Leveraging Antiprogestins in the Treatment of Metastatic Breast Cancer

Endocrinology ◽  
2021 ◽  
Author(s):  
Sailaja Kamaraju ◽  
Amy M Fowler ◽  
Elizabeth Weil ◽  
Kari B Wisinski ◽  
Thu H Truong ◽  
...  

Abstract Although incurable, the prognosis for patients with metastatic breast cancer (MBC) has considerably improved with the approvals of multiple targeted and cytotoxic therapies. For hormone receptor-positive (HR+), i.e., estrogen receptor and progesterone receptor positive (ER+/PgR+) and Human Epidermal Growth Factor Receptor-2 negative (i.e.,ERBB2 gene non-amplified or HER2-) MBC, current approved treatment options include palliative endocrine therapy (ET), Cyclin-Dependent Kinase (CDK 4/6) inhibitors, mTOR inhibitors, and PI3 kinase inhibitors. Most treatments target ER+ disease regardless of PgR status. Although the presence of PgR is crucial for ER+ cell proliferation in both normal and malignant mammary tissue, currently, no approved treatments specifically target PgR. Recent literature has demonstrated, the potential of antiprogestins in the treatment of MBC both in preclinical and clinical studies.Antiprogestins, including selective PgR modulators (SPRMs) that act as PgR antagonists, are a promising class of therapeutics for overcoming endocrine resistance in patients who develop activating estrogen receptor 1 (ESR1) and phosphatidylinositol 3-kinase (PI3K) gene mutations after prior endocrine therapy. Herein, we summarize the role of PgR and antiprogestins in the treatment of MBC. Other aspects on the use of functional imaging, clinical trials incorporating novel antiprogestins and potential treatment combinations to overcome endocrine resistance will be briefly discussed.

2002 ◽  
pp. 267-276 ◽  
Author(s):  
C Morris ◽  
A Wakeling

Since its introduction more than 30 years ago, tamoxifen has been the most widely used endocrine therapy for the treatment of women with advanced breast cancer. More recently, a number of alternative endocrine treatments have been developed, including several selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs) and, most recently, fulvestrant ('Faslodex'). Fulvestrant is an estrogen receptor (ER) antagonist, which, unlike the SERMs, has no known agonist (estrogenic) effect and downregulates the ER protein. Tamoxifen is effective and well tolerated, although the non-steroidal AIs, anastrozole and letrozole, are more effective treatments for advanced disease than tamoxifen. Fulvestrant has recently gained US Food and Drug Administration approval for the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy. In two global phase III clinical trials fulvestrant was at least as effective and as equally well tolerated as anastrozole for the treatment of postmenopausal women with advanced and metastatic breast cancer. In a retrospective analysis of the combined data from these trials, mean duration of response was significantly greater for fulvestrant compared with anastrozole. These new hormonal treatments expand the choice of endocrine therapy for women with advanced breast cancer and offer new options for sequencing and combining treatments.


2014 ◽  
Vol 32 (26_suppl) ◽  
pp. 155-155
Author(s):  
Mahmoud Charif ◽  
Elyse E. Lower ◽  
Diane Kennedy ◽  
Harriet Kumar ◽  
Shugufta Khan ◽  
...  

155 Background: Overexpression of HER2/neu is associated with tamoxifen resistance in breast cancer (Osborne CK et al. J Natl Canc Inst 2003; 95:353-361). However pts may present with both estrogen receptor (ER) and HER2/neu + tumors. The benefit of adding fulvestrant to trastuzumab is unclear. The objective of the study was to determine the effect of trastuzumab on fulvestrant therapy. Methods: This was an IRB approved record review of patients (pts) from three medical oncologists with biopsy-proven ER+ metastatic breast cancer treated with fulvestrant who also had their primary tumor tested for HER2/neu. Demographic data collected included age at diagnosis, type and stage of cancer, original and metastatic ER, progesterone receptor (PR), and HER-2/neu biomarkers, and site(s) of metastasis, and primary local and systemic treatment. All pts with HER-2/neu + primary tumors received trastuzumab. The duration of fulvestrant therapy was calculated. Time to clinical disease progression on fulvestrant was measured as a surrogate for duration of clinical benefit. Results: Eighty-five metastatic ER+ fulvestrant treated breast cancer pts with known primary tumor HER2/neu status were identified and the duration of therapy calculated. All eleven (13%) pts with documented HER2/neu + primary tumors received trastuzumab. The duration of therapy for HER2/neu + pts (772 (51-1911) days (median (range)) was longer than HER2/neu negative pts (360 (60-2,739) days, p=0.059). The median duration of fulvestrant therapy was 425 days. Pts with HER2/neu + tumors were more likely to be treated beyond the median fulvestrant therapy with an odds ratio of 6.2 (1.26 to 30.92 95% confidence interval, p=0.0249). Conclusions: Trastuzumab plus fulvestrant therapy was associated with a more prolonged clinical response than fulvestrant alone in pts with metastatic breast cancer. This synergism may be due to the effect of trastuzumab inhibiting the activation of transcriptional coactivator MED1, a recently discovered key crosstalk point between HER2/neu and ER signaling pathways in mediating endocrine resistance (Cancer Res 2012;72(21):5625;PLoS One 2013; 8:e70641).


Breast Care ◽  
2020 ◽  
Vol 15 (6) ◽  
pp. 608-618
Author(s):  
Andreas Schneeweiss ◽  
Ingo Bauerfeind ◽  
Tanja Fehm ◽  
Wolfgang Janni ◽  
Christoph Thomssen ◽  
...  

<b><i>Background:</i></b> In order to offer optimal treatment approaches based on available evidence, the Commission Breast of the Working Group Gynecologic Oncology (AGO) of the German Cancer Society developed therapy algorithms for eight complex treatment situations in primary and advanced breast cancer. <b><i>Summary:</i></b> Therapy algorithms for the following complex treatment situations are outlined in this paper: (neo)adjuvant therapy of human epidermal growth factor receptor 2 (HER2)-positive breast cancer; axillary surgery and neoadjuvant chemotherapy; adjuvant endocrine therapy in premenopausal patients; adjuvant endocrine therapy in postmenopausal patients; hormone receptor (HR)-positive/HER2-negative metastatic breast cancer: strategies; HR-positive/HER2-negative metastatic breast cancer: endocrine-based first-line treatment; HER2-positive metastatic breast cancer: first to third-line; metastatic triple-negative breast cancer. <b><i>Key Messages:</i></b> The therapy options shown in these algorithms are based on the current AGO recommendations updated in January 2020 but cannot represent all evidence-based treatment options. Prior therapies, performance status, comorbidities, patient preference, etc. must be taken into account for the actual treatment choice. Therefore, in individual cases, other evidence-based treatment options not listed here may also be appropriate and justified.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 1073-1073
Author(s):  
J. Wang ◽  
S. Jain ◽  
W. Heller ◽  
D. Mackie ◽  
V. Watson ◽  
...  

1073 Background: Endocrine therapy is a key modality in the management of estrogen receptor positive metastatic breast cancer. Fulvestrant (ICI 182,780) is an estrogen receptor downregulator. It has previously been shown to be as effective as anastrozole in patients who had previously progressed on tamoxifen. Methods: A retrospective study was carried out of metastatic breast cancer patients treated at Charing Cross Hospital between 2002–2005 who had received fulvestrant following treatment failure with tamoxifen and a third generation aromatase inhibitor. All patients were postmenopausal and received fulvestrant 250mg IM every 28 days. Measurable disease was assessed by response evaluation criteria in solid tumors (RECIST). Results: A total of 45 patients were identified with a median age of 60 (range 36 to 90). The ER status was known in 95% (n=43) of patients and was positive in all cases, it was unknown in 2% (n=2). At the time of commencing fulvestrant, 96% (n=43) had metastatic disease and 4% (n=2) locally advanced disease. All patients had received at least 2 lines of prior endocrine therapy (including adjuvant therapy), at time of starting fulvestrant the median number of prior regimens was 3 (range 3–5). Fulvestrant was administered for a median of 4 months (range 1 to 20 months), with 4 patients currently still receiving therapy as of 1 November 2006. Of the 45 patients, 2.2% (n=1) achieved a partial response, while 31% (n=14) achieved stable disease for at least 6 months. Thus, 33.3% (n=15) obtained clinical benefit (defined as PR or SD for at least 6 months). The response rates based on line of therapy will be presented. Of the 45 patients, 41 were evaluable for survival data. The median survival of the remaining patients from the start of fulvestrant therapy was 9 months (range 1 to 48 months). Of the 44 patients, 14% (n=6) remain alive. The treatment was well tolerated and toxicity data will be presented. Conclusions: Fulvestrant is well tolerated and is efficacious as treatment for advanced breast cancer that has failed tamoxifen and a third generation aromatase inhibitors. No significant financial relationships to disclose.


Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1242 ◽  
Author(s):  
Daniele Presti ◽  
Erica Quaquarini

Endocrine-based treatments are the normal standard-of-care in women with hormone receptor-positive/Human Epidermal growth factor Receptor 2-negative metastatic breast cancer. Despite the well-known efficacy of these drugs as first-line therapies, about 50% of women develop endocrine resistance and disease progression. The treatment of these patients has represented one of the most important research fields in the last few years, with several multicenter phase II/III trials published or still ongoing. Novel therapies, such as cyclin-dependent kinase (CDK)4/6 and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) inhibitors, have significantly changed the prognosis of patients progressing to a previous endocrine treatment, allowing a great benefit in terms of progression-free survival and, in some cases, of overall survival. However, identifying response predictors is essential for the rational use of these drugs to avoid unnecessary toxicity and costs, and to ensure the optimal therapeutic sequence is used. In this review, we analyze the PI3K/AKT/mTOR and CDK4/6 pathways and their roles in endocrine resistant metastatic breast cancer. We then focus on the new treatments developed and the roles of these drugs in overcoming endocrine resistance, describing the latest clinical trials that led to the approval of the drugs in clinical practice.


2020 ◽  
Vol 10 ◽  
Author(s):  
Hao Liao ◽  
Wenfa Huang ◽  
Wendi Pei ◽  
Huiping Li

Endocrine therapy is the main treatment option for estrogen receptor-positive (ER+) breast cancer (BC). Compared with other clinical subtypes, ER+ BC patients usually have a more favorable prognosis. However, almost all ER+ BCpatients develop endocrine resistance and disease progression eventually. A large number of studies based on liquid biopsy suggest that ESR1 mutations may play a key role in this process. For patients with ER+ metastatic BC (MBC), ESR1 is an important prognostic factor and may associate with the resistance to endocrine therapy, like aromatase inhibitors. The advances of sequencing technologies allow us to conduct longitudinal monitoring of disease and unveil the clinical implications of each ESR1 sub-clone in ER+ MBC. Moreover, since the ESR1-related endocrine resistance has not been fully addressed by existing agents, more potent cornerstone drugs should be developed as soon as possible. Herein, we reviewed the recent progress of detecting ESR1 mutations based on liquid biopsy and different sequencing technologies in ER+ MBC and discussed its clinical impacts and prospects.


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