Request Demo

Last update 24 Oct 2026

Tamoxifen Citrate

Last update 24 Oct 2026

Overview

R&D Status

Clinical Result

Translational Medicine

Overview

Basic Info

Drug Type

Small molecule drug

Synonyms

(Z)-2-(4-(1,2-Diphenyl-1-butenyl)phenoxy)-N,N-dimethylethanamine, (Z)-2-(para-(1,2-Diphenyl-1-butenyl)phenoxy)-N,N-dimethylamine, 1-p-beta-Dimethylaminoethoxyphenyl-trans-1,2-diphenylbut-1-ene

+ [20]

Target

Action

antagonists

Mechanism

ERs antagonists(Estrogen receptors antagonists)

Therapeutic Areas

NeoplasmsSkin and Musculoskeletal Diseases

Active Indication

Estrogen receptor positive breast cancerNoninfiltrating Intraductal CarcinomaBreast Cancer

Inactive Indication

Advanced Malignant Solid NeoplasmBreast Cancer, FamilialDementia+ [10]

Originator Organization

AstraZeneca PLC

Active Organization

Mayne Pharma Commercial LLC

Suzhou First Pharmaceutical Co., Ltd.AstraZeneca KK

Inactive Organization

AstraZeneca PLCAstraZeneca Pharmaceuticals LP

Daré Bioscience, Inc.

License Organization

Midatech Pharma US, Inc.

DARA BioSciences, Inc.

Drug Highest PhaseApproved

First Approval Date

United States (30 Dec 1977),

Breast Cancer

RegulationOrphan Drug (European Union)

Structure/Sequence

Molecular FormulaC32H37NO8

InChIKeyFQZYTYWMLGAPFJ-OQKDUQJOSA-N

CAS Registry54965-24-1

442

Clinical Trials associated with Tamoxifen Citrate

NCT07729046

/ Not yet recruitingPhase 2IIT

Neu Direction: A Single Center Phase II Randomized Clinical Trial to Assess the Efficacy of Adding HER Inhibition to Standard of Care in Patients With Metastatic MLH1-low Endocrine-resistant ER+/HER2- Breast Cancer

The goal of this clinical trial is to learn if neratinib, an FDA-approved oral pan-HER2/3/4 inhibitor, improves disease control for participants with metastatic endocrine-resistant ER+/HER2-negative breast cancer. Neratinib is already approved for the treatment of HER2-postive breast cancers. The study will also learn about the safety of adding this drug to standard of care treatments. The main questions it aims to answer are:
1. Does adding neratinib to standard of care systemic therapy improve disease control for patients with metastatic hormone-driven breast cancer that is resistant to endocrine therapy?
2. What side effects do participants have when adding neratinib to standard of care therapy? Researchers will compare standard of care endocrine therapy regimens with and without neratinib to see if neratinib improves control of treatment-resistant metastatic breast cancer that has continued to progress while eon first line endocrine therapy.
Participants will:
1. Take standard of care endocrine therapy for metastatic endocrine-resistant breast cancer as determined by their medical oncologist or standard of care therapy with neratinib daily
2. Visit the clinic every 3 months for checkups, tests and imaging studies

Start Date01 Jul 2027

Sponsor / Collaborator

University of California San Diego

NCT07535905

/ RecruitingPhase 2IIT

Phase II Controlled Clinical Trial to Test Efficacy and Observe Longitudinal Effects of Tamoxifen for Testosterone Recovery in Medically Castrated Prostate Cancer Patients

Androgen deprivation therapy (ADT) is a cornerstone therapy in the treatment of curable prostate cancer (PCa). However, ADT often leads to a protracted testosterone recovery period in most men or absence of complete recovery in 10-25% of cases. The hypogonadal state has significant psychosocial and physical side effects. Therefore, limiting ADT effect's duration beyond the prescribed castration period is very compelling to patients and providers alike.
Tamoxifen, a well-established selective estrogen receptor modulator, offers a novel and cost-effective approach to accelerate testosterone recovery in men with secondary hypogonadism. This project addresses a critical gap in global cancer care by evaluating Tamoxifen as a viable solution for reducing the burden of delayed testosterone recovery and its associated side effects, particularly in resource-limited settings.

Start Date31 Dec 2026

Sponsor / Collaborator

University Health Network

NCT07806630

/ Active, not recruitingPhase 2IIT

SHORTened Duration of TAMoxifen for Risk Reduction in Breast Intraepithelial Neoplasms in Post-menopausal Women

The purpose of this study is to learn whether a shorter-duration, low-dose tamoxifen regimen can reduce the risk of developing breast cancer or breast cancer recurrence in post-menopausal women who are at increased risk for breast cancer.

