526 Clinical Efficacy and Safety of Oral Sirolimus Therapy in Patients with Klippel-Trenaunay Syndrome in a Single Specialist Centre

Aim The evidence on the efficacy and safety of sirolimus therapy in patients with Klippel-Trenaunay Syndrome (KTS) remained scarce. This study aimed to assess this for patients for whom standard treatment alone was inadequate. Method This was a retrospective study of all adult patients with diagnosed KTS who were treated with oral sirolimus where standard therapy was inadequate in a single specialist centre since May 2016. Demographic and clinical data including patient-reported responses, visual analogue scores for pain and adverse effects, and quality-of-life scores (SF-36) were reviewed. Results Fourteen KTS patients (6 males: 8 females) with a median age of 44 (range: 27-57) years were included. Six patients stopped sirolimus within two months due to extensive rashes and itching, mouth ulceration, severe chest infection, worsening KTS symptoms, and multiple intolerable side effects. The median duration was 803 (IQR: 1106) days if sirolimus was tolerated. Four patients reported significant reduction in pain, 3 patients had reduced limb swelling, 1 had reduced episodes of cellulitis, 1 had improved coagulopathy and only 2 patients demonstrated limited improvements from sirolimus. The most common adverse effects were headaches (n=5), fatigue (n=5) and abdominal discomfort (n=5). There was an improvement in the mean scores for physical functioning (5.0), role limitations due to emotional problems (11.1), pain (2.5), depression (2.25) and anxiety (0.7). Conclusions Oral sirolimus therapy was clinically effective and safe in some complicated patients with KTS when standard therapy alone was inadequate. Longer follow-up would be needed to evaluate oral sirolimus therapy in KTS patients.