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Goetz MP, Bagegni NA, Batist G, Brufsky A, Cristofanilli MA, Damodaran S, Daniel BR, Fleming GF, Gradishar WJ, Graff SL, Grosse Perdekamp MT, Hamilton E, Lavasani S, Moreno-Aspitia A, O'Connor T, Pluard TJ, Rugo HS, Sammons SL, Schwartzberg LS, Stover DG, Vidal GA, Wang G, Warner E, Yerushalmi R, Plourde PV, Portman DJ, Gal-Yam EN. Lasofoxifene versus fulvestrant for ER+/HER2- metastatic breast cancer with an ESR1 mutation: results from the randomized, phase II ELAINE 1 trial. Ann Oncol 2023; 34:1141-1151. [PMID: 38072514 DOI: 10.1016/j.annonc.2023.09.3104] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/24/2023] [Accepted: 09/13/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Acquired estrogen receptor alpha (ER/ESR1) mutations commonly cause endocrine resistance in ER+ metastatic breast cancer (mBC). Lasofoxifene, a novel selective ER modulator, stabilizes an antagonist conformation of wild-type and ESR1-mutated ER-ligand binding domains, and has antitumor activity in ESR1-mutated xenografts. PATIENTS AND METHODS In this open-label, randomized, phase II, multicenter, ELAINE 1 study (NCT03781063), we randomized women with ESR1-mutated, ER+/human epidermal growth factor receptor 2 negative (HER2-) mBC that had progressed on an aromatase inhibitor (AI) plus a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) to oral lasofoxifene 5 mg daily or IM fulvestrant 500 mg (days 1, 15, and 29, and then every 4 weeks) until disease progression/toxicity. The primary endpoint was progression-free survival (PFS); secondary endpoints were safety/tolerability. RESULTS A total of 103 patients received lasofoxifene (n = 52) or fulvestrant (n = 51). The most current efficacy analysis showed that lasofoxifene did not significantly prolong median PFS compared with fulvestrant: 24.2 weeks (∼5.6 months) versus 16.2 weeks (∼3.7 months; P = 0.138); hazard ratio 0.699 (95% confidence interval 0.434-1.125). However, PFS and other clinical endpoints numerically favored lasofoxifene: clinical benefit rate (36.5% versus 21.6%; P = 0.117), objective response rate [13.2% (including a complete response in one lasofoxifene-treated patient) versus 2.9%; P = 0.124], and 6-month (53.4% versus 37.9%) and 12-month (30.7% versus 14.1%) PFS rates. Most common treatment-emergent adverse events with lasofoxifene were nausea, fatigue, arthralgia, and hot flushes. One death occurred in the fulvestrant arm. Circulating tumor DNA ESR1 mutant allele fraction (MAF) decreased from baseline to week 8 in 82.9% of evaluable lasofoxifene-treated versus 61.5% of fulvestrant-treated patients. CONCLUSIONS Lasofoxifene demonstrated encouraging antitumor activity versus fulvestrant and was well tolerated in patients with ESR1-mutated, endocrine-resistant mBC following progression on AI plus CDK4/6i. Consistent with target engagement, lasofoxifene reduced ESR1 MAF, and to a greater extent than fulvestrant. Lasofoxifene may be a promising targeted treatment for patients with ESR1-mutated mBC and warrants further investigation.
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Affiliation(s)
- M P Goetz
- Department of Oncology, Mayo Clinic, Rochester.
