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Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Escalating Multiple Oral Doses of AG-348 in Subjects With Stable Sickle Cell Disease

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04000165
Recruitment Status : Recruiting
First Posted : June 27, 2019
Last Update Posted : May 1, 2020
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Heart, Lung, and Blood Institute (NHLBI) )

Tracking Information
First Submitted Date  ICMJE June 22, 2019
First Posted Date  ICMJE June 27, 2019
Last Update Posted Date May 1, 2020
Actual Study Start Date  ICMJE July 11, 2019
Estimated Primary Completion Date December 31, 2020   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: April 15, 2020)
Safety and tolerability [ Time Frame: day 51 ]
Frequency and severity of AEs, and changes in laboratory parameters, including levels in hemoglobin, reticulocyte counts, bilirubin and lactate dehydrogenase
Original Primary Outcome Measures  ICMJE
 (submitted: June 26, 2019)
safety and tolerability [ Time Frame: day 51 ]
frequency and severity of AEs, and changes in laboratory parameters, including levels in hemoglobin, reticulocyte counts, bilirubin and lactate dehydrogenase
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: April 15, 2020)
PK & PD [ Time Frame: Day 51 ]
RBC 2,3-DPG activities from baseline, 2,3-DPG, ATP level sat different doses of AG-348 and change from baseline etc.
Original Secondary Outcome Measures  ICMJE
 (submitted: June 26, 2019)
PK & PD [ Time Frame: day 51 ]
RBC 2,3-DPG activities from baseline, 2,3-DPG, ATP levels at different doses of AG-348 and change from baseline etc.
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Escalating Multiple Oral Doses of AG-348 in Subjects With Stable Sickle Cell Disease
Official Title  ICMJE A Pilot Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Escalating Multiple Oral Doses of AG-348 in Subjects With Stable Sickle Cell Disease
Brief Summary


Sickle Cell Disease (SCD) is an inherited blood disorder. People with SCD have abnormal hemoglobin in their red blood cells. Researchers are investigating the safety and efficacy of an investigational medicine called AG-348 (mitapivat sulfate) to determine if it will help people with SCD.


To test the tolerability and safety of AG-348 in people with SCD.


People ages 18 and older with SCD.


Participants will have 8 visits over approximately 14 weeks. At the first visit participants will be screened with a medical history; a physical exam; and blood, urine, and heart tests. At the following 5 visits participants will stay at the clinic for 1 night each. Participants will take study drug in increasing doses upto visit 6, after which the drug will be tapered off. All visits will include physical exam, blood, and urine tests. The last visit will occur 4 weeks after stopping the drug and also includes a heart test. Participants will provide DNA from the blood samples they provide. The DNA will be tested for an inherited gene that can cause differences in response to the study drug. Researchers may also test other genes to see if they can find any genes that interact with SCD.

Detailed Description

Sickle cell disease (SCD) is a multisystem disorder associated with episodes of acute clinical events and progressive organ damage. Episodic pain, triggered by micro-vasoocclusion induced by sickled red blood cells, is the most common acute complication and the leading cause of hospitalization. Management strategies for SCD have evolved very slowly, and treatment of acute pain is still limited to supportive therapy with opioid medication. Until recently in 2017, the only approved therapy for SCD was hydroxyurea (HU), indicated to reduce frequency of acute painful crises but not universally effective. In addition to HU, transfusions with normal red blood cells are widely used to treat severe sickle crises, but this strategy has limitations (not uniformly accessible, accompanied by risks of alloimmunization, hemolytic transfusion reactions and transfusional iron overload). The only curative treatment is bone marrow transplantation, but this option carries significant risks and is limited by the availability of histocompatible donors.

As the root cause of SCD is polymerization of deoxy-HbS, there is a strong rationale for exploring agents that could inhibit/reduce the polymerization process itself. HbS polymerizes only when deoxygenated, its oxygenation is influenced by a few factors, one key factor being the 2,3- diphosphoglycerate (2,3-DPG) concentration in the red blood cell. Increased intracellular 2,3-DPG decreases oxygen binding and stabilizes the deoxygenated form (T form) of hemoglobin. In addition, increased 2,3-DPG concentration decreases intracellular red cell pH further promoting HbS polymerization. 2,3-DPG is an intermediate substrate in the glycolytic pathway, the only source of ATP production in red blood cells. Pyruvate kinase (PK) is a key enzyme in the final step of glycolysis; PK converts phosphoenolpyruvate to pyruvate, creating 50% of the total red cell ATP that is essential for maintaining integrity of the red cell membrane. Reduced PK activity leads to accumulation of the upstream enzyme substrates, including 2,3- DPG, that favours polymerization of deoxy-HbS. In humans with SCD, and even in sickle carriers who are generally asymptomatic, reduced oxygen affinity will favour deoxygenation of HbS and its polymerisation, and thus sickling. Indeed, the combination of PK deficiency and sickle cell trait causing an acute sickling syndrome has been previously reported in two cases.

