A Study to Compare Vincristine to Sirolimus for Treatment of High Risk Vascular Tumors

In this research study we want to learn more about which treatment works better for patients diagnosed with a vascular tumor called Kaposiform Hemangioendothelioma (KHE) or other high risk vascular tumors such as Tufted Angioma (TA). In these tumors, the blood cells that help your blood clot called platelets become trapped in the tumor causing swelling, pain, and bruising. Vascular tumors can be life threatening. There are few medical treatments that will work to shrink the vascular tumor. Some doctors will use steroids and vincristine to try and shrink vascular tumors. In this research study, the study doctor will compare two different drugs to see which one will work better to help shrink your vascular tumor. One of the drugs is vincristine. Vincristine is approved by the Food and Drug Administration (FDA) to treat people with cancer. Vincristine is used to stop the abnormal cells from growing such as cells that make up blood vessels. The other drug to be used in this study is sirolimus. Sirolimus is currently approved by the Food and Drug Administration (FDA) to prevent transplanted organ rejection. Sirolimus is not approved by the FDA for treatment of vascular abnormalities and is considered experimental. Sirolimus belongs to a class of drugs call 'mTOR inhibitors'. mTOR (mammilian target of rapamycin) helps cells to grow and may also help blood vessels to grow in a more normal fashion. Sirolimus is currently being tested in patients with vascular tumors and cancer. In vascular tumors, we hope sirolimus will stop the blood vessel growth. Funding Source: FDA - OOPD (Office of Orphan Products Development)