CLINICAL TRIALS PROFILE FOR DANAZOL

All Clinical Trials for DANAZOL

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00003946 ↗	Danazol in Treating Patients With Advanced or Recurrent Endometrial Cancer	Completed	National Cancer Institute (NCI)	Phase 2	1999-08-01	RATIONALE: Hormone therapy may be an effective treatment for endometrial cancer. PURPOSE: Phase II trial to study the effectiveness of danazol in treating patients with advanced or recurrent endometrial cancer.
NCT00003946 ↗	Danazol in Treating Patients With Advanced or Recurrent Endometrial Cancer	Completed	Gynecologic Oncology Group	Phase 2	1999-08-01	RATIONALE: Hormone therapy may be an effective treatment for endometrial cancer. PURPOSE: Phase II trial to study the effectiveness of danazol in treating patients with advanced or recurrent endometrial cancer.
NCT00206544 ↗	Anti-Estrogens - A Potential Treatment for Bipolar Affective Disorder in Women?	Completed	National Health and Medical Research Council, Australia	Phase 2	2004-01-01	OBJECTIVE: To test the use of two adjunctive hormonal agents in a 28 day three-arm, double-blind, placebo-controlled study in the treatment of acute mania/hypomania. HYPOTHESIS: That women receiving adjunctive Tamoxifen or Progesterone will demonstrate a more rapid and more substantial decrease in manic symptoms over the course of the study than women receiving adjunctive placebo. STUDY POPULATION: Sixty females with a current diagnosis of Bipolar Affective Disorder or Schizoaffective disorder - Manic Phase, according to the operationalised criteria of the Diagnostic and Statistical Manual, 4th edition (DSM-IV) of the American Psychiatric Association. STUDY MEDICATION: Tamoxifen. One third of patients (twenty) will be randomized to receive adjunctive Tamoxifen at 40 mg/day for 28 days. The Tamoxifen will be administered within a plain capsule to maintain "blinding" of treatment arm. Progesterone. One third of patients (twenty) will be randomized to receive adjunctive oral Provera (progesterone) at 20 mg/day. The Progesterone will be administered within a plain capsule identical to that used with Tamoxifen. Placebo. The remaining one third of patients will be randomized to receive adjunctive placebo (inert substance). The placebo substance will be administered within a plain capsule identical to that used with Tamoxifen and Progesterone. STUDY EVALUATIONS: Data will be collected over a 28-day period for each patient. Visits will be performed at baseline, and then at weekly intervals. A total of five visits will be completed for each patient. The following evaluations will be performed: - Psychiatric evaluation to determine diagnosis. (Baseline visit only) - General clinical evaluation including medical history, current conditions and a non-invasive physical examination, body weight, vital signs. (Baseline visit only) - Medication history (baseline and evaluation visits). - Demographics (baseline visits only). - Completion of clinical rating scales; CARS-M, PANSS, MADRS, AIMS, Barnes Akathisia scale (BA), and Simpson-Angus scale (SA) (baseline and evaluation visits). A Menstrual Cycle Interview and a cognitive assessment (RBANS) will be performed at baseline and endpoint (day 28) visit. - Laboratory tests including; Serum levels of mood stabilizer, luteinizing hormone (LH), follicle-stimulating hormone (FSH), Estrogen, Progesterone, Prolactin, dehydroepiandrosterone (DHEA), Testosterone and protein kinase C(PKC) (baseline and evaluation visits). - Inclusion/exclusion checklist (baseline visit only). - Informed consent (baseline visit only).
NCT00206544 ↗	Anti-Estrogens - A Potential Treatment for Bipolar Affective Disorder in Women?	Completed	Stanley Medical Research Institute	Phase 2	2004-01-01	OBJECTIVE: To test the use of two adjunctive hormonal agents in a 28 day three-arm, double-blind, placebo-controlled study in the treatment of acute mania/hypomania. HYPOTHESIS: That women receiving adjunctive Tamoxifen or Progesterone will demonstrate a more rapid and more substantial decrease in manic symptoms over the course of the study than women receiving adjunctive placebo. STUDY POPULATION: Sixty females with a current diagnosis of Bipolar Affective Disorder or Schizoaffective disorder - Manic Phase, according to the operationalised criteria of the Diagnostic and Statistical Manual, 4th edition (DSM-IV) of the American Psychiatric Association. STUDY MEDICATION: Tamoxifen. One third of patients (twenty) will be randomized to receive adjunctive Tamoxifen at 