The following article features coverage from the American Society of Hematology 2021 meeting. Click here to read more of Hematology Advisor‘s conference coverage.

Compared with standard of care (SOC), pegcetacoplan appears to both better stabilize hemoglobin levels, and reduce lactate dehydrogenase (LDH) levels, among patients with complement inhibitor-naïve paroxysmal nocturnal hemoglobinuria (PNH), according to research presented at the 2021 American Society of Hematology (ASH) Annual Meeting.

PNH, a rare and dangerous disease linked with both hemolysis and thrombosis, is frequently treated by C5 inhibitors, such as eculizumab, which prevent intravascular, but not extravascular, hemolysis. Persistent extravascular hemolysis is, furthermore, linked with anemia in more than 70% of patients, which often necessitates annual transfusion.

The US Food and Drug Administration (FDA) previously approved pegcetacoplan, an inhibitor of C3, for the treatment of PNH because of evidence that the drug effectively combats both intravascular and extravascular hemolysis, and helps to stabilize hemoglobin levels more effectively than eculizumab. For the randomized phase 3 PRINCE study ( Identifier: NCT04085601), researchers compared the safety and efficacy of pegcetacoplan with that of SOC, excluding complement inhibitors, among complement inhibitor-naïve patients with PNH.

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Overall, 53 patients were enrolled and randomly assigned 2:1 to receive pegcetacoplan (35 patients) or SOC (18 patients), with the possibility of crossover to pegcetacoplan. The study’s primary endpoints were hemoglobin stabilization and change in LDH levels from baseline.

Analysis showed that, compared with SOC, pegcetacoplan was superior for both hemoglobin stabilization (85.7% vs 0% with SOC; P <.0001) and mean LDH level reduction from baseline to week 26 (-1870.5 U/L vs -400.1 U/L, respectively; P <.0001).

Patients in the pegcetacoplan group also had improved least-squares mean changes in hemoglobin levels by week 26 (2.9 g/dL vs 0.3 g/dL in SOC; P =.0019) and improved transfusion avoidance (91.4% vs 5.6%, respectively; P <.0001).

Patients treated with pegcetacoplan had a lower rate of serious adverse events (8.7% vs 16.7% with SOC). A patient in each group died because of an adverse event, although neither were considered related to treatment.

Disclosure: The study author(s) declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

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Wong RS, Navarro JR, Comia NS, et al. Efficacy and safety of pegcetacoplan treatment in complement-inhibitor naïve patients with paroxysmal nocturnal hemoglobinuria: results from the phase 3 PRINCE study. Presented at ASH 2021; December 11-14, 2021. Abstract 606.