Entrectinib

Pharmaceuticals -> Listed in ZINC15

Pharmaceuticals -> Antineoplastic and immunomodulating agents -> Antineoplastic agents

Breast Feeding; Lactation; Milk, Human; Antineoplastic Agents; Enzyme Inhibitors; Janus Kinase Inhibitors; Protein Kinase Inhibitors; Tyrosine Kinase Inhibitors

FDA approved drugs -> Active ingredient

EMA approved medicines: Human medicine

FDA approved drugs -> Active ingredient

In the prelicensure clinical trials of entrectinib in patients with NTRK fusion gene positive solid tumors and ROS1 fusion gene positive non-small cell lung cancer, liver test abnormalities were frequent although usually mild. Some degree of ALT elevation arose in 38% of entrectinib treated patients, but were above 5 times the upper limit of normal (ULN) in only 2% to 3% (although the incidence may have been underestimated as 4.5% of patients had no post-treatment liver function tests). In these trials that enrolled approximately 355 patients, entrectinib was discontinued early due to increased AST or ALT in 0.8% of patients. Thus, in preregistration trials of entrectinib there were no instances of clinically apparent liver injury with jaundice, but therapy was associated with a high rate of serum ALT elevations and the total clinical experience with its use has been limited. The product label for entrectinib recommends monitoring for routine liver tests before, at 2 week intervals during the first month of therapy, and monthly thereafter as clinically indicated.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Entrectinib

Ambiguous-DILI-concern

3

Warnings & precautions

DOI:10.1016/j.drudis.2016.02.015

L - Antineoplastic and immunomodulating agents

QL - Antineoplastic and immunomodulating agents

Entrectinib is a tyrosine kinase inhibitor which acts on several receptors. It functions as an ATP competitor to inhibit tropomyosin receptor tyrosine kinases (TRK) TRKA, TRKB, TRKC, as well as proto-oncogene tyrosine-protein kinase ROS1 and anaplastic lymphoma kinase (ALK). TRK receptors produce cell proliferation via downstream signalling through the mitogen activated protein kinase, phosphoinositide 3-kinase, and phospholipase C-γ. ALK produces similar signalling with the addition of downstream JAK/STAT activation. Inhibition of these pathways suppresses cancer cell proliferation and shifts the balance in favor of apoptosis resulting in shrinking of tumor volume.

CYP3A4 is responsible for 76% of entrectinib metabolism in humans including metabolism to the active metabolite, M5. M5 has similar pharmacological activity to entrectinib and exists at approximately 40% of the steady state concentration of the parent drug. In rats, six in vivo metabolites have been identified including N-dealkylated, N-oxide, hydroxylated, and glucuronide conjugated metabolites.

Entrectinib has a Tmax of 4-5 h after administration of a single 600 mg dose. Food does not produce a significant effect on the extent of absorption.

After a single radio-labeled dose of entrectinib, 83% of radioactivity was present in the feces and 3% in the urine. Of the dose in the feces, 36% was present as entrectinib and 22% as M5.

Entrectinib has an apparent volume of distribution of 551 L. The active metabolite, M5, has an apparent volume of distribution of 81.1 L. Entrectinib is known to cross the blood-brain barrier.

The apparent clearance of entrectinib is 19.6 L/h while the apparent clearance of the active metabolite M5 is 52.4 L/h.