Start Date01 Sep 2026

Sponsor / Collaborator

Rutgers State University of New Jersey

100 Clinical Results associated with Tamoxifen Citrate

100 Translational Medicine associated with Tamoxifen Citrate

100 Patents (Medical) associated with Tamoxifen Citrate

12,060

Literatures (Medical) associated with Tamoxifen Citrate

01 Sep 2026·JAMA Surgery

Lumpectomy Margins and Local Recurrence in DCIS

Article

Author: Brufsky, Adam M. ; Siddique, Shahzad ; Albain, Kathy S. ; Hopkins, Judith O. ; Kuerer, Henry M. ; Mamounas, Eleftherios P. ; Dignam, James J. ; Lyons, Janice A. ; Wapnir, Irene L. ; Zeitzer, Kenneth ; Li, Jiahe ; Suga, J. Marie ; Conlin, Alison K. ; Vallow, Laura A. ; Boileau, Jean François ; Wolmark, Norman ; Julian, Thomas B. ; Cianfrocca, Mary E. ; Cecchini, Reena S. ; Anderson, Stewart J.

Importance:

The NRG Oncology research organization and NSABP B-35 randomized clinical trial prospectively collected margin width data on postmenopausal women with hormone receptor (HR)–positive ductal carcinoma in situ (DCIS) who underwent lumpectomy, whole-breast irradiation (WBI), and randomly assigned adjuvant anastrozole or tamoxifen therapy. This permitted analysis of outcomes per margin width.

Objective:

To analyze the effect of margin width on ipsilateral breast tumor recurrence (IBTR).

Design, Setting, and Participants:

NSABP B-35 was a phase 3, double-blind, randomized clinical trial in which patients were randomized to either 5 years of tamoxifen or anastrozole. Postmenopausal women with HR-positive DCIS and tumor-free margins were eligible. Enrollment was from January 6, 2003, to June 15, 2006, in academic and community hospital members of the NSABP. Study data were analyzed from July 2024 to April 2025.

Interventions:

There were no specific interventions based on lumpectomy margin width.

Main Outcomes and Measures:

Lumpectomy margin width data were prospectively collected within 3 months of randomization. A pathology form classified margins as positive (ink on tumor), close (&lt;1 mm), or negative (≥1 mm). For the negative margin subgroup, closest margin width was stated separately. Thus, an ancillary analysis using 1-mm and 2-mm margin width partitions was performed.

Results:

A total of 3104 postmenopausal women (mean [SD] age, 61 [7.8] years) were enrolled in NSABP B-35. In an ancillary analysis, 2707 patients were included in the 1-mm margin width partition group, and 2546 patients were included in the 2-mm margin width partition group. IBTR was the most common first event, occurring in 90 of 2707 patients (3.3%): 24 of 502 patients (4.8%) with a margin width less than 1 mm and 66 of 2205 patients (3.0%) with a margin width greater than or equal to 1 mm. Ten-year unadjusted cumulative incidence of IBTR events was 5.6% vs 4.0% for margins less than 1 mm vs margins greater than or equal to 1 mm ( P = .04). Using 2 mm as the discriminant threshold for margin width, 39 of 879 patients (4.4%) with margins less than 2 mm and 49 of 1667 patients (2.9%) with margins greater than or equal to 2 mm experienced an IBTR first. Ten-year unadjusted cumulative incidence of IBTR events with margins less than or equal to 2 mm was 5.3% vs 3.8% for those with margins greater than 2 mm ( P = .05). In models adjusting for other patient and tumor factors, margin width was not a significant predictor of IBTR risk (2-mm threshold hazard ratio, 1.33; 95% CI, 0.86-2.06).

Conclusions and Relevance:

Results of this ancillary analysis of the NSABP B-35 trial show that absolute differences in IBTR rates using margin width groupings of less than 1 mm or greater than or equal to 1 mm and margin width groupings of less than 2 mm or greater than or equal to 2 mm in postmenopausal women with HR-positive DCIS receiving lumpectomy, WBI, and adjuvant endocrine therapy were small. Omission of reexcision lumpectomies based on margin widths of less than 1 mm or less than 2 mm can be reconsidered in appropriate patients.

Trial Registration:

ClinicalTrials.gov Identifier: NCT00053898

01 Aug 2026·JOURNAL OF CLINICAL ONCOLOGY

Low-Dose Tamoxifen in Noninvasive Breast Neoplasia: Long-Term Results From an Individual-Participant Data Pooled Analysis

Article

Author: Cortesi, Laura ; Serra, Patrizia ; Digennaro, Maria ; Debiasi, Marcio ; Rizzo, Roberta ; Buttiron Webber, Tania ; Bonanni, Bernardo ; Johansson, Harriet ; Giordano, Livia ; DeCensi, Andrea ; Sousa, Berta ; Gandini, Sara ; Carbone, Alessio ; Serrano, Davide ; Aurilio, Gaetano ; Aprile, Giuseppe ; Gallerani, Elisa ; Lazzeroni, Matteo ; Cagossi, Katia ; Guerrieri-Gonzaga, Aliana ; Millo, Francesco ; Puntoni, Matteo ; Gouveia, Pedro

PURPOSE:

Tamoxifen 20 mg once-daily reduces the risk of breast cancer recurrence after ductal carcinoma in situ (DCIS), but its use is limited by adverse effects. Lower doses may be effective, but benefit durability and differences according to menopausal status and site of recurrence remain uncertain.

