Clinical trialNCT05068388CompletedPhase 2Interventional

Effect of Oral (Z)-Endoxifen in Premenopausal Women With Measurable Breast Density

SponsorAtossa Therapeutics, Inc.Enrollment240Breast Density

View the registry record on ClinicalTrials.gov

Summary

The lay summary the sponsor registered on ClinicalTrials.gov.

This is a randomized, double-blinded, placebo-controlled dose-response efficacy study of oral (Z)-endoxifen in premenopausal women with measurable breast density. There will be 5 in-clinic visits (Screening, Day 1, Months 1, 3 and 6) and 3 self-report visits (Months 2, 4 and 5). Standard of care mammograms will be used for the screening mammogram as well as the 24-month follow up visit.

clinicaltrials.gov ↗

Investigators

The overall officials registered on this study. Names that resolve to a FindMyKOL profile link to it; the rest are shown as registered.

Per Hall, MD
Södersjukhuset, Stockholm, Sweden
Principal Investigator
clinicaltrials.gov ↗
Steven Quay, MD
Atossa Therapeutics, Inc.
Study Director
clinicaltrials.gov ↗

A profile link is shown only when the registered name resolves to a person record with a confident, namesake-checked match; ambiguous names stay unlinked.

Sites

1 registered facility, with the per-site recruitment status where the registry publishes one. ClinicalTrials.gov does not publish per-site enrollment counts.

Sweden

Karma Study Centre
Stockholm, Sweden

Site investigator names are published by ClinicalTrials.gov only while a study recruits, so completed studies list sites without them.

Drugs studied

The drug and biological interventions registered on this study, normalized to their RxNorm ingredient where possible.

PlaceboEndoxifen

Linked drugs open the directory filtered to KOLs working with them.clinicaltrials.gov ↗

Registration & key dates

Registry attributes as recorded on the ClinicalTrials.gov study record.

Start: 21 Dec 2021
Primary completion: 14 Jun 2024
Completion: 12 Mar 2026
Last update posted: 20 May 2026
Registered enrollment: 240
Registry id: NCT05068388

clinicaltrials.gov ↗

Source: ClinicalTrials.gov, via the CTTI AACT database, data as of 11 Nov 2026. Registry facts are shown as registered by the study sponsor; FindMyKOL does not interpret them.