Long-term Extension Study of Ulviprubart (ABC008) in Subjects With Inclusion Body Myositis

An Open-label, Multicenter Study to Evaluate the Long-term Safety and Efficacy of Ulviprubart (ABC008) in Subjects Who Have Completed a Trial of Ulviprubart for the Treatment of Inclusion Body Myositis

ABC008-IBM-202 is an open-label, multicenter study to evaluate the safety and efficacy of long-term administration of ulviprubart (ABC008) in subjects with IBM who have completed either Study ABC008-IBM-101 or Study ABC008-IBM-201. Subjects may be enrolled in this study if they meet study eligibility criteria and:

• Have completed the Part 2 (Multiple Ascending Dose [MAD]) End of-Treatment (EOT) Visit in Study ABC008-IBM-101; subjects who continued further on into Part 3 of the study (MAD Extension) prior to enrolling in this study are also eligible; OR
• Have completed the Week 80 Follow-up Visit in Study ABC008-IBM-201.

Study Overview

• Status: Active, not recruiting
• Conditions: Inclusion Body Myositis (IBM)
• Intervention / Treatment: Drug: Ulviprubart (ABC008)

Detailed Description

ABC008-IBM-202 is an open-label, multicenter study to evaluate the safety and efficacy of long-term administration of ulviprubart (ABC008) in subjects with IBM who have completed either Study ABC008-IBM-101 or Study ABC008-IBM-201. Subjects may be enrolled in this study if they meet study eligibility criteria and:

• Have completed the Part 2 (Multiple Ascending Dose [MAD]) End of-Treatment (EOT) Visit in Study ABC008-IBM-101; subjects who continued further on into Part 3 of the study (MAD Extension) prior to enrolling in this study are also eligible; OR
• Have completed the Week 80 Follow-up Visit in Study ABC008-IBM-201. Subjects will enter this study following their initial study such that dosing continues every eight weeks (Q8W) between the last dose in the initial study and the first dose in this long-term extension (LTE) Study IBM-202. Study subjects will continue to receive any ongoing concomitant medications from the initial study.

Subjects will be required to sign an informed consent form before undertaking any study-specific procedures or assessments. Screening is intended to be done at the final visit of the initial study, which will coincide with the Baseline (Day 1) Visit for this study; if this is not possible, the Baseline (Day 1) Visit for this study, including screening, may be conducted at a separate visit (provided it occurs within the visit window defined in Appendix 1 of the protocol). Subsequent study visits will occur every eight weeks until EOT at Week 156, or withdrawal from the study.

• Study Type: Interventional
• Enrollment (Estimated): 270
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Australia
  • New South Wales
    • Saint Leonards, New South Wales, Australia, 2065
      • Royal North Shore Hospital
  • Queensland
    • Herston, Queensland, Australia, 4006
      • Royal Brisbane and Women's Hospital
  • Washington
    • Nedlands, Washington, Australia, 6009
      • Perron Institute for Neurological and Translational Science
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85028
      • Neuromuscular Research Center
  • California
    • Irvine, California, United States, 92868
      • University of California Irvine Medical Center (UCIMC) - Amyotrophic Lateral Sclerosis (ALS) and Neuromuscular Center
    • Los Angeles, California, United States, 90033
      • Keck Hospital of USC
  • Connecticut
    • New Haven, Connecticut, United States, 06519
      • Yale School of Medicine
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Neuromuscular Diagnostic Center - Massachusetts General Hospital
    • Boston, Massachusetts, United States, 021158
      • Brigham and Womens Hospital
  • New York
    • New York, New York, United States, 10021
      • Hospital for Special Surgery
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke Neurological Disorders Clinic
  • Ohio
    • Cleveland, Ohio, United States, 44106
      • University Hospitals Cleveland Medical Center
    • Columbus, Ohio, United States, 43210
      • Ohio State University Wexner Medical Center
  • Pennsylvania
    • Hershey, Pennsylvania, United States, 17033
      • Penn State Health Milton S. Hershey Medical Center
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Arthritis and Autoimmunity Center, Falk Clinic
  • Texas
    • Austin, Texas, United States, 78759
      • Austin Neuromuscular Center
    • Dallas, Texas, United States, 75206
      • Texas Neurology
    • Houston, Texas, United States, 75206
      • Nerve And Muscle Center Of Texas
  • Virginia
    • Henrico, Virginia, United States, 23233
      • Virginia Commonwealth University
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Medical College of Wisconsin

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• 1. Able to read, understand, and provide signed informed consent prior to the performance of any study-related procedures.

  2. Has participated in and completed either Study ABC008-IBM-101 or Study ABC008-IBM-201; completion of the prior study will be defined as completion of the Part 2 (MAD) EOT Visit in Study ABC008-IBM-101 (subjects may have continued into Part 3 [MAD Extension]) or completion of the Week 80 Follow-up Visit in Study ABC008-IBM-201.

