An Open-label Study of Povetacicept in Participants With Autoimmune Cytopenias

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.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Immune Thrombocytopenia Anemia Anemia, Hemolytic Anemia, Hemolytic, Autoimmune Autoimmune Diseases Blood Coagulation Disorders Blood Platelet Disorders Cold Agglutinin Disease Cytopenia Hematologic Diseases Hemic and Lymphatic Diseases Hemorrhage Hemorrhagic Disorders Idiopathic Thrombocytopenic Purpura Immune System Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Purpura Purpura, Thrombocytopenic Purpura, Thrombocytopenic, Idiopathic Signs and Symptoms Skin Manifestations Thrombocytopenia Thrombotic Microangiopathies Warm Autoimmune Hemolytic Anemia

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

Investigational Site (410), Box Hill, Australia

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Key Inclusion Criteria:

Indication-specific Criteria

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
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
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
(All indications) If receiving protocol-specified standard-of-care medications, doses must be stable for protocol-specified durations

Key Exclusion Criteria:

Secondary AIHA, CAD, or ITP
Treatment with any of the following within the noted period prior to study entry

rituximab: <12 weeks
IVIg: <4 weeks
sutimlimab, any use after initiation of screening is exclusionary
plasmapheresis, plasma exchange, or double-filtration plasmapheresis: <8 weeks
transfusions with blood, blood products or other rescue medications: <2 weeks
splenectomy: <12 weeks
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
Recent serious or ongoing infection; risk or history of serious infection

Other protocol defined Inclusion/Exclusion criteria may apply.

Treatment and study plan

Povetacicept

Drug

Administered by subcutaneous injection every 4 weeks

Other names: ALPN-303

Primary outcomes

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

Sponsors and collaborators

Lead sponsor

Alpine Immune Sciences, Inc.

Industry

Registry information

Official study title

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

Acronym: RUBY-4

Important dates

Study start: 2023
Primary completion: 2026
Study completion: 2026
First posted: Mar 7, 2023
Registry last updated: Jul 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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