| | - N A Bagegni
- Division of Oncology, Washington University School of Medicine, St. Louis, USA
| | - G Batist
- Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - A Brufsky
- University of Pittsburgh Medical Center-Magee Women's Hospital, Pittsburgh
| | - M A Cristofanilli
- Division of Hematology and Medical Oncology, Weill Cornell Medicine, New York
| | - S Damodaran
- The University of Texas MD Anderson Cancer Center, Department of Breast Medical Oncology, Houston
| | | | - G F Fleming
- The University of Chicago Medical Center, Chicago
| | - W J Gradishar
- Division of Hematology/Oncology, Northwestern University, Chicago
| | - S L Graff
- Lifespan Cancer Institute/Legorreta Cancer Center at Brown University, Providence
| | | | - E Hamilton
- Sarah Cannon Research Institute/Tennessee Oncology, Nashville
| | - S Lavasani
- Division of Hematology and Medical Oncology, UC Irvine, Orange
| | | | - T O'Connor
- Roswell Park Comprehensive Cancer Center, Department of Medicine, Buffalo
| | - T J Pluard
- Saint Luke's Cancer Institute, Kansas City
| | - H S Rugo
- Department of Medicine (Hematology/Oncology), University of California San Francisco, San Francisco
| | - S L Sammons
- Dana Farber Cancer Institute, Harvard Medical School, Boston
| | | | - D G Stover
- Ohio State University Comprehensive Cancer Center, Ohio State University, Columbus
| | - G A Vidal
- Breast Oncology Division, West Cancer Center, Memphis
| | - G Wang
- Medical Oncology, Miami Cancer Institute at Baptist Health, Miami, USA
| | - E Warner
- Division of Medical Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - R Yerushalmi
- Rabin Medical Center, Beilinson Hospital, Petah Tikva, Tel-Aviv University, Tel-Aviv, Israel
| | | | | | - E N Gal-Yam
- Breast Oncology Institute, Sheba Medical Center, Ramat Gan, Israel
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Damodaran S, O'Sullivan CC, Elkhanany A, Anderson IC, Barve M, Blau S, Cherian MA, Peguero JA, Goetz MP, Plourde PV, Portman DJ, Moore HCF. Open-label, phase II, multicenter study of lasofoxifene plus abemaciclib for treating women with metastatic ER+/HER2- breast cancer and an ESR1 mutation after disease progression on prior therapies: ELAINE 2. Ann Oncol 2023; 34:1131-1140. [PMID: 38072513 DOI: 10.1016/j.annonc.2023.09.3103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/11/2023] [Accepted: 09/08/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Acquired ESR1 mutations in estrogen receptor-positive (ER+) metastatic breast cancer (mBC) drive treatment resistance and tumor progression; new treatment strategies are needed. Lasofoxifene, a next-generation, oral, endocrine therapy and tissue-specific ER antagonist, provided preclinical antitumor activity, alone or combined with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) in ESR1-mutated mBC. PATIENTS AND METHODS In the open-label, phase II, ELAINE 2 trial (NCT04432454), women with ESR1-mutated, ER+/human epidermal growth factor receptor 2-negative (HER2-) mBC who progressed on prior therapies (including CDK4/6i) received lasofoxifene 5 mg/day and abemaciclib 150 mg b.i.d until disease progression/toxicity. The primary endpoint was safety/tolerability. Secondary endpoints included progression-free survival (PFS), clinical benefit rate (CBR), and objective response rate (ORR). RESULTS Twenty-nine women (median age 60 years) participated; all but one were previously treated with a CDK4/6i (median duration 2 years). The lasofoxifene-abemaciclib combination was well tolerated with primarily grade 1/2 treatment-emergent adverse events (TEAEs), most commonly diarrhea, nausea, fatigue, and vomiting. One patient (with no prior CDK4/6i) discontinued treatment due to grade 2 diarrhea. No deaths occurred during the study. Median PFS was 56.0 weeks [95% confidence interval (CI) 31.9 weeks-not estimable; ∼13 months]; PFS rates at 6, 12, and 18 months were 76.1%, 56.1%, and 38.8%, respectively. CBR at 24 weeks was 65.5% (95% CI 47.3% to 80.1%). In 18 patients with measurable lesions, ORR was 55.6% (95% CI 33.7% to 75.4%). ESR1-mutant circulating tumor DNA (ctDNA) allele fraction decreased from baseline to week 4 in 21/26 (80.8%) patients. CONCLUSIONS Lasofoxifene plus abemaciclib had an acceptable safety profile, was well tolerated, and exhibited meaningful antitumor activity in women with ESR1-mutated, ER+/HER2- mBC after disease progression on prior CDK4/6i. Observed decreases in ESR1-mutant ctDNA with lasofoxifene concordant with clinical response suggest target engagement. If the ELAINE 2 findings are confirmed in the initiated, phase III, ELAINE 3 trial, these data could be practice-changing and help address a critical unmet need.
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Affiliation(s)
- S Damodaran
- Department of Breast Medical Oncology, The University of Texas, MD Anderson Cancer Center, Houston.
| | | | - A Elkhanany
- Baylor College of Medicine, Duncan Cancer Center - Breast, Houston
| | | | - M Barve
- Mary Crowley Cancer Research, Dallas
| | - S Blau
- Oncology Division, Northwest Medical Specialties, PPLC, Puyallup
| | - M A Cherian
- Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus
| | - J A Peguero
- Department of Research, Oncology Consultants PA, Houston
| | - M P Goetz
- Department of Oncology, Mayo Clinic, Rochester
| | | | | | - H C F Moore
- Cleveland Clinic Taussig Cancer Institute, Cleveland, USA
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Abstract
Selective estrogen receptor modulators (SERMs) represent a class of drugs that act as agonist or antagonist for estrogen receptor in a tissue-specific manner. The SERMs drugs are initially used for the prevention and treatment of osteoporosis in postmenopausal women. Bone health in prostate cancer patients has become a significant concern, whereby patients undergo androgen deprivation therapy is often associated with deleterious effects on bone. Previous preclinical and epidemiological findings showed that estrogens play a dominant role in improving bone health as compared to testosterone in men. Therefore, this evidence-based review aims to assess the available evidence derived from animal and human studies on the effects of SERMs on the male skeletal system. The effects of SERMs on bone mineral density (BMD)/content (BMC), bone histomorphometry, bone turnover, bone strength and fracture risk have been summarized in this review.
