A Study of Giredestrant in Patients with Grade 1 Endometrial Cancer

Prior treatment

• Pregnancy or breastfeeding, or intention of becoming pregnant during the study or within 30 days after the final dose of giredestrant or within the time period specified per local prescribing guidelines after the final dose of the investigator’s choice of endocrine therapy
• Treatment for cancer including but not limited to, chemotherapy, immunotherapy, cyclin-dependent kinase (CDK)4/6i, endocrine therapy, biologic therapy, or herbal therapy within 28 days prior to the initiation of study enrollment

Other illness

• Any gastrointestinal condition causing malabsorption or obstruction
• Planned surgery, either for the treatment of cancer or any other surgery, during the study treatment period and up to 10 days after the completion of study treatment
• Participants who have clinically significant liver disease consistent with Child-Pugh Class B or C, including active hepatitis, current alcohol abuse, cirrhosis, or positive test for viral hepatitis

Lab values

• Any serious medical condition or abnormality in clinical laboratory tests that precludes the participant’s safe participation in and completion of the study

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
• Confirmed Grade 1 endometrial carcinoma (EC) of endometrioid histology for which participants are willing to receive 6-cycles of study therapy. An endometrial biopsy (EMB) or dilation and curettage (D&C) fresh collected within the screening period or archival sample collected within 3 months prior to screening must be provided to a central laboratory for histologic confirmation to determine eligibility
• Magnetic resonance imaging (MRI)-confirmation of non-deeply invasive tumor (<50% myometrial invasion)
• MRI or computed tomography (CT)-confirmation of no extrauterine disease
• Willing to undergo a minimum of 6 continuous cycles of therapy before decision on surgery
• Adequate hematologic and end-organ function