Who is sponsoring NCT03317405?

NCT03317405 is sponsored by National Cancer Institute (NCI).

What drugs are being tested in NCT03317405?

Interventions in NCT03317405: Endoxifen Hydrochloride, Placebo Administration, Questionnaire Administration.

What condition does NCT03317405 study?

NCT03317405 studies Breast Ductal Carcinoma In Situ, Breast Lobular Carcinoma In Situ, Stage 0 Breast Cancer AJCC v6 and v7, Stage I Breast Cancer AJCC v7, Stage IA Breast Cancer AJCC v7, Stage IB Breast Cancer AJCC v7, Stage II Breast Cancer AJCC v6 and v7, Stage IIA Breast Cancer AJCC v6 and v7, Stage IIB Breast Cancer AJCC v6 and v7, Stage III Breast Cancer AJCC v7, Stage IIIA Breast Cancer AJCC v7, Stage IIIB Breast Cancer AJCC v7, Stage IIIC Breast Cancer AJCC v7.

Is NCT03317405 still recruiting?

NCT03317405 is currently active, enrolled. Last updated 28 August 2025.

Are results published for NCT03317405?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2025-08-28 · How we verify

NCT03317405

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

Phase I Trial of Endoxifen Gel Versus Placebo in Women Undergoing Breast Surgery

Active, enrolled Phase 1 Results posted Last updated 28 August 2025

What this trial tests

Phase 1 trial testing Endoxifen Hydrochloride in Breast Ductal Carcinoma In Situ in 32 participants. Participants enrolled and being followed up; not accepting new ones.

Timeline

31 October 2018

Primary endpoint
22 February 2021

12 August 2026

Quick facts

Lead sponsor	National Cancer Institute (NCI)
Phase	Phase 1
Status	Active, enrolled
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	triple
Primary purpose	prevention
Enrollment	32
Start date	31 October 2018
Primary completion	22 February 2021
Estimated completion	12 August 2026
Sites	3 locations across United States

Drugs / interventions tested

Endoxifen Hydrochloride — full drug profile →
Placebo Administration — full drug profile →
Questionnaire Administration

Conditions studied

Breast Ductal Carcinoma In Situ — all drugs for Breast Ductal Carcinoma In Situ →
Breast Lobular Carcinoma In Situ — all drugs for Breast Lobular Carcinoma In Situ →
Stage 0 Breast Cancer AJCC v6 and v7 — all drugs for Stage 0 Breast Cancer AJCC v6 and v7 →
Stage I Breast Cancer AJCC v7 — all drugs for Stage I Breast Cancer AJCC v7 →

Sponsor

National Cancer Institute (NCI)

Who can join

18 and older, female only, with Breast Ductal Carcinoma In Situ or Breast Lobular Carcinoma In Situ. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Number of Participants With Dermal Toxicity on Breast Skin at the Application Site Primary · Up to 60 days

Number of participants with dermal toxicity on breast skin at the transdermal gel application site. Will be assessed by Common Terminology Criteria for Adverse Events version 4.

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	4
Endoxifen Hydrochloride Gel 20 mg Daily	2
Placebo	0

Drug Concentration in Tissue Secondary · up to 28 days

Concentrations of (E) and (Z) Isomers ENX in right and left breast tissue at end of intervention (up to 4 weeks) in tissue samples

Central Subareolar Left Breast Z_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.47	0.15 – 0.79
Endoxifen Hydrochloride Gel 20 mg Daily	0.76	0.65 – 1.01
Placebo	0.00	0.00 – 0.00

Central Subareolar Left Breast E_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.16	0.16 – 0.28
Endoxifen Hydrochloride Gel 20 mg Daily	0.25	0.16 – 0.39
Placebo	0.00	0.00 – 0.00

Central Subareolar Right Breast Z_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.37	0.15 – 0.44
Endoxifen Hydrochloride Gel 20 mg Daily	1.00	0.62 – 1.51
Placebo	0.00	0.00 – 0.00

Central Subareolar Right Breast E_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.16	0.16 – 0.16
Endoxifen Hydrochloride Gel 20 mg Daily	0.30	0.16 – 0.58
Placebo	0.00	0.00 – 0.08

