The study of vascular anomalies is a rapidly progressing field in medicine. The development of new knowledge in the pathology and management of these disease processes are exemplified in the treatment of hemangiomas with propranolol and generalized lymphatic malformations with sirolimus. Central conducting lymphatic anomalies have traditionally been refractory to medical and surgical interventions. We report a case of a central conducting lymphatic anomaly that was responsive to sirolimus. A 14-year-old boy presented with chylothorax and chyluria with a lymphangiogram demonstrating abnormal lymphatic flow and reflux along the entire course of the central channels. Traditionally, medical management has been limited to somatostatin and low-fat diet with poor response and surgical interventions that are palliative. Sirolimus allows a new medical option that could improve management of this unresponsive population.

8566 Background: Checkpoint blockade through CTLA4 with ipilimumab has for the first time improved survival in patients with advanced melanoma. Immune-mediated toxicity and increase in humoral and T-cell anti-NY-ESO-1 immune responses after treatment are both linked with benefit. However there is currently no broadly relevant, immunological biomarker for predicting outcome prior to initiation of therapy. Methods: Using a novel immunological assay developed by Serametrix Corporation we analysed the presence of antibodies to a proprietary panel of tumour associated antigens (TAAs) in 34 patients with advanced melanoma, given ipilimumab at 3mg/kg as second or subsequent line of treatment. Results: 34 patients were consented and analysed, 22 females, 13 males. With a median age of 63 years median overall survival was 24 weeks; 6/34 patients had an objective response to ipilimumab (17.6%, median survival not reached). Antibody (AB) responses were tested against the panel of 26 TAAs. This panel includes BRAF, Cancer/Testis and other described or novel TAAs. We observed a wide range in the incidence and levels of antibody response. 12 patients had no detectable immunity, 6 an AB response to a single antigen, 5 AB response to 2, and 11 patients to 3 or more TAA. Five patients had either pre-existing anti-BRAF antibodies or developed these after CTLA4-blockade. Survival was significantly longer in those patients with pre-existing antibodies to 2 or more TAA, compared to those with 0 or 1 specificities (median survival 39.4 vs 16.4 weeks p=0.02). Conclusions: Patients with advanced melanoma had variable levels of humoral immunity to a large number of TAA, including to BRAF. The presence of antibody response to 2 or more TAA correlated with longer survival following treatment with ipilimumab and appears to provide a biomarker for identifying those patients that are most likely to respond to checkpoint blockade with ipilimumab.