong CYP3A inducer. In 12 healthy subjects receiving a single 100 mg dose of LORBRENA with multiple daily doses of rifampin, Grade 3 or 4 increases in ALT or AST occurred in 83% of subjects and Grade 2 increases in ALT or AST occurred in 8%. A possible mechanism for hepatotoxicity is through activation of the pregnane X receptor (PXR) by LORBRENA and rifampin, which are both PXR agonists. The risk of hepatotoxicity with concomitant use of LORBRENA and moderate CYP3A inducers that are also PXR agonists is unknown.
LORBRENA is contraindicated in patients taking strong CYP3A inducers. Discontinue strong CYP3A inducers for 3 plasma half-lives of the strong CYP3A inducer prior to initiating LORBRENA.
Avoid concomitant use of LORBRENA with moderate CYP3A inducers. If concomitant use of moderate CYP3A inducers cannot be avoided, monitor ALT, AST, and bilirubin as recommended [see DOSAGE AND ADMINISTRATION (2.3), WARNINGS AND PRECAUTIONS (5.1), CLINICAL PHARMACOLOGY (12.3)].
Effect of Strong CYP3A Inhibitors
Concomitant use with a strong CYP3A inhibitor increased lorlatinib plasma concentrations, which may increase the incidence and severity of adverse reactions of LORBRENA. Avoid the concomitant use of LORBRENA with a strong CYP3A inhibitor. If concomitant use cannot be avoided, reduce LORBRENA dose as recommended [see DOSAGE AND ADMINISTRATION (2.4), CLINICAL PHARMACOLOGY (12.3)].
7.2 Effect of LORBRENA on Other Drugs
CYP3A Substrates
Concomitant use of LORBRENA decreases the concentration of CYP3A substrates [see CLINICAL PHARMACOLOGY (12.3)], which may reduce the efficacy of these substrates. Avoid concomitant use of LORBRENA with CYP3A substrates, where minimal concentration changes may lead to serious therapeutic failures. If concomitant use is unavoidable, increase the CYP3A substrate dosage in accordance with approved product labeling.
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Risk Summary
Based on findings from animal studies and its mechanism of action [see CLINICAL PHARMACOLOGY (12.1)], LORBRENA can cause embryo-fetal harm when administered to a pregnant woman. There are no available data on LORBRENA use in pregnant women. Administration of lorlatinib to pregnant rats and rabbits by oral gavage during the period of organogenesis resulted in malformations, increased post-implantation loss, and abortion at maternal exposures that were equal to or less than the human exposure at the recommended dose of 100 mg once daily based on AUC (see DATA). Advise a pregnant woman of the potential risk to a fetus.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies are 2 to 4% and 15 to 20%, respectively.
Data
Animal Data
Preliminary embryo-fetal development studies investigating the administration of lorlatinib during the period of organogenesis were conducted in rats and rabbits. In rabbits, lorlatinib administration resulted in abortion and total loss of pregnancy at doses of 15 mg/kg (approximately 3 times the human exposure at the recommended dose of 100 mg) or greater. At a dose of 4 mg/kg (approximatel |
