The goal of this clinical trial is to determine if NTB-928 can be given safely to adult females with ovarian cancer that has come back (relapsed) or stopped responding to treatment (refractory), how NTB-928 moves through the body, and how the immune system reacts to it. The study will also look for early signs of anti-cancer activity of NTB-928. The main questions the study aims to answer are:

• What side effects do participants experience when receiving NTB-928, including side effects that limit how much of it can be safely given?
• How is NTB-928 processed by the body at different dose levels?
• Does the immune system react to NTB-928 during treatment?
• What dose of NTB-928 can be given safely that shows early signs of activity against ovarian cancer?

Inclusion Criteria:

• Aged 18 years or older
• Have a confirmed diagnosis of ovarian cancer, including high-grade serous, high-grade endometrioid, low-grade serous, or clear cell ovarian cancer, or carcinosarcoma of the ovary. Patients with mucinous carcinoma are not eligible.
• Have relapsed or refractory ovarian cancer and have already received standard treatments known to provide benefit; participants are eligible if they have platinum-refractory, platinum-resistant, or platinum-sensitive ovarian cancer (with clearly documented ineligibility for further platinum chemotherapy).
• Are able to understand the study requirements and are willing to provide written informed consent
• Are willing to use effective birth control during the study and for a period after the last dose of study treatment, if of childbearing potential

Exclusion Criteria:

• Have another active cancer that could interfere with assessment of this study treatment
• Have received another investigational drug or certain cancer treatments within a recent period before starting this study
• Are pregnant or breastfeeding