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Transfusion-dependent Alpha-ThalassemiaPhase 3ENERGIZEKids-TNCT07506863

A Study to Investigate the Efficacy, Pharmacokinetics, and Safety of Mitapivat in Pediatric Participants With Transfusion-Dependent Alpha- or Beta-Thalassemia (α- or β-TDT)

A Phase 3 study testing Mitapivat in people with Transfusion-dependent Alpha-Thalassemia and Transfusion-dependent Beta-Thalassemia, run by Agios Pharmaceuticals, Inc. at 4 sites in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The primary objective of this study is to compare the effect of mitapivat versus placebo on transfusion burden in pediatric participants with α- or β-transfusion-dependent thalassemia. Read more about this study

Who is it for?
Ages 1 year to 17 years
What is being tested?
Mitapivat
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
54 participants
Where
4 sitesUnited States
Study dates
24 Sep 2026to Jun 2032
Phase
Phase 3
Are there results?
Not yet: the study is under way

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 1 year to 17 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Written informed consent/assent from the participant (or their legally authorized representative, parent(s), or legal guardian) must be obtained before any study-related procedures are conducted and participants must be willing to comply with all study procedures for the duration of the study.
  • Aged 1 to <18 years and weighing at least 7 kilograms (kg) at the time of providing informed consent/assent.
  • Documented diagnosis of thalassemia (β-thalassemia with or without α-globin gene mutations, hemoglobin E (HbE)/β-thalassemia, or α-thalassemia/hemoglobin H (HbH) disease) based on Hemoglobin (Hb) electrophoresis, Hb high-performance liquid chromatography, and/or DNA analysis from the participant's medical record. If this information is not available from the participant's medical record, the test(s) can be performed by a local laboratory during the Screening Period. If a local laboratory is unable to perform the test(s), results from the comprehensive α- and β-globin genotyping performed by the study central laboratory can be used.
  • Transfusion dependent, defined as 6 to 20 transfusion episodes (also referred to as "transfusion events") and a ≤6-week transfusion-free period during the 24-week period before randomization.
  • If taking hydroxyurea, the hydroxyurea dose must be stable for ≥16 weeks before randomization.
  • Female participants who have attained menarche must be abstinent of sexual activities that may induce pregnancy as part of their usual lifestyle, or agree to use 2 forms of contraception, 1 of which must be considered highly effective, from the time of informed consent/assent, throughout the study, and for 28 days after the last dose of study drug. The second form of contraception can include an acceptable barrier method.

Who cannot join

  • Pregnant or breastfeeding.
  • Documented history of homozygous or heterozygous hemoglobin S (HbS) or hemoglobin C (HbC).
  • Prior exposure to gene therapy or prior bone marrow or stem cell transplantation, including any prior exposure to myeloablative chemotherapy.
  • Any conditions other than thalassemia expected to affect sexual maturation.
  • Currently receiving treatment with luspatercept; the last dose must have been administered ≥36 weeks before randomization.
  • Currently receiving treatment with hematopoietic stimulating agents; the last dose must have been administered ≥36 weeks before randomization.
Show all 26Show fewer
  • History of malignancy (active or treated) ≤5 years before providing informed consent/assent, except for nonmelanomatous skin cancer in situ, cervical carcinoma in situ, or breast carcinoma in situ.
  • History of active and/or uncontrolled cardiac or pulmonary disease or clinically relevant QT prolongation within 6 months before providing informed consent/assent.
  • Hepatobiliary disorders, including but not limited to:
  • Liver disease with histopathological evidence or clinical diagnosis of cirrhosis or severe fibrosis.
  • Clinically symptomatic cholelithiasis or cholecystitis (prior cholecystectomy is not exclusionary).
  • History of drug-induced cholestatic hepatitis.
  • Aspartate Aminotransferase (AST) >2.5*Upper Limit of Normal (ULN) (unless due to hemolysis and hepatic iron deposition) and Alanine Transaminase (ALT) >2.5*ULN (unless due to hepatic iron deposition).
  • Renal dysfunction as defined by an estimated glomerular filtration rate <60 milliliters per minute (mL/min)/1.73-meter square (m^2).
  • Nonfasting triglycerides >215 milligrams per deciliter (mg/dL) [5 millimole per liter (mmol/L)].
  • Active infection requiring systemic antimicrobial therapy at the time of providing informed consent/assent. If antimicrobial therapy is required during the Screening Period, screening procedures should not be performed while antimicrobial therapy is being administered, and the last dose of antimicrobial therapy must be administered ≥7 days before randomization.
  • Participants with known active hepatitis B or hepatitis C virus infection.
  • Participants with known human immunodeficiency virus (HIV) infection.
  • History of major surgery (including splenectomy) ≤ 6 months before providing informed consent/assent and/or a major surgical procedure planned during the study.
  • Current enrollment or past participation (within ≤12 weeks or a timeframe equivalent to 5 half-lives of the investigational study drug before administration of the first dose of study drug, whichever is longer) in any other clinical study involving an investigational treatment or device.
  • Receiving strong Cytochrome3A4/5 (CYP3A4/5) inhibitors that have not been stopped for ≥5 days or a timeframe equivalent to 5 half-lives (whichever is longer), or strong CYP3A4/5 inducers that have not been stopped for ≥4 weeks or a timeframe equivalent to 5 half-lives (whichever is longer), before randomization.
  • Receiving anabolic steroids that have not been stopped for at least 4 weeks before randomization. Testosterone replacement therapy to treat hypogonadism is allowed; the testosterone dose and preparation must be stable for ≥12 weeks before randomization.
  • Known allergy, or other contraindication, to mitapivat or its excipients (microcrystalline cellulose, croscarmellose sodium, sodium stearyl fumarate, mannitol, magnesium stearate, and the Opadry filmcoat [hypromellose, titanium dioxide, lactose monohydrate triacetin, and FD\&C Blue #2]).
  • Any medical, hematological, psychological, or behavioral condition(s) or prior or current therapy that, in the opinion of the Investigator, may confer an unacceptable risk to participating in the study and/or could confound the interpretation of the study data. Also excluded are:
  • Participants who are institutionalized by regulatory or court order.
  • Participants with any condition(s) that could create undue influence (including but not limited to incarceration, involuntary psychiatric confinement, and financial or familial affiliation with the Investigator or Sponsor).

