Breast Cancer

The use of the PARP inhibitor olaparib (Lynparza) for 1 year after receiving standard chemotherapy in the neoadjuvant or the adjuvant setting significantly improved invasive disease-free survival in patients with high-risk, early-stage, HER2-negative breast cancer and BRCA1 or BRCA2 mutations, according to results presented at the American Society of Clinical Oncology 2021 virtual meeting.

The addition of the tyrosine kinase inhibitor tucatinib (Tukysa) to trastuzumab (Herceptin) and capecitabine continued to improve overall survival (OS) and progression-free survival (PFS) in patients with HER2 positive metastatic breast cancer, according to updated results from the pivotal HER2CLIMB trial. The findings were presented at the American Society of Clinical Oncology 2021 virtual annual meeting by lead investigator Giuseppe Curigliano, MD, PhD, Associate Professor, Medical Oncology, University of Milano, Italy, and Director, New Drugs and Early Drug Development for Innovative Therapies, Istituto Europeo di Oncologia, Istituto di Ricovero e Cura a Carattere Scientifico, San Giovanni Rotondo, Italy.

Results of the SWOG S1007 RxPONDER clinical trial suggest that many postmenopausal women with early-stage hormone receptor (HR)-positive, HER2-negative breast cancer, and 1 to 3 positive axillary lymph nodes may be able to avoid adjuvant chemotherapy. By contrast, premenopausal women can derive benefit from adjuvant chemotherapy, based on findings of a prespecified interim analysis of the phase 3 RxPONDER clinical trial; the findings were presented at the 2020 San Antonio Breast Cancer Symposium.

The addition of the cyclin-dependent kinase (CDK)4/6 inhibitor abemaciclib (Verzenio) to standard endocrine therapy reduced the risk for invasive disease recurrence or death compared with endocrine therapy alone by almost 30% in patients with high-risk, hormone receptor (HR)-positive, HER2-negative early breast cancer. These results come from the primary analysis of the phase 3 monarchE clinical trial that was presented at the 2020 San Antonio Breast Cancer Symposium.

Sacituzumab govitecan (Trodelvy) led to increased response rates and improved progression-free survival (PFS) compared with chemotherapy in heavily pretreated patients with metastatic triple-negative breast cancer (TNBC) and stable brain metastases, according to a subgroup analysis of the phase 3 ASCENT clinical trial. The drug did not lead to improved overall survival (OS) in patients with stable brain metastases. These results were presented at the 2020 San Antonio Breast Cancer Symposium (SABCS).

Pembrolizumab (Keytruda) plus chemotherapy improved progression-free survival (PFS) compared with chemotherapy alone as first-line treatment of metastatic triple-negative breast cancer (TNBC), according to the results of KEYNOTE-355. Improvement in PFS with the addition of pembrolizumab to chemotherapy was more robust in patients with TNBC and PD-L1 expression. These results from KEYNOTE-355 were presented at the 2020 San Antonio Breast Cancer Symposium (SABCS) and add to a growing body of evidence supporting the first-line use of pembrolizumab plus chemotherapy combinations for TNBC.

A small-molecule CD73 inhibitor (AB680) induced a 41% overall response rate (ORR) when combined with chemotherapy (with nab-paclitaxel and gemcitabine), plus the novel PD-1 inhibitor zimberelimab, as a first-line treatment for patients with metastatic pancreatic ductal adenocarcinoma, according to results of the dose-escalation portion of a phase 1/1b study known as ARC-8.

On December 16, 2020, the FDA approved margetuximab-cmkb (Margenza; MacroGenics) in combination with chemotherapy for the treatment of adults with metastatic HER2-positive breast cancer who have received ≥2 previous anti-HER2 regimens, of which at least 1 was for metastatic disease. The application for this approval received a fast-track designation.

On November 13, 2020, the FDA accelerated the approval of pembrolizumab (Keytruda; Merck), a PD-1 inhibitor, plus chemotherapy, for the treatment of locally recurrent unresectable or metastatic triple-negative breast cancer (TNBC) in patients with PD-L1 (combined positive score [CPS] ≥10), as determined by an FDA-approved test.

Early locoregional therapy with surgery and radiation does not improve overall survival (OS) in women with newly diagnosed stage IV breast cancer and an intact primary tumor compared with systemic therapy alone, according to the results of the randomized ECOG-ACRIN E2108 phase 3 clinical trial.