Efficacy and Safety of Sirolimus in Vascular Anomalies That Are Refractory to Standard Care

The complex vascular malformations induce chronical pains and organic dysfunctions causing significant morbidity and mortality. Therefore, the investigators need to establish guidelines in order to treat these pathologies. Standard treatments such as surgery or interventional radiology are of limited efficacy and related to a high level of recurrences as well as complications. Recent preclinical studies have shown the important role of the PI3Kinase/AKT/mTor pathway on the development and the venous/lymphatic vascular organisations suggesting an appealing therapeutic target to treat patients with venous, lympathic or complex vascular malformations.

Investigators will realize a multicentric phase III study enrolling a higher number of patients to statistically evaluate the efficacy and the safety of the Rapamycin, an mTOR inhibitor, in the treatment of children and adults with vascular malformations for which conventional therapies such as surgery or sclerotherapy are ineffective or associated with high risk of important complications. Nearly 250 patients (200 adults and 50 children) will be enrolled in several european centers.

Inclusion criteria

• Patients with complex vascular anomalies that are refractory to standard care such as medical treatment, surgical resection and/or sclerotherapy/embolization (ineffective or accompanied by major complications)
• Patients must have adequate medullary function: Hemoglobine> 10,0 g/dl, neutrophils >1500/mm³ and platelets > 100.000/mm³
• Patients must have the following laboratory values:
• Total serum bilirubin ≤ 1.5 x ULN (or totally bilirubin ≤ 3 x ULN with direct bilirubin ≤ 1.5 x ULN in patients with well documented Gilbert Syndrome)
• Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 x ULN (or < 5.0 x ULN if hepatic metastases are present)
• Serum creatinine 1.5 x ULN. If the serum creatinine is ≥ 1.5 x ULN, then a 24-hour Creatinine Clearance must be conducted and the result must be ≥ 60 mL/min.
• Karnofsky > 50
• Patients have to be able to sign the informed consent
• Women in age of procreation have to be informed that contraceptive methods are mandatory during the study time

Exclusion criteria

• Any of the following concurrent severe and/or uncontrolled medical conditions, which could compromise participation in the study or interfere with the study results:
• Impaired cardiac function or clinically significant cardiac diseases, including unstable angina pectoris, ventricular arrhythmia, valvular disease with documented compromise in cardiac function, myocardial infarction within the last 6 months, documented by persistent elevated cardiac enzymes or persistent regional wall abnormalities on assessment of LVEF function, history of documented congestive heart failure (New York Heart Association functional classification III-IV), documented cardiomyopathy, family history of congenital long or short QT, or known history of QT/QTc prolongation of Torsades de Pointes (TdP)
• Impairment of Gastro-Intestinal (GI) function or GI disease that may significantly alter the absorption of sirolimus (e.g., ulcerative diseases, uncontrolled nausea, vomiting, diarrhea ≥ Grade 2, malabsorption syndrome, or small bowel resection)
• Known hypersensitivity to drugs or metabolites from similar classes as study treatment.
• Patient has other concurrent severe and /or uncontrolled medical condition that would,in the investigator's judgment, contraindicated participation in the clinical study (e.g. acute or chronic pancreatitis, liver cirrhosis, active chronic hepatitis, severely impaired lung function with a spirometry ≤ 50% of the normal predicted value and/or O2 saturation ≤ 88% at rest, etc.)
• Immunocompromised patients, including known seropositivity for HIV
• Pregnant or lactating women
• Prior treatment with PI3K and/or mTOR inhibitors