Copanlisib in Treating Patients With Persistent or Recurrent Endometrial Cancer

PRIMARY OBJECTIVES: I. To assess the activity of copanlisib (BAY 80-6946) in patients with persistent or recurrent endometrial carcinoma harboring phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PI3KCA) hotspot mutations with the frequency of objective response. SECONDARY OBJECTIVES: I. To estimate 6 month progression-free survival (PFS) and median PFS. II. To estimate the distribution of the duration of overall survival (OS). III. To assess the safety profile of copanlisib in endometrial cancer patients. TERTIARY OBJECTIVES: I. To systematically evaluate by sequencing the site (i.e., exome) and characteristics of PIK3CA mutations in endometrial cancer patients and correlate such mutations to overall response (OR), PFS, and OS in patients treated with copanlisib. OUTLINE: Patients receive copanlisib intravenously (IV) over 1 hour on days 1, 8, and 15. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 2 years and then every 6 months for 3 years.