A Study to Determine the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of AG-348 in Adult Participants With Non-transfusion-dependent Thalassemia

March 27, 2026 updated by: Agios Pharmaceuticals, Inc.

A Phase 2, Open-label, Multicenter Study to Determine the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of AG-348 in Adult Subjects With Non-transfusion-dependent Thalassemia

Study AG348-C-010 is a multicenter study to evaluate the efficacy, safety, pharmacokinetics, and pharmacodynamics of treatment with AG-348 in adult participants with non-transfusion-dependent thalassemia (NTDT). This study includes a core period (up to 24 weeks) followed by an extension period (up to 10 years) for eligible participants. 20 participants with NTDT were enrolled. The initial dose of AG-348 was 50 milligrams (mg) twice daily (BID) with one potential dose-level increase to 100 mg BID at the Week 6 visit based on the participant's safety and hemoglobin (Hb) concentrations.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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.
20

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

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G 2C4
        • University Health Network (Toronto General Hospital)
  • United Kingdom
      • London, United Kingdom, W12 0HS
        • Imperial College Healthcare NHS Trust (Hammersmith Hospital)
  • United States
    • California
      • Oakland, California, United States, 94609
        • UCSF Benioff Children's Hospital Oakland
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital

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

Inclusion Criteria:

  • Informed consent;
  • Known medical history of thalassemia, including β-thalassemia intermedia, Hb E β-thalassemia, α-thalassemia (Hb H disease), or β-thalassemia with mutations of 1 or more α genes;
  • Documented clinical laboratory confirmation of thalassemia by Hb electrophoresis/high-performance liquid chromatography (HPLC) or deoxyribonucleic acid (DNA) analysis, either from medical records or during the screening period;
  • Hb concentration ≤10.0 grams per deciliter (g/dL), regardless of sex, based on an average of at least 2 Hb measurements (separated by a minimum of 7 days) during the screening period;
  • Considered non-transfusion-dependent, defined as having no more than 5 units of red blood cells (RBCs) transfused during the 24-week period up to the first day of study drug and no RBC transfusions in the 8 weeks prior to the first day of study drug;
  • Adequate organ function;
  • For women of reproductive potential: negative serum pregnancy test during the screening period and a negative serum or urine pregnancy test on Day 1;
  • For women of reproductive potential as well as men with partners who are women of reproductive potential: be abstinent as part of their usual lifestyle, or agreement to use 2 forms of contraception, 1 of which must be considered highly effective, from the time of giving informed consent, during the study, and for 28 days following the last dose of study drug for women and 90 days following the last dose of study drug for men;
  • Willingness to comply with all study procedures for the duration of the study;

Exclusion Criteria:

  • Known history of diagnosis of Hb S or Hb C forms of thalassemia;
  • Significant medical condition that confers an unacceptable risk to participating in the study, and/or could confound the interpretation of the study data;
  • Splenectomy scheduled during the study treatment period or having undergone splenectomy within 12 months prior to signing informed consent;
  • Currently enrolled in another therapeutic clinical trial involving ongoing therapy with any investigational or marketed product or placebo;
  • Exposure to any investigational drug, device, or procedure within 3 months prior to the first day of study drug;
  • Prior exposure to sotatercept (ACE-011), luspatercept (ACE-536), ruxolitinib, or gene therapy;
  • Prior bone marrow or stem cell transplant;
  • Currently pregnant or breastfeeding;
  • History of major surgery within 6 months of signing informed consent;
  • Currently receiving medications that are strong inhibitors of cytochrome P450 (CYP)3A4, strong inducers of CYP3A4, strong inhibitors of P-glycoprotein (P-gp), or digoxin (a P-gp sensitive substrate medication) that have not been stopped for a duration of at least 5 days or a timeframe equivalent to 5 half-lives (whichever is longer) prior to the first day of study drug;
  • Currently receiving chronic anticoagulant therapy, unless started and on a stable dose for at least 28 days prior to first day of study drug;
  • Currently receiving anabolic steroids, including testosterone preparations, if initiated ≤28 days prior to the first day of study drug;
  • Currently receiving hematopoietic stimulating agents (e.g., erythropoietins, granulocyte colony stimulating factors, thrombopoietins), if initiated ≤8 weeks prior to the first day of study drug;
  • History of allergy to sulfonamides if characterized by acute hemolytic anemia, drug-induced liver injury, anaphylaxis, rash of erythema multiforme type or Stevens-Johnson syndrome, cholestatic hepatitis, or other serious clinical manifestations;
  • History of allergy to AG-348 or its excipients (microcrystalline cellulose, croscarmellose sodium, sodium stearyl fumarate, and mannitol).

