Infigratinib is a kinase inhibitor indicated for the treatment of adult patients with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma, who have tested positive for FGFR2 gene fusion or rearrangement.
How to Use Infigratinib
Confirmation of Prerequisites for Medication Use
Before using infigratinib, the presence of FGFR2 gene fusion or rearrangement in the patient must be confirmed by an FDA-approved testing method.
Standard Dosing Regimen
The standard recommended dose of infigratinib is 125mg (1×100mg capsule plus 1×25mg capsule), administered orally once daily for 21 consecutive days followed by a 7-day drug holiday, forming a complete 28-day treatment cycle.
This dosing cycle should be repeated until disease progression or unacceptable toxicity occurs.
Specific Administration Requirements
Fasting administration: Take at least 1 hour before meals or 2 hours after meals, and administer at approximately the same time each day to maintain stable blood drug concentrations.
Swallow whole: Take the intact capsule with a full glass of water; do not crush, chew, or dissolve the capsule.
Management of missed doses: If a dose is missed by more than 4 hours or vomiting occurs after administration, do not make up the missed dose. Instead, resume the regular dosing schedule the next day.
Dosage Adjustment of Infigratinib
Dosage Adjustment Based on Adverse Reactions
The first dose reduction is to 100mg (1×100mg capsule), the second reduction to 75mg (3×25mg capsules), and the third reduction to 50mg (2×25mg capsules).
For retinal pigment epithelial detachment (RPED), if no resolution occurs within 14 days, suspend administration until resolution, then resume treatment at the original dose or a lower dose.
Management of Hyperphosphatemia
When serum phosphate levels are >7.5mg/dL or >9mg/dL in a single test, suspend administration until levels decrease to ≤5.5mg/dL.
Determine the resumption dose based on the duration of hyperphosphatemia: if >7.5mg/dL persists for <7 days, resume at the original dose.
If >7.5mg/dL persists for >7 days or there was a previous reading of >9mg/dL, resume at a reduced dose level.
Medication for Special Populations of Infigratinib
Patients with Renal Impairment
For patients with mild to moderate renal impairment (creatinine clearance 30-89mL/min), the recommended dose is 100mg once daily, following a 28-day cycle of 21 consecutive days of administration and 7 days of drug holiday.
The recommended dose for patients with severe renal impairment (CLcr <30mL/min) or end-stage renal disease receiving intermittent hemodialysis has not been established.
Patients with Hepatic Impairment
The recommended dose for patients with mild hepatic impairment is 100mg once daily.
For patients with moderate hepatic impairment, 75mg once daily is recommended, both following a 28-day cycle of 21 days of administration and 7 days of drug holiday.
The efficacy of infigratinib in patients with severe hepatic impairment has not been determined.
Elderly Patients
In clinical studies, approximately 33% of patients were 65 years of age or older, and 10% were 75 years of age or older.
No overall difference in efficacy was observed between elderly patients and younger adult patients, so no special dosage adjustment is required for elderly patients.
Pregnant and Lactating Women
Based on animal study results and its mechanism of action, infigratinib may cause fetal harm.
Pregnant women should be informed of the potential fetal risks, and women of reproductive potential are advised to use effective contraceptive measures during treatment and for 1 month after the last dose.
Female partners of male patients should also use contraceptive measures during the same period.
Lactating women should discontinue breastfeeding during treatment and for 1 month after the last dose.
