Pyruvate Kinase Activators for Sickle Cell Disease: An Exploratory Systematic Review and Meta-Analysis

Pyruvate kinase (PK) activators enhance glycolytic flux, increasing ATP production and lowering red blood cell (RBC) 2,3-diphosphoglycerate (2,3-DPG), thereby improving oxygen affinity and potentially reducing hemoglobin S polymerization in sickle cell disease (SCD). Through these biochemical effects, PK activation may decrease hemolysis and improve anemia. This systematic review and meta-analysis evaluated the impact of PK activators on hematologic and hemolytic parameters in adults with SCD. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception through April 2025 for clinical trials evaluating PK activators in adults with SCD treated for ≥2 weeks. The primary outcome was mean change in hemoglobin (Hb). Secondary outcomes included changes in lactate dehydrogenase (LDH) and absolute reticulocyte count (ARC). Random-effects models were used for all pooled analyses. Five early-phase clinical trials (n = 115) were included, predominantly involving adults with HbSS, most receiving concomitant hydroxyurea. PK activator therapy significantly increased Hb (mean difference [MD] 1.23 g/dL; 95% CI 1.03-1.43), reduced LDH (MD -83.2 U/L; 95% CI -115.9 to -50.2), and decreased ARC (MD -62.8 × 10³/µL; 95% CI -92.1 to -33.5). Heterogeneity was low to moderate across outcomes, and sensitivity analyses confirmed the robustness of effect estimates. PK activators improve key hematologic and hemolytic markers in adults with SCD, supporting their mechanistic potential as disease-modifying agents. Larger, randomized Phase 3 trials are needed to determine effects on clinical endpoints such as vaso-occlusive crises, transfusion requirements, and long-term safety.