METHODS:

We conducted an individual-participant pooled analysis of three clinical studies involving women with estrogen receptor–positive or unknown DCIS, microinvasive carcinoma, or high-risk breast lesions. Participants received low-dose tamoxifen (5 mg once daily or 10 mg once-every other day for 2-5 years) or a control intervention. The primary end point was breast cancer–free interval, defined as the first occurrence of any ipsilateral or contralateral invasive breast cancer, DCIS, regional recurrence, or distant recurrence. Hazard ratios (HRs) were estimated with mixed-effects Cox models accounting for between-study variability.

RESULTS:

Among 1,545 women included with a median follow-up of 9.4 years, low-dose tamoxifen reduced breast cancer events overall, with evidence of treatment heterogeneity according to menopausal status ( P = .01). In postmenopausal women, breast cancer events occurred in 40 of 335 receiving low-dose tamoxifen versus 93 of 401 controls (HR, 0.51 [95% CI, 0.35 to 0.73]), with a 10-year absolute reduction of 11.2%. Among premenopausal women, no significant reduction was observed (HR, 0.90 [95% CI, 0.70 to 1.17]), although contralateral breast cancer was reduced (HR, 0.45 [95% CI, 0.26 to 0.76]). Serious adverse events were infrequent and similar between groups.

CONCLUSION:

Low-dose tamoxifen was associated with a sustained reduction in breast cancer events, with differences by menopausal status and site of event. These findings support endocrine dose de-escalation to improve the benefit-risk profile of preventive therapy in DCIS and high-risk lesions.

01 Apr 2026·NEUROMUSCULAR DISORDERS

Safety and Efficacy of Tamoxifen in Patients with Duchenne muscular dystrophy: open Label Extension of TAMDMD Trial

Article

Author: Spinty, Stefan ; Zwingli, Gaëtan ; Lawrence, Fiona ; Lopez Lobato, Mercedes ; Houwen-van Opstal, Saskia ; Schara-Schmidt, Ulrike ; Laugel, Vincent ; Amthor, Helge ; Schaedelin, Sabine ; Nascimento Osorio, Andrés ; Rubino-Nacht, Daniela ; Hafner, Patricia ; Deconinck, Nicolas ; Putananickal, Niveditha ; Fischer, Dirk ; Horrocks, Iain ; von Moers, Arpad ; Childs, Anne-Marie ; Henzi, Bettina C ; Dorchies, Olivier M ; Nagy, Sara ; Schmidt, Simone

Safety and efficacy of tamoxifen in boys with Duchenne muscular dystrophy was assessed in the double-blind, randomised, placebo-controlled, multicenter phase 3 trial (TAMDMD), which was followed by an 48 weeks open label extension study. The aim of the open label extension study was to investigate if earlier initiation of tamoxifen could reduce the progression of the disease compared to delayed initiation of tamoxifen. Of the initial TAMDMD trial participants, 66 patients were enrolled in the open label extension (OLE). The objective was to investigate the efficacy of prolonged treatment with tamoxifen 20 mg daily, adjunct to corticosteroids, in individuals with DMD over 48 weeks. We aimed to analyse the sustained effect and the timing effect of tamoxifen in patients with DMD on the basis of a set of motor function tests. The sustained effect corresponds to the treatment effect seen in the tamoxifen treatment arm of the RCT phase of the trial being sustained after all patients got the treatment in the OLE phase. The timing effect addresses if patients with earlier tamoxifen initiation show more favourable disease trajectory than patients with delayed tamoxifen initiation. This study was registered with ClinicalTrials.gov (NCT03354039). Between May 28th 2019 and July 28th 2021, 66 patients in 10 study centres in seven European countries could be enrolled into the OLE phase. Of those, 32 had previously been treated with tamoxifen and 34 had been assigned to placebo. The efficacy outcome defined as the change in the motor function did not differ significantly between the early tamoxifen treatment group and the delayed tamoxifen treatment group. There was neither a sustained nor a timing effect of tamoxifen. Overall tamoxifen was well tolerated. No deaths or life-threatening serious adverse events occurred. The OLE phase of the TAMDMD trial showed that treatment with tamoxifen continued to be well tolerated overall; however, there was neither a sustained nor a timing effect of tamoxifen treatment in patients with DMD. We cannot provide statistical nor clinical evidence that prolonged treatment with tamoxifen is effective in delaying disease progression in DMD when used as an adjunct to corticosteroids.

