“Final results from two large phase III trials confirm that the drug-antibody conjugate trastuzumab emtansine improves overall survival (OS) over other treatment options in patients with previously treated HER2-positive metastatic breast cancer. The results of the EMILIA and TH3RESA trials confirm the agent’s role in this setting.
“Trastuzumab emtansine, which links the antibody trastuzumab with the cytotoxic microtubule inhibitor DM1, was approved based on earlier results of the EMILIA study. The new analysis of that trial offers approximately twice the length of follow-up, at a median of 24.1 months.”
“Another potential drug for HER2-positive breast cancer received strong numeric support from an FDA advisory committee, tempered by reservations about a broad indication, modest clinical benefit, and toxicity issues.
“By a 12-4 vote, the Oncologic Drugs Advisory Committee (ODAC) supported FDA approval of the dual HER2/EGFR inhibitor neratinib for early HER2-positive breast cancer that relapses after trastuzumab (Herceptin) maintenance therapy.”
“Over the last decade, the treatment landscape in HER2-positive breast cancer has changed dramatically, says Sara Hurvitz, MD.
” ‘I believe that a patient diagnosed today has a much greater chance of being alive 5 or 10 years from now—some of them may even be cured—and that compares very favorably with the outlook of 10 years ago when we just had 1 or 2 therapies and no evidence to support using HER2-targeted therapies after a patient’s disease grew,’ Hurvitz said.
“In an interview with Targeted Oncology, Hurvitz director of the Hematology/Oncology Breast Cancer Program and an associate professor in the Department of Medicine at the University of California, Los Angeles, discusses ongoing advances that continue to revolutionize the treatment of patients with HER2+ breast cancer.”
“A cost-effectiveness analysis found that 9 weeks of trastuzumab therapy is better than the more standard 12 months in patients with HER2-positive breast cancer, without loss of clinical efficacy. The analysis is limited, though, by the need to combine various trials rather than any head-to-head comparisons.
“Trastuzumab has been shown to significantly improve survival in women with HER2-positive disease. ‘The budget impact of trastuzumab is high, mostly due to the drug’s high cost, and the most serious adverse effect observed is cardiac dysfunction,’ wrote study authors led by Caroline Clarke, PhD, of University College London in the United Kingdom. Though 12 months is considered the standard duration of therapy, some studies have also found similar results with only 9 or 10 weeks of trastuzumab.”
“A phase I trial found that the HER2 inhibitor ONT-380 had a lower incidence of certain adverse events associated with this class of agent and notable anti-tumor activity in heavily pretreated patients with HER2-positive metastatic breast cancer (MBC).
” ‘Though existing targeted therapies are improving outcomes in patients with HER2-positive MBC, disease resistance does eventually develop in most patients,’ wrote study authors led by Stacy Moulder, MD, of the MD Anderson Cancer Center in Houston. Also, some agents preclude combination with other regimens due to off-target effects such as skin rash and diarrhea.”
“A prospective study is investigating whether breast cancer surgery can be eliminated in patients who respond well to neoadjuvant systemic therapy.
“The phase II single-center trial, conducted out of The University of Texas MD Anderson Cancer Center (NCT02945579), aims to determine how often breast cancer recurs in patients who previously received chemotherapy and follow-up radiation therapy, but not surgery, and have no evidence of disease. Forty patients with early-stage, triple-negative or HER2-positive breast cancer care underwent image-guided biopsy after completing chemotherapy and before beginning radiation therapy to see if surgery is necessary.”
“Data from the phase II PERTAIN trial presented late last year at the 2016 San Antonio Breast Cancer Symposium (SABCS) showed that adding an aromatase inhibitor (AI) to pertuzumab (Perjeta) and trastuzumab (Herceptin) extended progression-free survival (PFS) by over 3 months versus trastuzumab plus an AI in patients with HER2-positive, HR-positive locally advanced or metastatic breast cancer.
“The median PFS was 18.89 months with the pertuzumab triplet compared with 15.80 months for trastuzumab and an AI alone (HR, 0.65; 95% CI, 0.48-0.89; P = .007). The objective response rates were 63.3% versus 55.7%, respectively.”
“The Fc-modified monoclonal antibody margetuximab in combination with chemotherapy may offer a new treatment option for patients with HER2-positive metastatic breast cancer.
“In the ongoing phase III SOPHIA trial (NCT02492711), researchers are comparing margetuximab plus chemotherapy with trastuzumab (Herceptin) plus chemotherapy. In a previous phase I study, margetuximab demonstrated single-agent activity in HER2-positive tumors, leading researchers to explore the regimen in the phase III trial.”
“Brain metastases from primary breast cancer tumors often acquire clinically actionable genetic alterations, according to a small study. About one fifth of ERBB2/HER2-negative cases switched to HER2-positivity in the brain metastases.
” ‘Limited therapeutic options exist for patients with brain metastases,’ wrote study authors led by Nolan Priedigkeit, BS, of the University of Pittsburgh. ‘ERBB2/HER2-positive brain metastases have demonstrated encouraging responses to ERBB2/HER2-targeted therapies in recent clinical trials.’ ERBB2/HER2-negative brain metastases, however, have shown no such response.”