A Study of Sapablursen Evaluating the Safety and Efficacy in Participants With Polycythemia Vera (PV)

May 6, 2026 updated by: Ono Pharmaceutical Co., Ltd.

A Phase 3 Randomized, Double-blind, Placebo-controlled Global Study of Sapablursen in Polycythemia Vera

The purpose of this study is to evaluate the efficacy and safety of sapablursen when added on to current standard of care (SOC) for Polycythemia Vera (PV) therapy. The study will be conducted in three sequential parts (Part 1a blinded treatment, Part 1b open-label treatment, & Part 2 long-term extension). Participants may receive treatment for up to 156 weeks.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

250

Phase

  • Phase 3

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 Locations

  • United States
    • Florida
      • Miami, Florida, United States, 33126
        • Recruiting
        • Regis Clinical Research LLC.
        • Contact:
        • Principal Investigator:
          • Yilena Rodriguez Marrero, MD

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Meet revised 2022 World Health Organization (WHO) and 2022 International Consensus Classification criteria for the diagnosis of PV.
  2. Participants must be phlebotomy-dependent.
  3. Hct less than (<) 45% at study start.
  4. Participants receiving Cytoreduction therapy (CRT) must be on a stable regimen at study start.
  5. Adequate organ function and electrolytes.

Exclusion Criteria:

  1. Prior treatment of PV with Transmembrane serine protease 6 (TMPRSS6) inhibitors, including sapablursen, or hepcidin mimetics.
  2. Clinically significant thrombosis (eg, myocardial infarction, stroke, deep vein thrombosis or splenic vein thrombosis) within 1 month prior to randomization.
  3. Participants who require phlebotomy at Hct levels <45%.
  4. Meet the criteria for post-PV myelofibrosis as defined by the International Working Group-Myeloproliferative Neoplasms Research and Treatment.
  5. Any serious or unstable medical condition or uncontrolled psychiatric condition that would interfere with their ability to comply with study requirements.

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Sapablursen
Sapablursen (32 Weeks) - Sapablursen (124 Weeks Open-label)
Drug: Sapablursen
Administered subcutaneously (SC)
Other Names:
  • ISIS 702843
  • ONO-0530
Experimental: Placebo
Placebo (32 Weeks) - Sapablursen (124 Weeks Open-label)
Drug: Placebo
Administered SC
Drug: Sapablursen
Administered subcutaneously (SC)
Other Names:
  • ISIS 702843
  • ONO-0530

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of Participants with Absence of Phlebotomy Eligibility
Time Frame: Week 20 through Week 32
Response is defined as absence of phlebotomy eligibility.
Week 20 through Week 32

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Phlebotomies
Time Frame: Week 0 through Week 32
Week 0 through Week 32
Percentage of Participants with Hct Control
Time Frame: Week 0 to Week 32
Defined as all local laboratory Hct <45% without phlebotomy.
Week 0 to Week 32
Change from Baseline in Patient Reported Outcomes Measurement Information System (PROMIS) Fatigue Short Form Total T-score
Time Frame: Baseline, Week 32
Baseline, Week 32
Change from Baseline in Myelofibrosis Symptom Assessment Form (MFSAF) Total Symptom Score (TSS)
Time Frame: Baseline, Week 32
Baseline, Week 32
Percentage of Participants with Absence of Phlebotomy Eligibility
Time Frame: Week 20 through Week 52
Response is defined as absence of phlebotomy eligibility.
Week 20 through Week 52
Number of Phlebotomies
Time Frame: Week 0 through Week 52
Week 0 through Week 52
Percentage of Participants with Hct Control
Time Frame: Week 0 through Week 52
Defined as all local laboratory Hct <45% without phlebotomy.
Week 0 through Week 52

Collaborators and Investigators

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

Sponsor

Ono Pharmaceutical Co., Ltd.

Collaborators

Deciphera Pharmaceuticals, LLC

Investigators

  • Study Director: Clinical Team, Deciphera Pharmaceuticals, LLC

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 (Estimated)

June 1, 2026

Primary Completion (Estimated)

September 1, 2028

Study Completion (Estimated)

January 1, 2031

Study Registration Dates

First Submitted

February 18, 2026

First Submitted That Met QC Criteria

February 18, 2026

First Posted (Actual)

February 24, 2026

Study Record Updates

Last Update Posted (Actual)

May 8, 2026

Last Update Submitted That Met QC Criteria

May 6, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ONO-0530-03-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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