Trial locations and contacts

4 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Agios Medical Affairs contact

833-228-8474

medinfo@agios.com

United States4 sites, 4 recruiting
  • Emory-Children's Center/ Children's Healthcare of Atlanta: Arthur M. Blank Hospital

    Atlanta, Georgia, 30322

    Recruiting
  • University of Texas Southwestern Medical Center

    Dallas, Texas, 75390

    Recruiting
  • Weill Cornell Medical College/ New York Presbyterian

    New York, New York, 10065

    Recruiting
  • Children's Hospital of Philadelphia

    Philadelphia, Pennsylvania, 19104-4318

    Recruiting

Other trials in United States

About this study

Official title: A Phase 3, Double-Blind, Randomized, Placebo-Controlled, Multicenter Study Evaluating the Efficacy, Pharmacokinetics, and Safety of Mitapivat in Pediatric Subjects With α- or β- Transfusion-Dependent Thalassemia

The primary objective of this study is to compare the effect of mitapivat versus placebo on transfusion burden in pediatric participants with α- or β-transfusion-dependent thalassemia.

Being tested
Mitapivat Matched Placebo, Mitapivat

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mitapivat Matched PlaceboDrug

    Tablets or Granules

  • MitapivatDrug

    Also called AG-348, Mitapivat sulfate

    Tablets or Granules

Study groups in NCT07506863
Study groupRoleWhat they receive
MitapivatExperimentalParticipants will receive oral mitapivat twice daily (BID), with dose determined by age and weight, for 48 weeks during the double blind (DB) period. Enrollment is conducted sequentially by age cohort, beginning with the oldest cohort. Cohort 1: 12 to <18 years Cohort 2: 6 to <12 years Cohort 3: 1 to <6 years Participants who complete the DB period may continue receiving mitapivat in the open label extension (OLE) period for up to 144 weeks.
Receives: Drug: Mitapivat
PlaceboPlacebo comparatorParticipants will receive oral placebo matching mitapivat, administered BID, with dosing based on age and weight, for 48 weeks during the DB period. Enrollment is conducted sequentially by age cohort, beginning with the oldest cohort. Cohort 1: 12 to <18 years Cohort 2: 6 to <12 years Cohort 3: 1 to <6 years Participants who complete the DB period may transition to receive mitapivat in the OLE period for up to 144 weeks.
Receives: Drug: Mitapivat Matched Placebo; Drug: Mitapivat

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Percentage of Participants Who Achieved Transfusion Reduction Response (TRR) Through Week 48

    TRR is defined as ≥50 percent (%) reduction in transfused red blood cells (RBC) volume (normalized by weight) in any consecutive 12-week period through Week 48 compared with historical RBC transfusion volume (normalized by weight) and standardized to 12 weeks.

    Measured: Baseline, through Week 48

Secondary outcomes (26)
  1. Percentage of Participants Who Achieved TRR2 From Week 13 to Week 24

    TRR2 is defined as ≥50% reduction in transfused RBC volume (normalized by weight) from week 13 to week 24 compared with historical RBC transfusion volume (normalized by weight) and standardized to 12 weeks.

    Measured: Baseline, Week 13 through Week 24

  2. Percentage of Participants Who Achieved TRR3 From Week 25 to Week 36

    TRR3 is defined as ≥50% reduction in transfused RBC volume (normalized by weight) from week 25 to week 36 compared with historical RBC transfusion volume (Normalized by Weight) and standardized to 12 weeks.

