FDA Approves Bosutinib for Pediatric Chronic Myelogenous Leukemia Patients
核心洞察
The FDA has approved bosutinib (Bosulif) for pediatric patients aged 1 year or older with Philadelphia chromosome-positive chronic-phase chronic myelogenous leukemia.
The approval covers both newly diagnosed patients and those with disease resistant or intolerant to previous therapy.
Clinical trial data showed major cytogenetic response rates of 76.2% in newly diagnosed patients and 82.1% in resistant/intolerant patients.
The FDA has approved bosutinib (Bosulif) for the treatment of pediatric patients aged 1 year or older with Philadelphia chromosome-positive chronic-phase chronic myelogenous leukemia (CP-CML), marking a significant advancement in pediatric oncology treatment options. The approval encompasses both newly diagnosed cases and patients with disease that is resistant or intolerant to previous therapy.
Clinical Trial Evidence
The approval was based on results from the multicenter, nonrandomized, open-label phase 1/2 BCHILD study (NCT04258943), which enrolled pediatric patients between 1 and 17 years of age with cytogenetic and molecular diagnosis of Philadelphia chromosome-positive CML.
In the newly diagnosed CP-CML population, bosutinib demonstrated robust efficacy with a median follow-up of 4.2 months (range, 1.1-26.3 months). The treatment achieved a major cytogenetic response rate (MCyR) of 76.2% (95% CI, 52.8-91.8) and complete cytogenetic response rate (CCyR) of 71.4% (95% CI, 47.8-88.7). The major molecular response rate was 28.6% (95% CI, 11.3-52.3).
Among patients with relapsed/refractory CP-CML, the results were equally promising with a median follow-up of 23.2 months (range, 1-61.5 months). The MCyR observed with bosutinib was 82.1% (95% CI, 63.1-93.9), and the CCyR was 78.6% (95% CI, 59-91.7). Fourteen patients from this cohort achieved a major molecular response, though two patients lost MMR after 13.6 and 24.7 months on treatment, respectively.
Dosing and Administration
The FDA has established specific dosing recommendations based on treatment indication. For pediatric patients with newly diagnosed Philadelphia chromosome-positive CP-CML, the recommended dose is 300 mg/m² administered orally once daily with food. For patients with resistant/intolerant Philadelphia chromosome-positive CP-CML, the recommended dose is 400 mg/m² administered orally once daily with food.
To facilitate pediatric dosing, the FDA has also approved new capsule formulations of bosutinib in 50 mg and 100 mg strengths, providing greater flexibility in achieving appropriate dosing for younger patients.
Safety Profile
The safety profile of bosutinib in pediatric patients was consistent with known adverse events in adult populations. The most common adverse events occurring in at least 20% of patients included diarrhea, abdominal pain, vomiting, nausea, rash, fatigue, hepatic dysfunction, headache, pyrexia, decreased appetite, and constipation.
Laboratory abnormalities were also observed, with the most common being increased creatinine, increased alanine aminotransferase or aspartate aminotransferase, decreased white blood cell count, and decreased platelet count, which were observed in 45% of patients or more.
Clinical Significance
This approval addresses a significant unmet medical need in pediatric oncology, as bosutinib showed preliminary efficacy compared with other second-generation tyrosine kinase inhibitors while maintaining a tolerable safety profile in pediatric patients. The availability of multiple dosing strengths will enable more precise dosing for the pediatric population, potentially improving treatment outcomes and reducing adverse events.