40 mg/day for 28 days. The Tamoxifen will be administered within a plain capsule to maintain "blinding" of treatment arm. Progesterone. One third of patients (twenty) will be randomized to receive adjunctive oral Provera (progesterone) at 20 mg/day. The Progesterone will be administered within a plain capsule identical to that used with Tamoxifen. Placebo. The remaining one third of patients will be randomized to receive adjunctive placebo (inert substance). The placebo substance will be administered within a plain capsule identical to that used with Tamoxifen and Progesterone. STUDY EVALUATIONS: Data will be collected over a 28-day period for each patient. Visits will be performed at baseline, and then at weekly intervals. A total of five visits will be completed for each patient. The following evaluations will be performed: - Psychiatric evaluation to determine diagnosis. (Baseline visit only) - General clinical evaluation including medical history, current conditions and a non-invasive physical examination, body weight, vital signs. (Baseline visit only) - Medication history (baseline and evaluation visits). - Demographics (baseline visits only). - Completion of clinical rating scales; CARS-M, PANSS, MADRS, AIMS, Barnes Akathisia scale (BA), and Simpson-Angus scale (SA) (baseline and evaluation visits). A Menstrual Cycle Interview and a cognitive assessment (RBANS) will be performed at baseline and endpoint (day 28) visit. - Laboratory tests including; Serum levels of mood stabilizer, luteinizing hormone (LH), follicle-stimulating hormone (FSH), Estrogen, Progesterone, Prolactin, dehydroepiandrosterone (DHEA), Testosterone and protein kinase C(PKC) (baseline and evaluation visits). - Inclusion/exclusion checklist (baseline visit only). - Informed consent (baseline visit only).
NCT00206544 ↗	Anti-Estrogens - A Potential Treatment for Bipolar Affective Disorder in Women?	Completed	The Alfred	Phase 2	2004-01-01	OBJECTIVE: To test the use of two adjunctive hormonal agents in a 28 day three-arm, double-blind, placebo-controlled study in the treatment of acute mania/hypomania. HYPOTHESIS: That women receiving adjunctive Tamoxifen or Progesterone will demonstrate a more rapid and more substantial decrease in manic symptoms over the course of the study than women receiving adjunctive placebo. STUDY POPULATION: Sixty females with a current diagnosis of Bipolar Affective Disorder or Schizoaffective disorder - Manic Phase, according to the operationalised criteria of the Diagnostic and Statistical Manual, 4th edition (DSM-IV) of the American Psychiatric Association. STUDY MEDICATION: Tamoxifen. One third of patients (twenty) will be randomized to receive adjunctive Tamoxifen at 40 mg/day for 28 days. The Tamoxifen will be administered within a plain capsule to maintain "blinding" of treatment arm. Progesterone. One third of patients (twenty) will be randomized to receive adjunctive oral Provera (progesterone) at 20 mg/day. The Progesterone will be administered within a plain capsule identical to that used with Tamoxifen. Placebo. The remaining one third of patients will be randomized to receive adjunctive placebo (inert substance). The placebo substance will be administered within a plain capsule identical to that used with Tamoxifen and Progesterone. STUDY EVALUATIONS: Data will be collected over a 28-day period for each patient. Visits will be performed at baseline, and then at weekly intervals. A total of five visits will be completed for each patient. The following evaluations will be performed: - Psychiatric evaluation to determine diagnosis. (Baseline visit only) - General clinical evaluation including medical history, current conditions and a non-invasive physical examination, body weight, vital signs. (Baseline visit only) - Medication history (baseline and evaluation visits). - Demographics (baseline visits only). - Completion of clinical rating scales; CARS-M, PANSS, MADRS, AIMS, Barnes Akathisia scale (BA), and Simpson-Angus scale (SA) (baseline and evaluation visits). A Menstrual Cycle Interview and a cognitive assessment (RBANS) will be performed at baseline and endpoint (day 28) visit. - Laboratory tests including; Serum levels of mood stabilizer, luteinizing hormone (LH), follicle-stimulating hormone (FSH), Estrogen, Progesterone, Prolactin, dehydroepiandrosterone (DHEA), Testosterone and protein kinase C(PKC) (baseline and evaluation visits). - Inclusion/exclusion checklist (baseline visit only). - Informed consent (baseline visit only).

