A Study of Ivonescimab in People With Leiomyosarcoma

Prior therapy with an anti PD1/PDL1 inhibitor and/or VEGF inhibitor (including multi-tyrosine kinase inhibitors with VEGF inhibition such as pazopanib/cabozantinib/sunitinib).

History or evidence of symptomatic autoimmune disease (e.g., pneumonitis, glomerulonephritis, vasculitis, or other), or history of active autoimmune disease that has required systemic treatment (i.e., use of corticosteroids, immunosuppressive drugs or biological agents used for treatment of autoimmune diseases) in past 2 years prior to enrollment. Replacement therapy (e.g., thyroxine for hypothyroidism, insulin for diabetes or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment for autoimmune disease.

Evidence of clinically significant immunosuppression such as the following: o Primary immunodeficiency state such as Severe Combined Immunodeficiency Disease o Concurrent opportunistic infection o Receiving systemic immunosuppressive therapy (> 2 weeks) including oral steroid doses > 10 mg/day of prednisone or equivalent within 7 days prior to enrollment. However, in the setting of non-immune mediated indications for steroid use, chronic/active low dose steroid use may be permitted at the discretion of the principal investigator. The dose of steroid allowed in this setting is also at the discretion of the principal investigator. (Use of inhaled or topical steroids is permitted.)

Major surgical procedures or serious trauma within 4 weeks prior to randomization, or plans for major surgical procedures within 4 weeks after the first dose (as determined by the investigator). Minor local procedures (excluding central venous catheterization and port implantation) within 3 days prior to randomization.