Pegcetacoplan for refractory paroxysmal nocturnal haemoglobinuria associated with the C5 genetic variant

Case report: Transfusion independence and abolition of extravascular hemolysis in a PNH patient treated with pegcetacoplan

More than half of patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with complement fraction C5 inhibitors experience residual anemia and hemolysis. This is partly due to the persistent activation of the complement cascade upstream C5, resulting in C3 deposition on PNH erythrocytes and extravascular hemolysis in the reticuloendothelial system. Pegcetacoplan is the first proximal C3 inhibitor to be approved for PNH basing on favorable efficacy and safety data in both naïve and eculizumab treated PNH. Here we report the first Italian patient treated with pegcetacoplan in a named patient program. The patient suffered from hemolytic PNH associated with CALR+ myeloproliferative neoplasm and was heavily transfusion dependent despite eculizumab therapy. Treatment with pegcetacoplan induced a dramatic improvement in Hb, along with normalization of unconjugated bilirubin and reticulocytes, as markers of extravascular hemolysis. Sequential laboratory workup showed the disappearance of C3 deposition on erythrocytes by direct anti-globulin test, the increase of PNH clone on erythrocytes, and a peculiar right shift of the ektacytometry curve. The drug was well tolerated, and the patient reported a significant improvement in his quality of life. Overall, pegcetacoplan appears a safe and effective option "ready to use" in the clinic for patients with PNH and suboptimal response to anti-C5 agents.

Novel targeted C3 inhibitor pegcetacoplan for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening acquired blood disease characterized by chronic complement-mediated hemolysis and thrombosis. On May 14, 2021, the US FDA approved a new targeted C3 therapy Empaveli (pegcetacoplan), once called APL-2, for use in adult PNH. This review aims to review the pharmacological properties, clinical safety and efficacy of pegcetacoplan, and provides comprehensive drug information about pegcetacoplan. Pegcetacoplan is a pegylated peptide that targets the proximal complement protein C3. Pegcetacoplan plays a role in the complement cascade that controls C3b-mediated extravascular hemolysis and terminal complement-mediated intravascular hemolysis. Early pharmacokinetic and pharmacodynamic trials proved that pegcetacoplan had good tolerability and acceptable safety, while reducing complement activity. The pivotal phase III trial PEGASUS of PNH patients with a suboptimal response to eculizumab reported that pegcetacoplan improved hemoglobin levels better than eculizumab (p < 0.001). Compared with eculizumab, patients who received pegcetacoplan had a higher chance of not requiring a blood transfusion within 16 weeks (85% vs. 15%, p < 0.001). The safety of pegcetacoplan was similar to that of eculizumab. Adverse events such as injection site reactions and diarrhea occurred frequently following pegcetacoplan administration. The prescription recommended dosage is 1080 mg, subcutaneously infusion twice a week.

Pegcetacoplan for Paroxysmal Nocturnal Hemoglobinuria

Approximately a third of patients with paroxysmal nocturnal hemoglobinuria (PNH) remain transfusion dependent or have symptomatic anemia despite treatment with a C5 inhibitor. Pegcetacoplan inhibits complement proximally at the level of C3 and is highly effective in treating persistent anemia resulting from C3-mediated extravascular hemolysis. We describe the rationale for C3 inhibition in the treatment of PNH and discuss preclinical and clinical studies using pegcetacoplan and other compstatin derivatives. We propose an approach for sequencing complement inhibitors in PNH.