Current approaches to reduce HbS polymerization include fetal haemoglobin induction via multiple strategies and drugs that targets HbS polymerization through increasing affinity of hemoglobin for oxygen (eg. Oxbryta (TM) / Voxelotor / GBT440). Increasing red cell PK (PK-R) activity, leading to a decrease in intracellular 2,3-DPG concentration, presents a potentially attractive therapeutic target for thwarting HbS polymerization and acute sickle pain. AG-348 is a novel, orally bioavailable, small molecule allosteric activator of PK-R, that is currently in Phase II/III clinical trials in humans with PK deficiency (NCT02476916, NCT03548220 / AG348-C-006; NCT03559699 / AG348-C-007). Overview of the preclinical AG-348 data and other data support dose-dependent changes in blood glycolytic intermediates consistent with glycolytic pathway activation at all multiple ascending doses tested, supporting the potential role of AG-348 in the treatment of sickle cell disease. The overall objective of the present study is to determine the clinical safety and tolerability of AG-348 in subjects with SCD.

Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 1
Study Design  ICMJE Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Condition  ICMJE Sickle Cell Disease
Intervention  ICMJE Drug: AG-348
All subjects will receive an initial dose of 5 mg BID of AG-348 for 2 weeks followed by 2 dose increases, from 5 to 20 mg BID and from 20 to 50 mg BID, depending on safety and tolerability. Specifically, the treating clinician will assess the safety and tolerability of the current dose level before a decision is taken to escalate the dose to the next level.
Study Arms  ICMJE Experimental: AG-348
Single arm, intrapatient dose escalation Q 2 weeks
Intervention: Drug: AG-348
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Recruiting
Estimated Enrollment  ICMJE
 (submitted: June 26, 2019)
Original Estimated Enrollment  ICMJE Same as current
Estimated Study Completion Date  ICMJE December 31, 2020
Estimated Primary Completion Date December 31, 2020   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

For enrollment, subjects must meet all of the following criteria during the screening period:

  1. Have provided signed written informed consent prior to performing any study procedure, including screening procedures.
  2. Age between 18-70 years

5.1.3 Unequivocal diagnosis of HbSS confirmed by hemoglobin electrophoresis performed on patients at least 90 days after a blood transfusion if previously transfused, or DNA genotyping within 30 days prior to study enrollment

4 No transfusion in the 90 days prior to the first dose of study drug

5 Have adequate organ function, as defined by:

  1. Serum aspartate aminotransferase (AST) less than or equal to 2.5 (SqrRoot) Upper Limit of Normal (ULN) (unless the increased AST is assessed by the Investigator as due to hemolysis and/or hepatic iron deposition) and alanine aminotransferase (ALT)

    less than or equal to 2.5 (SqrRoot) ULN (unless the increased ALT is assessed by the Investigator as due to hepatic iron deposition).

  2. Serum creatinine less than or equal to 1.25 (SqrRoot) ULN. If serum creatinine is >1.25 (SqrRoot) ULN, then glomerular filtration rate (based on creatinine) must be greater than or equal to 60 mL/min.
  3. Absolute neutrophil count greater than or equal to 1.0 (SqrRoot) 109/L.
  4. Hemoglobin greater than or equal to 7 g/dL
  5. Platelet count greater than or equal to 100 (SqrRoot) 109/L.
  6. Activated partial thromboplastin time and international normalized ratio less than or equal to 1.5 (SqrRoot) ULN, unless the subject is receiving therapeutic anticoagulants.

    6 For women of reproductive potential, have a negative serum or urine pregnancy test during the screening period. Women of reproductive potential are defined as sexually mature women who have not undergone a hysterectomy, bilateral oophorectomy, or tubal occlusion; or who have not been naturally postmenopausal (i.e., who have not menstruated at all for at least the preceding 12 months prior to signing informed consent and have an elevated folliclestimulating hormone level indicative of menopause during the screening period).

    7 For women of reproductive potential as well as men and their partners who are women of reproductive potential, be abstinent as part of their usual lifestyle, or agree to use 2 effective forms of contraception from the time of giving informed consent, during the study, and for 28 days (both men and women) following the last dose of study treatment. An effective form of contraception is defined as

hormonal oral contraceptives, injectables, patches, and barrier methods.

