An Open-label Study of Povetacicept in Participants With Autoimmune Cytopenias (RUBY-4)

July 27, 2026 updated by: Alpine Immune Sciences, Inc.

Open-Label Study to Assess the Safety, Efficacy, Pharmacokinetics, and Pharmacodynamics of Povetacicept in Subjects With Autoimmune Cytopenias (RUBY-4)

The goal of this clinical study is to evaluate povetacicept in adults with autoimmune cytopenias of immune thrombocytopenia, autoimmune hemolytic anemia, and cold agglutinin disease to determine if povetacicept is safe and potentially beneficial in treating these diseases. During the study treatment period participants will receive povetacicept approximately every 4 weeks for 6 months, with the possibility of participating in a 6-month study treatment extension period.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Australia
      • Box Hill, Australia, 3128
        • Investigational Site (410)
      • Concord, Australia, 2139
        • Investigational Site (519)
      • Douglas, Australia, 4814
        • Investigational Site (517)
      • Liverpool, Australia, 2170
        • Investigational Site (413)
      • West Perth, Australia, 6005
        • Investigational Site (407)
      • Westmead, Australia, 2145
        • Investigational Site (409)
  • Austria
      • Vienna, Austria, 1090
        • Investigational Site (434)
  • Canada
      • Greenfield Park, Canada, J4V2H1
        • Investigational Site (406)
      • Hamilton, Canada, L8S 4K1
        • Investigational Site (403)
      • Toronto, Canada, M5B 1W8
        • Investigational Site (444)
  • Germany
      • Essen, Germany, 45147
        • Investigational Site (438)
  • Italy
      • Meldola, Italy, 47014
        • Investigational Site (432)
      • Milan, Italy, 20122
        • Investigational Site (428)
      • Novara, Italy, 28100
        • Investigational Site (431)
      • Trieste, Italy, 34128
        • Investigational Site (443)
  • Norway
      • Grålum, Norway, 1714
        • Investigational Site (433)
      • Trondheim, Norway, 7030
        • Investigational Site (437)
  • Spain
      • Barcelona, Spain, 08003
        • Investigational Site (436)
      • Burgos, Spain, 9006
        • Investigational Site (429)
      • Madrid, Spain, 28007
        • Investigational Site (430)
      • Murcia, Spain, 30008
        • Investigational Site (426)
      • Seville, Spain, 41013
        • Investigational Site (427)
  • Turkey (Türkiye)
      • Ankara, Turkey (Türkiye), 06200
        • Investigational Site (415)
      • Ankara, Turkey (Türkiye), 06800
        • Investigational Site (416)
      • Istanbul, Turkey (Türkiye), 34718
        • Investigational Site (418)
  • United Kingdom
      • Leeds, United Kingdom, SE1 9RT
        • Investigational Site (442)
      • London, United Kingdom, E1 1BB
        • Investigational Site (439)
      • London, United Kingdom, SE1 9RT
        • Investigational Site (441)
      • London, United Kingdom, W12 0HS
        • Investigational Site (440)
  • United States
    • California
      • Los Angeles, California, United States, 90033
        • Investigational Site (230)
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20007
        • Investigational Site (401)
    • Florida
      • Cooper City, Florida, United States, 33024
        • Investigational Site (419)
      • Miami, Florida, United States, 33143
        • Investigational Site (425)
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • Investigational Site (219)
    • Maryland
      • Columbia, Maryland, United States, 21044
        • Investigational Site (435)
    • New York
      • Lake Success, New York, United States, 11042
        • Investigational site (405)
      • New Hyde Park, New York, United States, 11040
        • Investigational Site (423)
      • New York, New York, United States, 10028
        • Investigational Site (421)
      • New York, New York, United States, 10065
        • Investigational Site (404)
      • Shirley, New York, United States, 11967
        • Investigational Site (420)
      • The Bronx, New York, United States, 10469
        • Investigational Site (422)
    • North Carolina
      • Charlotte, North Carolina, United States, 28204
        • Investigational Site (414)
      • Greenville, North Carolina, United States, 27834
        • Investigational Site (402)
    • Washington
      • Seattle, Washington, United States, 98109
        • Investigational Site (411)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Indication-specific Criteria

