Outcomes With Eculizumab and Responses to Withdrawal for Atypical Hemolytic Uremic Syndrome

Withdrawal of eculizumab may be safe for some patients with atypical hemolytic uremic syndrome (aHUS), according to results reported in the British Journal of Haematology.

Traditionally, aHUS has shown a poor prognosis, but eculizumab therapy has been efficacious in treating this condition. However, the optimal duration of treatment with eculizumab is unclear, and use of the drug poses some risks, such as meningococcal disease.

Researchers from the United Kingdom recently completed a retrospective analysis of treatment outcomes for 22 patients who were treated with eculizumab for acute aHUS after a median of 6 days of plasmapheresis.

All patients showed hematologic recovery after a median of 11 weeks of treatment with eculizumab. At this point, 81% of patients with initial renal impairment showed a higher estimated glomerular filtration rate (eGFR), with a median increase of 49 mL/min/1.73 m².

Follow-up occurred at a median period of 85 weeks, at which point 54.5% of patients had reached an eGFR of at least 60 mL/min/1.73 m². By this time, 4.5% of patients had died, and 14% were receiving dialysis. Poorer renal recovery was associated with higher initial creatinine levels.

Upon complete hematologic and renal recovery, 59% of patients underwent withdrawal of eculizumab. Relapse occurred for 3 patients within the first year following withdrawal. Each patient completely recovered after promptly restarting eculizumab therapy. Among patients who had eculizumab withdrawn, 76.9% were still in remission by the final follow-up, for a median of 66 weeks since eculizumab was withdrawn.

Complement genetic abnormalities were found in 40.9% of patients, though these abnormalities did not show a significant relationship to disease severity. However, relapse risk was significantly greater for patients with a complement genetic abnormality (P =.035).

The authors noted the need for randomized controlled trials to confirm the safety of eculizumab withdrawal and suggested a minimum of 6 months of eculizumab administration to avoid the increased relapse risk seemingly associated with shorter durations of therapy.

Reference

1. Neave L, Gale DP, Cheesman S, Shah R, Scully M. Atypical haemolytic uraemic syndrome in the eculizumab era: presentation, response to treatment and evaluation of an eculizumab withdrawal strategy [published online March 27, 2019]. Br J Haematol. doi:10.1111/bjh.15899