Recurrent or Progressive Endometrial Cancer

The purpose of this study is to compare how well Rina-S (GEN1184) works compared to treatment of physician's choice (paclitaxel or doxorubicin) that are considered standard medical care for the treatment of recurrent or progressive endometrial cancer (EC) following prior therapy. There is an equal (50:50) chance of getting either Rina-S or a chemotherapy agent as treatment in this study. The study duration will be approximately 3 years. The treatment duration will be different for every participant, but an average of 4 to 6 months is expected. All participants will receive active drug; no one will be given placebo. Participation in the study will require visits to the study site(s).