Real World-clinical Outcomes of Tucatinib, Trastuzumab, and Capecitabine Following Trastuzumab Deruxtecan (T-DXd) for the Treatment of HER2-postive Metastatic Breast Cancer.

Not yet recruiting

• Conditions: Metastatic HER2+ Advanced Breast Cancer
• Interventions: Drug: Tucatinib; Drug: Trastuzumab; Drug: Capecitabine

• Registration Number: NCT06961331
• Lead Sponsor: Pfizer

Brief Summary

A retrospective study of de-identified (to preserve patient privacy) patient information from the Flatiron Health Database to describe 3L and 4L real-world (rw) outcomes (e.g. time to next treatment, time to discontinuation, and overal survival) of the tucatinib-trastuzumab-capecitabine triplet therapy immediately following T-DXd therapy in patients diagnosed with HER2+ metastatic breast cancer (mBC) in the United States.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-04
• Study First Submitted: 2025-04-29
• Study First Submitted QC: 2025-04-29
• Last Update Submitted: 2025-04-29
• Study Start: 2025-04-30
• Primary Completion: 2025-05-07
• Study Completion: 2025-05-07
• Study First Posted: 2025-05-07
• Last Update Posted: 2025-05-07

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 1

Inclusion Criteria

Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:

1. mBC diagnosis between January 1, 2017 and 6 months prior to database cutoff
2. Evidence of human epidermal growth factor receptor 2 (HER2) receptor positivity prior to or up to 90 days following the mBC diagnosis date
3. At least 18 years old on the mBC diagnosis date
4. Treated with systemic anticancer treatment in the metastatic setting, i.e., post mBC diagnosis.
5. Treated with T-DXd in the 2L or 3L setting, followed immediately by the tucatinib triplet, and at least 1 additional prior HER2-targeted regimen

Exclusion Criteria

Patients meeting any of the following criteria will not be included in the study:

1. Patients with evidence of other cancers prior to the mBC diagnosis date will be identified with the following International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) and International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) codes in all databases: 140.xx - 195.xx, 200.xx - 208.xx, C00.xx - C76.xx, C81.xx - C96.xx. (exclude - ICD-9: 174.X, 175.X; ICD-10: C50.XX)
2. Patients treated with tucatinib or T-DXd prior to the 2L or 3L T-DXd treatment
3. Patients participating in clinical trials
4. Patients receiving concomitant endocrine therapy

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
3L+4L tucatinib triplet	Tucatinib	Non-interventional, retrospective cohort analysis of participants receiving the tucatinib triplet in the 3L or 4L setting immediately following T-DXd.
3L+4L tucatinib triplet	Trastuzumab	Non-interventional, retrospective cohort analysis of participants receiving the tucatinib triplet in the 3L or 4L setting immediately following T-DXd.
3L+4L tucatinib triplet	Capecitabine	Non-interventional, retrospective cohort analysis of participants receiving the tucatinib triplet in the 3L or 4L setting immediately following T-DXd.

Primary Outcome Measures

Name	Time	Method
Time to Next Treatment	1 Year	Time to next treatment defined as the time in months from the initiation of therapy to the initiation of subsequent LOT or death.
Time to Discontinuation	1 Year	Time to treatment discontinuation defined as the time in months from initiation of therapy to discontinuation for any reason or death.
Overall survival (OS)	1 Year	OS will be defined as the time in months from initiation of therapy to death from any cause.