“Amsterdam, The Netherlands: Approximately a quarter of women with HER2 positive breast cancer, who were treated with a combination of the targeted drugs lapatinib and trastuzumab before surgery and chemotherapy, saw their tumours shrink significantly or even disappear, according to results from a clinical trial.
“Professor Nigel Bundred told the 10th European Breast Cancer Conference (EBCC-10) today (Thursday): ‘This has ground-breaking potential because it allows us to identify a group of patients who, within 11 days, have had their tumours disappear with anti-HER2 therapy alone and who potentially may not require subsequent chemotherapy. This offers the opportunity to tailor treatment for each individual woman.’
“Prof Bundred, who is Professor of Surgical Oncology at The University of Manchester and the University Hospital of South Manchester NHS Foundation Trust (UK), was presenting results from the UK EPHOS-B multi-centre, clinical trial, in which 257 women with newly-diagnosed, operable, HER2 positive disease were recruited between November 2010 and September 2015.”
“A tumor’s immune response to a single dose of the HER2 inhibitor trastuzumab predicted which patients with HER2-positive breast cancer would respond to the drug on a more long-term basis, according to the results of a study published recently in Clinical Cancer Research.
“In addition, Vinay Varadan, PhD, assistant professor at Case Western Reserve University School of Medicine and member of the Case Comprehensive Cancer Center, and his colleagues found that women with the HER2-enriched subtype of HER2-positive breast cancer—a subtype that is estrogen and progesterone receptor negative—had the highest rate of immune response to treatment with trastuzumab, with significant increases in immune response after a single dose of the drug.
“ ‘Our study showed, for the first time, that the immune-cell–activating properties of trastuzumab are likely related to the subtypes of breast cancer,’ Varadan said. ‘Knowing this can inform future trials studying the usefulness of adding immunotherapy drugs to trastuzumab.’ “
“Treatment with the tyrosine kinase inhibitor neratinib demonstrated a 2-year disease-free survival (DFS) rate of 93.9% in patients with early-stage HER2-positive breast cancer, representing a 33% improvement compared with placebo, according to findings from the phase III ExteNET study published in The Lancet Oncology.
“In the phase III study, which was also presented at the 2015 ASCO Annual Meeting, the 2-year DFS rate with placebo was 91.6% (HR, 0.67; 95% CI, 0.50-0.91; P = .009). In patients with both HER2- and HR-positive disease, the 2-year DFS rate was 95.4% with neratinib and 91.2% with placebo, representing a 49% benefit (HR, 0.51; P = .001).”
TNBC has long been considered to be more amenable to immune system-based treatments than other types of breast cancer because it is more immunogenic; that is, relatively high levels of immune cells accumulate within or adjacent to TNBC tumors. These immune cells could be triggered to attack tumors if properly activated. TNBC tumors are also likely to have a higher mutational burden (number of genetic mutations). This is one of the predictors of sensitivity to a type of treatment called immune checkpoint blockade. Drugs known as checkpoint inhibitors block the proteins PD-1 or PD-L1. In cancer, PD-L1 proteins on tumor cells bind to PD-1 proteins on immune T cells and inhibit their tumor-killing activity. Immune checkpoint drugs disable this interaction and enable activation of T cells. These drugs are actively being explored in TNBC in clinical trials.
“Recurrence of HER2-positive breast cancer after treatment may be due to a specific and possibly cancer-induced weakness in the patient’s immune system—a weakness that in principle could be corrected with a HER2-targeted vaccine—according to a new study from the Perelman School of Medicine at the University of Pennsylvania. Results of the study show that T cells from patients whose breast cancer had recently recurred showed far weaker response to the HER2 receptor protein, compared to T cells from patients whose breast cancer had not recurred over a long period following treatment. The study, published in JAMA Oncology this week, suggests that patients with HER2-positive breast cancer—which accounts for roughly 20 percent of the 260,000 invasive breast cancers diagnosed in the US each year—might someday undergo immune status monitoring with blood tests before, during and after treatment, to allow physicians to gauge the risk of recurrence, and possibly to reduce that risk with therapies that boost anti-HER2 immunity.”
“Among patients with HER2-positive, metastatic breast cancer that had progressed despite treatment with two or more forms of HER2-targeted therapy (trastuzumab [Herceptin] and lapatinib [Tykerb]), median overall survival was increased for those treated with trastuzumab emtansine (T-DM1 [Kadcyla]) compared with those who received treatment of physician’s choice, according to results from the phase III TH3RESA clinical trial presented at the 2015 San Antonio Breast Cancer Symposium, held Dec. 8–12.
“The HER2-targeted antibody-drug conjugate T-DM1 was approved by the U.S. Food and Drug Administration in February 2013 for treating patients with HER2-positive, metastatic breast cancer that had progressed after treatment with trastuzumab and a taxane.”
Erika P. Hamilton, MD, associate director, Breast Cancer and Gynecologic Cancer Research Program, principal investigator, Sarah Cannon Research Institute, on ONT-380 for HER2-positive breast cancer and the treatment’s ability to cross the blood-brain barrier. Hamilton says the reason ONT-380’s ability to cross that barrier is important is because patients with HER2-positive breast cancer have a predilection to develop brain metastases.
She added that ONT-380 was proven to be effective when combined with capecitabine (Xeloda) and trastuzumab (Herceptin), though sometimes a combination of all three proved most useful. ONT-380 is a HER2-specific inhibitor and showed promising results when tested in patients with HER2-positive breast cancer who had previously received trastuzumab and T-DM1.
In 2013, Lyndsay Sung noticed something new on the edge of her right breast. “I felt something weird—an odd thickening along the rib,” she recalls. At the time, her son was only a year old, so she thought it might have been related to breastfeeding. But then she felt it again in September 2014. Lyndsay knew she was at risk for breast cancer because her grandmother had had it, and she also knew her breasts from years of self-exams. So she went to see her family doctor. Continue reading…
“The primary analysis of the phase III CALGB 40601 trial found that pathologic complete response (pCR) to dual HER2 blockade was not statistically higher than anti-HER2 monotherapy. However, there was a high level of intertumoral heterogeneity, and patients with the HER2-enriched subtype had a high pCR with both single and dual anti-HER2 therapy, according to data recently published in the Journal of Clinical Oncology.
“ ‘This trial paves the way for integrating molecular analyses into other trials in HER2-positive breast cancer, and may allow us to take a less-is-more approach for women who are selected to be highly sensitive to targeted treatments and to have a good prognosis,’ said lead study author Lisa Carey, MD, a UNC Lineberger member, the Richardson and Marilyn Jacobs Preyer Distinguished Professor in Breast Cancer Research at the University of North Carolina School of Medicine, and the physician-in-chief of the North Carolina Cancer Hospital, in a statement.”