A Phase 1/2 Study to Evaluate the Safety and Efficacy of Dibotatug (DR-01) in Adults With Bone Marrow Failure Syndromes

NCT07712562 | Not Yet Recruiting Phase 1 FDA Drug

• 1 other identifier: DR-01-HEM-001
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 10

Brief Summary

This is a multicenter, open-label, Phase 1/2 basket study to evaluate the safety and efficacy of Dibotatug (DR-01) in adults with Bone Marrow Failure syndromes.

Conditions

Bone Marrow Failure Syndromes; Aplastic Anemias; Severe Aplastic Anemia (SAA); Severe Aplastic Anemia, Refractory; Non-severe Aplastic Anemia; Severe Aplastic Anemia, Relapse

Keywords

DR-01; Dibotatug; aplastic anemia; transfusion dependent; hematologic diseases; hematology; Blood disorder; pancytopenia; stem cell disorder; red blood cell disease; white blood cell disease

Outcome Measures

Primary Outcomes (2)

• Overall Response Rate of Dibotatug (defined as proportion of subjects with a Complete Response or Partial Response) [Efficacy]

  Overall Response Rate (ORR), defined as the proportion of subjects with Complete Response (CR) or Partial Response (PR) based on disease-specific response criteria.

  By 6 months

• Incidence and severity of adverse events as assessed by CTCAE v6.0 [Safety and Tolerability]

  Incidence and severity of adverse events as assessed by CTCAE v6.0.

  52 weeks

Study Arms (1)

Dibotatug (DR-01)

EXPERIMENTAL

Subjects in this arm will receive 20 weeks of dosing with dibotatug. Subjects with a CR or PR by Week 24 have the option to continue dosing through Week 48; Dibotatug will be administered via IV infusion.

Drug: Dibotatug (DR-01)

Interventions

Dibotatug (DR-01) DRUG

Dibotatug (DR-01) administered by IV infusion

Dibotatug (DR-01)

Eligibility Criteria

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

You may qualify if:

• Age ≥ 18 years old
• Women of childbearing potential and males must agree to use 2 methods of effective contraception, with at least 1 method being highly effective.
• Participants with SAA must have a current or prior diagnosis of SAA or very SAA.
• Received one ≥ 3-month course of ATG and/or CSA-based IST.
• Refractory SAA, defined as failure to achieve CR or PR ≥ 3 months after starting ATG and/or CSA-based IST.
• Relapsed SAA, defined as relapse following a CR or PR that was achieved ≥ 3 months after starting ATG- and/or cyclosporine A (CSA)-based IST.
• Current or prior diagnosis of NSAA
• No current or prior diagnosis of SAA.
• Received at least 1 prior course of IST such as ATG- or CSA, with or without a TPO-R agonist (lasting ≥ 3 months).
• Meets criteria for transfusion dependence (either RBC or platelet):
• RBC transfusion dependence: transfusion of ≥ 2 units of RBCs in the past 56 days
• Platelet transfusion dependence: transfusion of ≥ 1 unit of apheresis platelets in the past 28 days
• Participants entering the Extension Treatment Period must meet the following criteria:
• Signed informed consent form (ICF) for the Extension Treatment Period.
• CR or PR by Week 24 during the Main Treatment Period

You may not qualify if:

• Diagnosis of Fanconi anemia, dyskeratosis congenita, or other congenital BMF syndrome.
• Prior HCT.
• Planning to receive HCT as treatment for AA.
• Evidence of a clonal disorder with poor risk cytogenetics per Revised International Prognostic Scoring System (IPSS-R) for MDS.
• Use of a T-cell depleting agent (e.g., ATG, alemtuzumab, thymoglobulin) within 3 months prior to Day 1.
• Use of a B-cell depleting agent (e.g., rituximab, ocrelizumab, ofatumumab, ublituximab) within 28 days prior to Day 1.
• Use of any of the following within 14 days of Day 1, unless used as an established therapy at screening and there is evidence of either progressive cytopenia or lack of count improvement over the 3 months before screening:
• Calcineurin inhibitor (e.g., cyclosporine), TPO-R agonist (e.g., eltrombopag), Androgen (e.g., danazol), Oral Janus kinase (JAK) inhibitor
• Regardless of their use as an established therapy at screening, use of the above medications is prohibited for all participants from 3 months after Day 1.
• Current infection not adequately responding to appropriate therapy or requiring hospitalization.
• Human immunodeficiency virus (HIV) infection.
• Current or prior infection with hepatitis B virus (HBV)
• Current hepatitis C virus (HCV) infection
• Latent tuberculosis (TB) infection as indicated by IFN-γ release assay without documentation of appropriate treatment (appropriate therapy as defined by the World Health Organization \[WHO\] and/or the United States Centers for Disease Control and Prevention).
• Estimated glomerular filtration rate \< 30 mL/min/1.73 m2 at screening (using the Chronic Kidney Disease Epidemiology Collaboration formula; Levey 2009).

Sponsors & Collaborators

• Dren Bio: lead

Study Sites (10)

Dren Investigational Site

Duarte, California, 91010, United States

Location

Dren Investigational Site

Palo Alto, California, 94304, United States

Location

Dren Investigational Site

Miami, Florida, 33136, United States

Location

Dren Investigational Site

Atlanta, Georgia, 30342, United States

Location

Dren Investigational Site

New York, New York, 10065, United States

Location

Dren Investigational Site

Cleveland, Ohio, 44195, United States

Location

Dren Investigational Site

Columbus, Ohio, 43210, United States

Location

Dren Investigational Site

Houston, Texas, 77030, United States

Location

Dren Investigational Site

Fairfax, Virginia, 22031, United States

Location

Dren Investigational Site

Seattle, Washington, 98109, United States

Location

MeSH Terms

Conditions

Bone Marrow Failure Disorders; Anemia, Aplastic; Recurrence; Hematologic Diseases; Pancytopenia; Leukocyte Disorders

Condition Hierarchy (Ancestors)

Bone Marrow Diseases; Hemic and Lymphatic Diseases; Anemia; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Cytopenia

Study Officials

• Wan-Jen Hong, MD

  Dren Bio

  STUDY DIRECTOR

Central Study Contacts

Dren Bio Central Contact

CONTACT

415-737-5277; DR-01-HEM-001_inquiries@drenbio.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR
• Expanded Access: Yes

Model Details: Single Arm Basket trial - 3 cohorts will receive the same treatment paradigm in parallel

Study Record Dates

• First Submitted: July 14, 2026
• First Posted: July 17, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): April 1, 2029
• Study Completion (Estimated): October 1, 2030
• Last Updated: July 24, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (10)