Low-Dose Danazol for the Treatment of Telomere Related Diseases

Low Dose Danazol for the Treatment of Telomere Related Diseases

Low-Dose Danazol for the Treatment of Telomere Related Diseases (NCT03312400) is a Phase 2 interventional studying Telomere Disease, sponsored by National Heart, Lung, and Blood Institute (NHLBI). RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

Background: DNA is a structure in the body. It contains data about how the body develops and works. Telomeres are found on the end of chromosomes in DNA. Some people with short telomeres or other gene changes can develop diseases of the bone marrow, lung, and liver. Researchers want to see if low doses of the hormone drug danazol can help. Objective: To study the safety and effect of low dose danazol. Eligibility: People ages 3 and older with a telomere disease who have either very short telomeres and a specific gene change. They must also show signs of aplastic anemia, lung, or liver disease. Design: Participants will be screened in another protocol. Participants will have: * Medical history * Physical exam * Blood tests * Lung exam. They will breathe into an instrument that records the amount and rate of air breathed in and out over a period of time. 6-minute walking test. * Abdominal ultrasound and liver scan. These tests use sound waves to measure the fibrosis in the liver. Some participants will have: * Pregnancy test * Small sample of the liver removed * Bone marrow biopsy. The bone will be numbed and a small needle will take a sample of the marrow. All participants will have hormone levels checked. All child participants will see a pediatric endocrinologist. Children may need to have a hand x-ray. We will monitor patients for 6 months before starting danazol. Participants will take danazol by mouth twice a day for 1 year. Participants must return to the clinic at 6 months and 12 months while on danazol and 6 months after stopping it. They will have blood and urine tests, a lung exam, abdominal ultrasound, and liver scan.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Telomere Disease and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 40 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

* Who May Qualify: 1. Age-adjusted telomere length less than or equal to the first percentile by flow-FISH method. In patients with a known pathogenic or likely pathogenic mutation in a telomere maintenance gene, age adjusted telomere length less than or equal to the 10th percentile is sufficient. 2. A mutation in telomere maintenance genes (TERT, TERC, DKC1, TINF2, NHP2, NOP10, WRAP53, TERF2, PARN, RTEL1, ACD, CTC1, USB1) as tested in a CLIA (or international equivalent) certified laboratory 3. Age greater than or equal to 3 years 4. Weight greater than or equal to 12 Kg AND 5. At least one of the following criteria: 1. Anemia with a hemoglobin less than or equal to 10 g/dL without red blood cell transfusion 2. Thrombocytopenia with a platelet count less than or equal to 50,000/microliter without transfusion 3. Neutropenia with an absolute neutrophil count less than or equal to 1,000/ microliter OR Pulmonary fibrosis diagnosed by either a lung biopsy or computed tomography scan of the chest according to guidelines from the American Thoracic Society and European Respiratory Society. OR 6. Hepatic fibrosis diagnosed by Transient Elastography by Fibroscan value greater than 10 kpa or US evidence of cirrhotic liver or splenomegaly, or transjugular liver biopsy demonstrating fibrosis. Who Should NOT Join This Trial: 1. Patients on androgen hormones to include testosterone or high dose estrogen (estradiol 0.5 mg/day or greater) for the12 months prior to enrollment 2. Patients with active thrombosis or thromboembolic disease and history of such events, undiagnosed abnormal genital bleeding, porphyria, androgendependent tumor, or prostatic hypertrophy 3. Patients with pulmonary fibrosis who are receiving anti-fibrotic drug treatment, such as pirfenidone or nintedanib unless stable on anti-fibrotic drug for at least 6 months prior to starting on danazol as demonstrated by PFTs. 4. Patients with active hepatitis B or C ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

* INCLUSION CRITERIA: 1. Age-adjusted telomere length less than or equal to the first percentile by flow-FISH method. In patients with a known pathogenic or likely pathogenic mutation in a telomere maintenance gene, age adjusted telomere length less than or equal to the 10th percentile is sufficient. 2. A mutation in telomere maintenance genes (TERT, TERC, DKC1, TINF2, NHP2, NOP10, WRAP53, TERF2, PARN, RTEL1, ACD, CTC1, USB1) as tested in a CLIA (or international equivalent) certified laboratory 3. Age greater than or equal to 3 years 4. Weight greater than or equal to 12 Kg AND 5. At least one of the following criteria: 1. Anemia with a hemoglobin less than or equal to 10 g/dL without red blood cell transfusion 2. Thrombocytopenia with a platelet count less than or equal to 50,000/microliter without transfusion 3. Neutropenia with an absolute neutrophil count less than or equal to 1,000/ microliter OR Pulmonary fibrosis diagnosed by either a lung biopsy or computed tomography scan of the chest according to guidelines from the American Thoracic Society and European Respiratory Society. OR 6. Hepatic fibrosis diagnosed by Transient Elastography by Fibroscan value greater than 10 kpa or US evidence of cirrhotic liver or splenomegaly, or transjugular liver biopsy demonstrating fibrosis. EXCLUSION CRITERIA: 1. Patients on androgen hormones to include testosterone or high dose estrogen (estradiol 0.5 mg/day or greater) for the12 months prior to enrollment 2. Patients with active thrombosis or thromboembolic disease and history of such events, undiagnosed abnormal genital bleeding, porphyria, androgendependent tumor, or prostatic hypertrophy 3. Patients with pulmonary fibrosis who are receiving anti-fibrotic drug treatment, such as pirfenidone or nintedanib unless stable on anti-fibrotic drug for at least 6 months prior to starting on danazol as demonstrated by PFTs. 4. Patients with active hepatitis B or C 5. Patients who have received a bone marrow transplant 6. Patient with other hereditary bone marrow failure syndromes such as Fanconi anemia or Diamond Blackfan anemia 7. Patients with infections not adequately responding to appropriate therapy 8. Current pregnancy, or unwillingness to take oral contraceptives or use the barrier methods of birth control or practice abstinence to refrain from pregnancy if of childbearing potential during the course of the study 9. Lactating women, due to the potentially harmful effects on the nursing child 10. Patients with cancer who are actively receiving systemic chemotherapeutic treatment or who take drugs with hematological effects 11. Patients with decompensated liver disease to include persistent ascites, encephalopathy, variceal hemorrhage, or MELD score of 10 or greater 12. Inability to understand the investigational nature of the study or to give informed consent or without a legally authorized representative or surrogate that can provide informed consent 13. Inability to swallow a capsule

Treatments Being Tested

DRUG

Danazol

Adult: 200 mg daily versus 400 mg daily Pediatric: 4 mg/kg/day divided in twice daily dose (max 400 mg daily) for 6 months or 2 mg/kg/day divided in twice daily dose (max 200 mg daily) for 6 months.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

National Institutes of Health Clinical Center

Bethesda, Maryland, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT03312400), the sponsor (National Heart, Lung, and Blood Institute (NHLBI)), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT03312400 clinical trial studying?

Who can participate in NCT03312400?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT03312400?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT03312400. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT03312400. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.