140

News (Medical) associated with Tamoxifen Citrate

15 Oct 2026

·www.biospace.com

EdenDx Assay Validated as Supportive Endometrial Cancer Triage Tool in Peer-Reviewed Study

ORANGE, CA / ACCESS Newswire / October 15, 2026 / Unlike most cancers, endometrial cancer is rising in incidence and mortality in the U.S., yet there is no population screening program or FDA-cleared noninvasive test to identify it early. Today, Gnosis , a CLIA- and CAP-accredited clinical laboratory, announced a peer-reviewed study in Gynecologic Oncology Reports providing early evidence that the biomarkers behind EdenDx , previously studied predominantly in Asian populations, perform in a cohort including U.S. patients. In cervical cytology specimens collected like a liquid-based Pap test, EdenDx demonstrated 96.8% specificity, which compares favorably with transvaginal ultrasound. In endometrial biopsy tissue from U.S. patients, it detected 85% of cancers with 90% specificity. The American Cancer Society projects 68,270 new cases and 14,450 deaths in 2026 from endometrial cancer, the most common gynecologic cancer in the U.S. Between 2015 and 2019, mortality rose 1.9% per year, while incidence among Black women climbed 2.4% per year, nearly five times the rate among White women. In April 2026, the American College of Obstetricians and Gynecologists (ACOG) began recommending tissue sampling alongside ultrasound for most patients with postmenopausal bleeding, even though biopsy yields insufficient tissue in about 31% of cases and more than nine in ten of these women do not have endometrial cancer . Other tools have limitations like transvaginal ultrasound with specificity ranges from 24% to 72% , and Pap cytology detects only 25% to 45% of cancers . EdenDx (Early Detection for Endometrial Neoplasia) takes a different approach by detecting hypermethylation of CDO1 and CELF4, two genes associated with endometrial cancer, in a sample preserved in a standard ThinPrep® vial. Unlike ultrasound, its results do not depend on endometrial thickness, which varies with hormonal changes, and to the company's knowledge, it is the only CLIA laboratory-developed CDO1/CELF4 methylation test in the U.S. Because these biomarkers had been studied predominantly in Asian populations, which differ in risk factors and genetics, the authors, Gnosis scientists Rojeet Shrestha, PhD, Bo-Ram Bang, PhD, and Safedin Beqaj, PhD, evaluated them in a cohort including U.S. patients. Cervical specimens from Singapore and California showed specificity consistent with the 86.6% to 98.8% range reported in prior studies, while biopsy tissue from 40 U.S. patients provided preliminary evidence of similar performance in U.S. patients. A positive result raised the odds of cancer more than 22-fold, helping physicians prioritize which patients need a biopsy. In cervical specimens, the test detected 72.2% of cancers, including 82% of grade 1 tumors and 81% of endometrioid adenocarcinomas, the disease's most common forms. The analytical results further support the test's use in routine clinical practice. EdenDx detected cancer DNA when cancer cells made up as little as 1.5% of a sample, with run-to-run variation below 10%. Results were unaffected by common vaginal infections, blood, semen, or over-the-counter vaginal products, and there were no false positives in specimens with HPV-related abnormal Pap results, metastatic ovarian cancer, or benign ovarian cysts. "CDO1 and CELF4 methylation changes arise early in the development of endometrial cancer, in some cases before symptoms appear, and that is precisely what makes them so valuable diagnostically," said Dr. Safedin Beqaj, Laboratory Director at Gnosis. "EdenDx detects those changes directly in a routine cervical specimen, without relying on how cells look under a microscope. For a disease whose evaluation has long relied on tissue sampling alone, that represents a genuine advance." EdenDx is intended for symptomatic women and those at elevated risk from abnormal uterine bleeding, obesity, chronic anovulation, Lynch syndrome, or Tamoxifen therapy, as well as premenopausal women, in whom ultrasound is less reliable. It requires no new equipment or workflow changes and supports, but does not replace, endometrial sampling for definitive diagnosis. Because invasive procedures are often the first step in evaluation, health systems, OB/GYN practices, public health agencies, and research institutions can add EdenDx to routine care, offering patients a noninvasive option to help guide that decision. The study is available open access in Gynecologic Oncology Reports . To offer EdenDx or explore partnerships, visit or contact support@gnosisdx.com . About Gnosis Gnosis is a CLIA- and CAP-accredited clinical laboratory based in Orange, California, specializing in advanced testing for women's health, pharmacogenomics, and molecular diagnostics. Formerly Mountain View Medical Laboratory, Gnosis is a community-anchored, innovation-driven lab helping providers make confident decisions and connect patients to timely, effective care. Learn more at . About INEX Innovate Based in Singapore, INEX Innovate is a molecular diagnostics company focused on unmet clinical needs in women's and fetal health. Its proprietary technologies include epiHERA ™ , which powers EdenDx, and OvaCis ® . Learn more at . Media Contact Elizabeth Wood 888-539-0525 liz@truarchealth.com SOURCE : Gnosis View the original press release on ACCESS Newswire

Clinical ResultClinical StudyDiagnostic Reagents

24 Sep 2026

·www.businesswire.com

New Data Shows Physicians Changed Extended Endocrine Therapy Recommendations for Over 40% of Patients Following Breast Cancer Index Testing

