A Phase 1b/2a Study of Budoprutug in Subjects With Immune Thrombocytopenia (ITP)

NCT07043946 | Recruiting Phase 1 FDA Drug

• 1 other identifier: TNT119-ITP-201
• Study Type: interventional
• Target: 24
• Locations: 5 countries
• Sites: 20

Brief Summary

The main objective is to assess the safety and tolerability of budoprutug in adults with ITP. Pharmacokinetics, pharmacodynamics, and preliminary clinical efficacy will also be assessed.

Conditions

Biologics; Monoclonal; Immune Thrombocytopenia (ITP); ITP; Anti-CD19

Outcome Measures

Primary Outcomes (1)

• Incidence of Treatment-Emergent Adverse Events (TEAEs)

  Number of participants experiencing TEAEs, graded per NCI CTCAE v5.0.

  Up to week 48

Secondary Outcomes (10)

• Area Under the Curve (AUC)

  Up to week 48

• Maximum Observed Plasma Concentration (Cmax)

  Up to week 48

• Time to Maximum Observed Concentration (Tmax)

  Up to week 48

• Terminal Half-Life (T1/2)

  Up to week 48

• Apparent Clearance (CL/F)

  Up to week 48

Study Arms (4)

Cohort 1: Dose Level A

EXPERIMENTAL

Single IV dose of study product on Day 1 and on Day 15

Drug: Budoprutug

Cohort 2: Dose Level B

EXPERIMENTAL

Single IV dose of study product on Day 1 and on Day 15

Drug: Budoprutug

Cohort 3: Dose Level C

EXPERIMENTAL

Single IV dose of study product on Day 1 and on Day 15

Drug: Budoprutug

Dose Expansion Cohort

EXPERIMENTAL

Single IV dose of study product on Day 1 and Day 15

Drug: Budoprutug

Interventions

Budoprutug DRUG

Single IV dose of study product on Day 1 and Day 15

Also known as: TNT119

Cohort 1: Dose Level A; Cohort 2: Dose Level B; Cohort 3: Dose Level C; Dose Expansion Cohort

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 18 years at the time of consent.
• 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.
• Partial thromboplastin time \< 1.5 x upper limit of normal (ULN), prothrombin time \< 1.5 x ULN, total bilirubin \< 1.5 x ULN unless due to Gilbert's syndrome, or an international normalized ratio \< 1.5 at screening.

You may not qualify if:

• CD19+ B cell count \< 80 cells/µL at Screening, or \< 40 cells/µL if B-cell depleting therapy was received within 24 weeks to 2 years prior.
• Diagnosis of paroxysmal nocturnal hemoglobinuria, Evan's Syndrome, or other bleeding disorders affecting safety or data integrity.
• Prior B-cell depleting therapy (e.g., rituximab) within 24 weeks before first dose or planned during the study.
• Chronic use of anticoagulants or antiplatelet agents (e.g., aspirin, NSAIDs, thienopyridines) within 14 days before dosing through follow-up. Intermittent NSAID use is allowed.
• Immunosuppressants (excluding corticosteroids) within 30 days or 5× half-life before Screening; alkylating agents within 180 days.
• IVIg treatment within 90 days prior to Screening.
• Active ITP treatment (other than steroids or TPO agonists) within 30 days or 5× half-life before first dose, unless approved by Medical Monitor.
• Active, chronic, or latent infections including hepatitis B/C or HIV.
• Active TB or high TB risk.

Sponsors & Collaborators

• Climb Bio, Inc.: lead

Study Sites (20)

Climb Bio Investigative Site #359202

Plovdiv, 4002, Bulgaria

RECRUITING

Climb Bio Investigative Site #359203

Plovdiv, 4003, Bulgaria

RECRUITING

Climb Bio Investigative Site #359201

Sofia, 1797, Bulgaria

RECRUITING

Climb Bio Investigative Site #300204

Athens, Attica, 11527, Greece

RECRUITING

Climb Bio Investigative Site #300203

Chaïdári, Attica, 12462, Greece

RECRUITING

Climb Bio Investigative Site #300202

Ioannina, 45500, Greece

RECRUITING

Climb Bio Investigative Site #300201

Thessaloniki, 57010, Greece

RECRUITING

Climb Bio Investigative Site #381201

Belgrade, Serbia

RECRUITING

Climb Bio Investigative Site #381202

Belgrade, Serbia

RECRUITING

Climb Bio Investigative Site #381203

Novi Sad, Serbia

RECRUITING

Climb Bio Investigative Site #340206

Burgos, 9006, Spain

NOT YET RECRUITING

Climb Bio Investigative Site #340204

Madrid, 28041, Spain

RECRUITING

Climb Bio Investigative Site #340202

San Pedro, Spain

RECRUITING

Climb Bio Investigative Site #340203

Valencia, 46010, Spain

RECRUITING

Climb Bio Investigative Site #380208

Cherkasy, Ukraine

NOT YET RECRUITING

Climb Investigative Site #380204

Ivano-Frankivsk, Ukraine

RECRUITING

Climb Investigative Site #2380203

Kyiv, Ukraine

RECRUITING

Climb Investigative Site #380202

Kyiv, Ukraine

RECRUITING

Climb Investigative Site #380206

Kyiv, Ukraine

RECRUITING

Climb Investigative Site #380201

Lviv, Ukraine

RECRUITING

MeSH Terms

Conditions

Purpura, Thrombocytopenic, Idiopathic

Condition Hierarchy (Ancestors)

Purpura, Thrombocytopenic; Purpura; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombotic Microangiopathies; Thrombocytopenia; Blood Platelet Disorders; Cytopenia; Hemorrhagic Disorders; Autoimmune Diseases; Immune System Diseases; Hemorrhage; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Skin Manifestations; Signs and Symptoms

Study Officials

• Study Director

  Climb Bio, Inc.

  STUDY DIRECTOR

Central Study Contacts

Climb Bio Study Director

CONTACT

+1 866 857 2596; clinicaltrials@climbbio.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This is an open-label study in which subjects will be enrolled into three dose ascending cohorts. Each subject's participation will last approximately 51 weeks including the Screening and Qualifying Visits (up to 3 weeks), Treatment Period (2 weeks), and follow-up visits though Week 48. Following completion of the dose escalation phase, additional subjects will be enrolled into an expansion cohort at the selected dose level(s) identified in Part 1b.

Study Record Dates

• First Submitted: June 20, 2025
• First Posted: June 29, 2025
• Study Start: June 30, 2025
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2028
• Last Updated: March 27, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

UA (6); ES (4); SE (3); GR (4); BU (3)