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Affiliation(s)
- Sok Kuan Wong
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
| | - Nur-Vaizura Mohamad
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
| | - Putri Ayu Jayusman
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
| | - Ahmad Nazrun Shuid
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
| | - Soelaiman Ima-Nirwana
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
| | - Kok-Yong Chin
- a Department of Pharmacology, Faculty of Medicine , Universiti Kebangsaan Malaysia , Cheras , Kuala Lumpur , Malaysia
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Abstract
Although hormone therapy using estrogens plus progestogens (EPT) is effective for the management of menopausal symptoms (e.g., vasomotor symptoms and vulvar/vaginal atrophy) and prevention/treatment of postmenopausal osteoporosis, EPT is associated with safety and tolerability concerns. A new alternative to EPT is the tissue selective estrogen complex (TSEC), which partners a selective estrogen receptor modulator (SERM) with one or more estrogens and is designed to treat menopausal symptoms and prevent postmenopausal osteoporosis without the tolerability concerns associated with EPT. The first TSEC to reach advanced clinical development is a combination of the SERM bazedoxifene (BZA) with conjugated estrogens (CE). BZA has been shown to inhibit the stimulatory activity of CE on uterine tissue and breast in vitro and in vivo. In clinical studies, BZA/CE treatment has been associated with significant improvements in menopausal symptoms including hot flushes and vulvar/vaginal atrophy and significant increases in bone mineral density, coupled with reductions in bone turnover marker levels and improvements in sleep and health-related quality of life. Additionally, BZA/CE has been shown to have a neutral effect on endometrial and breast tissue because BZA inhibits the stimulatory effects of estrogens in tissue-selective fashion in these 2 organs. Taken together, results of these preclinical and clinical studies indicate that the benefits of estrogens for treating menopausal symptoms are maintained with BZA/CE without endometrial or breast stimulation, resulting in a safe and effective treatment for symptomatic postmenopausal women.
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Maximov PY, Lee TM, Jordan VC. The discovery and development of selective estrogen receptor modulators (SERMs) for clinical practice. Curr Clin Pharmacol 2013; 8:135-55. [PMID: 23062036 PMCID: PMC3624793 DOI: 10.2174/1574884711308020006] [Citation(s) in RCA: 239] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 07/11/2012] [Accepted: 10/03/2012] [Indexed: 01/13/2023]
Abstract
Selective estrogen receptor modulators (SERMs) are structurally different compounds that interact with intracellular estrogen receptors in target organs as estrogen receptor agonists or antagonists. These drugs have been intensively studied over the past decade and have proven to be a highly versatile group for the treatment of different conditions associated with postmenopausal women's health, including hormone responsive cancer and osteoporosis. Tamoxifen, a failed contraceptive is currently used to treat all stages of breast cancer, chemoprevention in women at high risk for breast cancer and also has beneficial effects on bone mineral density and serum lipids in postmenopausal women. Raloxifene, a failed breast cancer drug, is the only SERM approved internationally for the prevention and treatment of postmenopausal osteoporosis and vertebral fractures. However, although these SERMs have many benefits, they also have some potentially serious adverse effects, such as thromboembolic disorders and, in the case of tamoxifen, uterine cancer. These adverse effects represent a major concern given that long-term therapy is required to prevent osteoporosis or prevent and treat breast cancer. The search for the 'ideal' SERM, which would have estrogenic effects on bone and serum lipids, neutral effects on the uterus, and antiestrogenic effects on breast tissue, but none of the adverse effects associated with current therapies, is currently under way. Ospemifene, lasofoxifene, bazedoxifene and arzoxifene, which are new SERM molecules with potentially greater efficacy and potency than previous SERMs, have been investigated for use in the treatment and prevention of osteoporosis. These drugs have been shown to be comparably effective to conventional hormone replacement therapy in animal models, with potential indications for an improved safety profile. Clinical efficacy data from ongoing phase III trials are available or are awaited for each SERM so that a true understanding of the therapeutic potential of these compounds can be obtained. In this article, we describe the discovery and development of the group of medicines called SERMs. The newer SERMs in late development: ospemifene, lasofoxifene, bazedoxifene, are arzoxifene are described in detail.