MARLBOROUGH, Mass.--(BUSINESS WIRE)--Hologic, Inc. and its subsidiary, Biotheranostics, Inc., today announced newly published data in JAMA Network Open showing that Breast Cancer Index® (BCI®) test results led physicians to change their extended endocrine therapy recommendations for 42% of patients. In two-thirds of those cases, physicians changed their recommendation against extending treatment.1 "[This study] reinforces the clinical utility of the Breast Cancer Index test to provide individualized insight into tumor biology that can meaningfully change how physicians and patients approach these decisions.” - Tara B. Sanft, M.D. The findings come from a large-scale BCI Registry Study conducted across multiple institutions at the Sarah Cannon Research Institute, involving nearly 3,000 patients with early-stage, hormone receptor-positive (HR+) breast cancer who received the BCI test. 1 Endocrine therapy is the standard of care for breast cancer survivors to help limit the effects of hormones that can fuel cancer growth — but it is also often the longest phase of a breast cancer patient’s treatment and can cause adverse health outcomes that impact quality of life.2-8 In this analysis, 83% of patients reported side effects ranging from muscle and joint pain to vaginal, sexual and psychological complaints.1 “Decisions about extended endocrine therapy can be challenging, and assumptions based on standard information, such as nodal involvement and tumor size and grade, may be misleading,” said Tara B. Sanft, M.D., of Hartford Healthcare and lead author of the study. “This final analysis of the BCI Registry Study reinforces the clinical utility of the Breast Cancer Index test to provide individualized insight into tumor biology that can meaningfully change how physicians and patients approach these decisions.” Approximately half of recurrences in HR+ breast cancer occur beyond five years post-diagnosis.9 Yet studies suggest that roughly 30–50% of women discontinue endocrine therapy before reaching the five-year mark, often due to side effects or uncertainty about whether continued treatment is necessary.10-13 Multiple trials have demonstrated that while extended endocrine therapy may be beneficial for some women in reducing their risk of late recurrence, not all benefit.14-17 As of July 2026, physicians can now access an updated report option from the same BCI test, providing additional clinical insights earlier — at the time of diagnosis — to support greater clarity as patients plan for treatment.18-20 The updated report offers additional context on 10-year recurrence risk, which can either reinforce the case for medication adherence or help identify whether a patient’s risk may be low enough to consider a less intensive approach to endocrine therapy. “The Breast Cancer Index test’s updated report supports a more informed plan for the years ahead, allowing physicians to further personalize patient care and provide them with a clear roadmap from the time of diagnosis,” said Lloyd Sanders, Vice President and General Manager, Oncology Services at Hologic. “That clarity can make a real difference as patients plan for treatment and life as a cancer survivor.” The BCI test is the only genomic assay recognized by both the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) and the ASCO® Clinical Practice Guideline to predict which patients with early-stage, HR+, HER2- breast cancer are likely to benefit from extended endocrine therapy.2-3 The test has been used by more than 10,000 healthcare providers and evaluated across multiple clinical studies involving more than 15,000 patients.14-27 The recently published results from the BCI Registry Study solidify the clinical impact and value of the Breast Cancer Index test beyond its extensive validation and exclusive guideline recognition. Additional clinical insights from the same established test now enable earlier treatment planning and greater Clarity from the Start™.18-20 About the Breast Cancer Index Test The Breast Cancer Index test is a molecular, gene expression-based test uniquely positioned to provide information to help physicians individualize treatment decisions for patients with early-stage, HR+ breast cancer. This breakthrough test helps oncology care teams and patients navigate the difficult trade-offs between taking steps to prevent recurrence of their disease and facing significant side effects and safety challenges related to unnecessary treatment. The Breast Cancer Index test has guideline designation from the American Joint Committee on Cancer for cancer staging based on molecular profile. The ASCO® Clinical Practice Guideline and the NCCN Guidelines® acknowledge the Breast Cancer Index test as a biomarker to help inform extended endocrine treatment decisions.2-3 