Clinical Trial Conditions for DANAZOL

Condition Name

Condition Name for DANAZOL
Intervention	Trials
Immune Thrombocytopenia	9
Endometriosis	8
Adenomyosis	3
Primary Myelofibrosis	3

Condition MeSH

Condition MeSH for DANAZOL
Intervention	Trials
Thrombocytopenia	12
Purpura, Thrombocytopenic, Idiopathic	11
Endometriosis	8
Anemia	4

Clinical Trial Locations for DANAZOL

Trials by Country

Trials by Country for DANAZOL
Location	Trials
United States	104
Australia	14
France	13
Japan	13
China	12

Trials by US State

Trials by US State for DANAZOL
Location	Trials
California	7
Colorado	6
New York	6
Arizona	5
Illinois	4

Clinical Trial Progress for DANAZOL

Clinical Trial Phase

Clinical Trial Phase for DANAZOL
Clinical Trial Phase	Trials
PHASE2	1
Phase 4	6
Phase 3	6

Clinical Trial Status

Clinical Trial Status for DANAZOL
Clinical Trial Phase	Trials
Completed	21
Not yet recruiting	13
Recruiting	10

Clinical Trial Sponsors for DANAZOL

Sponsor Name

Sponsor Name for DANAZOL
Sponsor	Trials
Peking University People's Hospital	10
Beijing Hospital	4
Navy General Hospital, Beijing	3

Sponsor Type

Sponsor Type for DANAZOL
Sponsor	Trials
Other	92
Industry	12
NIH	4

Danazol Clinical Trials, Market Analysis, Patent Status and 2030 Projection

Last updated: July 31, 2026

Danazol is an established generic androgenic steroid with no active branded exclusivity, no meaningful patent barrier, and limited current clinical-development activity. Its commercial use is concentrated in hereditary angioedema, endometriosis and selected off-label hematologic or gynecologic indications. Demand should remain stable to modestly declining through 2030, with supply continuity, safety monitoring and generic manufacturer participation driving the market more than innovation or patent protection.

What is the current FDA status of danazol?

Danazol is an FDA-approved oral synthetic androgen available in capsules. The historical branded product is Danocrine. U.S. generic products are marketed in 50 mg, 100 mg and 200 mg capsules, subject to manufacturer-specific availability.

Regulatory item	Status
Active ingredient	Danazol
Dosage form	Oral capsule
FDA approval history	Original approval in the 1970s
Historical reference brand	Danocrine
Common strengths	50 mg, 100 mg, 200 mg
U.S. prescription status	Prescription only
Primary approved uses	Endometriosis, fibrocystic breast disease, hereditary angioedema
Current innovation pathway	Generic-drug market
Biologic status	Not applicable
FDA exclusivity	Expired
U.S. regulatory risk	Product availability, labeling, safety and manufacturing continuity

Danazol suppresses pituitary gonadotropin secretion and has weak androgenic and anabolic activity. In hereditary angioedema, it increases hepatic production of C1 esterase inhibitor and can reduce attack frequency. In endometriosis, it suppresses ovarian steroidogenesis and produces a hypoestrogenic environment.[1][2]

The principal safety limitations are weight gain, acne, hirsutism, voice changes, menstrual disruption, adverse lipid effects, hepatotoxicity and fetal virilization. The FDA label advises against use during pregnancy and recommends liver-function monitoring during treatment.[1]

What clinical trials are studying danazol?

The current danazol clinical-trial landscape is small and predominantly investigator-led. Danazol does not have an active late-stage program comparable with modern hereditary-angioedema products such as lanadelumab, berotralstat, garadacimab or plasma-derived C1-inhibitor products.

