“In women with estrogen receptor-positive, hormone-refractory metastatic breast cancer, oral Z-endoxifen hydrochloride, the potent metabolite of tamoxifen, provided substantial drug exposure regardless of CYP2D6 genotype, acceptable toxicity, and promising antitumor activity, researchers reported.
“Results from a phase I study in 38 patients with metastatic breast cancer demonstrated a clinical benefit rate (stable disease ≥ 6 months) of 26.3%. including a partial response by RECIST criteria in three patients who experienced progression during prior tamoxifen therapy, according to Matthew P. Goetz, MD, of the Mayo Clinic in Rochester, Minnesota, and colleagues.”
“As research of early-stage estrogen receptor (ER)-positive breast cancer continues, experts are relying more on extended adjuvant hormonal therapy with aromatase inhibitors, but are concerned about patient quality of life (QoL) with such treatment.
” ‘My passion is to really try to figure out how to make the side effects of these therapies more tolerable and how to help women be able to actually have reasonably good and normal QoL while they’re taking these therapies, so that we can increase compliance,’ said Michelle E. Melisko, MD.”
“The FDA granted fast track designation to elacestrant for the treatment of ER-positive, HER-2-negative advanced or metastatic breast cancer, according to the drug’s manufacturer.
“Elacestrant (RAD1901, Radius Health) an investigational oral selective ER downregulator/degrader is under investigation as a nonsteroidal treatment for hormone-driven or hormone-resistant breast cancer.”
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…
“Adding taselisib to letrozole before surgery significantly improved outcomes for patients with early breast cancer that was both estrogen receptor positive and HER2-negative (ER+/HER2-) according to results of the LORELEI trial, presented at the ESMO 2017 Congress in Madrid.
” ‘We were able to detect a reduction in tumor size after only 16 weeks of treatment, compared to patients who received letrozole plus placebo,’ said study investigator Dr. Cristina Saura, from Vall d’Hebron University Hospital in Barcelona, Spain. ‘Any decrease in tumor measurements is something positive for patients because this means the drug has had activity against their tumor in a short period of time.’ ”
“Z-endoxifen, a potent derivative of the drug tamoxifen, could itself be a new treatment for the most common form of breast cancer in women with metastatic disease. This finding was reported from a clinical trial conducted by researchers at Mayo Clinic and the National Cancer Institute, and published in the Journal of Clinical Oncology.
“The final results of a first-in-human phase I study of Z-endoxifen in women with estrogen receptor positive metastatic breast cancer showed that the treatment was safe and resulted in tumor shrinkage in women whose tumors had progressed on standard anti-estrogen therapies, including tamoxifen.”
“Previously the drug was approved as second-line monotherapy for women failing anti-estrogen therapy, and as second-line combination therapy with palbociclib (Ibrance). It was first approved by the FDA in 2002.”
“A duration of endocrine therapy beyond 5 years has gained traction in the treatment of endocrine receptor (ER)-positive early-stage breast cancer. Long-term use of aromatase inhibitors (AIs), however, may increase the risk of bone loss and bone fracture. Data suggest that the use of bone-targeted agents can substantially reduce the risk of osteoporotic complications associated with AI use, and even reduce the risk of bone recurrence in postmenopausal women with early-stage breast cancer.”