Trial results for the study NCT04770779 evaluating mitapivat in participants with transfusion-dependent alpha- or beta-thalassemia were posted on ClinicalTrials.gov on 2025-05-25. The study demonstrated that 30.4% of participants treated with mitapivat achieved a transfusion reduction response (TRR), compared to 12.6% for those on placebo.
Background
The study investigated mitapivat for the treatment of transfusion-dependent alpha- or beta-thalassemia (α- or β-TDT). Thalassemia is a genetic blood disorder that causes the body to have less hemoglobin than normal, leading to anemia and often requiring regular blood transfusions.
Trial design
The study (NCT04770779) was a Phase 3 trial with an enrollment of 258 participants. It evaluated the efficacy and safety of mitapivat in individuals with transfusion-dependent alpha- or beta-thalassemia. Participants were randomized to receive either mitapivat or a placebo matching mitapivat. The primary objective was to compare the effect of mitapivat versus placebo on transfusion burden in these participants.
Key results
The trial results showed differences in transfusion reduction between the mitapivat and placebo groups during the double-blind period:
- For "Percentage of Participants Who Achieved Transfusion Reduction Response (TRR)": 30.4% of participants in the mitapivat group achieved this, compared to 12.6% in the placebo group. A Mantel-Haenszel analysis showed a Common Risk Difference on Response Rate of 17.6 (95.0% CI: 8.0 to 27.2) with a p-value of 0.0003.
- For "Percentage of Participants Who Achieved TRR2": 13.5% in the mitapivat group versus 2.3% in the placebo group. A Mantel-Haenszel analysis showed a Common Risk Difference on Response Rate of 11.1 (95.0% CI: 5.1 to 17.0) with a p-value of 0.0003.
- For "Percentage of Participants Who Achieved TRR3": 14.6% in the mitapivat group versus 1.1% in the placebo group. A Mantel-Haenszel analysis showed a Common Risk Difference on Response Rate of 13.4 (95.0% CI: 7.7 to 19.1) with a p-value of 0.0001.
- For "Percentage of Participants Who Achieved TRR4": 7.6% in the mitapivat group versus 1.1% in the placebo group. A Mantel-Haenszel analysis showed a Common Risk Difference on Response Rate of 6.4 (95.0% CI: 1.9 to 10.9) with a p-value of 0.0056.
- For "Percent Change From Baseline in Transfused RBC Units": The mitapivat group showed a Least Squares Mean of 10.96% (Standard Error: 2.149) change, while the placebo group showed 3.32% (Standard Error: 2.846).
- For "Percentage of Participants Who Achieved Transfusion-Independence": 9.9% of participants in the mitapivat group achieved this, compared to 1.1% in the placebo group.
What this means
The results indicate that mitapivat significantly reduced transfusion burden in participants with transfusion-dependent alpha- or beta-thalassemia compared to placebo. The higher rates of transfusion reduction response (TRR) and transfusion independence observed in the mitapivat group suggest that it could offer a meaningful therapeutic benefit for patients requiring regular blood transfusions due to thalassemia. These findings are important for clinicians evaluating new treatment options to manage the disease and improve patient outcomes.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04770779, titled "A Study Evaluating the Efficacy and Safety of Mitapivat in Participants With Transfusion-Dependent Alpha- or Beta-Thalassemia (α- or β-TDT)," were posted on 2025-05-25 on clinicaltrials.gov.