Agios' Mitapivat Receives Positive CHMP Opinion for Thalassemia Treatment in Europe
Key Insights
Agios' PYRUKYND (mitapivat) received a positive CHMP opinion for treating adults with thalassemia (search) in Europe, marking a significant regulatory milestone for this first-in-class pyruvate kinase (search) activator.
The approval is supported by two global Phase 3 trials, ENERGIZE and ENERGIZE-T, which demonstrated efficacy in both non-transfusion-dependent and transfusion-dependent thalassemia (search) patients.
An estimated 18,000 to 23,000 children and adults are living with thalassemia (search) in the U.S. and five largest European countries, representing a significant unmet medical need.
Agios Pharmaceuticals announced that its oral pyruvate kinase (search) activator PYRUKYND (mitapivat) has received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) for the treatment of adults with thalassemia (search) in Europe. This regulatory milestone represents a significant advancement for patients with this inherited blood disorder, which affects an estimated 18,000 to 23,000 children and adults in the U.S. and five largest European countries.
Clinical Evidence Supporting Approval
The positive CHMP opinion is based on results from two pivotal Phase 3 trials: ENERGIZE and ENERGIZE-T. These global, randomized, double-blind, placebo-controlled studies evaluated mitapivat's efficacy and safety in adults with alpha- or beta-thalassemia (search) across different disease severities.
The ENERGIZE trial focused on 194 non-transfusion-dependent patients, randomizing them 2:1 to receive either mitapivat 100 mg twice daily or placebo. The primary endpoint measured the proportion of patients achieving a hemoglobin response, defined as an increase of ≥1.0 g/dL in average hemoglobin concentrations from week 12 through week 24 compared with baseline. Key secondary endpoints included changes in Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scores and average hemoglobin concentration improvements.
For transfusion-dependent patients, the ENERGIZE-T trial enrolled 258 participants in a similar 2:1 randomization scheme. The primary endpoint focused on transfusion reduction response (TRR), defined as a ≥50% reduction in transfused red blood cell units with a reduction of ≥2 units in any continuous 12-week period through week 48. The study also evaluated achievement of transfusion independence as a secondary endpoint.
Mechanism of Action and Clinical Impact
Mitapivat represents a first-in-class oral medication that activates pyruvate kinase (search) (PK) to increase cellular energy production. This mechanism helps improve red blood cell health, prevents premature breakdown, and reduces symptoms of hemolytic anemia (search). The drug is already approved in the United States for treating hemolytic anemia in adults with pyruvate kinase deficiency (search).
All patients with thalassemia (search) experience significant disease burden, including comorbidities, reduced quality of life, and shortened life expectancy. Some individuals require regular transfusions (transfusion-dependent thalassemia), while others need them only intermittently (non-transfusion-dependent thalassemia). Current management options are limited to transfusions, iron chelation therapy, and off-label hydroxyurea use.
Safety Profile and Regulatory Considerations
The drug carries important safety considerations, including risks of acute hemolysis following abrupt discontinuation and potential hepatocellular injury. Healthcare providers must obtain liver tests prior to treatment initiation and monthly thereafter for the first six months. The most common adverse reactions in patients with PK deficiency include decreased estrone levels in males, increased urate, back pain, decreased estradiol in males, and arthralgia.
The European Commission will now review the CHMP opinion, with Agios expecting regulatory decisions in other countries, including potential U.S. approval for thalassemia (search) indications. This development represents a significant step forward for patients with thalassemia, who have had limited therapeutic options beyond supportive care measures.