Acute hemolysis can be managed effectively with intensive subcutaneous or intravascular pegcetacoplan (PEG) treatment in patients with paroxysmal nocturnal hemoglobinuria (PNH), according to results presented at the 64th ASH Annual Meeting and Exposition.

These results from a subset of patients enrolled in the ongoing phase 3 PEG 307 open-label extension study also demonstrate that this treatment approach can quickly control lactate dehydrogenase levels in these patients. Moreover, intense treatment with PEG is safe and well-tolerated.

The nonrandomized, multicenter trial is evaluating the long-term safety and efficacy of PEG in patients with PNH who previously completed PEG clinical trials.

In this trial, investigators assessed whether a higher and sustained dosing regimen of PEG could help manage acute hemolysis events that some patients experience despite treatment.

Read more about guidelines in PNH

Thirteen patients received the intensive PEG treatment, which comprised a single intravenous or subcutaneous dose of 1080 mg of PEG every 24 hours for 3 doses while already on a steady-state dose of 1080 mg of subcutaneous PEG twice a week. This was followed by an increased maintenance regimen of 1080 mg of subcutaneous PEG every 3 days.

The mean level of lactate dehydrogenase in the 13 patients was 249 U/L.

The results showed that following intensive PEG treatment, levels of lactate dehydrogenase decreased between days 1 and 2 in 8 of 12 evaluable patients, and at days 7 to 12 in all 13 patients.

The incidence and severity of adverse events were comparable with what was seen in the overall trial with 8 patients experiencing a treatment-emergent adverse event and 4 experiencing a serious treatment-emergent adverse event, none of which led to the discontinuation of treatment. There were no cases of meningitis or thrombosis.

PEG is the first C3 complement inhibitor therapy for the treatment of PNH approved by the US Food and Drug Administration and the European Medicines Agency.


Griffin M, Kelly R, Deeren D, et al. Intensive pegcetacoplan dosing in the management of acute hemolysis as part of the 307 open-label extension study. 64th ASH Annual Meeting and Exposition. New Orleans, LA, December 10-13, 2022. Poster number 1255.

Pegcetacoplan long term safety and efficacy extension study. Last updated July 26, 2021. Accessed November 21, 2022.