“Adding to a growing list of similar results, the Short-HER study was unable to show noninferiority of 9 weeks of trastuzumab compared with the standard 1 year when given along with chemotherapy in women with HER2-positive breast cancer. Shorter administration does, however, reduce the risk of cardiotoxicity.
” ‘Adjuvant pivotal trials with 1-year trastuzumab have significantly improved the prognosis of HER2-positive early breast cancer,’ wrote study authors led by Pierfranco Conte, MD, of the Istituto Oncologico Veneto in Italy. Several studies have attempted to reduce the duration of trastuzumab, though most have failed to show noninferiority.”
“Outcomes for patients with HER2-positive breast cancer did not differ when treated with sequential chemotherapy plus trastuzumab compared with a concurrent approach, according to a new phase III trial.
” ‘The effectiveness of trastuzumab with chemotherapy in the neoadjuvant setting is evident; however, the cardiac safety of trastuzumab combined with anthracyclines has been questioned,’ wrote study authors led by Kelly K. Hunt, MD, of the University of Texas MD Anderson Cancer Center in Houston.”
“Tucatinib used in combination with capecitabine, trastuzumab (Herceptin), or both agents showed promising antitumor activity in heavily pretreated women with HER2-positive breast cancer with or without brain metastases, according to findings published in The Lancet Oncology.
“In phase Ib results from a nonrandomized, open-label study, 83% (5/6) of patients with measurable disease treated with tucatinib/capecitabine had an objective response, as did 40% (6/15) of patients receiving tucatinib/trastuzumab. Sixty-one percent (14/23) of patients treated with the combination of all 3 drugs had an objective response.”
“The adjuvant treatment landscape for patients with HER2-positive breast cancer continues to grow, particularly following the recent FDA approval of pertuzumab (Perjeta) in combination with trastuzumab (Herceptin) and chemotherapy, which was based on findings from the APHINITY trial.
“In the phase III trial, the combination demonstrated a 3-year invasive disease-free survival (DFS) rate of 94.1%, which represented an 18% reduction in the risk of developing invasive disease or death. The benefit was more pronounced among higher-risk patients. The DFS rate for patients with node-positive disease was 92.0% with pertuzumab versus 90.2% with standard therapy.”
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…
“Twelve weeks of neoadjuvant T-DM1 (ado-trastuzumab emtansine; Kadcyla) with or without endocrine therapy induced superior pathologic complete response (pCR) compared with trastuzumab (Herceptin) plus endocrine therapy in patients with HER2-positive/HR-positive early breast cancer, according to findings recently published online in theJournal of Clinical Oncology.
“In the prospective, neoadjuvant phase II ADAPT trial conducted by the West German Study Group, pCR was 41.0% for patients assigned to T-DM1 alone and 41.5% for those who received T-DM1 and endocrine therapy. In contrast, 15.1% of patients assigned to trastuzumab and endocrine therapy had a pCR (P<.001).”
“The triplet combination of HER2-targeted therapy and an aromatase inhibitor (AI) improved progression-free survival (PFS) by more than 5 months compared with the combination of trastuzumab (Herceptin) and an AI in patients with HER2+/HR+ breast cancer.
“In phase III results from the ALTERNATIVE trial presented at the 2017 ASCO Annual Meeting, the median PFS was 11 months (95% CI, 8.3-13.8) for postmenopausal women with HER2+/HR+ metastatic breast cancer assigned to lapatinib (Tykerb) plus trastuzumab plus an AI compared with 5.7 months (95% CI, 5.5-8.4) for patients assigned to trastuzumab plus an AI. Lead study author William J. Gradishar MD, interim chief of hematology and oncology at Northwestern University’s Feinberg School of Medicine, said that represented a 38% reduction in the risk of progression (HR, 0.62; 95% CI, 0.45-0.88; P = .0064).”
Last month, the annual American Society of Clinical Oncology (ASCO) meeting took place in Chicago. Thousands of oncologists, patients, and journalists gathered to learn about the most recent developments in cancer research and treatment. Here are some breast cancer highlights from the meeting:
Triple negative breast cancer (TNBC) is considered more responsive to treatment with immune checkpoint drugs than any other type of breast cancer. So far, these drugs have primarily been explored in metastatic TNBC, in combination with chemotherapy. The combination of “anti-PD-L1” and “anti-PD-1” immune checkpoint drugs with chemotherapy has now been examined in early-stage TNBC, in which a breast tumor can be surgically removed after neoadjuvant chemotherapy. Continue reading…
“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.”