Non-metastatic breast cancers are most often treated with surgery, but if the tumors are fairly large, or involve nearby lymph nodes, neoadjuvant (pre-operative) treatments with chemotherapy (NAC) are done first. NAC often reduces the tumor size and kills cancer cells in lymph nodes, if present, prior to surgery, improving the outcome. The best possible result of neoadjuvant treatment is pCR (pathologic compete response), when the tumor is no longer visible in imaging studies. Here, I review the new directions in which neoadjuvant treatments are evolving.
Today, treatments for metastatic breast cancers are tailored for specific subtypes. Starting with the introduction of the drug trastuzumab (Herceptin) for HER2-positive cancers, new, more specific treatment options were eventually developed and approved for other types as well. Estrogen deprivation endocrine therapies, lately prescribed in combination with CDK4/6 inhibitors, are used in estrogen receptor (ER)-positive cancers. Triple negative cancers (TNBC) are still treated mostly with chemotherapy, but immune checkpoint drugs and PARP inhibitors are explored in clinical trials, with some successes reported.
However, neoadjuvant treatments (except for HER2+ cancers) remain largely limited to chemotherapy regimens. This is starting to change now, with new approaches tailored to the cancer type being investigated in clinical trials.
In this regard, it is important to mention the I-SPY2 trial, NCT01042379, which started in 2010 and is for women with stage II-III breast cancer. It offers about a dozen drugs that are chosen based on particular features of the newly diagnosed cancers. This trial has a unique design and has produced some important results. Additional treatments and trials for various types of breast cancer are discussed below. Continue reading…
“Chemotherapy-free neoadjuvant treatment with trastuzumab emtansine (T-DM1; Kadcyla) demonstrated a pathological complete response (pCR) rate of 40.5% in patients with HER2+ and HR+ early breast cancer, according to findings from the phase II ADAPT trial presented at the 2015 ASCO Annual Meeting.
” ‘After 12 weeks without systemic chemotherapies we observed more than a 40% pCR in both the breast and nodes in our T-DM1-treated HER+/HR+ patients,’ said lead investigator Nadia Harbeck, MD, PhD, head of the Breast Center, Oncological Therapy and Clinical Trials Unit, University of Munich, Germany. ‘We did see very low overall toxicity, and did not detect any new safety signals.’
“The ADAPT trial is a large umbrella trial that has enrolled 5000 patients with various breast cancer phenotypes. In the arm of the trial presented at ASCO, 376 patients with HER2+ and HR+ breast cancer were randomized to receive neoadjuvant T-DM1 at 3.6 mg/kg with or without endocrine therapy or trastuzumab plus endocrine therapy. Treatment was administered for 4 cycles followed by surgery and 1-year of standard adjuvant chemotherapy plus trastuzumab.”
“Results from a phase II trial showed that neoadjuvant TDM-1 is effective in treating HER2-positive, hormone receptor (HR)-positive breast cancer, with or without endocrine therapy, in comparison with trastuzumab and endocrine therapy. Results of the study (abstract 506) were presented at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting held May 29 to June 2 in Chicago.
“The WSG-ADAPT trial is an umbrella trial that included around 5,000 patients. This sub-study of that trial included patients with HER2-positive, HR-positive early breast cancer; it enrolled 376 patients at 48 sites, and this interim analysis included 130 of those patients. The trial has been closed early because efficacy was reached.
“The patients were randomized to receive either TDM-1 monotherapy (37 patients), TDM-1 with endocrine therapy (48 patients), or trastuzumab with endocrine therapy (45 patients). ‘This was not a low-risk population,’ said study presenter Nadia Harbeck, MD, PhD, of the University of Munich, noting that over half of the patients were premenopausal and about half had tumors that were larger than 2 cm.”
“Promising clinical trial results presented at the American Society for Clinical Oncology (ASCO) Annual Meeting 2015 show activity of the investigational anti-cancer agent ONT-380 against HER2+ breast cancer, in one case specifically against brain metastases and in another case in overall survival of heavily pretreated HER2+ breast cancer patients.
” ‘I am thrilled to have been able to offer this therapy to a patient in her early 40s. She didn’t have any other great treatment options that we would have expected to have any meaningful impact, especially on her brain. Now she’s been on the study over a year. The mets in her body are gone and the brain lesion has shrunk down to a little nubbin. She’s living a normal life, fretting about the family business and how the kids are doing – normal stuff,’ says Virginia Borges, MD, MMSc, director of the Breast Cancer Research Program and Young Women’s Breast Cancer Translational Program at the University of Colorado Cancer Center and one of the study’s authors.
“Both sets of results being presented are from ongoing phase 1b clinical trials of ONT-380, one in combination with the drug TDM-1, and the other in combination with capecitabine and/or trastuzumab. Women on these studies include those whose disease had progressed after at least two previous rounds of therapy (sometimes including previous drugs used to target HER2).”
Pertuzumab (Perjeta) is a relatively new drug that targets HER2, a protein found at higher-than-normal levels in about 15% to 20% of all breast cancers. Too much HER2 leads to tumor growth. Currently, all newly diagnosed breast cancer patients have their tumors’ HER2 levels tested. Knowing whether a patient’s HER2 levels are abnormally high (HER2-positive) or normal (HER2-negative) is a major factor in choosing a treatment, thanks to the availability of trastuzumab (Herceptin) and, now, other HER2-targeted drugs such as Perjeta, T-DM1 (Kadcyla), and lapatinib (Tykerb). These drugs are all used to treat HER2-positive patients. Continue reading…
The gist: A clinical trial that tested a new drug called TDM-1 (Kadcyla) found disappointing results for patients with metastatic, HER2-positive breast cancer. The trial found that treatment with T-DM1 plus the drug pertuzumab is no better than treatment with trastuzumab plus chemotherapy. For more on TDM-1, see this recent news about its potential benefits for patients whose cancer has spread to the central nervous system (CNS).
“Results of the anticipated phase III MARIANNE trial found that HER2-positive metastatic breast cancer patients treated with trastuzumab emtansine (T-DM1) plus pertuzumab had similar progression-free survival (PFS) compared with those treated with trastuzumab plus a taxane-based chemotherapy.
“Though the trial met its noninferiority endpoint, showing a similar PFS in the first-line setting between the two combination therapies along with T-DM1 alone, it failed to demonstrate that T-DM1 performs better than trastuzumab plus chemotherapy.
“The study has been anticipated by clinicians as two of the treatment arms do not include a taxane, which often causes patients to lose their hair, among other toxicities. The full results of the study will be presented at a future medical meeting…
“ ‘In my opinion, given the substantial survival associated with [docetaxel plus trastuzumab and pertuzumab of over 56 months], it remains the current first-line standard regimen especially for those patients who have never been exposed to trastuzumab,’ said Hurvitz.”