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Affiliation(s)
- Philipp Y Maximov
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, 3970 Reservoir Rd NW, Research Building, Suite E204A, Washington, DC 20057, USA
| | - Theresa M Lee
- Division of Hematology and Oncology, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC 20057, USA
| | - V. Craig Jordan
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, 3970 Reservoir Rd NW, Research Building, Suite E204A, Washington, DC 20057, USA
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Abstract
Selective estrogen receptor modulators (SERMs) or estrogen agonists/antagonists have shown promise in osteoporosis in that they have the potential to reduce the risk of fracture, and also reduce the risk of breast cancer. SERMs maybe classified according to their core structure, which is typically a variation of the 17 beta-estradiol template and subclassified according to the side chain at the helix 12 affector region. The best known are the triphenylethylenes such as tamoxifen, used in the management of breast cancer. However, the clinical application of this class of SERMs has been limited due to endometrial stimulation. A second class is the benzothiophenes such as raloxifene and arzoxifene, which have skeletal benefit with little, if any, uterine stimulation. Indole-based SERMs such as bazedoxifene have a 2-phenyl ring system that serves as a core binding unit. Other classes include benzopyrans and naphthalenes (eg, lasofoxifene). In this review article, I will discuss raloxifene and three new SERMs--arzoxifene, bazedoxifene, and lasofoxifene--that have been recently studied. I will discuss their effect on bone, breast, and the cardiovascular system, as well as on safety.
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Affiliation(s)
- Stuart L Silverman
- Cedars-Sinai/UCLA, 8641 Wilshire Boulevard, Suite 301, Beverly Hills, CA 90211, USA.
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Abstract
Introduction: Osteoporosis is a skeletal disorder characterized by compromised bone strength and increased risk of fracture. It is a common disorder in elderly subjects and represents a major public health problem, affecting up to 40% postmenopausal women and 15% of men. Among the several therapeutical interventions, hormone replacement therapy (HRT) was traditionally seen as the gold standard for preventing osteoporotic fractures in postmenopausal women, as well as for the management of menopausal symptoms. However HRT, especially if administered long-term, may lead to an increased risk of breast and, when unopposed by progestins, endometrial cancers. Alternative therapies include bisphosphonates and raloxifene, a selective estrogen receptor modulator (SERM). While the former have been associated with suboptimal adherence, the latter was considerably less potent than estrogen and its effect in the prevention of nonvertebral fractures remain uncertain. Aims: The purpose of this article is to review the clinical trials of lasofoxifene, a new SERM for the treatment of postmenopausal osteoporosis. The medical literature was reviewed for appropriate articles containing the terms “lasofoxifene” and SERMs”. Evidence review: There are three (phase II or phase III) clinical trials that clearly demonstrate efficacy and safety of this new SERM in the suppression of bone loss and the prevention of vertebral and nonvertebral fractures. Moreover, lasofoxifene treatment also reduced breast cancer risk and the occurrence of vaginal atrophy. Place in therapy: With its increased potency and efficacy on the prevention of nonvertebral fractures lasofoxifene may be an alternative and cost-effective therapy for osteoporosis in postmenopausal women.
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Affiliation(s)
- Luigi Gennari
- Department of Internal Medicine, Endocrine-Metabolic Sciences and Biochemistry, University of Siena, Policlinico Le Scotte 53100-Siena, Italy
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Gennari L, Merlotti D, Nuti R. Selective estrogen receptor modulator (SERM) for the treatment of osteoporosis in postmenopausal women: focus on lasofoxifene. Clin Interv Aging 2010; 5:19-29. [PMID: 20169039 PMCID: PMC2817938 DOI: 10.2147/cia.s6083] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Selective estrogen receptor modulators (SERMs) represent a class with a growing number of compounds that act as either estrogen receptor agonists or antagonists in a tissue-specific manner. This article reviews lasofoxifene, a new-generation SERM that has completed phase III development for the prevention and treatment of osteoporosis in postmenopausal women. Consistent with preclinical observations, this new SERM demonstrated improved skeletal efficacy over raloxifene and at an oral dose of 0.5 mg/day was effective in the prevention of both vertebral and nonvertebral fractures in postmenopausal women with osteoporosis. At the same dosage, lasofoxifene treatment also reduced estrogen receptor-positive breast cancer risk and the occurrence of vaginal atrophy, but, like the other SERMs, was associated with hot flushes and an increased risk of venous thromboembolic events. With its increased efficacy on the prevention of nonvertebral fractures than current available SERMs and its positive effects on the vagina, this new compound may represent an alternative and cost-effective therapy for osteoporosis in postmenopausal women.
