QINLOCK® (ripretinib) tablets
Ripretinib is a kinase inhibitor. The chemical name of ripretinib is 1-(4-bromo-5-[1-ethyl-7-(methylamino)-2oxo-1,2-dihydro-1,6-naphthyridin-3-yl]-2-fluorophenyl)-3-phenylurea. The molecular formula is C24H21BrFN5O2 and the molecular weight is 510.36 g/mol.
Ripretinib is a white to off-white crystalline solid. Ripretinib is a lipophilic, weak base, and practically insoluble in aqueous media.
QINLOCK is available as a white to off-white, oval tablets for oral use containing 50 mg of ripretinib. The tablet is debossed with “DC1” on one side. Each tablet contains the following inactive ingredients: crospovidone, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and silicon dioxide.
INDICATIONS AND USAGE
QINLOCK is indicated for the treatment of adult patients with advanced gastrointestinal stromal tumor (GIST) who have received prior treatment with 3 or more kinase inhibitors, including imatinib.
Mechanism of Action
Ripretinib is a tyrosine kinase inhibitor that inhibits KIT proto-oncogene receptor tyrosine kinase (KIT) and platelet derived growth factor receptor A (PDGFRA) kinase, including wild type, primary, and secondary mutations. Ripretinib also inhibits other kinases in vitro, such as PDGFRB, TIE2, VEGFR2, and BRAF.
DOSAGE AND ADMINISTRATION
The recommended dosage of QINLOCK is 150 mg orally once daily with or without food until disease progression or unacceptable toxicity. Instruct patients to swallow tablets whole. Advise patients to take QINLOCK at the same time each day.
Advise patients to take a missed dose if less than 8 hours have passed since the missed scheduled dose. Advise patients not to take an additional dose if vomiting occurs after taking QINLOCK and to continue with their next scheduled dose.
Dose Modifications for Moderate CYP3A Inducers
Avoid concomitant use of moderate CYP3A inducers during QINLOCK treatment.
If a moderate CYP3A inducer cannot be avoided, increase the QINLOCK dosing frequency from the recommended dose of 150 mg once daily to 150 mg twice daily during the co-administration period. Monitor for clinical response and tolerability. If the concomitant moderate CYP3A inducer is discontinued, resume QINLOCK dosage back to 150 mg once daily 14 days after the discontinuation of the moderate CYP3A inducer.
WARNINGS AND PRECAUTIONS
Palmar-Plantar Erythrodysesthesia Syndrome: In INVICTUS, Grade 1-2 palmar-plantar erythrodysesthesia syndrome (PPES) occurred in 21% of the 85 patients who received QINLOCK. PPES led to dose discontinuation in 1.2% of patients, dose interruption in 2.4% of patients, and dose reduction in 1.2% of patients.
Based on severity, withhold QINLOCK and then resume at same or reduced dose.
New Primary Cutaneous Malignancies: In INVICTUS, cutaneous squamous cell carcinoma (cuSCC) occurred in 4.7% of the 85 patients who received QINLOCK, with a median time to event of 4.6 months (range: 3.8 to 6 months). In the pooled safety population, cuSCC and keratoacanthoma occurred in 7% and 1.9% of patients, respectively.
In INVICTUS, melanoma occurred in 2.4% of the 85 of patients who received QINLOCK. In the pooled safety population, melanoma occurred in 0.9% of patients.
Perform dermatologic evaluations when initiating QINLOCK and routinely during treatment. Manage suspicious skin lesions with excision and dermatopathologic evaluation. Continue QINLOCK at the same dose.
Hypertension: Do not initiate QINLOCK in patients with uncontrolled hypertension. Adequately control blood pressure prior to initiating QINLOCK. Monitor blood pressure as clinically indicated during treatment with QINLOCK, and initiate or adjust antihypertensive therapy as appropriate. Based on severity, withhold QINLOCK and then resume at same or reduced dose or permanently discontinue.
Cardiac Dysfunction: Assess ejection fraction by echocardiogram or MUGA scan prior to initiating QINLOCK and during treatment, as clinically indicated. Permanently discontinue QINLOCK for Grade 3 or 4 left ventricular systolic dysfunction.