Central Deepest Left Breast Z_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.40	0.15 – 1.73
Endoxifen Hydrochloride Gel 20 mg Daily	1.55	0.34 – 2.85
Placebo	0.00	0.00 – 0.00

Central Deepest Left Breast E_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.16	0.16 – 1.39
Endoxifen Hydrochloride Gel 20 mg Daily	0.91	0.16 – 1.78
Placebo	0.00	0.00 – 0.16

Central Deepest Right Breast Z_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.46	0.15 – 1.58
Endoxifen Hydrochloride Gel 20 mg Daily	2.57	1.3 – 15.06
Placebo	0.00	0.00 – 0.100

Central Deepest Right Breast E_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.28	0.16 – 1.69
Endoxifen Hydrochloride Gel 20 mg Daily	1.70	1.13 – 17.20
Placebo	0.00	0.00 – 0.00

Drug Concentration in Plasma Secondary · baseline and up to 28 days

Concentration of (E) and (Z) Isomers ENX in plasma at the end of intervention (up to 4 weeks)

Z_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg	0.15	0.15 – 0.15
Endoxifen Hydrochloride Gel 20 mg	0.44	0.15 – 0.54
Placebo	0.00	0.00 – 0.00

E_ENX

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg	0.00	0.00 – 0.00
Endoxifen Hydrochloride Gel 20 mg	0.00	0.00 – 0.00
Placebo	0.00	0.00 – 0.00

Change in Plasma Estrogenic and Coagulation Parameters Secondary · baseline and up to 28 days

Change in plasma Estrogenic and Coagulation Parameters from baseline to end of intervention (up to 28 days) including: IGF1, IGFBP3, SHBG.

IGF1

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-1.7	-9.9 – 6.6
Endoxifen Hydrochloride Gel 20 mg	3.0	-8.6 – 15
Placebo	-1.0	-17 – 15

IGFBP3

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	48	-29 – 125
Endoxifen Hydrochloride Gel 20 mg	-2.5	-216 – 211
Placebo	-60	-205 – 84

SHBG

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-9.4	-26 – 6.8
Endoxifen Hydrochloride Gel 20 mg	1.9	-13 – 17
Placebo	-4.4	-12 – 3.8

Change in Pre-therapy and Post-therapy Symptoms Captured by BESS Questionnaire Secondary · baseline and up to 60 days

Assessed using the Breast Cancer Prevention Trial (BCPT) Eight Symptom Scale (BESS) questionnaire. A patient reported outcome, subscale scores range from 0 (Not at All) to 4 (Extremely) when asked about experiencing symptoms. A positive change in scores indicates an increase in symptoms experienced and a negative change in scores indicates a decrease in symptoms experienced.

Cognitive

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-0.16	-0.60 – 0.29
Endoxifen Hydrochloride Gel 20 mg Daily	-0.05	-1.0 – 0.88
Placebo	-0.19	-0.62 – 0.24

Body Pain

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-0.18	-0.44 – 0.08
Endoxifen Hydrochloride Gel 20 mg Daily	-0.38	-1.2 – 0.48
Placebo	-0.10	-0.73 – 0.54

Vasomotor

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-0.02	-0.26 – 0.21
Endoxifen Hydrochloride Gel 20 mg Daily	-0.05	-0.16 – 0.07
Placebo	0.19	-0.64 – 1.0

Gastrointestinal

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-0.07	-0.19 – 0.06
Endoxifen Hydrochloride Gel 20 mg Daily	-0.24	-0.53 – 0.06
Placebo	0.10	-0.20 – 0.39

Sexual Problems

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.13	-0.15 – 0.42
Endoxifen Hydrochloride Gel 20 mg Daily	-0.57	-1.8 – 0.64
Placebo	-0.29	-0.74 – 0.17

Body Image

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	-0.20	-0.54 – 0.14
Endoxifen Hydrochloride Gel 20 mg Daily	-0.64	-1.3 – 0.00
Placebo	-0.43	-1.4 – 0.55

Vaginal

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.13	-0.21 – 0.47
Endoxifen Hydrochloride Gel 20 mg Daily	-0.29	-0.77 – 0.20
Placebo	-0.24	-0.53 – 0.06

Bladder Problem

Group	Value	95% CI
Endoxifen Hydrochloride Gel 10 mg Daily	0.03	-0.04 – 0.10
Endoxifen Hydrochloride Gel 20 mg Daily	-0.86	-1.8 – 0.06
Placebo	0.07	-0.10 – 0.25