Clinical-trial activity by indication

Indication	Current development position	Commercial relevance
Hereditary angioedema	Historical evidence and guideline-supported use; limited new interventional development	Residual demand where cost or access favors oral generic therapy
Endometriosis	Historical randomized studies; no major current registration program	Declining use because of tolerability and newer hormonal options
Fibrocystic breast disease	Historical approved indication; limited contemporary trial activity	Low
Immune thrombocytopenia and other hematologic disorders	Off-label, case-series and small-study use	Niche and specialist-dependent
Myelofibrosis or marrow-failure syndromes	Historical or exploratory androgen use, generally not a danazol growth market	Limited
Emerging anti-aging or performance uses	No accepted FDA development pathway	Not a regulated growth segment

ClinicalTrials.gov remains the principal U.S. registry for identifying active and completed danazol studies. Registry records include older studies and studies in which danazol is a comparator, background therapy or investigational treatment. The presence of a registry record does not indicate an active commercial development program.[3]

No current evidence supports a new-drug application, priority review, breakthrough designation or pivotal trial program for danazol. Its development profile is therefore best described as mature, generic and indication-specific.

What are the most important recent clinical developments?

The major clinical change is substitution, not innovation. For hereditary angioedema, modern prophylactic therapies have reduced reliance on danazol because they avoid the androgenic adverse-effect burden.

Guidelines continue to place attenuated androgens such as danazol among effective prophylactic options, particularly where newer treatments are unavailable or unaffordable. They are generally not preferred when safer long-term alternatives exist.[4]

For endometriosis, danazol has largely been displaced by combined hormonal contraceptives, progestins, gonadotropin-releasing hormone antagonists and other hormonal strategies. Its adverse-effect profile limits chronic use. Contemporary trials are focused on newer mechanisms rather than reformulating or repositioning danazol.

When does danazol lose exclusivity?

Danazol lost meaningful U.S. market exclusivity decades ago. The product is a small-molecule generic, not a biologic, and it does not have biosimilar exclusivity issues.

Exclusivity category	Danazol position
New chemical entity exclusivity	Expired
Orphan-drug exclusivity	No current relevant exclusivity identified
Pediatric exclusivity	Expired or not commercially relevant
Patent term extension	No current commercial significance
Generic approval pathway	Abbreviated New Drug Application
Biosimilar competition	Not applicable

The commercial market is governed by abbreviated generic approvals, manufacturing capacity, regulatory compliance and wholesaler contracting. New entrants may face formulation, bioequivalence and supply-chain requirements, but not an effective blocking patent estate.

What patents protect danazol and its formulations?

No active, commercially meaningful patent barrier is expected to prevent generic danazol sales in the United States. The original compound, basic oral capsule technology and historical therapeutic-use claims are long past ordinary patent terms.

Patent-estate assessment

Patent category	Current risk
Compound patent	Expired
Salt or polymorph patent	No material blocking estate identified
Immediate-release capsule patent	Expired or commercially irrelevant
Endometriosis method-of-use patent	Expired
Hereditary-angioedema method-of-use patent	Expired or not blocking generic entry
Manufacturing patent	Potentially relevant to individual suppliers, not a market-wide barrier
Device or delivery-system patent	Not material for current oral capsules

The remaining intellectual-property risk is operational. A manufacturer could hold confidential process know-how, supplier contracts, analytical methods or regulatory documentation. Those assets may affect production economics but do not create branded exclusivity.

What is the Orange Book status of danazol?

Danazol is associated historically with the Danocrine reference product and generic capsule approvals. Current Orange Book analysis should distinguish between an approved product, a marketed product and a product listed as discontinued. A discontinued branded product may remain relevant as the reference product for generic approval history without representing an active commercial brand.

The expected Orange Book position is:

1. No active patent listings that block ordinary generic danazol entry.
2. No current three-year or five-year exclusivity of commercial significance.
3. Generic approvals based on bioequivalence to the reference product.
4. Manufacturer-specific marketing status that may change as suppliers enter or leave the market.[5]

Paragraph IV litigation is therefore unlikely to be a central issue. A new generic applicant would generally face more practical risk from approval timing, product availability, quality compliance and market size than from challenging an unexpired danazol patent.

Which companies are challenging danazol exclusivity?

No significant current Paragraph IV challenger landscape is associated with danazol. The market is already genericized, and competition is primarily among existing or potential ANDA holders.

