Agios’s PKR Activator, Mitapivat’s strategy for Sickle Cell Disease (SCD)
Agios Pharmaceuticals, shared the proof of clinical concept that has been established based on preliminary analysis in the phase 1 study of mitapivat (AG-348) in patients with sickle cell anemia.
We, Mellalta Meets would like to touch some key points on clinical findings.
Agio Pharmaceutical received the Fast Track designation from the USFDA and an orphan drug designation to its first class mitapivat pyruvate kinase-R (PKR) activator from both the USFDA and EMA.
Mitapivat (AG348) Mechanism of Action
Mitapivat (AG348) is a first-class small molecule, and oral allosteric activator of wild-type and a variety of mutated pyruvate kinase-R (PKR) enzymes that has given promising signals to reduce 2,3-diphosphoglycerate (2, 3 -DPG) and increase adenosine triphosphate (ATP) and further leading to the reduction of the polymerization of hemoglobin (Hb) S and the sickle cell of red blood cells.
PKR Activation in Pyruvate Kinase Deficiency, Thalassemia and Sickle Cell Disease
Agios Strategy for Mitapivat (AG348)
Agios JP Morgan Conference, 2020
Mitapivat (AG348) results in Phase I
Technically the Agios is pursuing a simpler approach with the oral small molecule mitapavant and reported results from EHA has suggested that the five of the eight evaluable sickle cell subjects administered up to 50 mg twice a day achieved an increase in hemoglobin of at least 1 g / dl. The trial aims to enroll 25 subjects, dosing up to 100 mg, according to a modified protocol.
Nine patients were enrolled in ongoing Phase I, of which eight completed all expected dose levels except one patient which discontinued it in the first week. Clinical data results showed that seven of the eight (88%) patients who completed all expected dose levels of mitapivat had an increase in Hb, while five of the eight patients (63%) who achieved an increase in hemoglobin of ≥ 1.0 g / dL from baseline (range 1.0-2.7 g / dL). However, mitapivat treatment has been associated with a reduction in hemolytic markers such as bilirubin, lactic acid dehydrogenase and reticulocytes. And as expected, mitapivat showed a decrease in 2,3-DPG and increases in ATP levels were observed, consistent with the proposed mechanism of action and comparable to those observed in healthy voluntary studies with mitapivat.
Along with this, the evaluation of sickle cell curves (t50) and oxygen dissociation curves (p50) was consistent with decreases in sickle cell polymerization and HbS, further supporting the proposed mechanism of action.
The company’s clinical results were supported by pharmacodynamic and biomarker data for mitapivat’s proposed mechanism of action and with two ongoing global, pivotal trials in adults with PK deficiency that are fully enrolled named ACTIVATE and ACTIVATE-T. Agios Pharmaceuticals is focusing on advancing mitapivat to pivotal development, with the goal of initiating a pivotal study by next year.
Clinical Trials of Agios’s Mitapivat therapy
|
Study Aim |
Drug |
Indications |
NCT Number |
|
Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of AG-348 in Adult Participants with Non-transfusion-dependent Thalassemia |
AG-348 |
Thalassemia |
|
|
Efficacy and Safety of AG-348 in Regularly Transfused Adult Participants With Pyruvate Kinase Deficiency (PKD) |
AG-348 |
Pyruvate Kinase Deficiency|Anemia, Hemolytic |
|
|
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Escalating Multiple Oral Doses of AG-348 in Subjects With Stable Sickle Cell Disease |
AG-348 |
Sickle Cell Disease |
|
|
Efficacy and Safety of AG-348 in Not Regularly Transfused Adult Participants With Pyruvate Kinase Deficiency (PKD) |
AG-348 |
Pyruvate Kinase Deficiency|Anemia, Hemolytic |
|
|
AG-348 in Adult Participants With Pyruvate Kinase (PK) Deficiency |
AG-348 |
Pyruvate Kinase Deficiency |
|
|
Extension Study of AG-348 in Adult Participants with Pyruvate Kinase Deficiency Previously Enrolled in AG-348-006 or AG348-C-007 |
AG-348 |
Pyruvate Kinase Deficiency |
|
|
Pyruvate Kinase Deficiency Global Longitudinal Registry |
Pyruvate Kinase Deficiency |
FAQs
Mitapivat (AG348) is different from other therapies as it works by increasing the activity of PKR and the production of ATP, to avoid red blood cells sickling in SCD by preventing the buildup of 2,3-DPG and maintaining membrane integrity.
Early results from preclinical studies and early clinical studies of mitapivat have shown dose-dependent changes in glycolysis in red blood cells and showed a decrease in 2,3-DPG and increases in ATP levels. These changes were consistent with mitapivat’s mechanism of action and supported his study as a potential treatment for SCD
To date, the ongoing Phase 1 study has enrolled nine patients. Eight patients completed all expected dose levels and one patient discontinued within the first week due to a pre-existing condition and was subsequently lost to follow-up.
