A study to find how well budoprutug (TNT119) works and how safe it is in participants with immune thrombocytopenia

Phase 1/2

Withdrawn

• Conditions: Immune Thrombocytopenia (ITP)

• Registration Number: 2024-519745-30-00
• Lead Sponsor: Climb Bio Inc.

Brief Summary

To evaluate the safety and tolerability of ascending doses of budoprutug in subjects with ITP.

Detailed Description

Not available

Study Timeline

• Study First Posted: 2025-06-23
• Last Update Posted: 2025-06-23

Recruitment & Eligibility

• Status: Not authorised
• Sex: Not specified
• Target Recruitment: 6

Inclusion Criteria

1. Aged > 18 years at the time of informed consent.

2. Platelet count < 30,000/μL despite an adequate trial of at least one prior therapeutic attempt. Platelet counts of < 30,000/μL must be confirmed on 2 occasions at least 5 days apart, but no more than 14 days apart.

3. Partial thromboplastin time < 1.5 × upper limit of normal (ULN), prothrombin time < 1.5 × ULN, total bilirubin < 1.5 × ULN unless due to Gilbert’s syndrome, or an international normalized ratio < 1.5 at screening.

4. Adequate hematologic, hepatic, and renal function

5. If being treated with corticosteroids or thrombopoietin (TPO) agonists, subjects must be on a stable dose (< 20% change in dose over the 14 days prior to the first dose of study drug). Corticosteroid treatment should not be > 1 mg/kg methylprednisolone (or equivalent) for 2 weeks prior to the first dose of study drug.

6. Diagnosed with primary ITP

Exclusion Criteria

1. CD19+ B-cell count < 80 cells/μL at Screening or < 40 cells/μL if B-cell depleting treatment was received within 24 weeks to 2 years prior to Screening.

2. Diagnosis of paroxysmal nocturnal hemoglobinuria, Evan’s Syndrome, or any other bleeding disorder that could confound results and impact patient safety.

3. Prior treatment with rituximab or other B-cell depleting agents within 24 weeks prior to the first dose of study drug or plan to receive B-cell depleting agents during the study.

4. Current or planned treatment with any chronic anticoagulants or platelet aggregation-inhibiting drugs such as aspirin, nonsteroidal anti-inflammatory drugs, or thienopyridines within 14 days of planned dosing through the end of follow-up. Symptom-based intermittent dosing of nonsteroidal anti-inflammatory drugs is permitted.

5. Prior treatment with immunosuppressants (other than corticosteroids) within 30 days or 5 times the elimination half-life (whichever is longer) of the Screening Visit (e.g., calcineurin inhibitors, mycophenolate mofetil, azathioprine), or alkylating agents within 180 days of the Screening Visit.

6. Active or uncontrolled infection at the time of informed consent or study drug initiation.

7. Recent hospitalization for any reason within 14 days prior to Screening, unless approved by the Medical Monitor.

8. Receipt of a live vaccine within 28 days prior to the first dose of study drug or during the study. All other vaccines must be completed within 21 days prior to the first dose of study drug.

9. Secondary cause of ITP (e.g., malignancy, hepatitis B or C, HIV, or other autoimmune diseases [e.g., thyroiditis], or drug-induced ITP).

Study & Design

• Study Type: Not specified
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
1. Incidence, relatedness, severity, and duration of treatment-emergent adverse events (TEAEs) and dose-limiting toxicities (DLTs).		1. Incidence, relatedness, severity, and duration of treatment-emergent adverse events (TEAEs) and dose-limiting toxicities (DLTs).

Secondary Outcome Measures

Name	Time	Method
1. Budoprutug PK parameters (including area under the concentration-time curve, time to maximum observed concentration, terminal half-life, apparent clearance, and volume of distribution).		1. Budoprutug PK parameters (including area under the concentration-time curve, time to maximum observed concentration, terminal half-life, apparent clearance, and volume of distribution).
2. The change from baseline in absolute peripheral cluster of differentiation (CD)20+ B-cell count.		2. The change from baseline in absolute peripheral cluster of differentiation (CD)20+ B-cell count.
3. The change in platelet count observed with budoprutug over time in subjects with ITP.		3. The change in platelet count observed with budoprutug over time in subjects with ITP.
4. The percentage of subjects with ITP who achieve a stable, partial, and complete response by Week 12. Note: A stable, partial, and complete response is defined as a platelet count ≥ 30,000/μL, ≥ 50,000/μL, or ≥ 100,000/μL, respectively, on at least 2 occasions at least 7 days apart within a 30-day time frame.		4. The percentage of subjects with ITP who achieve a stable, partial, and complete response by Week 12. Note: A stable, partial, and complete response is defined as a platelet count ≥ 30,000/μL, ≥ 50,000/μL, or ≥ 100,000/μL, respectively, on at least 2 occasions at least 7 days apart within a 30-day time frame.
5. The change in serum IgG, IgM, and IgA from baseline over time.		5. The change in serum IgG, IgM, and IgA from baseline over time.
6. The incidence of subjects who develop ADAs at any time after study drug administration.		6. The incidence of subjects who develop ADAs at any time after study drug administration.
7. The percentage of subjects on a steroid at baseline who are able to stop steroid treatment.		7. The percentage of subjects on a steroid at baseline who are able to stop steroid treatment.

Trial Locations

Locations (5)

Hospital Clinico Universitario De Valencia; 🇪🇸 Valencia, Spain

Complexo Hospitalario Universitario A Coruna; 🇪🇸 A Coruna, Spain

Hospital San Pedro De Alcantara; 🇪🇸 Caceres, Spain

Hospital Universitario 12 De Octubre; 🇪🇸 Madrid, Spain

Hospital Universitario De Burgos; 🇪🇸 Burgos, Spain

Hospital Clinico Universitario De Valencia

🇪🇸Valencia, Spain

Maria Luisa Calabuig Muñoz

Site contact

+34961973838

marisacalabuig@yahoo.es