  3. Demonstrated adequate compliance, in the opinion of the Investigator, with the study procedures during Study ABC008-IBM-101 or Study ABC008-IBM-201.

  4. Willing and able to comply with the requirements of the protocol, including traveling to the site for study-related assessments and SC injections of ulviprubart.

  5. Women of childbearing potential (WOCBP) and male subjects with female partners who are WOCBP (based on sex assignation at birth) must agree to use highly effective (< 1% failure rate) contraception for the duration of the study through 180 days after EOT/ETV.

  6. WOCBP (based on sex assignation at birth) must have a negative urine pregnancy test at the Baseline (Day 1) Visit.

  7. Male subjects (based on sex assignation at birth) must refrain from sperm donation for the duration of the study through 180 days after EOT/ETV.

Exclusion Criteria:

• 1. Has an unresolved clinically significant AE or a clinically significant finding on a clinical laboratory test, ECG, or physical examination during Study ABC008-IBM-101 or Study ABC008 IBM-201 that, in the Investigator's opinion, would limit the subject's ability to participate in or comply with this study.

  2. Participation in another investigational drug study (other than Study ABC008-IBM-101 or Study ABC008-IBM-201) within 30 days prior to the Baseline (Day 1) Visit or five times the half-life of the investigational drug, whichever is longer.

  3. Is not willing or able to comply with the restrictions regarding the use of prohibited medications throughout the study.

  4. Women who are pregnant, lactating, or who plan to become pregnant or initiate lactation during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ulviprubart (ABC008) 2.0 mg/kg SC; All eligible subjects, regardless of treatment assignment or dose level in their initial study, will be administered ulviprubart at a dose of 2.0 mg/kg via subcutaneous (SC) injection Q8W.	Drug: Ulviprubart (ABC008); All eligible subjects, regardless of treatment assignment or dose level in their initial study, will be administered ulviprubart at a dose of 2.0 mg/kg via subcutaneous (SC) injection Q8W.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Endpoint	The primary endpoint for the study will be the incidence, type, and severity of treatment-emergent adverse events (TEAEs). Safety as assessed by the incidence, type and severity of Treatment Emergent Adverse Events (TEAEs)	From Baseline (Day 1) through study completion, an average of 156 weeks.]

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Treatment Emergent Serious Adverse Events (TEASAEs)	Incidence, type, and severity of treatment-emergent serious adverse events (TESAEs)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Treatment Emergent Adverse Events (TEAEs) onset within 24 hours of Study Medication Administration.	Incidence of TEAEs leading to study medication or study discontinuation	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Adverse Events of Special Interest (AESI)	Incidence of Adverse events of special interest (AESIs)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline standard laboratory parameters (Hematology)	Incidence of clinically significant changes in standard laboratory parameters (Hematology)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard laboratory parameters (Chemistry)	Incidence of clinically significant changes from baseline in standard laboratory parameters (Chemistry)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard laboratory parameters (Coagulation)	Incidence of clinically significant changes from baseline standard laboratory parameters (Coagulation)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Inclusion Body Myositis Functional Rating Scale (IBMFRS)	Mean change from Baseline (Day 1) in IBMFRS over the duration of the study	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Manual Muscle Test 12 (MMT 12)	Mean change from Baseline (Day 1) in MMT 12 over the duration of the study	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard vital signs (respiratory rate)	Incidence of clinically significant changes in vital signs (respiratory rate)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard vital signs blood pressure	Incidence of clinically significant changes in standard vital signs blood pressure (Systolic and diastolic) blood pressure)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard vital signs (temperature)	Incidence of clinically significant changes in standard vital signs (temperature)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Change from baseline in standard vital signs (pulse rate)	Incidence of clinically significant changes in standard vital signs (pulse rate)	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Counts of absolute and KLRG1+ lymphocytes by flow cytometry.	Blood samples will be collected for immunophenotyping. Counts of absolute and KLRG1+ lymphocytes and other lymphocyte subsets will be performed by flow cytometry.	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Presence and titer of antidrug antibodies (ADA)	The incidence and titers of ADAs to ulviprubart will be evaluated in blood samples	From Baseline (Day 1) through study completion, an average of 156 weeks.]
Serum concentration of ulviprubart	Individual and mean serum concentration time profiles will be presented graphically using nominal time points.	From Baseline (Day 1) through study completion, an average of 156 weeks.]

Collaborators and Investigators

• Sponsor: Abcuro, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): October 21, 2024
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): April 1, 2029

Study Registration Dates

• First Submitted: June 4, 2024
• First Submitted That Met QC Criteria: June 7, 2024
• First Posted (Actual): June 10, 2024

Study Record Updates

• Last Update Posted (Actual): July 28, 2025
• Last Update Submitted That Met QC Criteria: July 24, 2025
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Myositis; Myositis, Inclusion Body
• Other Study ID Numbers: ABC008-IBM-202

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