Efficacy of systemic sirolimus in the treatment of generalized lymphatic anomaly and Gorham-Stout disease

BACKGROUND

Generalized lymphatic anomaly (GLA) and Gorham-Stout disease (GSD) are rare complicated lymphatic malformations that occur in multiple body sites and are associated with significant morbidity and mortality. Treatment options have been limited, and conventional medical therapies have been generally ineffective. Emerging data suggest a role for sirolimus as a treatment option for complex lymphatic anomalies.

PROCEDURE

Disease response was evaluated by radiologic imaging, quality of life (QOL), and clinical status assessments in children and young adults with GLA and GSD from a multicenter systematic retrospective review of patients treated with oral sirolimus and the prospective phase 2 clinical trial assessing the efficacy and safety of sirolimus in complicated vascular anomalies (NCT00975819). Sirolimus dosing regimens and toxicities were also assessed.

RESULTS

Eighteen children and young adults with GLA (n = 13) or GSD (n = 5) received oral sirolimus. Fifteen patients (83%) had improvement in one or more aspects of their disease (QOL 78%, clinical status 72%, imaging 28%). No patients with bone involvement had progression of bone disease, and the majority had symptom or functional improvement on sirolimus. Improvement of pleural and pericardial effusion(s) occurred in 72% and 50% of affected patients; no effusions worsened on treatment.

CONCLUSIONS

Sirolimus appears effective at stabilizing or reducing signs/symptoms of disease in patients with GLA and GSD. Functional impairment and/or QOL improved in the majority of individuals with GLA and GSD with sirolimus treatment.

Response of Blue Rubber Bleb Nevus Syndrome to Sirolimus Treatment

BACKGROUND

Blue rubber bleb nevus syndrome (BRBNS) is a rare multifocal venous malformation syndrome involving predominantly the skin and gastrointestinal tract. Traditional treatment modalities include corticosteroids, interferon-α, sclerotherapy, and aggressive surgical resection. Sirolimus has been used in several single case reports.

PROCEDURE

We performed a single-institution retrospective review of four children with BRBNS, who received sirolimus as part of their treatment regimens. A diagnosis of BRBNS was based on clinical, radiologic, and pathologic criteria.

RESULTS

Median age was 6.5 years (range: 2-16 years). Pathologic evaluations revealed a combined malformation with venous and lymphatic components. The novel finding of a lymphatic component was confirmed with PROX-1 immunostaining. Patients received oral sirolimus with target drug levels between 10 and 13 ng/ml. Responses to treatment were defined as stabilization/decrease in size of lesions; resolution of transfusion requirements; reduction in pain, and improvement in quality of life (QOL). Median time to response was 1.5 months (SD ± 0.96 month, range: 1-3 months). Median follow-up was 21 months (range: 18-26 months). Lesion size and characteristics improved in all patients. All patients reported decrease in pain and improvement in QOL. All three patients requiring transfusions became transfusion-independent. One patient had resolution of coagulopathy. Adverse effects of sirolimus consisted of mucositis in three patients and neutropenia in one patient.

CONCLUSIONS

Sirolimus is safe and efficient for the treatment of BRBNS. Further prospective studies are needed to evaluate the long-term effectiveness of this drug. This is the first report that identifies a lymphatic component as part of BRBNS.