Updated Data for Metastatic HER2+ Breast Cancer

Ruth O’Regan, MD; Joyce A. O’Shaughnessy, MD; Hope S. Rugo, MD, FASCO; and Debu Tripathy, MD, provide insight regarding recent updates from key clinical trials on the management of metastatic HER2+ breast cancer.

Data from the following clinical trials are discussed:

• Latest findings from the phase 2 SUMMIT basket trial on neratinib plus trastuzumab plus fulvestrant for HR-positive MBC with activating HER2 mutations (Jhaveri K, et al. 2020 SABCS. Poster PD1-05).

• Impact of neratinib on outcomes in HER2-positive metastatic breast cancer patients with central nervous system disease at baseline: Findings from the phase 3 NALA trial (Saura C, et al. 2020 SABCS. Poster PD13-09).

• Neratinib + capecitabine sustains health-related quality of life (HRQoL) while improving progression-free survival (PFS) in patients with HER2+ metastatic breast cancer and ≥2 prior HER2-directed regimens (Moy B, et al. 2020 SABCS. Poster PS9-02).

• Final analysis of PERTAIN: A randomized, 2-arm, open-label, multicenter phase 2 trial assessing the efficacy and safety of first-line pertuzumab given in combination with trastuzumab plus an aromatase inhibitor in patients with HER2-positive and hormone receptor–positive metastatic or locally advanced breast cancer (Arpino G, et al. 2020 SABCS. Poster PD3-02).

• A randomized, open-label, phase 3 trial of pertuzumab re-treatment in HER2-positive, locally advanced/metastatic breast cancer patients previously treated with pertuzumab, trastuzumab, and chemotherapy: The Japan Breast Cancer Research Group-M05 (PRECIOUS) study (Yamamoto Y, et al. 2020 SABCS. Poster PD3-11).

• Updated results from DESTINY-Breast01, a phase 2 trial of trastuzumab deruxtecan (T-DXd ) in HER2-positive metastatic breast cancer (Modi S, et al. 2020 SABCS. Poster PD3-06).

• Trastuzumab deruxtecan (T-DXd; DS-8201) with nivolumab in patients with HER2-expressing, advanced breast cancer: A 2-part, phase 1b, multicenter, open-label study (Hamilton E, et al. 2020 SABCS. Poster PD3-07).

• Tucatinib vs placebo in combination with trastuzumab and capecitabine for patients with locally advanced unresectable or HER2-positive metastatic breast cancer (HER2CLIMB): Outcomes by hormone receptor status (Hamilton E, et al. 2020 SABCS. Poster PD3-08).

• Impact of tucatinib on health-related quality of life in patients with HER2+ metastatic breast cancer with stable and active brain metastases (Wardley A, et al. 2020 SABCS. Poster PD13-04).