Combining pozelimab and cemdisiran appears to be a promising strategy for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), according to research presented at the 2022 ASH Annual Meeting.

Cemdisiran and pozelimab — 2 drugs under investigation for suppressing complement activity — have shown promise in preclinical study of PNH. For this randomized phase 2 trial ( Identifier: NCT04811716), researchers are evaluating the safety and efficacy of combination pozelimab and cemdisiran among patients with PNH who have received pozelimab monotherapy. At the 2022 ASH meeting, the authors presented the trial’s safety and efficacy results.

Overall, 22 patients were randomly assigned to receive 200 mg every 4 weeks with pozelimab 400 mg every 4 weeks or every 2 weeks (arms 1 and 2, respectively). At data analysis, all patients had been randomly assigned and were receiving treatment per the study protocol, with a median duration of treatment of 57 days.

Continue Reading

Analysis showed that 95.5% of patients in the overall cohort had maintained control of lactate dehydrogenase levels through data cut-off, which was defined as 1.5 times or less the upper limit of normal. Furthermore, 90.9% of patients had hemoglobin stabilization, which was defined as lack of red blood cell transfusion and no decrease in hemoglobin levels of 2 g/dL or more.

No serious treatment-related adverse events were noted; no patients died or discontinued treatment because of an adverse event. However, 1 patient in arm 2 developed severe anemia.

“The combination of pozelimab and cemdisiran was generally well tolerated in patients with PNH who transitioned from pozelimab monotherapy…regardless of treatment arm,” the authors noted in their presentation. “Over 90% of patients maintained adequate control of hemolysis and achieved hemoglobin stabilization.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of authors’ disclosures.


Jang JH, Wong R, Pavani R, et al. A phase 2, randomized trial evaluating the safety and efficacy of pozelimab and cemdisiran in patients with paroxysmal nocturnal hemoglobinuria. Presented at ASH 2022. December 10-13, 2022. Abstract 3651.