The relevant competitive groups are:

• Generic capsule manufacturers with approved U.S. ANDAs.
• Contract manufacturers supplying national or regional distributors.
• International manufacturers selling danazol in markets with local approvals.
• Specialty distributors serving hereditary-angioedema patients.
• Manufacturers of newer hereditary-angioedema therapies competing clinically rather than through patent litigation.

Company-level market shares are difficult to interpret because danazol may be supplied through multiple labelers, wholesalers and contract manufacturing arrangements. A labeler’s product listing does not necessarily equal a dedicated manufacturing facility or a significant share of prescriptions.

What patent litigation and settlement agreements affect danazol?

No major active U.S. patent litigation or settlement agreement is central to the current danazol market. The absence of litigation reflects the age of the product and the lack of a commercially valuable unexpired patent estate.

Potential disputes are more likely to involve:

• ANDA product quality or bioequivalence;
• manufacturing-site compliance;
• recalls or supply interruptions;
• trademark or labeling issues;
• state reimbursement and pharmacy contracting.

These matters can affect a supplier’s market position without changing the competitive structure of the active ingredient.

How strong is the danazol patent estate?

The danazol patent estate is weak for exclusivity purposes and moderate only as an operational barrier.

Strength factor	Assessment
Core molecule protection	None of current commercial value
Formulation protection	Low
Method-of-use protection	Low
Manufacturing know-how	Potentially moderate for individual suppliers
Regulatory barrier	Low to moderate
Switching barrier	Low for many indications; higher in stable HAE patients
Generic entry risk	High
Brand pricing power	Minimal

The strongest practical barrier is physician and patient reluctance to switch a stable hereditary-angioedema regimen, especially where a patient has responded to danazol and newer products are expensive. That barrier is clinical and reimbursement-based, not patent-based.

How does danazol compare with newer hereditary-angioedema drugs?

Danazol competes mainly on acquisition cost and historical familiarity. Newer products compete on safety, convenience, mechanism and prophylactic efficacy.

Product class	Route	Main advantage over danazol	Main limitation
Danazol	Oral capsule	Low cost and oral administration	Androgenic toxicity and monitoring
Lanadelumab	Subcutaneous injection	Long-acting prophylaxis and non-androgenic profile	High cost and injection
Berotralstat	Oral tablet	Oral, targeted kallikrein inhibition	Higher cost; drug-interaction considerations
C1-inhibitor products	Intravenous or subcutaneous	Replacement therapy with established use	Administration burden and cost
Garadacimab	Subcutaneous, jurisdiction-dependent	Long-acting targeted prophylaxis	Patent-protected branded competition and access constraints

Danazol remains relevant in lower-resource settings and in treatment pathways where newer agents are unavailable. In higher-income markets, use is likely to contract as guidelines and payers favor non-androgenic prophylaxis.

What is the danazol market outlook through 2030?

Public company filings generally do not report danazol revenue separately. Market-research estimates for the global danazol market vary because they use different assumptions about prescription volume, international availability, hospital use and off-label demand. A precise global revenue figure cannot be treated as an audited industry metric.

Base-case projection

The base case is a low-growth or declining mature-generic market through 2030.

Driver	2025-2030 effect
Expired exclusivity	Sustained price pressure
Newer HAE prophylaxis	Reduced use in developed markets
Low-cost access	Continued demand in price-sensitive markets
Endometriosis substitution	Continued volume erosion
Generic supplier turnover	Periodic supply volatility
Manufacturing concentration	Potential short-term shortages
New clinical trials	Unlikely to create material demand

Scenario analysis

Scenario	Market outcome through 2030	Main assumptions
Downside	Moderate volume and revenue decline	Rapid conversion to modern HAE therapy and continued endometriosis substitution
Base case	Stable to modest decline	Persistent low-cost use, especially outside premium markets
Upside	Temporary volume stabilization	Supply shortages or reimbursement pressure increase use of low-cost prophylaxis

Revenue exposure is concentrated in generic suppliers and distributors rather than an originator. Pricing power is limited, and a supplier’s value is tied to reliable production, regulatory compliance and access to active pharmaceutical ingredient sources.

What generic launch risks exist for danazol?

A new generic entrant would face low intellectual-property risk but meaningful commercial and operational risk.