The Breast Cancer Index test is intended for routine clinical use, and physician treatment decisions based on results are the responsibility of the physician. It is a sole-source laboratory-developed test (LDT) performed by Biotheranostics, Inc., a CLIA-certified and CAP-accredited diagnostic laboratory. For more information and the full intended use and limitations, visit www.breastcancerindex.com. About Hologic, Inc. Hologic, Inc. is a global leader in women’s health dedicated to developing innovative medical technologies that effectively detect, diagnose and treat health conditions and raise the standard of care around the world. To learn more, visit www.hologic.com and connect with us on LinkedIn, Facebook, X, Instagram and YouTube. Forward-Looking Statements This news release may contain forward-looking information that involves risks and uncertainties, including statements about the use of Hologic products. There can be no assurance these products will achieve the benefits described herein or that such benefits will be replicated in any particular manner with respect to an individual patient, as the actual effect of the use of the products can only be determined on a case-by-case basis. In addition, there can be no assurance that these products will be commercially successful or achieve any expected level of sales. Hologic expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any such statements presented herein to reflect any change in expectations or any change in events, conditions or circumstances on which any such data or statements are based. Hologic, Biotheranostics, Breast Cancer Index, BCI and Clarity from the Start are trademarks and/or registered trademarks of Hologic, Inc. and/or its subsidiaries in the United States and/or other countries. All other trademarks are the property of their respective owners. References Sanft T, et al. JAMA Netw Open. 2026;9(9):e2634974. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Breast Cancer V.6.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed September 8, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. Andre F, et al. J Clin Oncol. 2022;40(16):1816-1837. Referenced with permission from the American Society of Clinical Oncology (ASCO® Clinical Practice Guideline) Clinical Practice Guideline Biomarkers for Adjuvant Endocrine and Chemotherapy in Early-Stage Breast Cancer. © American Society of Clinical Oncology. 2026. All rights reserved. To view the most recent and complete version of the guideline, go online to https://ascopubs-org.libproxy1.nus.edu.sg/jco/special/guidelines . ASCO makes no warranties of any kind whatsoever regarding their content, use of application and disclaims any responsibility for their application or use in any way. Breastcancer.org. Side Effects of Hormonal Therapy for Breast Cancer. Breastcancer.org. Last updated June 11, 2026. Accessed on September 8, 2026. https://www.breastcancer.org/treatment/hormonal-therapy/side-effects U.S. Food & Drug Administration. Armidex Full Prescribing Information. Last updated December 16, 2024. Accessed June 16, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/020541s036lbl.pdf U.S. Food & Drug Administration. Aromasin Full Prescribing Information. Last updated December 16, 2024. Accessed September 8, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/020753s025lbl.pdf U.S. Food & Drug Administration. Femara Full Prescribing Information. Last updated September 16, 2025. Accessed September 8, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/209092Orig1s025,209935Orig1s031lbl.pdf U.S. Food & Drug Administration. Soltamox Full Prescribing Information. Last updated April 8, 2019. Accessed June 16, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/021807s006lbl.pdf Pan H, et al. N Engl J Med. 2017;377:1836-1846. Hershman DL, et al. J Clin Oncol. 2010;20;28(27):4120-4128. Friese CR, et al. Breast Can Res Treat. 2013;138(3):931-39. Saha P, et al. J Clin Oncol. 2017;(35):3113-3122. Wei J, et al. Breast Cancer Res Treat. 2025;214(2):239-246. Sgroi DC, et al. J Natl Cancer Inst. 2013;105(14):1036-1042. Bartlett JMS, et al. Clin Cancer Res. 2022;28(9):1871-1880. Noordhoek I, et al. Clin Cancer Res. 2021;27(1):311-319. Mamounas EP, et al. Clin Cancer Res. 2024;30(9):1984-1991. Jilderda MF, et al. Clin Cancer Res. 2025;3;31(11):2222-2229. Jilderda MF, et al. npj Breast Cancer. 2026;12;21. O’Regan RM, et al. Breast. 2026;86:104714. Data on file. Zhang Y, et al. Clin Cancer Res. 2013;19(15):4196-4205. Sgroi DC, et al. Lancet Oncol. 2013;14(11):1067-1076. Zhang Y, et al. Clin Cancer Res. 2017;23(23):7217-7224. Bartlett JMS, et al. Clin Cancer Res. 2024;30(8):1509-1517. O’Regan RM, et al. JAMA Oncol. 2024;10;(10):1379-1389. O’Regan RM, et al. JAMA Netw Open. 2025;8(11):e2540931.

ASCOClinical Result

24 Sep 2026

·www.prnewswire.com

Atossa Therapeutics CEO Dr. Steven Quay to Participate in ARDD 2026 Panel on Clinical Trials and Regulatory Pathways for Diseases of Aging

Panel at Harvard University will explore translating evidence in diseases of aging into new therapeutics and regulatory pathways SEATTLE, Sept. 24, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company, today announced that Steven Quay, M.D., Ph.D., Atossa's President and Chief Executive Officer, will participate as a panelist at the 13th Aging Research and Drug Discovery Meeting (ARDD 2026), being held October 1–3, 2026, at the David Rubenstein Treehouse at Harvard University in Boston, MA. The discussion will explore the translation of scientific evidence in aging and age-related diseases into clinical development programs, including the design of clinical trials, development of new therapeutics and regulatory considerations for advancing potential treatments to patients. "Advances in our understanding of the biology underlying aging and progressive disease are creating opportunities to approach drug development in new ways," said Dr. Quay. "Turning promising science into meaningful therapies requires clinical trials that are grounded in strong biological evidence, use appropriate and measurable endpoints, and are designed with a clear understanding of the regulatory pathway. These considerations are particularly relevant as Atossa expands its development efforts in rare diseases, and I look forward to exchanging perspectives with this distinguished group of leaders." ARDD brings together leaders from the pharmaceutical and biotechnology industries, academia, clinical medicine and other disciplines to discuss advances in aging research and the translation of scientific discoveries into potential new medicines. The 2026 program includes discussions addressing clinical trials and regulatory pathways, drug discovery and development, emerging technologies and approaches to extending healthy longevity. Event Details Event: ARDD 2026 – Aging Research and Drug Discovery Meeting Panel: Clinical Trials in Diseases of Aging: From Evidence to New Therapeutics and Regulatory Pathways Date: Thursday, October 1, 2026 Time: 11:20 a.m. – 12:00 p.m. ET Location: David Rubenstein Treehouse at Harvard University, Boston, Massachusetts Moderator: Sebastien Thuault, Editor at Nature Medicine Other Panelists: Jill Lee, Director, Regulatory Policy & Intelligence at Novo Nordisk; Calum MacRae, Professor at Mass General Brigham; and Steve Horvath, Professor at UCLA Additional information about ARDD 2026 and the full program is available at agingpharma.org. About Atossa Therapeutics Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of significant unmet need. The Company's lead product candidate, (Z)-endoxifen, is currently in development across several clinical settings. (Z)-Endoxifen is a potent Selective Estrogen Receptor Modulator/Degrader (SERM/D) with demonstrated activity across multiple mechanisms of interest. Atossa is evaluating its potential applications in oncology and rare diseases. The Company's proprietary oral formulation has shown a favorable safety profile and pharmacology distinct from tamoxifen, including ER-targeted effects and PKC inhibition. Atossa's (Z)-endoxifen is not approved for any indication. Atossa's (Z)-endoxifen program is supported by a growing global intellectual property portfolio, including multiple recently issued U.S. patents and numerous pending applications worldwide. More information is available at . Forward-Looking Statements This press release contains certain "forward-looking statements" within the meaning of applicable securities laws, including, but not limited to, our expectations regarding the Company's development and regulatory strategy and related milestones, including the potential indications that the Company may pursue for (Z)-endoxifen, the potential role of (Z)-endoxifen in endocrine therapies, the potential for (Z)-endoxifen to receive regulatory approval and the timing thereof, and the potential market and growth opportunities for the Company. Words such as "expect," "potential," "continue," "may," "will," "should," "could," "would," "seek," "intend," "plan," "estimate," "anticipate," "believe," "design," "predict," "future," or other similar expressions or statements regarding intent, belief or current expectations, are forward-looking statements. Forward-looking statements in this press release are subject to risks and uncertainties that may cause actual results, outcomes, or the timing of actual results or outcomes to differ materially from those projected or anticipated, including, without limitation, risks and uncertainties associated with: our ability to successfully execute our strategy to shorten our clinical development timelines and pursue a MAS indication or other indications for our lead program, (Z)-endoxifen; expected timing, completion and results of our preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; the outcome or timing of necessary regulatory approvals; our ability to maintain compliance with Nasdaq listing requirements; our ability to establish and maintain intellectual property rights covering our products; the impact of general macroeconomic conditions on our business; our ability to raise capital; and other risks and uncertainties detailed from time to time in Atossa's filings with the SEC, including, without limitation, its Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q. Forward-looking statements are presented as of the date of this press release. Except as required by law, we do not intend to update any forward-looking statements. SOURCE Atossa Therapeutics Inc 21% more press release views with Request a Demo

100 Deals associated with Tamoxifen Citrate

External Link

KEGG	Wiki	ATC	Drug Bank
D00966	Tamoxifen Citrate	L02BA01	DB00675

R&D Status

Approved

10 top approved records.

to view more data

Indication	Country/Location	Organization	Date
Estrogen receptor positive breast cancer	United States	Mayne Pharma Commercial LLC	25 Sep 2018
Noninfiltrating Intraductal Carcinoma	United States	Mayne Pharma Commercial LLC	29 Oct 2005
Breast Cancer	United States	AstraZeneca Pharmaceuticals LP	30 Dec 1977

Developing

10 top R&D records.

to view more data

Indication	Highest Phase	Country/Location	Organization	Date
Gynecomastia	Phase 3	Italy	AstraZeneca PLC	01 Dec 2003
Prostatic Cancer	Phase 3	Italy	AstraZeneca PLC	01 Dec 2003
Invasive Mammary Carcinoma	Phase 3	-	AstraZeneca PLC	01 Jul 1996
Hormone receptor positive breast cancer	Phase 3	Austria	AstraZeneca PLC	01 Jan 1996
Early Stage Breast Carcinoma	Phase 3	-	AstraZeneca PLC	01 Dec 1990
Vulvovaginal atrophy	Phase 2	Australia	Daré Bioscience, Inc.	22 Nov 2021
Dementia	Phase 2	United States	AstraZeneca PLC	01 Jan 2007
Dementia	Phase 2	Italy	AstraZeneca PLC	01 Jan 2007
Metastatic Neoplasm to the Bladder	Phase 2	United States	AstraZeneca PLC	01 Jan 2007
Metastatic Neoplasm to the Bladder	Phase 2	Italy	AstraZeneca PLC	01 Jan 2007

Clinical Result

Indication

Phase

Evaluation

View All Results

Study	Phase	Population	Analyzed Enrollment	Group	Results	Evaluation	Publication Date


