A real-world study of sirolimus in the treatment of pediatric head and neck lymphatic malformations.

ABSTRACT:

Objective

Sirolimus has shown promise in treating lymphatic malformations (LMs); however, previous studies were all single-arm clinical trials. Prior studies have reported that some LMs lesions can spontaneously reduce, which poses a potential confounding factor in evaluating therapeutic outcomes. Our study aimed to assess the effectiveness and safety of oral sirolimus objectively for LMs in the head and neck by comparing the outcomes in a control group.

Methods

This real-world study involved 57 children with LMs from 2020 to 2023 at Beijing Children's Hospital. The patients were divided into nonintervention and oral sirolimus groups. The primary outcome was lesion volume change on magnetic resonance imaging, and the secondary outcome was improvement in clinical symptoms. Safety was assessed based on adverse reactions (regular laboratory tests and patient follow-ups) and sirolimus blood concentrations in the oral sirolimus group.

Results

Twenty-one children were enrolled in the nonintervention group (14 male and 7 female), with a median age of 33 months (interquartile range [IQR], 9-53.5 months); 36 children were enrolled in the oral sirolimus group (15 male and 21 female), with a median age of 24 months (IQR, 7.5-51.25 months). The median volume reduction ratio in the nonintervention group was 0.08 (IQR, 0.30-0.40), and eight cases (38.1%) had an effective response. The median volume reduction ratio in the oral sirolimus group was 0.67 (IQR, 0.40-0.92), and 33 cases (91.7%) had an effective response. Clinical symptoms improved in 9 children (42.9%) in the nonintervention group and 35 (97.2%) in the oral sirolimus group. The effective rate and volume changes differed statistically significantly (P < .001). The most common adverse reaction in the oral sirolimus group was an increase in myocardial enzyme levels (n = 23 [63.9%]), followed by oral ulcers (n = 16 [44.4%]). The overall blood concentration of sirolimus was low during the drug administration in the oral sirolimus group, among which 10 children (27.8%) had a mean blood concentration of <5 ng/mL.

Conclusions

Sirolimus significantly decreased lesion volume and improved clinical symptoms in most patients with LMs, especially those with macrocystic components. Conservative observations were only helpful in some patients, with relatively modest volume changes.

SUBMITTER: Wang J 

PROVIDER: S-EPMC12433909 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature