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

September 10, 2026 updated by: Alpine Immune Sciences Inc, A Subsidiary of Vertex

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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Alpine Immune Sciences Inc, A Subsidiary of Vertex

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 3, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 12, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 12, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 24, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 24, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 7, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • AIS-D04
  • 2023 (U.S. NIH Grant/Contract: GRAMMY Museum Foundation)
  • 2023-507067-19-00 (Ctis: 2023-507067-19-00)
  • VX24-AIS-D04 (Other Identifier: Vertex Pharmaceuticals Incorporated)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/

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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