Drugs / Endoxifen
Endoxifen
also known as
(z)-endoxifen · 4-hydroxy-n-desmethyltamoxifen · ENX · N-desmethyl-4-hydroxytamoxifen · NSC-749798 · Z-Endoxifen HCl
Trials 12
News releases announcing trial results or a regulatory action · 20
| Date | Issuer | Release |
|---|---|---|
| 2026-07-21 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces Presentation of Mechanism-Driven (Z)-Endoxifen Data in McCune-Albright Syndrome at AACR Special Conference on Rare Cancers atossatherapeutics.com ↗
The poster supports a dual mechanism of action for (Z)-endoxifen in estrogen-driven pathology relevant to McCune Albright Syndrome-associated Peripheral Precocious Puberty (MAS-PPP): the blockade of ER-mediated transcription downstream of autonomous estrogen production and suppression of PKC-β/AKT-associated proliferative and cell-cycle signaling. |
| 2026-05-27 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces ASCO 2026 Abstracts Highlighting (Z)-Endoxifen Activity Across ESR1 Mutations and Ongoing EVANGELINE Phase 2 Trial atossatherapeutics.com ↗
Preclinical Data Abstract Demonstrates Robust Estrogen Receptor (ER) Inhibition in ESR1-Mutant Breast Cancer Models at Clinically Relevant Concentrations |
| 2026-05-06 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces Publication of KARISMA Endoxifen Trial Demonstrating Significant Reduction in Mammographic Breast Density in Healthy Premenopausal Women atossatherapeutics.com ↗
The randomized, double-blind, placebo-controlled Phase 2 study evaluated daily oral Endoxifen and demonstrated that low-dose Endoxifen significantly reduced MBD, a key risk factor for breast cancer. |
| 2026-05-04 | Atossa Therapeutics, Inc. | Regulatory Atossa Therapeutics Receives FDA Rare Pediatric Disease Designation for (Z)-Endoxifen for McCune-Albright Syndrome atossatherapeutics.com ↗
Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announced that the U.S. Food and Drug Administration ("FDA") has granted Rare Pediatric Disease ("RPD") designation to (Z)-endoxifen for the treatment of McCune-Albright Syndrome ("MAS") in females. |
| 2026-03-12 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Presents Clinical Trial Update Highlighting (Z)-Endoxifen Research at the 2026 MDA Clinical & Scientific Conference atossatherapeutics.com ↗
(Z)-Endoxifen improved muscle strength and motor performance in both juvenile and adult dystrophic mice |
| 2026-01-16 | Atossa Therapeutics, Inc. | Regulatory Atossa Therapeutics Receives FDA Orphan Drug Designation for (Z)-Endoxifen for the Treatment of Duchenne Muscular Dystrophy atossatherapeutics.com ↗ |
| 2026-01-06 | Atossa Therapeutics, Inc. | Regulatory Atossa Therapeutics Receives FDA "Study May Proceed" Letter for (Z)-Endoxifen Investigational New Drug Application for Metastatic Breast Cancer atossatherapeutics.com ↗
This letter marks an important regulatory milestone for Atossa and to potentially expand the use of (Z)-endoxifen for metastatic ER+/HER2- Breast Cancer. |
| 2025-12-15 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Presents Four Clinical Trial Updates Highlighting (Z)-Endoxifen Research at the 2025 San Antonio Breast Cancer Symposium atossatherapeutics.com ↗
Functional assays confirmed strong suppression of ER signaling in both wild-type and mutant ESR1 backgrounds, demonstrating robust inhibitory activity even under estrogen-rich conditions and validating the mechanistic modeling findings |
| 2025-12-11 | Atossa Therapeutics, Inc. | Regulatory Atossa Therapeutics Receives FDA Rare Pediatric Disease Designation for (Z)-Endoxifen for Duchenne Muscular Dystrophy atossatherapeutics.com ↗
Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announced that the U.S. Food and Drug Administration ("FDA") has granted Rare Pediatric Disease ("RPD") designation to (Z)-Endoxifen for the treatment of Duchenne Muscular Dystrophy ("DMD"). |
| 2025-12-02 | Atossa Therapeutics, Inc. | Results Insilico Medicine and Atossa Therapeutics Publish AI-Driven Study in Nature Scientific Reports Identifying (Z)-Endoxifen as a Potential Therapeutic Candidate for Glioblastoma atossatherapeutics.com ↗
Through this systematic evaluation, GBM emerged as a top candidate for further investigation. |
| 2025-05-14 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces Full Results from I‑SPY 2 Endocrine‑Optimization Sub‑Study Evaluating Low‑Dose (Z)‑Endoxifen atossatherapeutics.com ↗
Median Ki‑67 fell from 10.5 percent at baseline to 5 percent by Week 3 (prior to ovarian suppression); 65 percent of patients achieved Ki‑67 ≤ 10 percent at that time point, and suppression was maintained at surgery. |
| 2024-12-12 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics to Present Poster Describing the Discovery of Molecules Synergistic with (Z)-endoxifen for the Treatment of Breast Cancer at the 2024 San Antonio Breast Cancer Symposium atossatherapeutics.com ↗
The combination of these newly discovered compounds was shown to induce cell death in MCF-7 cells, a widely used human breast cancer cell line in scientific research, at levels greater than with either agent alone. |
