Pralsetinib (Gavreto) is a kinase inhibitor targeting RET gene fusions, and it demonstrates significant value in the treatment of metastatic RET fusion-positive non-small cell lung cancer and thyroid cancer. A rational medication regimen is not only related to treatment efficacy, but also directly affects patients' quality of life and safety.

Dosage and Administration, Recommended Dose of Pralsetinib (Gavreto)

Recommended Dosage Regimen

The standard recommended dose of pralsetinib is 400 mg orally once daily for adults and pediatric patients aged 12 years and older.

It is particularly important to note that this drug should be administered on an empty stomach, i.e., no food should be consumed for at least 2 hours before dosing and at least 1 hour after dosing.

Treatment should continue until disease progression or unacceptable toxicity occurs.

Management of Missed Doses

If a dose is missed, it can be taken as soon as the patient remembers on the same day, and the normal dosing schedule should be resumed the next day.

If vomiting occurs after taking the drug, no additional dose should be taken; instead, continue with the next scheduled dose as planned.

Dose Adjustment of Pralsetinib (Gavreto)

Interstitial Lung Disease/Pneumonitis

For grade 1-2 reactions, treatment should be withheld until symptoms resolve, then resumed at a reduced dose. Permanent discontinuation is required if the reaction recurs.

For grade 3-4 reactions, permanent discontinuation of the drug is required immediately.

Hypertension Management

If grade 3 hypertension persists despite optimal antihypertensive therapy, treatment should be withheld and resumed at a reduced dose after blood pressure is controlled.

For grade 4 hypertension, permanent discontinuation is required.

Dose Adjustment for Drug Interactions

Caution should be exercised when co-administering with CYP3A and/or P-gp inhibitors.

When combined with P-gp and strong CYP3A inhibitors, the 400 mg dose should be reduced to 200 mg.

When combined with strong CYP3A inhibitors alone, moderate CYP3A inhibitors, or P-gp inhibitors, the dose should be reduced to 300 mg.

The dose prior to inhibitor use can be resumed 3-5 half-lives after discontinuation of the inhibitor.

If co-administration with CYP3A inducers is unavoidable, the dose needs to be increased: for strong CYP3A inducers, the 400 mg dose should be increased to 800 mg; for moderate inducers, the dose should be increased to 600 mg.

Administration in Special Populations

Pediatric Use

The efficacy of pralsetinib has been established in pediatric patients aged 12 years and older, and it is indicated for the treatment of RET fusion-positive thyroid cancer.

However, it should be noted that the efficacy of this drug has not been established in pediatric patients under 12 years of age.

In adolescent patients, growth plate status should be monitored; if abnormalities occur, consideration should be given to interrupting or discontinuing treatment.

Patients with Hepatic or Renal Impairment

No dose adjustment is required for patients with mild to moderate hepatic impairment.

No dose adjustment is required for patients with mild renal impairment, but clinical experience is limited in patients with severe renal impairment.

Reproductive-Age Patients

Based on animal study results, pralsetinib may cause fetal harm.

Reproductive-age females are advised to use effective non-hormonal contraception during treatment and for 2 weeks after the last dose.

Male patients with female partners of childbearing potential should use effective contraception during treatment and for 1 week after the last dose.