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: N/A
  • Interventional Model: Single Group 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: AG-348
Participants with alpha or beta thalassemia received AG-348 50 mg twice daily (BID), orally up to Week 6. Following Week 6, depending on the participants' safety and hemoglobin (Hb) concentrations, they could undergo one potential dose-level increase from 50 to 100 mg BID. After completion of the Core Period of 24 weeks, participants were eligible to continue to receive AG-348 in the Extension Period which is up to 10 years.
Drug: AG-348
AG-348 tablet orally BID
Other Names:
  • Mitapivat

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
Measure Description
Time Frame
Percentage of Participants Achieving a Hemoglobin Response (HR)
Time Frame: Up to 12 weeks
HR was defined as a ≥1.0 gram per deciliter (g/dL) increase in Hb concentration from Baseline at 1 or more assessments between Week 4 and Week 12 (inclusive). A participant's Baseline Hb concentration was defined as the average of all the participant's available Hb concentrations during the screening period up to the first dose of study drug.
Up to 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Average Change From Baseline in Hb Concentrations From Week 12 to Week 24
Time Frame: Baseline, Week 12 to Week 24
A participant's Baseline Hb concentration was defined as the average of all the participant's available Hb concentrations during the screening period up to the first dose of study drug.
Baseline, Week 12 to Week 24
Percentage of Participants Achieving a Sustained Hb Response (sHR)
Time Frame: Week 12 to Week 24
sHR was defined as achieving HR and achieving a ≥1.0 g/deciliter (dL) increase in Hb concentration at 2 or more evaluable Hb assessments out of the 4 scheduled assessments between the Week 12 visit and Week 24 visit.
Week 12 to Week 24
Percentage of Participants Achieving a Delayed Hb Response
Time Frame: Week 12 to Week 24
Delayed Hb response was defined as not achieving HR and achieving a ≥1.0 g/dL increase in Hb concentration at 1 or more Hb assessments after Week 12.
Week 12 to Week 24
Change From Baseline in Hb Concentration Over the Duration of the Extension Period
Time Frame: Baseline up to approximately 10.5 years
Baseline up to approximately 10.5 years
Time to First ≥1.0 g/dL Increase in Hb Concentration
Time Frame: Up to Week 24
Up to Week 24
Change From Baseline in Reticulocyte Count
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Bilirubin
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Lactate Dehydrogenase (LDH)
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Haptoglobin
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Nucleated Red Blood Cells (NRBCs)
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Erythropoietin (EPO)
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Change From Baseline in Soluble Transferrin Receptor
Time Frame: Up to approximately 10.5 years
Up to approximately 10.5 years
Drug Concentrations Over Time for AG-348
Time Frame: Predose (60 minutes) and 0.00 hour, 0.50 hour, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 0.00 hour, 0.50 hour, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
AUC0-8h: Area Under the Plasma Concentration-time Curve From Time 0 to 8 Hours of AG-348
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
AUC0-t: Area Under the Plasma Concentration-time Curve From Time 0 to Time of the Last Quantifiable Concentration of AG-348
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Cmax: Maximum Observed Plasma Concentration of AG-348
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Tmax: Time to Reach the Maximum Plasma Radioactivity Concentration (Cmax)
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Tlast: Time of the Last Quantifiable Concentration of AG-348
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Ctrough: Observed Plasma Concentration at the End of a Dosing Interval of AG-348
Time Frame: Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Predose (60 minutes) and 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours postdose on Day 1 and Week 12
Percentage of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs), AEs of Special Interest (AESIs), and TEAEs Leading to Study Drug Dose Reduction, Study Drug Interruption, and Study Drug Discontinuation
Time Frame: From signing the inform consent form up to data cut-off date: 20 August 2020 (Up to approximately 19 months)
An AE is any unfavorable and unintended sign, symptom, or disease, whether or not related to the investigational product. A TEAE was defined as any AE with onset post study drug treatment. An SAE was defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is medically important. AESIs are predefined AEs that required close monitoring and prompt reporting to the sponsor. AESIs included protocol-specified transaminase increase.
From signing the inform consent form up to data cut-off date: 20 August 2020 (Up to approximately 19 months)

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.
Agios Pharmaceuticals, Inc.

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 Chair: Medical Affairs, Agios Pharmaceuticals, Inc.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
March 20, 2019

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 20, 2020

Study Completion (Estimated)

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.
September 30, 2030

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).
September 10, 2018

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.
September 28, 2018

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.
October 2, 2018

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.
March 30, 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.
March 27, 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.
March 1, 2026

More Information

Terms related to this study

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.
  • AG348-C-010
  • 2018-002217-35 (EudraCT Number)

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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