Sirolimus reduces venous malformation size, eases GI bleeding in BRBNS

Oral sirolimus, also known as rapamycin, reduces the size of venous malformations (VMs), relieves gastrointestinal (GI) bleeding, and removes transfusion dependence of patients with blue rubber bleb nevus syndrome (BRBNS), results of a study have shown. Moreover, drug-related adverse effects are mild and typically self-limited.

This prospective study was conducted for both paediatric and adult BRBNS patients who received sirolimus 1.0 mg/m² to maintain a trough concentration of 3–10 ng/mL. The investigators performed laboratory tests including complete blood count, biochemical profile, D-dimer, and whole-body magnetic resonance imaging at baseline and 3, 6, and 12 months after treatment.

The following clinical indicators were also assessed: haemoglobin level, lesion size, and transfusion. Adverse effects were recorded on a regular basis.

Eleven patients (median age 14 years, seven females) participated in this study. The average lesion size decreased by 7.4 percent (p<0.001), 9.3 percent (p<0.001), and 13.0 percent (p<0.05) at 3, 6, and 12 months of sirolimus treatment, respectively. Haemoglobin significantly increased after 6 (p=0.006) and 12 months (p=0.019) of treatment. Only one patient received blood transfusion once.

Both quality of life and coagulation function improved. Grade 1–2 adverse events occurred, including oral ulcers (81.8 percent), acne (27.3 percent), transient elevation of liver enzymes (18.2 percent), and hair loss (9.1 percent).

“These findings support sirolimus as a first-line treatment for GI and cutaneous VMs of BRBNS,” the investigators said.

BRBNS is a rare systemic VM disease. GI bleeding arising from multiple VM lesions results in severe chronic anaemia which renders most patients dependent on lifelong blood transfusion and frequent endoscopic treatment with dismaying outcomes.