Risk of Impaired Wound Healing: Impaired wound healing complications can occur in patients who receive drugs that inhibit the vascular endothelial growth factor (VEGF) signaling pathway. Therefore, QINLOCK has the potential to adversely affect wound healing.
Withhold QINLOCK for at least 1 week prior to elective surgery. Do not administer for at least 2 weeks following major surgery and until adequate wound healing. The safety of resumption of QINLOCK after resolution of wound healing complications has not been established.
Photosensitivity: QINLOCK may cause photosensitivity reactions. In all patients treated with QINLOCK in clinical trials (n=621), photosensitivity reactions occurred in 0.6% of patients.
Advise patients to limit direct ultraviolet exposure during treatment with QINLOCK and for at least one week after discontinuation of treatment.
Embryo-Fetal Toxicity: Based on findings from animal studies and its mechanism of action, QINLOCK can cause fetal harm when administered to a pregnant woman. Oral administration of ripretinib to pregnant rats and rabbits during the period of organogenesis resulted in malformations primarily associated with the cardiovascular and skeletal systems, anatomic variations, decreased fetal body weight, and increased post-implantation loss at exposures approximately one half of the recommended dose of 150 mg once daily based on area under the curve (AUC).
Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with QINLOCK and for 1 week after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with QINLOCK and for 1 week after the last dose.
Effect of Other Drugs on QINLOCK
Strong CYP3A Inhibitors: Coadministration of QINLOCK with a strong CYP3A inhibitor increased the exposure of ripretinib and its active metabolite (DP-5439), which may increase the risk of adverse reactions.
Monitor patients more frequently for adverse reactions.
Strong and Moderate CYP3A Inducers: Coadministration of QINLOCK with a strong CYP3A inducer decreased the exposure of ripretinib and its active metabolite (DP-5439), which may decrease QINLOCK anti-tumor activity.
Coadministration of QINLOCK with moderate CYP3A inducers is predicted to decrease the exposure of ripretinib and its active metabolite (DP-5439), which may decrease QINLOCK anti-tumor activity
- Avoid concomitant use of QINLOCK with strong CYP3A inducers.
- Avoid concomitant use of QINLOCK with moderate CYP3A inducers. If a moderate CYP3A inducer cannot be avoided, increase QINLOCK dosing frequency from the recommended dose of 150 mg once daily to 150 mg twice daily during the co-administration period. Monitor for clinical response and tolerability
USE IN SPECIFIC POPULATIONS
Pregnancy: Based on findings from animal studies and its mechanism of action, QINLOCK can cause fetal harm when administered to a pregnant woman. There are no available data on the use of QINLOCK in pregnant women to inform a drug-associated risk. Administration of ripretinib to pregnant rats and rabbits during the period of organogenesis resulted in malformations primarily associated with the cardiovascular and skeletal systems, anatomic variations, reduced fetal body weight, and increased post-implantation loss at maternal exposures that were approximately equal to the human exposure at the recommended dose of 150 mg. Advise pregnant women of the potential risk to a fetus.
Lactation: There are no data regarding the presence of ripretinib or its metabolites in either human milk or its effects on a breastfed child or on milk production. Because of the potential for serious adverse reactions in the breastfed child, advise women not to breastfeed during treatment with QINLOCK and for 1 week after the last dose.
Infertility: Based on findings from animal studies, QINLOCK may impair fertility in males of reproductive potential
Pediatric Use: The safety and effectiveness of QINLOCK in pediatric patients have not been established.
Geriatric Use: Of the 85 patients in INVICTUS who received QINLOCK 150 mg orally once daily, 24% were between 65 to 74 years of age and 9% were 75 years of age or older. Clinical studies of QINLOCK did not include sufficient numbers of patients aged 65 and older to determine whether they respond differently from younger patients.
Hepatic Impairment: No dose adjustment is recommended in patients with mild hepatic impairment (total bilirubin ≤ULN and AST >ULN or total bilirubin 1 to 1.5 × ULN and any AST). A recommended dosage of QINLOCK has not been established for patients with moderate or severe hepatic impairment