Key launch risks

1. The total addressable market is small relative to high-volume generic products.
2. Several suppliers may compete for a limited prescription base.
3. Price erosion can occur quickly after launch.
4. FDA manufacturing observations or supply interruptions can create volatility.
5. Hereditary-angioedema patients may not switch easily from a stable regimen.
6. Newer products can displace demand even when danazol remains clinically effective.
7. Endometriosis demand is structurally weaker than historical demand.
8. Procurement contracts may favor established suppliers.

The strongest launch opportunity is a reliable, competitively priced product with uninterrupted supply. A novel formulation would need a clear tolerability, adherence or dosing advantage to support meaningful differentiation.

Where is danazol commercial demand strongest?

Demand is likely to persist in three geographic segments:

• Countries where hereditary-angioedema biologics and targeted small molecules are not reimbursed.
• Health systems that prioritize low acquisition cost over long-term androgenic safety.
• Markets with established specialist familiarity and local generic manufacturing.

North America and Western Europe have the greatest access to newer therapies and therefore the highest substitution risk. Emerging markets may retain danazol longer because price and availability determine treatment selection.

International status varies by national registration, reimbursement and supply. FDA approval does not establish automatic authorization in Europe, Asia-Pacific, Latin America or the Middle East.

What manufacturing and intellectual-property barriers affect danazol?

Danazol manufacturing is technically mature, but suppliers must maintain control over steroid synthesis, impurity profiles, analytical validation, capsule uniformity and dissolution performance. The relevant risks include:

• Active pharmaceutical ingredient availability;
• steroid-related impurity control;
• validated bioequivalence;
• content uniformity at low capsule strengths;
• supplier qualification;
• facility compliance;
• packaging and stability;
• recall management.

These factors can produce temporary shortages or supplier exits. They do not support durable premium pricing unless the market experiences a sustained supply disruption.

Key Takeaways

• Danazol is an old, FDA-approved generic oral androgen with no meaningful remaining market exclusivity.
• Current clinical activity is limited; no major commercial development program is evident.
• Hereditary angioedema is the most durable demand segment, but newer non-androgenic therapies are displacing use.
• Endometriosis and fibrocystic breast disease are no longer major growth indications.
• The patent estate is commercially weak, and Paragraph IV litigation is not a major market issue.
• Orange Book relevance is tied to reference-product and generic-approval history rather than active patent protection.
• Market revenue is not separately disclosed by most suppliers; a stable-to-declining outlook through 2030 is the most defensible base case.
• Generic supply reliability, manufacturing compliance and pricing will determine commercial performance.

FAQs About Danazol Clinical Trials and Market Forecasts

Is danazol still FDA approved?

Yes. Danazol remains an FDA-approved oral capsule for indications including endometriosis, fibrocystic breast disease and hereditary angioedema, subject to product-specific marketing status.[1][5]

Is danazol a biologic or a biosimilar?

No. Danazol is a synthetic small-molecule drug. Biosimilar regulation does not apply.

Can a generic company launch danazol without a patent challenge?

Ordinarily, yes, if the applicant satisfies the applicable ANDA requirements and no relevant unexpired patent or exclusivity blocks approval.

Why do some hereditary-angioedema patients still use danazol?

Low cost, oral administration, historical familiarity and limited access to newer therapies support continued use in selected patients.[4]

Does danazol have a meaningful reformulation opportunity?

The opportunity is limited. A reformulation would need to reduce androgenic toxicity, improve tolerability or materially simplify dosing while preserving efficacy. Without that differentiation, generic pricing and newer HAE therapies constrain commercial returns.

References

1. U.S. Food and Drug Administration. (n.d.). Danazol prescribing information. FDA. https://www.accessdata.fda.gov/drugsatfda_docs/label/
2. National Library of Medicine. (n.d.). Danazol. DailyMed. https://dailymed.nlm.nih.gov/dailymed/
3. National Library of Medicine. (n.d.). ClinicalTrials.gov: Danazol studies. https://clinicaltrials.gov/search?term=danazol
4. Maurer, M., Magerl, M., Betschel, S., et al. (2022). The international WAO/EAACI guideline for the management of hereditary angioedema. Allergy, 77(7), 1961-1990. https://doi.org/10.1111/all.15214
5. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm