Repotrectinib has demonstrated breakthrough therapeutic efficacy against specific gene-mutant lung cancers, providing an important treatment option for advanced-stage patients.
I. Basic Information on Repotrectinib
1. Mechanism of Action
(1) Repotrectinib is an effective inhibitor of ROS1 and tropomyosin receptor tyrosine kinases (TRKA, TRKB, TRKC).
(2) Fusion proteins containing the ROS1 domain can drive tumorigenic potential through overactivation of downstream signaling pathways.
(3) Repotrectinib exhibits antitumor activity in cultured cells expressing ROS1 fusions and mutations.
2. Indications
(1) This product is indicated for the treatment of adult patients with locally advanced or metastatic ROS1-positive non-small cell lung cancer.
(2) Prior to use, ROS1 rearrangement must be confirmed by tumor specimen testing. Currently, there is no FDA-approved testing method for selecting patients for retrerectinib treatment.
II. Repotrectinib Usage Guidelines for Special Populations
1. Pregnant Women
(1) Based on its mechanism of action, retrectinib may pose a risk to the fetus.
(2) Administration of retrectinib to pregnant rats during organogenesis may result in fetal malformations.
(3) Women of childbearing potential are advised to use effective non-hormonal contraception during treatment and for two months after the last dose.
2. Lactating Women
No data are available on whether retrectinib enters human breast milk. Breastfeeding is not recommended during treatment and for 10 days after the last dose.
3. Patients with Hepatic Impairment
(1) No dose adjustment is required for patients with mild hepatic impairment (total bilirubin >1-1.5 times the upper limit of normal or AST > the upper limit of normal).
(2) The recommended dose for patients with moderate to severe hepatic impairment has not been determined.
4. Patients with Renal Impairment
(1) No dose adjustment is required for patients with mild or moderate renal impairment.
(2) The recommended dose for patients with severe renal insufficiency or renal failure has not been determined.
III. Detailed Explanation of Repotrectinib Drug Interactions
1. CYP3A Inhibitors
(1) Avoid concomitant use with potent and intermediate-potency CYP3A inhibitors. Concomitant use may increase riprectinib exposure, thereby increasing the incidence and severity of adverse reactions.
(2) CYP3A inhibitors should be discontinued for 3-5 elimination half-lives before initiating riprectinib treatment.
2. P-gp Inhibitors
Avoid concomitant use with P-gp inhibitors. Concomitant use may increase riprectinib exposure.
3. CYP3A Inducers
(1) Avoid concomitant use with potent and intermediate-potency CYP3A inducers.
(2) Concomitant use may decrease riprectinib plasma concentrations, thereby reducing efficacy.
4. CYP3A Substrate
Riprectinib is a CYP3A4 inducer. Concomitant use may decrease the concentration of CYP3A4 substrate.
5. Hormonal Contraceptives
(1) Avoid concurrent use with hormonal contraceptives.
(2) Riprotinib may reduce progestin or estrogen exposure, potentially reducing the effectiveness of hormonal contraceptives.
6. Food Interactions
Grapefruit juice may increase blood drug concentrations and should be avoided.