    1. Immune Thrombocytopenia (ITP)

      • Documented persistent or chronic primary ITP of at least 12 weeks duration from diagnosis to Cycle 1 Day 1
      • History of failure or relapse to at least 2 treatment regimens for ITP
      • History of exposure to a TPO-RA unless otherwise contraindicated or unavailable
      • Documented history of platelets <30 × 10^9/L

    2. Warm Autoimmune Hemolytic Anemia (wAIHA)

      • Diagnosis of primary wAIHA of at least 12 weeks duration documented with a current or prior positive direct antiglobulin test (DAT) for anti-IgG (±C3d)
      • Documented history of anemia with hemoglobin ≤10 g/dL
      • At least one of the following: (i) haptoglobin < lower limit of normal (LLN) (ii) indirect bilirubin > upper limit of normal (ULN) (iii) lactate dehydrogenase>ULN
      • History of failure or relapse to at least 2 treatment regimens for wAIHA

    3. Cold Agglutinin Disease (CAD)

      • Diagnosis of primary CAD of at least 12 weeks duration with all of the following: (i) chronic hemolysis (ii) polyspecific DAT positive (iii) monospecific DAT strongly positive for C3d (iv) cold agglutinin titer ≥64 at 4°C (v) IgG DAT ≤1+ (vi) no overt malignant disease
      • Documented history of anemia with hemoglobin ≤10 g/dL
      • Evidence of hemolysis during screening: (i) indirect bilirubin >ULN and (ii) lactate dehydrogenase>ULN or haptoglobin <LLN
      • History of failure or relapse to at least 1 treatment regimen for CAD
  2. (All indications) If receiving protocol-specified standard-of-care medications, doses must be stable for protocol-specified durations

Key Exclusion Criteria:

  1. Secondary AIHA, CAD, or ITP

  2. Treatment with any of the following within the noted period prior to study entry

    1. rituximab: <12 weeks
    2. IVIg: <4 weeks
    3. sutimlimab, any use after initiation of screening is exclusionary
    4. plasmapheresis, plasma exchange, or double-filtration plasmapheresis: <8 weeks
    5. transfusions with blood, blood products or other rescue medications: <2 weeks
    6. splenectomy: <12 weeks
    7. other immunomodulatory or investigational agents, except for investigational agents for COVID-19 that have been granted emergency use authorization or approved by the applicable national health authority: <5 half-lives and requires agreement of the Medical Monitor
  3. Recent serious or ongoing infection; risk or history of serious infection

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Part 1: Povetacicept 240mg
Participants grouped in 3 cohorts by diagnosis will be administered Povetacicept
Drug: povetacicept
Administered by subcutaneous injection every 4 weeks
Other Names:
  • ALPN-303
Experimental: Part 2: Povetacicept Dose A
Based on the findings of Part 1, one or two dose levels may be assessed in Part 2; if two dose levels are assessed participants will be randomized to receive one of the two dose levels of Povetacicept
Drug: povetacicept
Administered by subcutaneous injection every 4 weeks
Other Names:
  • ALPN-303

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Safety and Tolerability as Assessed by Adverse events (AEs) and Serious adverse events (SAEs)
Time Frame: Study Day 1 through 30 days after last dose of study drug
Study Day 1 through 30 days after last dose of study drug

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Alpine Immune Sciences, Inc.

Investigators

  • Study Director: Allison Naumovski, Alpine Immune Sciences, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 3, 2023

Primary Completion (Estimated)

July 1, 2026

Study Completion (Estimated)

July 1, 2026

Study Registration Dates

First Submitted

February 24, 2023

First Submitted That Met QC Criteria

February 24, 2023

First Posted (Actual)

March 7, 2023

Study Record Updates

Last Update Posted (Actual)

July 28, 2026

Last Update Submitted That Met QC Criteria

July 27, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AIS-D04
  • 2023-507067-19-00 (Ctis)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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