    Measured: Baseline, Week 25 through Week 36

  3. Percentage of Participants Who Achieved TRR4 From Week 37 to Week 48

    TRR4 is defined as ≥50% reduction in transfused RBC volume (normalized by weight) from week 37 to week 48 compared with historical RBC transfusion volume (normalized by weight) and standardized to 12 weeks.

    Measured: Baseline, Week 37 through Week 48

  4. Percentage of Participants Who Achieved TRR5 From Week 25 to Week 48

    TRR5 is defined as ≥50% reduction in transfused RBC volume (normalized by weight) from week 25 to week 48 compared with historical RBC transfusion volume (normalized by weight) and standardized to 24 weeks.

    Measured: Baseline, Week 25 through Week 48

  5. Percent Change in Transfused RBC Volume (Normalized by Weight) From Week 13 Through Week 48 Compared With Historical Transfusion Volume (Normalized by Weight) and Standardized to 36 Weeks

    Measured: Baseline, Week 13 through Week 48

  6. Percentage of Participants Who Achieved Transfused Independence Through Week 48

    Transfusion independence is defined as transfusion-free for greater than or equal to 8 consecutive weeks through Week 48.

    Measured: Baseline, through Week 48

  7. Change in the Number of Transfusion Episodes From Week 13 Through Week 48 Compared With Historical Number of Transfusion Episodes Standardized to 36 Weeks

    Measured: Baseline, Week 13 through Week 48

  8. Change From Baseline in Serum Iron at Week 48

    Measured: Baseline, Week 48

  9. Change From Baseline in Total Iron-Binding Capacity at Week 48

    Measured: Baseline, Week 48

  10. Change From Baseline in Transferrin at Week 48

    Measured: Baseline, Week 48

  11. Change From Baseline in Transferrin Saturation at Week 48

    Measured: Baseline, Week 48

  12. Change From Baseline in Serum Ferritin Levels at Week 48

    Measured: Baseline, Week 48

  13. Cohort 1: Change From Baseline in Estradiol Through Week 48

    Measured: Baseline, through Week 48

  14. Cohort 1: Change From Baseline in Estrone Through Week 48

    Measured: Baseline, through Week 48

  15. Cohort 1: Change From Baseline in Total Testosterone Through Week 48

    Measured: Baseline, through Week 48

  16. Cohort 1: Change From Baseline in Free Testosterone Through Week 48

    Measured: Baseline, through Week 48

  17. Cohort 1: Change From Baseline in Luteinizing Hormone Through Week 48

    Measured: Baseline, through Week 48

  18. Cohort 1: Change From Baseline in Sexual Maturity Rating With Tanner Stage Through Week 48

    Measured: Baseline, through Week 48

  19. Cohort 1: Percentage of Female Participants With Newly Developed Ovarian Cysts Through Week 48

    Measured: Baseline, through Week 48

  20. Change From Baseline Over Time in Height-for-age Z-Score, Weight-for-age Z-Score, and Body Mass Index (BMI)-for-age Z-Score Through Week 48

    Measured: Baseline, through Week 48

  21. Change from Baseline in Bone Mineral Density (BMD) Through Week 48

    Measured: Baseline, through Week 48

  22. Number of Participants With Treatment Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)

    Measured: From first dose of study drug up to end of study (up to Week 196)

  23. Plasma Concentration of Mitapivat

    Measured: Pre-dose, and at multiple timepoints (up to 7 hours post-dose) at Week 4

  24. Area Under the Plasma Concentration-Time Curve From Time Zero to Last Quantifiable Concentration (AUC0-last) of Mitapivat

    Measured: Pre-dose, and at multiple timepoints (up to 7 hours post-dose) at Week 4

  25. Maximum Observed Plasma Concentration (Cmax) of Mitapivat

    Measured: Pre-dose, and at multiple timepoints (up to 7 hours post-dose) at Week 4

  26. Time to Reach Maximum Observed Plasma Concentration (Tmax) of Mitapivat

    Measured: Pre-dose, and at multiple timepoints (up to 7 hours post-dose) at Week 4

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Apr 2026
  2. Study start24 Sep 2026
  3. Primary completionJun 2029 (estimated)
  4. Study completionJun 2032 (estimated)

Resources

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 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
54 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07506863
Sponsor's protocol ID
AG348-C-029
Other IDs
2025-524707-71-00, 2025
Acronym
ENERGIZEKids-T
Status last verified
Oct 2026
First submitted
26 Mar 2026
Last updated
29 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Mitapivat in people with Transfusion-dependent Alpha-Thalassemia and Transfusion-dependent Beta-Thalassemia, run by Agios Pharmaceuticals, Inc. at 4 sites in United States.

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 6 inclusion and 26 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: looking for participants now, as of the sponsor's last update on 29 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in United States. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Agios Medical Affairs (833-228-8474, medinfo@agios.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Percentage of Participants Who Achieved Transfusion Reduction Response (TRR) Through Week 48 (time frame: Baseline, through Week 48). 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 29 Oct 2026.

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