Clinical Data Six of 18 patients (33%) had tumor reductions of greater than 10% by RECIST, of whom three patients remain on treatment, and median progression-free survival (PFS) to date is 5.5 months. A total of five patients with angiosarcoma, a sarcoma subtype known to express high levels of endoglin, have been evaluated for response in the Phase 1b/2 study. All five patients have had radiographic reductions in tumor volume, and two patients have demonstrated ongoing durable complete responses by RECIST, and remain on study for 62 and 31 weeks, respectively. The Phase 2 portion of the study, which is also evaluating the combination of TRC105 and Votrient, has enrolled 62 of 63 planned patients to date.