Title
The COMPASSHER2 Trials (COMprehensive Use of Pathologic Response ASSessment to Optimize Therapy in HER2-Positive Breast Cancer): COMPASSHER2 Residual Disease (RD), A Double-Blinded, Phase III Randomized Trial of T-DM1 Compared with T-DM1 and Tucatinib

Description
The COMPASSHER2 Trials (COMprehensive Use of Pathologic Response ASSessment to Optimize Therapy in HER2-Positive Breast Cancer): COMPASSHER2 Residual Disease (RD), A Double-Blinded, Phase III Randomized Trial of T-DM1 Compared with T-DM1 and Tucatinib

Objective
PRIMARY OBJECTIVE:

I. To determine if the invasive disease-free survival (iDFS) with T-DM1 and tucatinib is superior to the iDFS in the control arm (T-DM1 + placebo) when administered to high risk patients with HER2-positive breast cancer and residual disease after neoadjuvant HER2-directed therapy.

SECONDARY OBJECTIVES:

I. To evaluate whether treatment with tucatinib plus T-DM1 compared to treatment with T-DM1 alone (T-DM1 plus placebo) improves the following:

Ia. Breast cancer free survival (BCFS). Ib. Distant recurrence-free survival (DRFS). Ic. Brain metastases-free survival (BMFS). Id. Overall survival (OS). II. To evaluate whether treatment with tucatinib plus T-DM1 compared to treatment with T-DM1 alone (T-DM1 plus placebo) reduces the incidence of brain metastases.

Treatment If you decide to take part in this study, you will either get treatment with T-DM1 and placebo (a
pill that looks like the study drug but contains no medication) or T-DM1 and tucatinib, for up to
14 cycles, unless your breast cancer returns or the side effects become too severe. If the breast
cancer returns while you are on the study, the treatment will be changed. You may also be told
whether you were receiving T-DM1 and placebo or T-DM1 and tucatinib.
After you finish T-DM1 and placebo, or T-DM1 and tucatinib, your doctor will continue to
follow your condition with clinic visits every 6 months for 10 years and watch you for side
effects and for signs of breast cancer returning. This means you will keep seeing your doctor for
10 years after you are enrolled in the study.

Key Eligibility For the full Eligibility Criteria, visit the ClinicalTrials.gov record for this trial.

Applicable Disease Sites
Breast

Participating Institutions
Johnson Creek, UW Cancer Center; Mercy Health Systems, Janesville ; UW Health 1 S. Park Medical Center; UW Health Carbone Cancer Center Rockford; UW Health Eastpark Medical Center; UW Health University Hospital