Prediction of the Transporter-Mediated Drug-Drug Interaction Potential of Dabrafenib and Its Major Circulating Metabolites.

Article Details

Citation

Ellens H, Johnson M, Lawrence SK, Watson C, Chen L, Richards-Peterson LE

Prediction of the Transporter-Mediated Drug-Drug Interaction Potential of Dabrafenib and Its Major Circulating Metabolites.

Drug Metab Dispos. 2017 Jun;45(6):646-656. doi: 10.1124/dmd.116.073932. Epub 2017 Mar 20.

PubMed ID
28320730 [ View in PubMed
]
Abstract

The BRAF inhibitor dabrafenib was recently approved for the treatment of certain BRAF V600 mutation-positive tumors, either alone or in combination therapy with the mitogen-activated extracellular signal regulated kinase 1 (MEK1) and MEK2 inhibitor, trametinib. This article presents the dabrafenib transporter-mediated drug-drug interaction (DDI) risk assessment, which is currently an important part of drug development, regulatory submission, and drug registration. Dabrafenib and its major circulating metabolites (hydroxy-, carboxy-, and desmethyl-dabrafenib) were investigated as inhibitors of the clinically relevant transporters P-gp, BCRP, OATP1B1, OATP1B3, OCT2, OAT1, and OAT3. The DDI Guidance risk assessment decision criteria for inhibition of BCRP, OATP1B1 and OAT3 were slightly exceeded and therefore a minor DDI effect resulting from inhibition of these transporters remained possible. Biliary secretion is the major excretion pathway of dabrafenib-related material (71.1% of orally administered radiolabeled dose recovered in feces), whereas urinary excretion was observed as well (22.7% of the dose). In vitro uptake into human hepatocytes of the dabrafenib metabolites, but not of dabrafenib parent compound, was mediated, at least in part, by hepatic uptake transporters. The transporters responsible for uptake of the pharmacologically active hydroxy- and desmethyl dabrafenib could not be identified, whereas carboxy-dabrafenib was a substrate of several OATPs. Dabrafenib, hydroxy-, and desmethyl-dabrafenib were substrates of P-gp and BCRP, whereas carboxy-dabrafenib was not. Although a small increase in exposure to carboxy-dabrafenib upon inhibition of OATPs and an increase in exposure to desmethyl-dabrafenib upon inhibition of P-gp or BCRP cannot be excluded, the clinical significance of such increases is likely to be low.

DrugBank Data that Cites this Article

Drugs
Drug Transporters
DrugTransporterKindOrganismPharmacological ActionActions
DabrafenibATP-binding cassette sub-family G member 2ProteinHumans
No
Substrate
Inhibitor
Details
DabrafenibSolute carrier family 22 member 2ProteinHumans
No
Inhibitor
Details
DabrafenibSolute carrier organic anion transporter family member 1A2ProteinHumans
No
Substrate
Details
DabrafenibSolute carrier organic anion transporter family member 1B1ProteinHumans
No
Substrate
Inhibitor
Details
DabrafenibSolute carrier organic anion transporter family member 1B3ProteinHumans
No
Substrate
Inhibitor
Details
Drug Reactions
Reaction
Details