Pomalidomide for the Treatment of Bleeding in Hereditary Hemorrhagic Telangiectasia Longitudinal Assessment Study (PATH-HHT ATLAS)

Pomalidomide for the Treatment of Bleeding in Hereditary Hemorrhagic Telangiectasia After Trial Longitudinal Assessment Study (PATH-HHT ATLAS)

This is a multicenter U.S. longitudinal study evaluating patients with hereditary hemorrhagic telangiectasia who participated in the PATH-HHT clinical trial of pomalidomide for the treatment of HHT. This study is a longitudinal assessment of safety and effectiveness of pomalidomide in HHT in clinical trial participants following completion of the double-blind, placebo-controlled study.

Study Overview

• Status: Active, not recruiting
• Conditions: Hereditary Hemorrhagic Telangiectasia (HHT)
• Intervention / Treatment: Drug: Pomalidomide

Detailed Description

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant condition characterized by disordered angiogenesis that affects 1 in 5,000 people. It results in numerous clinical complications including severe recurrent epistaxis, gastrointestinal bleeding, chronic iron deficiency anemia (and possible transfusion dependence), high-output cardiac failure, and many others. In recognition that elevated levels of vascular endothelial growth factor (VEGF) are elevated in HHT, anti-angiogenic drugs are now being used to treat HHT off-label to manage HHT-associated bleeding. A primary agent used for this purpose is pomalidomide, an oral immunomodulatory drug with antiangiogenic properties. Pomalidomide was demonstrated to be efficacious over a 6-month treatment period in the multicenter U.S. randomized controlled PATH-HHT Study. The present study is the successor to PATH-HHT, the PATH-HHT ATLAS (After Trial Longitudinal Assessment Study). This study will evaluate the long-term impact of pomalidomide on epistaxis (as measured by the validated ESS, epistaxis severity score), gastrointestinal bleeding, and iron deficiency anemia (as assessed by hemoglobin measurements, red blood cell transfusions, and intravenous iron infusions).

• Study Type: Observational
• Enrollment (Actual): 62

Contacts and Locations

Study Locations

• United States
  • California
    • San Diego, California, United States, 92093
      • University of California-San Diego
    • San Francisco, California, United States, 94143
      • University of California-San Francisco
  • Florida
    • Gainesville, Florida, United States, 32610
      • University of Florida
  • Maryland
    • Baltimore, Maryland, United States, 21218
      • Johns Hopkins University
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina, Chapel Hill
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Cleveland Clinic
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • University of Utah
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Medical College of Wisconsin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Individuals with hereditary hemorrhagic telangiectasia and moderate-to-severe bleeding who previously enrolled in the PATH-HHT trial

Description

Inclusion Criteria:

1. A clinical diagnosis of HHT as defined by the Curacao criteria
2. Age > 18 years
3. Platelet count ≥ 100 x 109/L prior to pomalidomide initiation
4. WBC ≥ 2.5 x 109/L prior to pomalidomide initiation
5. INR ≤ 1.4 and normal ± 2 sec activated partial thromboplastin time (aPTT) by local laboratory criteria (except for patients on a stable dose of warfarin or direct oral anticoagulants)
6. Epistaxis severity score ≥ 3 measured over the preceding month
7. A requirement for anemia, as determined by local laboratory normal ranges, and/or parenteral infusion of at least 250 mg of iron or transfusion of 1 unit of blood over the 24 weeks preceding the screening visit
8. All study participants must agree to be registered into the FDA mandated POMALYST REMS program, and be willing and able to comply with the requirements of the POMALYST REMS program
9. Females of childbearing potential (FCBP)† must adhere to the pregnancy testing schedule mandated by the POMALYST REMS program

10. Prior enrollment on PATH-HHT study (NCT03910244)

    • A female of childbearing potential is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months).

Exclusion Criteria:

1. Women currently breast feeding or pregnant
2. Renal insufficiency, serum creatinine > 2.0 mg/dl
3. Hepatic insufficiency, bilirubin > 2.0 (or >4.0 in the setting of a prior clinical or genetic diagnosis of Gilbert's syndrome) or transaminases > 3.0x normal
4. Prior treatment with thalidomide or other non-pomalidomide immunomodulatory imide drugs (IMiDs) within previous 6 months
5. Prior treatment with bevacizumab (systemic or nasal) within previous 6 weeks
6. Prior treatment with pazopanib within previous 6 weeks
7. The use of octreotide or estrogens within the previous month
8. History of prior unprovoked thromboembolism confirmed by venous ultrasound or other imaging modalities
9. Known peripheral neuropathy, confirmed by neurologic consultation
10. Known underlying hypoproliferative anemia (i.e. myelodysplasia, aplastic anemia)
11. Currently enrolled in other drug trials
12. Known hypersensitivity to thalidomide or lenalidomide
13. The development of erythema nodosum if characterized by a desquamating rash while taking thalidomide or similar drugs
14. Known SMAD-4 mutation, unless there has been a colonoscopy with normal (negative) results, or in which the patient has had no more than 5 small (in the opinion of the gastroenterologist) colonic polyps completely removed within the preceding 18 months
15. Anything that in the investigator's opinion is likely to interfere with completion of the study

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Epistaxis Severity Score	Validated bleeding scale in HHT scored between 0-10, higher scores indicate worse bleeding	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum hemoglobin (g/dL)		12 months
Hematologic Support Score	Composite hematologic endpoint, higher scores indicate more hematologic support requirements	12 months
Intravenous iron infusion (mg elemental iron)		12 months
Red cell transfusion (units of packed red blood cells)		12 months
Incidence of treatment-emergent adverse events (safety)		12 months

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Collaborators: Johns Hopkins University; Mayo Clinic; University of Pennsylvania; University of California, San Diego; The Cleveland Clinic; University of Florida; Medical College of Wisconsin; University of California, San Francisco; University of North Carolina, Chapel Hill; University of Utah
• Investigators: Study Director: Ellen Zhang, MD, Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Actual): April 8, 2025
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: May 28, 2025
• First Submitted That Met QC Criteria: June 4, 2025
• First Posted (Actual): June 12, 2025

Study Record Updates

• Last Update Posted (Estimated): September 23, 2025
• Last Update Submitted That Met QC Criteria: September 22, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: pomalidomide; HHT; hereditary hemorrhagic telangiectasia; Osler-Weber-Rendu; PATH-HHT; PATH-HHT ATLAS
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hematologic Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Hemostatic Disorders; Hemorrhagic Disorders; Vascular Malformations; Telangiectasis; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Hemic and Lymphatic Diseases; Telangiectasia, Hereditary Hemorrhagic; Antineoplastic Agents; Immunologic Factors; Physiological Effects of Drugs; Angiogenesis Inhibitors; Angiogenesis Modulating Agents; Growth Substances; Growth Inhibitors; pomalidomide
• Other Study ID Numbers: InHIBIT-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No