ESMO2026	Not Applicable	Genitourinary Syndrome of Menopause	169	Aromatase inhibitors (AIs)	rabunnqjou(vmfvfmnphv) = lvsirpxlel rtediktsmn (yflhovplwn ) View more	Positive	23 Oct 2026
NCT00053898 (NSABP B-35, Pubmed \| JAMA Surg)	Phase 3	Noninfiltrating Intraductal Carcinoma hormone receptor (HR)-positive	3,104	Tamoxifen	hjbmekfzbt(kvbxybwueq) = gkpbvylili riqjxyjmek (ijwnzjiraz ) View more	Positive	01 Sep 2026
				Anastrozole	hjbmekfzbt(kvbxybwueq) = wewxoqgkqo riqjxyjmek (ijwnzjiraz ) View more
NCT04570956 (CTgov)	Phase 2	Atypical lobular hyperplasia \| Breast Carcinoma in Situ \| Atypical Lobular Breast Hyperplasia ... View more	65	Questionnaire Administration+Tamoxifen (Oral Tamoxifen 10 mg/Day)	ncxvbmdcri(rqczbekhkx) = dmmaqdwsyv zhqpeduwmq (pdyivrrdts, tljjcjtzbc - hybevksxmr) View more	-	01 Sep 2026
				Questionnaire Administration+Topical 4-OHT( 4-hydroxytamoxifen)gel 4 mg/each breast/day (Topical 4-OHT (4-hydroxytamoxifen) Gel 4 mg/Each Breast/Day)	ncxvbmdcri(rqczbekhkx) = fepfrfavos zhqpeduwmq (pdyivrrdts, hbsltqkjsz - jkykxshfzf) View more
NCT02206984 (P3-05-14 \| TBCRC037, CTgov)	Phase 2	Invasive Lobular Breast Carcinoma	201	fulvestrant (Fulvestrant)	cmbikmiyqo(dowjitlnqf) = evbxkuiqcf nwdakwzwxv (bqhqagwybt, 1.1) View more	-	07 Aug 2026
				anastrozole (Anastrozole)	cmbikmiyqo(dowjitlnqf) = sukchsedkl nwdakwzwxv (bqhqagwybt, 1.1) View more
NCT06982313 (Pubmed \| J Clin Oncol)	Not Applicable	Neoplasms	1,545	Low-dose tamoxifen	jajionmomj(womglopsns): HR = 0.45 (95.0% CI, 0.26 - 0.76) View more	Positive	01 Aug 2026
				Placebo
NCT06982313 (ASCO2026)	Not Applicable	Breast Carcinoma in Situ \| Noninfiltrating Intraductal Carcinoma \| Inappropriate ADH Syndrome	1,772	Low-dose tamoxifen (Babytam)	iwtmjqaszp(zobelzsosx) = hzatzsyams qqtvikceod (dlswdtomuw ) View more	Positive	29 May 2026
				Placebo	iwtmjqaszp(zobelzsosx) = rsabfgjdru qqtvikceod (dlswdtomuw ) View more
NCT03346200 (KARISMA Tamoxifen, ESMO_BC2026)	Phase 2	-	585	Tamoxifen 5 mg	bbbjeqclqb(pdbeurspmk) = cdbifytoqk nyoprflymh (ahzgglnayc ) View more	Positive	07 May 2026
NCT04292886 (Pubmed \| Int J Gen Med)	Phase 3	-	120	Tamoxifen Combined with Hormone Replacement	cngtpewsee(qgtagfkhtm) = uphhlauycb cmirkkduwk (psanshbiiu, 0.93)	Positive	01 May 2026
				Hormone Replacement	cngtpewsee(qgtagfkhtm) = prphailena cmirkkduwk (psanshbiiu, 0.8)
NCT03354039 (TAMDMD, Pubmed \| Neuromuscul Disord)	Phase 3	Muscular Dystrophy, Duchenne	66	Delayed tamoxifen treatment group	vjdreklodq(gqogxiffdk) = dcfczexlrr buzuelcwtt (lzhvernrdd )	Negative	01 Apr 2026
POSITIVE (ESGO2026)	Not Applicable	Hormone receptor positive breast cancer hormone receptor-positive (HR+)	974	Paused tamoxifen	pwzhgikmet(xvlqntcjoj) = dudruwzbtm vgfrgffulc (cjyewdgpym ) View more	Positive	28 Feb 2026
				Tamoxifen users (Retrospective cohort)	nuvqbjggiu(isqmthqhfn) = cpztwgpijh hqcojvuffj (jtowojqhcp ) View more

Translational Medicine

Boost your research with our translational medicine data.

view full example data

Deal

Boost your decision using our deal data.

view full example data

Core Patent

Boost your research with our Core Patent data.

view full example data

Clinical Trial

Identify the latest clinical trials across global registries.

view full example data

Approval

Accelerate your research with the latest regulatory approval information.

view full example data

Regulation

Understand key drug designations in just a few clicks with Synapse.

view full example data

Hiro LS Researcher

The AI Search Engine Built to Accelerate Biopharma Decisions

Search across billion-scale life sciences data to uncover signals, validate evidence, and act with confidence.

Ask any biopharma research question→

Get started for free today!

Accelerate Strategic R&D decision making with Synapse, Patsnap’s AI-powered Connected Innovation Intelligence Platform Built for Life Sciences Professionals.

Discover Synapse Data Servers

Synapse data is now integrated into the PatSnap LS Model Context Protocol (MCP) service. Customize your LLM agent now using our MCP server!

Bio

Bio Sequences Search & Analysis

Chemical

Chemical Structures Search & Analysis