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NCT Number: NCT05431088

A Phase 2/3 Study in Adult and Adolescent Participants With SCD

The purpose of this study is to evaluate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of osivelotor.

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Key information

Conditions

Sickle Cell Disease Anemia Anemia, Hemolytic Anemia, Hemolytic, Congenital Anemia, Sickle Cell Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemoglobinopathies

Age range

12 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Hospital Universitario Professor Edgar Santos, Salvador, Estado de Bahia, Brazil

Loading trial locations.

About this study

This is a three-part, multicenter, Phase 2/3 study of orally administered osivelotor in participants with sickle cell disease (SCD).

Part A will evaluate the safety, tolerability, and efficacy of osivelotor in adult participants with SCD to determine an optimal dose.

Part B will evaluate the efficacy of osivelotor versus placebo in adult and adolescent participants with SCD for 48 weeks.

Open Label Extension (OLE) will evaluate the long-term safety and hematologic responses of open-label osivelotor in adult and adolescent participants having completed Part B.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

Part A, Part B, and OLE:

  • Male or female with SCD
  • Participants with stable Hb value as judged by the Investigator
  • For participants taking hydroxyurea and/or L-glutamine, the dose must be stable for at least 90 days prior to signing the ICF or assent and with no anticipated need for dose adjustments during the study in the opinion of the Investigator.

Part B:

  • Participants with SCD ages 12 to 65 years, inclusive
  • Participants with more than or equal to 2 and ≤ 10 VOCs within 12 months of Screening.

OLE:

  • Participants who have completed the Part B will be eligible.

Exclusion criteria

Part A, Part B, and OLE:

  • Participants who had more than 10 VOC within 12 months of screening
  • Female participant who is breastfeeding or pregnant
  • Participants who receive RBC transfusion therapy regularly or received an RBC transfusion ---for any reason within 90 days of Day 1
  • Participants hospitalized for sickle cell crisis or other vaso-occlusive event within 14 days of signing the ICF or anytime during the screening period.

Treatment and study plan

Osivelotor

Drug

Tablets which contain drug substance

Other names: PF-07940367 or GBT021601

Primary outcomes

  1. Part A

    Time frame: Through week 12

    Number of adult participants with change from baseline in hemoglobin (Hb) through week 12 as measured by change in osivelotor concentrations from baseline or percentage change from baseline of clinical measures of anemia Hb and hemolysis (including indirect bilirubin, reticulocytes and lactate dehydrogenase).

  2. Part B

    Time frame: Through week 48

    Co-primary endpoints: Hb response (increase from baseline of >1 g/dL) at Week 48 (based on average of Hb levels at Week 40 and Week 48) and the Annualized rate of VOC through end of Week 48.

    A VOC is defined as an acute episode of pain that:

    • Has no medically determined cause other than a vaso-occlusive event, and
    • Results in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), and
    • Requires parenteral narcotic agents, parenteral nonsteroidal anti-inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics.

    Complicated VOCs of acute chest syndrome (ACS), hepatic sequestration, splenic sequestration, priapism, and dactylitis that meet the requirements listed above will be included in this co-primary endpoint.

  3. OLE

    Time frame: Approximately 24 months after last patient enrolled

    Incidence of Treatment Emergent Adverse Events:

    • Incidence of SAEs
    • Incidence of AEs leading to discontinuation
    • Change from baseline in laboratory parameters.

Study contacts

Contact information is provided by the study sponsor or research team.

Pfizer Pfizer CT.gov Call Center

CONTACT

[email protected]

1-800-718-1021

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Registry information

Official study title

A Phase 2/3 Randomized, Multicenter Study of Osivelotor Administered Orally to Adult and Adolescent Participants With Sickle Cell Disease

Important dates

Study start
2022
Primary completion
2030
Study completion
2032
First posted
Jun 24, 2022
Registry last updated
Mar 20, 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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