Adverse events — posted to ClinicalTrials.gov

Time frame: AEs collected from the time informed consent was signed and baseline procedures were completed through 60 days post-intervention. In total AEs collected for a period of up to 3 months.. Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Endoxifen Hydrochloride Gel 10 mg Daily

Serious: 0/16 (0%)

Deaths: 0/16

Endoxifen Hydrochloride Gel 20 mg Daily

Serious: 0/8 (0%)

Deaths: 0/8

Placebo

Serious: 0/8 (0%)

Deaths: 0/8

Other adverse events (9 terms — click to expand)

Reaction	System	Endoxifen Hydrochloride Ge…	Endoxifen Hydrochloride Ge…	Placebo
General disorders and administration site conditions - Other, specify	General disorders	—	—	—
Hot flashes	Vascular disorders	—	—	—
Hyperhidrosis	Skin and subcutaneous tissue disorders	—	—	—
Vaginal Infections	Infections and infestations	—	—	—
Fatigue	General disorders	—	—	—
Insomnia	Psychiatric disorders	—	—	—
Breast pain	Reproductive system and breast disorders	—	—	—
Nausea	Gastrointestinal disorders	—	—	—
Headache	Nervous system disorders	—	—	—

Data from ClinicalTrials.gov NCT03317405 adverse events section.

Sponsor's own description

This randomized phase I trial studies the side effects and best dose of endoxifen hydrochloride in treating participants who are undergoing breast surgery. Endoxifen hydrochloride may treat or reduce the risk of breast cancer.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.

Verify or expand the search:

Other trials of Endoxifen Hydrochloride

Trials testing the same drug.

NCT02311933 — Tamoxifen Citrate or Z-Endoxifen Hydrochloride in Treating Patients With Locally Advanced or Metastatic, Estrogen Recept · Phase 2 · active not recruiting
NCT01327781 — Z-Endoxifen Hydrochloride in Treating Patients With Metastatic or Locally Recurrent Estrogen Receptor-Positive Breast Ca · Phase 1 · active not recruiting

Other recruiting trials for Breast Ductal Carcinoma In Situ

Currently open trials in the same condition.

NCT07339306 — A Novel Fluorescent Ductal Needle for Localization and Sampling of Micro Lesions in Breast Ducts · NA · recruiting
NCT06195306 — Low Dose Tamoxifen With or Without Omega-3 Fatty Acids for Breast Cancer Risk Reduction · Phase 2 · recruiting
NCT06184750 — Finding the Best Tamoxifen Dose for Breast Cancer Risk Reduction in Premenopausal Women, RENAISSANCE Trial · Phase 2 · recruiting
NCT05941520 — Acolbifene Versus Low Dose Tamoxifen for the Prevention of Breast Cancer in Premenopausal Women at High Risk for Develop · Phase 2 · recruiting
NCT05023967 — Metformin and Nightly Fasting in Women With Early Breast Cancer · Phase 2 · active not recruiting

Other National Cancer Institute (NCI) trials

Trials by the same sponsor.

NCT07147231 — Testing the Effectiveness of the Anti-cancer Drug Pidnarulex (CX-5461), in Combination With Another Anti-cancer Drug Cem · Phase 1, PHASE2 · recruiting
NCT07572123 — Evaluating the Addition of Maintenance Immunotherapy Compared to the Usual Treatment of Chemotherapy and Autologous Stem · Phase 2, PHASE3 · not yet recruiting
NCT07281417 — Testing the Addition of Cemiplimab (REGN2810) to Chemotherapy Treatment Given Prior to Surgery in Patients With Sinonasa · Phase 2 · recruiting
NCT07012044 — A Study to Find the Highest Dose of Cedazuridine and Decitabine Combination With Filgrastim as a Treatment Option After · Phase 1 · not yet recruiting
NCT07437950 — Comparing Different Treatment Lengths for Venetoclax in Older People With Newly Diagnosed Acute Myeloid Leukemia (A Myel · Phase 2 · not yet recruiting

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT03317405 (US National Library of Medicine, public domain)
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by National Cancer Institute (NCI)
Last refreshed: 28 August 2025

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03317405.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing