SARC046: A Phase II Trial of Nab-Sirolimus in Patients With Progressing or Symptomatic Epithelioid Hemangioendothelioma

Inclusion Criteria: * Participants must have histologically or cytologically confirmed EHE that is either progressing or clinically symptomatic, not a candidate for curative intent surgery, and requires systemic therapy in the opinion of the investigator. * Participants must have measurable disease by RECIST v1.1, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as ≥20 mm (≥2 cm) by chest x-ray or as ≥10 mm (≥1 cm) with CT scan, MRI, or calipers by clinical exam. See Section 12 (Measurement of Effect) for the evaluation of measurable disease. * Age ≥18 years * ECOG performance status ≤2 * Participants must meet the following organ and marrow function as defined below: * Platelets \>75,000μl * ANC \>1500μl * Hgb \>9g/dl * Creatinine \<1.5 x ULN or measured CrCl of \>30ml/m2/1.73 m2 * Total bilirubin \<2 x ULN * AST/ALT \<3 x ULN * Patients must have recovered from toxicity related to prior therapy to grade \<=1 (defined by CTCAE v5.0) (except alopecia and neuropathy, or immunotherapy related hypothyroidism). Toxicities that are permanent, like hearing loss from platinum agents, may be allowed if agreed to by the medical monitor. * The effects of nab-sirolimus on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth c…