Tucatinib, Trastuzumab, and Capecitabine for HER2-Positive Metastatic Breast Cancer
Rashmi K Murthy1, Sherene Loi1, Alicia Okines1
1From M.D. Anderson Cancer Center, Houston (R.K.M., G.H.); Peter MacCallum Cancer Centre, Melbourne, VIC, Australia (S. Loi); the Royal Marsden NHS Foundation Trust, London (A.O.), and Edinburgh Cancer Research Centre, Edinburgh (D.C.) - both in the United Kingdom; Winship Cancer Institute, Atlanta (E.P.); Sarah Cannon Research Institute/Tennessee Oncology-Nashville (E.H.) and Vanderbilt University Medical Center (V.A.), Nashville; University of California, Los Angeles, Medical Center-Jonsson Comprehensive Cancer Center, Los Angeles (S.A.H., D.S.), and Stanford Comprehensive Cancer Institute, Palo Alto (M.P.) - both in California; Dana-Farber Cancer Institute, Boston (N.U.L., I.K., E.P.W.); University of Colorado Cancer Center, Aurora (V.B.); Duke Cancer Institute, Durham (C.A.), and University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill (L.A.C.) - both in North Carolina; University Health Network, Princess Margaret Cancer Centre, Toronto (P.L.B.), and British Columbia Cancer, Vancouver (K.G.) - both in Canada; Hospital Universitario Vall D'Hebron, Barcelona (M.O.); Sygehus Lillebaelt-Vejle Sygehus, Vejle, Denmark (E.J.); Centre Léon Bérard, Lyon, France (T.B.); Rambam Health Care Campus, Haifa, Israel (S.S.S.); Universitaetsklinikum Hamburg-Eppendorf, Hamburg (V.M.), and German Breast Group, Neu-Isenburg (S. Loibl) - both in Germany; Hospital Cuf Descobertas R. Mário Botas, Lisbon, Portugal (S.B.); Cliniques Universitaires Saint-Luc, Brussels (F.P.D.); Third Medical Department, Paracelsus Medical University Salzburg, Salzburg Cancer Research Institute-Center for Clinical Cancer and Immunology Trials, and Cancer Cluster Salzburg, Salzburg, Austria (R.G.); Istituto Europeo di Oncologia, IRCCS, University of Milan, Milan (G.C.); and Seattle Genetics, Bothell, WA (M.C.P.-W., L.W., W.F.).
Background:
Patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer who have disease progression after therapy with multiple HER2-targeted agents have limited treatment options. Tucatinib is an investigational, oral, highly selective inhibitor of the HER2 tyrosine kinase.
Methods:
We randomly assigned patients with HER2-positive metastatic breast cancer previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine, who had or did not have brain metastases, to receive either tucatinib or placebo, in combination with trastuzumab and capecitabine. The primary end point was progression-free survival among the first 480 patients who underwent randomization. Secondary end points, assessed in the total population (612 patients), included overall survival, progression-free survival among patients with brain metastases, confirmed objective response rate, and safety.
Results:
Progression-free survival at 1 year was 33.1% in the tucatinib-combination group and 12.3% in the placebo-combination group (hazard ratio for disease progression or death, 0.54; 95% confidence interval [CI], 0.42 to 0.71; P<0.001), and the median duration of progression-free survival was 7.8 months and 5.6 months, respectively. Overall survival at 2 years was 44.9% in the tucatinib-combination group and 26.6% in the placebo-combination group (hazard ratio for death, 0.66; 95% CI, 0.50 to 0.88; P = 0.005), and the median overall survival was 21.9 months and 17.4 months, respectively. Among the patients with brain metastases, progression-free survival at 1 year was 24.9% in the tucatinib-combination group and 0% in the placebo-combination group (hazard ratio, 0.48; 95% CI, 0.34 to 0.69; P<0.001), and the median progression-free survival was 7.6 months and 5.4 months, respectively. Common adverse events in the tucatinib group included diarrhea, palmar-plantar erythrodysesthesia syndrome, nausea, fatigue, and vomiting. Diarrhea and elevated aminotransferase levels of grade 3 or higher were more common in the tucatinib-combination group than in the placebo-combination group.
Conclusions:
In heavily pretreated patients with HER2-positive metastatic breast cancer, including those with brain metastases, adding tucatinib to trastuzumab and capecitabine resulted in better progression-free survival and overall survival outcomes than adding placebo; the risks of diarrhea and elevated aminotransferase levels were higher with tucatinib. (Funded by Seattle Genetics; HER2CLIMB ClinicalTrials.gov number, NCT02614794.).
Insights
Adding tucatinib to standard therapy significantly improved progression-free and overall survival for patients with previously treated HER2-positive metastatic breast cancer. This combination therapy offers a new option for patients, including those with brain metastases.
Area of Science:
- Oncology
- Pharmacology
Background:
- Limited treatment options exist for patients with HER2-positive metastatic breast cancer progressing after multiple HER2-targeted therapies.
- Tucatinib is an investigational oral, highly selective HER2 tyrosine kinase inhibitor.
Purpose of the Study:
- To evaluate the efficacy and safety of tucatinib in combination with trastuzumab and capecitabine for patients with HER2-positive metastatic breast cancer.
- To assess progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and safety in this patient population.
Main Methods:
- A randomized trial assigned patients with previously treated HER2-positive metastatic breast cancer (with or without brain metastases) to tucatinib or placebo, plus trastuzumab and capecitabine.
- The primary endpoint was PFS in the first 480 randomized patients; secondary endpoints included OS, PFS in patients with brain metastases, ORR, and safety in the total population (612 patients).
Main Results:
- One-year PFS was 33.1% with tucatinib vs. 12.3% with placebo (HR 0.54, P<0.001); median PFS was 7.8 vs. 5.6 months.
- Two-year OS was 44.9% with tucatinib vs. 26.6% with placebo (HR 0.66, P=0.005); median OS was 21.9 vs. 17.4 months.
- In patients with brain metastases, one-year PFS was 24.9% with tucatinib vs. 0% with placebo (HR 0.48, P<0.001); median PFS was 7.6 vs. 5.4 months.
Conclusions:
- Adding tucatinib to trastuzumab and capecitabine significantly improved PFS and OS in heavily pretreated patients with HER2-positive metastatic breast cancer, including those with brain metastases.
- The combination demonstrated superior efficacy compared to placebo, although with increased risks of diarrhea and elevated aminotransferase levels.
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
02:50Combination Therapies and Personalized Medicine
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
02:56Treatment Resistant Cancers
01:27Tumor Immunotherapy
02:30Metastasis
Epithelial-to-Mesenchymal Transition
The epithelial-to-mesenchymal transition or EMT is a developmental process commonly observed in wound healing, embryogenesis, and cancer metastasis. EMT is induced by transforming growth factor-beta (TGF-β) or receptor tyrosine kinase (RTK) ligands, which further...
01:26Treatment for Pulmonary Arterial Hypertension: Receptor Tyrosine Kinase Inhibitors and Calcium Channel Blockers
TKIs, such as imatinib (Gleevec), are particularly effective in tackling the growth and mitogenic factors that become upregulated in PAH patients. These factors contribute to the...