NRG-GY026

Official Title

Testing the addition of Herceptin Hylecta or Phesgo to the usual chemotherapy for HER2 positive endometrial serous carcinoma or carcinosarcoma.

Study Purpose

To determine if the addition of the study drugs will lower the chance of this disease from coming back.

Diagnosis

Stage IA-IVB, non-recurrent HER2 positive endometrial serous carcinoma or endometrial carcinosarcoma.

Eligibility

Stage IA-IVB, non-recurrent HER2 positive endometrial serous carcinoma or endometrial carcinosarcoma that has not been previously treated with chemotherapy.

Intervention

Participants will be randomized at a 1:1:1 ratio into one of three arms of the study.

Arm 1:  Standard of care chemo every 3 weeks for 6 cycles.

Arm 2:  Standard of care chemo plus Herceptin and the study agent Herceptin Hylecta every 3 weeks for 6 cycles, then Herceptor Hylecta  every 3 weeks for up to a year.

Arm 3:  Standard of care chemo plus Herceptin and Perjeta and the study agent Phesgo every 3 weeks for 6 cycles, then Phesgo every 3 weeks for up to a year.