Eculizumab and ravulizumab are safe and efficient in the long term for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), according to 20-year-long data from the UK presented at the 64th ASH Annual Meeting and Exposition.

The study authors also reported that the overall survival of the treated patients remained high and complications such as thromboses, meningococcal infections, and clonal evolution were uncommon.

Complement protein 5 (C5) inhibition with eculizumab or ravulizumab is the standard of care for PNH. 

Here, a team of researchers led by Shreyans Ghandi, MD, from King’s College Hospital in London conducted a retrospective analysis of case records of all 509 patients with PNH treated with eculizumab or ravulizumab in the UK since May 2002. 

Read more about the etiology of PNH 

The researchers collected information about the clinical features of the patients before the start of the treatment, any previous history of bone marrow failure, and outcomes while being on treatment.

They reported that between May 2002 and July 2022, 91 patients died. This means that the survival rate of patients on either treatment was 79% over the 20-year period. In 44 (48.4%) patients, infection was implicated in the cause of death.

There were 11 cases of septicemia due to Neisseria meningitidis in 10 patients, which corresponded to a meningococcal infection rate of 1 event per 284.5 years.

Clonal evolution to acute leukemia was reported in 7 (1.4%) patients and to myelodysplastic syndrome in 10 (2%) patients.

Eculizumab and ravulizumab are C5 inhibitors that function by directly binding to C5, thereby stopping its cleavage to C5a and C5b. This prevents terminal complement activation and hemolysis, which are the characteristics of PNH, symptoms of which include hemoglobinuria, dysphagia, abdominal pain, breathlessness, fatigue, lethargy, and erectile dysfunction in men.


Kelly R, Holt M, Vidler J, et al. Treatment outcomes of complement protein C5 inhibition in 509 patients with paroxysmal nocturnal hemoglobinuria in the United Kingdom. 64th ASH Annual Meeting and Exposition. New Orleans, LA; December 10-13, 2022. Poster number 2566.