| 2024-12-11 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces Full Results from Phase 2 KARISMA-Endoxifen Study Demonstrating Statistically Significant Reductions in Mammographic Breast Density atossatherapeutics.com ↗
Atossa Therapeutics, Inc. (Nasdaq: ATOS) (“Atossa” or the “Company”), today announced full results from its Phase 2 KARISMA-Endoxifen trial conducted at the Karolinska Institute in Stockholm, Sweden. |
| 2024-12-10 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics to Present Pharmacokinetic and Tolerability Data from Phase 2 EVANGELINE Trial at the 2024 San Antonio Breast Cancer Symposium atossatherapeutics.com ↗
Primary Endpoint Achieved: 50 percent of patients (3/6) in the group that received 80 mg of (Z)-endoxifen with goserelin met the target steady-state plasma concentrations (Css) of 500–1000 ng/mL. |
| 2024-12-09 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Presents Data from Study Investigating Anti-Cancer Activity of (Z)-Endoxifen-Related Compounds at AACR Special Conference in Cancer Research atossatherapeutics.com ↗
All four byproducts exhibited greater anti-proliferative effects than (Z)-endoxifen in estrogen-deficient conditions, while (Z)-endoxifen remained the most potent at inducing cell cycle arrest and apoptosis, reinforcing its potential as a therapeutic agent. |
| 2024-11-20 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Announces Five Abstracts Highlighting (Z)-Endoxifen Research Accepted for Presentation at the 2024 San Antonio Breast Cancer Symposium atossatherapeutics.com ↗
The presentations will showcase significant findings from various studies evaluating the use of (Z)-endoxifen in breast cancer prevention and treatment, including phase 2 trials and innovative combination therapy research. |
| 2024-11-04 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Reports Positive KARISMA-Endoxifen Trial Results: atossatherapeutics.com ↗
The study, which was conducted through the Karolinska Institute in Stockholm, Sweden, demonstrated that low doses of (Z)-endoxifen significantly reduced MBD and was generally well tolerated. |
| 2024-10-31 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Releases Promising Preliminary Analysis Demonstrating (Z)-Endoxifen’s Potential to Rapidly Reduce Ki-67 and Tumor Volume in ER+/HER2- Breast Cancer atossatherapeutics.com ↗
The data also demonstrated (Z)-endoxifen activity in rapidly reducing key biomarkers such as Ki-67 by 69 percent from baseline and a 30.4 percent reduction in functional tumor volume (FTV) from baseline after 3 weeks of treatment. |
| 2024-04-09 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Presents Data from 40mg Cohort of Phase 2 EVANGELINE Clinical Trial Showing 100% Disease Control Rate After 24-Weeks of Treatment with (Z)-Endoxifen atossatherapeutics.com ↗
Ki-67 for the 40mg cohort patients was reduced from an average of 14.5% at screening to 5.3% at 28 days and 1.2% at 24-weeks. |
| 2024-03-19 | Atossa Therapeutics, Inc. | Results Atossa Therapeutics Provides Five-Year (Z)-Endoxifen Treatment Update on FDA-Approved "Expanded Access" Program for a U.S. Breast Cancer Patient atossatherapeutics.com ↗
As of the date of this press release, the patient remains cancer-free and has reported no significant safety or tolerability issues over the course of her treatment. |
All press releases naming this drug 45 releases
Evidence & citations 10 cited values
Every value below carries the sentence it was read from. 15 sources stand behind the page.
| Field | Value | Cited text |
|---|---|---|
| Known as | endoxifen | “The experimental drug Z-Endoxifen HCl (endoxifen) is related to tamoxifen” NCT01273168 ↗ |
| Known as | (z)-endoxifen | “Group 3: Patients will receive (Z)-endoxifen according to (Z)-endoxifen steady state plasma concentrations (phenotype) at screening (i.e. ≤ 15 nM receive 3 mg, \> 15 and ≤ 25...” NCT03931928 ↗11“BACKGROUND: (Z)-endoxifen is the tamoxifen metabolite that possesses the highest affinity to the estrogen receptor and is evolving as an alternative to tamoxifen.” PMID 42070780 ↗ Apr 2026 “(Z)-endoxifen is the most active metabolite of the selective estrogen receptor modulator (SERM), tamoxifen.” NCT06075953 ↗ “To describe the safety profile of Z-endoxifen (Z-endoxifen hydrochloride) at each of the doses examined.” NCT01327781 ↗ “The experimental drug Z-Endoxifen HCl (endoxifen) is related to tamoxifen” NCT01273168 ↗ |
| Known as | 4-hydroxy-n-desmethyltamoxifen | ChEMBL registry synonym — accepted as the source's own label CHEMBL1093458 ↗ |
| Known as | ENX | “endoxifen hydrochloride (endoxifen [ENX]) gel” NCT03317405 ↗ |
| Known as | N-desmethyl-4-hydroxytamoxifen | ChEMBL registry synonym — accepted as the source's own label CHEMBL1093458 ↗ |
| Known as | NSC-749798 | ChEMBL registry synonym — accepted as the source's own label CHEMBL1093458 ↗ |
| Known as | Z-Endoxifen HCl | “The experimental drug Z-Endoxifen HCl (endoxifen) is related to tamoxifen” NCT01273168 ↗ |
| Action | Inhibit | “lowering the amount of estrogen the body makes” NCT02311933 ↗ |
| Modality | Small molecule | — CHEMBL1093458 ↗ |
| Route | Oral | “Z-endoxifen: 10 mg QD, p.o.” NCT01042379 ↗ |