8 Be willing to comply with all study procedures for the duration of the study.


Subjects who meet any of the following criteria during screening will not receive AG348 and will not be counted toward the final enrollment count for statistical purposes:

  1. Documented pyruvate kinase deficiency
  2. Have a significant medical condition that confers an unacceptable risk to participating in the study, and/or that could confound the interpretation of the study data. Such significant medical conditions include, but are not limited to the following:

    1. Poorly controlled hypertension (defined as systolic blood pressure [BP] >150 mmHg or diastolic BP >90 mmHg) refractory to medical


    2. History of recent (within 6 months prior to signing informed consent) congestive heart failure; myocardial infarction or unstable angina pectoris; hemorrhagic, embolic, or thrombotic stroke; deep venous thrombosis; or pulmonary or arterial embolism.
    3. Cardiac dysrhythmias judged as clinically significant by the Investigator.
    4. Heart-rate corrected QT interval-Fredericia's method (QTcF) >480 msec with the exception of subjects with right or left bundle branch block.
    5. Clinically symptomatic cholelithiasis or cholecystitis. Prior cholecystectomy is not exclusionary. Subjects with symptomatic

      cholelithiasis or cholecystitis may be rescreened once the disorder has been treated and clinical symptoms have resolved.

    6. History of drug-induced cholestatic hepatitis.
    7. Iron overload sufficiently severe to result in a clinical diagnosis by the Investigator of cardiac (e.g., clinically significant impaired left ventricular ejection fraction), hepatic (e.g., fibrosis, cirrhosis), or pancreatic (e.g., diabetes) dysfunction.
    8. Have a diagnosis of any other congenital or acquired blood disorder, or any other hemolytic process as defined by a positive direct antiglobulin test (DAT), except mild allo-immunization as a consequence of transfusion therapy.
    9. Positive test for hepatitis B surface antigen or hepatitis C virus (HCV) antibody (Ab) with signs of active hepatitis B or C virus infection. If the subject is positive for HCV Ab, a reverse transcriptase-polymerase chain reaction test will be conducted. Subjects with hepatitis C may be rescreened after receiving appropriate hepatitis C treatment.
    10. Positive test for human immunodeficiency virus 1 or 2 Ab.
    11. Active infection requiring any use of systemic antimicrobial agents (parenteral or oral) or Grade greater than or equal to 3 in severity (per National Cancer Institute Common Terminology Criteria for Adverse Events) within 2 months prior to signing informed consent.
    12. Diabetes mellitus judged to be under poor control by the Investigator or requiring >3 antidiabetic agents, including insulin (all insulins are considered 1 agent); use of insulin per se is not exclusionary.
    13. History of any primary malignancy, with the exception of: curatively treated nonmelanomatous skin cancer; curatively treated cervical or breast carcinoma in situ; or other primary tumor treated with curative intent, no known active disease present, and no treatment administered during the last 3 years.
    14. Unstable extramedullary hematopoiesis that could pose a risk of imminent neurologic compromise.
    15. Current or recent history of psychiatric disorder that, in the opinion of the Investigator or Medical Monitor, could compromise the ability of the subject to cooperate with study visits and procedures.
    16. Are currently enrolled in another therapeutic clinical trial involving ongoing therapy with any investigational or marketed product or placebo. Sickle cell anemia subjects on hydroxyurea or L-glutamine will also be considered, provided that they have been on an unchanged dose of hydroxyurea or L-Glutamine for three months prior to enrollment.
    17. Have exposure to any investigational drug, device, or invasive procedure within 3 months prior to the first dose of study treatment. All noninvestigational invasive procedures within 3 months of starting study treatment may be considered as a potential exclusion criteria per the PI s discretion.
    18. Have had any prior treatment with a pyruvate kinase activator.
    19. Have a prior bone marrow or stem cell transplant.
    20. Are currently pregnant or breastfeeding.
    21. Are 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 dose of AG-348.
    22. Are currently receiving hematopoietic stimulating agents (e.g., erythropoietins, granulocyte colony stimulating factors, thrombopoietins) that have not been stopped for a duration of at least 28 days prior to the first dose of study treatment.
    23. Have a 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.
    24. Have a history of allergy to AG-348 or its excipients (microcrystalline cellulose, croscarmellose sodium, sodium stearyl fumarate, and mannitol).
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 70 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE
Contact: Ingrid C Frey (301) 402-6674
Listed Location Countries  ICMJE United States
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT04000165
Other Study ID Numbers  ICMJE 190097
Has Data Monitoring Committee Not Provided
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement  ICMJE Not Provided
Responsible Party National Institutes of Health Clinical Center (CC) ( National Heart, Lung, and Blood Institute (NHLBI) )
Study Sponsor  ICMJE National Heart, Lung, and Blood Institute (NHLBI)
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Principal Investigator: Swee Lay Thein, M.D. National Heart, Lung, and Blood Institute (NHLBI)
PRS Account National Institutes of Health Clinical Center (CC)
Verification Date April 29, 2020

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP