Idiopathic Thrombocytopenic PurpuraPhase 1/2NCT05757570
An Open-label Study of Povetacicept in Participants With Autoimmune Cytopenias (RUBY-4)
A Phase 1/2 study testing Povetacicept in people with Idiopathic Thrombocytopenic Purpura and Immune Thrombocytopenia, run by Alpine Immune Sciences Inc, A Subsidiary of Vertex at 44 sites in 10 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Idiopathic Thrombocytopenic Purpura, Immune Thrombocytopenia, Warm Autoimmune Hemolytic Anemia
- What is being tested?
- Povetacicept
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 44 sitesin 10 countries
- Study dates
- 3 Jul 2023to 12 Aug 2026
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
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- 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
Who cannot join
- 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
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- 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.
Trial locations and contacts
44 sites in 10 countries.
44 sites in 10 countries
United States15 sites
Investigational Site (414)
Charlotte, North Carolina, 28204
Investigational Site (435)
Columbia, Maryland, 21044
Investigational Site (419)
Cooper City, Florida, 33024
Investigational Site (402)
Greenville, North Carolina, 27834
Investigational Site (219)
Iowa City, Iowa, 52242
Investigational site (405)
Lake Success, New York, 11042
Investigational Site (230)
Los Angeles, California, 90033
Investigational Site (425)
Miami, Florida, 33143
Investigational Site (423)
New Hyde Park, New York, 11040
Investigational Site (421)
New York, New York, 10028
Investigational Site (404)
New York, New York, 10065
Investigational Site (411)
Seattle, Washington, 98109
Investigational Site (420)
Shirley, New York, 11967
Investigational Site (422)
The Bronx, New York, 10469
Investigational Site (401)
Washington D.C., District of Columbia, 20007
Australia6 sites
Investigational Site (410)
Box Hill, 3128
Investigational Site (519)
Concord, 2139
Investigational Site (517)
Douglas, 4814
Investigational Site (413)
Liverpool, 2170
Investigational Site (407)
West Perth, 6005
Investigational Site (409)
Westmead, 2145
Spain5 sites
Investigational Site (436)
Barcelona, 08003
Investigational Site (429)
Burgos, 9006
Investigational Site (430)
Madrid, 28007
Investigational Site (426)
Murcia, 30008
Investigational Site (427)
Seville, 41013
Italy4 sites
Investigational Site (432)
Meldola, 47014
Investigational Site (428)
Milan, 20122
Investigational Site (431)
Novara, 28100
Investigational Site (443)
Trieste, 34128
United Kingdom4 sites
Investigational Site (442)
Leeds, SE1 9RT
Investigational Site (439)
London, E1 1BB
Investigational Site (441)
London, SE1 9RT
Investigational Site (440)
London, W12 0HS
Canada3 sites
Investigational Site (406)
Greenfield Park, J4V2H1
Investigational Site (403)
Hamilton, L8S 4K1
Investigational Site (444)
Toronto, M5B 1W8
Turkey (Türkiye)3 sites
Investigational Site (415)
Ankara, 06200
Investigational Site (416)
Ankara, 06800
Investigational Site (418)
Istanbul, 34718
Norway2 sites
Investigational Site (433)
Grålum, 1714
Investigational Site (437)
Trondheim, 7030
About this study
Official title: 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.
- Conditions
- Idiopathic Thrombocytopenic Purpura, Immune Thrombocytopenia, Warm Autoimmune Hemolytic Anemia, Cold Agglutinin Disease
- Being tested
- Povetacicept
- Keywords
- Immune Thrombocytopenia, Warm Autoimmune Hemolytic Anemia, Cold Agglutinin Disease, Autoimmune Cytopenia, Idiopathic Thrombocytopenic Purpura, Immune Thrombocytopenic Purpura, Hemolytic Anemia, RUBY4, RUBY-4, Povetacicept, ALPN-303, ALPN303, Autoimmune Hemolytic Anemia, ITP, wAIHA, AIHA, CAD
- Medical subject headings
- Purpura, Thrombocytopenic, Idiopathic, Anemia, Hemolytic, Autoimmune, Anemia, Hemolytic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PovetaciceptDrug
Also called ALPN-303
Administered by subcutaneous injection every 4 weeks
| Study group | Role | What they receive |
|---|---|---|
| Part 1: Povetacicept 240mg | Experimental | Participants grouped in 3 cohorts by diagnosis will be administered Povetacicept. Receives: Drug: Povetacicept |
| Part 2: Povetacicept Dose A | Experimental | 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. Receives: Drug: Povetacicept |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Tolerability as Assessed by Adverse events (AEs) and Serious adverse events (SAEs)
Measured: Study Day 1 through 30 days after last dose of study drug
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Mar 2023
- Study start3 Jul 2023
- Primary completion12 Aug 2026
- Study completion12 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Idiopathic Thrombocytopenic PurpuraStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Alpine Immune Sciences Inc, A Subsidiary of Vertex
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05757570
- Sponsor's protocol ID
- AIS-D04
- Other IDs
- 2023-507067-19-00, VX24-AIS-D04, 2023
- Status last verified
- Sep 2026
- First submitted
- 24 Feb 2023
- Last updated
- 14 Sep 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: 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/
Study at a glance
From the registry record, last updated by the sponsor on 14 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-Label Study to Assess the Safety, Efficacy, Pharmacokinetics, and Pharmacodynamics of Povetacicept in Subjects With Autoimmune Cytopenias (RUBY-4)
- ClinicalTrials.gov ID
- NCT05757570
- Acronym / sponsor ID
- AIS-D04
- Conditions
- Idiopathic Thrombocytopenic Purpura, Immune Thrombocytopenia, Warm Autoimmune Hemolytic Anemia, Cold Agglutinin Disease
- Keywords
- Immune Thrombocytopenia, Warm Autoimmune Hemolytic Anemia, Cold Agglutinin Disease, Autoimmune Cytopenia, Idiopathic Thrombocytopenic Purpura, Immune Thrombocytopenic Purpura, Hemolytic Anemia, RUBY4
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Alpine Immune Sciences Inc, A Subsidiary of VertexIndustry (pharma, biotech, devices)
- Study start
- 3 Jul 2023 (actual)
- Primary completion
- 12 Aug 2026 (actual)
- Study completion
- 12 Aug 2026 (actual)
- First posted
- 7 Mar 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Part 1: Povetacicept 240mg | Experimental | Drug: PovetaciceptParticipants grouped in 3 cohorts by diagnosis will be administered Povetacicept. |
| Part 2: Povetacicept Dose A | Experimental | Drug: PovetaciceptBased 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (18 listed)
- Indication-specific Criteria
- >ULN and (ii) lactate dehydrogenase>ULN or haptoglobin <LLN
- (All indications) If receiving protocol-specified standard-of-care medications, doses must be stable for protocol-specified durations
Key exclusion criteria (10 listed)
- Secondary AIHA, CAD, or ITP
- Treatment with any of the following within the noted period prior to study entry
- Recent serious or ongoing infection; risk or history of serious infection Other protocol defined Inclusion/Exclusion criteria may apply.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PovetaciceptAlso: ALPN-303Administered by subcutaneous injection every 4 weeks | Drug | Part 1: Povetacicept 240mg, Part 2: Povetacicept Dose A |
Primary outcome
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
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Sep 2026.
- Individual participant dataSharing planned: No. 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/
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
44 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Povetacicept in people with Idiopathic Thrombocytopenic Purpura and Immune Thrombocytopenia, run by Alpine Immune Sciences Inc, A Subsidiary of Vertex at 44 sites in 10 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 18 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 44 sites in United States, Australia, Spain, Italy, United Kingdom and 5 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.