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Affiliation(s)
- Luigi Gennari
- Department of Internal Medicine, Endocrine-Metabolic Sciences and Biochemistry, University of Siena, Siena, Italy.
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Ouellet D, Bramson C, Roman D, Remmers AE, Randinitis E, Milton A, Gardner M. Effects of three cytochrome P450 inhibitors, ketoconazole, fluconazole, and paroxetine, on the pharmacokinetics of lasofoxifene. Br J Clin Pharmacol 2007; 63:59-66. [PMID: 16822276 PMCID: PMC2000715 DOI: 10.1111/j.1365-2125.2006.02709.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Accepted: 04/03/2006] [Indexed: 11/30/2022] Open
Abstract
AIMS Two studies were conduced to assess the effects of ketoconazole, a CYP3A4/5 inhibitor; fluconazole, a CYP2C9 inhibitor; and paroxetine, a CYP2D6 inhibitor, on lasofoxifene pharmacokinetics. METHODS The first parallel group study was conducted in 45 healthy postmenopausal women (15 per group) to compare the pharmacokinetics of a single dose of lasofoxifene (0.25 mg) administered alone and in combination with ketoconazole (400 mg daily x 20 days) or fluconazole (400 mg daily x 20 days). Lasofoxifene was administered on day 2 and blood samples were collected serially for up to 456 h postdose (20 days). The second study enrolled 20 healthy postmenopausal women (10 per group) to compare the pharmacokinetics of a single dose of lasofoxifene (0.25 mg) alone and in combination with paroxetine (30 mg qd x 21 days). Lasofoxifene was given on day 8 of paroxetine treatment and blood samples were collected serially for up to 336 h postdose. RESULTS All subjects completed the study and the treatments were well tolerated. Lasofoxifene C(max) and AUC ratios [90% confidence interval (CI)] with/without ketoconazole were 111% (98.4, 127) and 120% (105, 136), respectively, and were 91.3% (80.3, 104) and 104% (91.4, 118), respectively, with/without fluconazole. Lasofoxifene C(max) and AUC ratios (90% CI) with/without paroxetine were 118% (95.4, 146) and 135% (120, 152), respectively. CONCLUSIONS Coadministration of potent inhibitors of CYP3A4/5 and CYP2D6, but not CYP2C9, resulted in a moderate increase in lasofoxifene exposure. No dosage adjustment should be required when lasofoxifene is coadministered with ketoconazole, fluconazole, paroxetine or other agents that inhibit these CYP enzymes.
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Affiliation(s)
- D Ouellet
- Pfizer Global Research and Development, Ann Arbor, MI 48105, USA.
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Ouellet D, Bramson C, Carvajal-Gonzalez S, Roman D, Randinitis E, Remmers A, Gardner MJ. Effects of lasofoxifene on the pharmacokinetics and pharmacodynamics of single-dose warfarin. Br J Clin Pharmacol 2006; 61:741-5. [PMID: 16722839 PMCID: PMC1885106 DOI: 10.1111/j.1365-2125.2006.02589.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Accepted: 10/22/2005] [Indexed: 01/08/2023] Open
Abstract
AIM To investigate the effect of steady-state lasofoxifene on the pharmacokinetics and pharmacodynamics of warfarin. METHODS Twelve healthy postmenopausal women received warfarin (single 20-mg dose) alone and during lasofoxifene. R- and S-warfarin concentrations, prothrombin time (PT) and international normalized ratio (INR) were determined with each treatment. RESULTS Lasofoxifene had no clinically meaningful effect on R- or S-warfarin pharmacokinetics. The S-warfarin area under the plasma concentration-time curve (AUC) was 23% and 67% larger in subjects with *1/*2 and *1/*3 heterozygous mutations, relative to *1/*1, respectively. The mean PT AUC and Cmax ratio (90% confidence interval) was 91.9 (89.6, 94.2) and 84.2 (80.6, 87.8), respectively. INR results were similar. CONCLUSIONS Lasofoxifene has no clinically meaningful effect on the pharmacokinetics of warfarin. Although the decrease in PT/INR may not be clinically meaningful, more frequent INR monitoring may be considered during lasofoxifene introduction and discontinuation, consistent with warfarin's label.
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Affiliation(s)
- Daniele Ouellet
- Pfizer Global Research and Development, Ann Arbor, MI 48105, USA.
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