Normalisation of haemoglobin and control of breakthrough haemolysis with increased frequency pegcetacoplan dosing in treated paroxysmal nocturnal haemoglobinuria

Abstract

Paroxysmal nocturnal haemoglobinura is an acquired life-threatening haemolytic condition, which is generally well controlled with terminal complement blockade with eculizumab. Whilst almost all patients treated with terminal complement inhibitors develop extravascular haemolysis, only a small proportion of these results in symptomatic anaemia limiting their activities and requiring red cell transfusion. This case highlights the potential role for the C3 inhibitor, pegcetacoplan, in controlling both intravascular and extravascular haemolysis, and is the first case to report on the use of additional doses of pegcetacoplan to control breakthrough haemolysis.

Keywords: PNH; breakthrough haemolysis; pegcetacoplan.

FIGURE 1

Normalisation of haemoglobin (Hb) and LDH with introduction and subsequent increased dosing with pegcetacoplan in patient with paroxysmal nocturnal haemoglobinura (PNH). Red line shows haemoglobin (g/L) normalisation with introduction of pegcetacoplan. Red cell transfusions only required prior to pegcetacoplan and during crossover period of eculizumab and pegcetacoplan. P1 represents twice weekly pegcetacoplan 1080 mg s/c. Additional dose of eculizumab 1200 mg IV for unexplained breakthrough haemolysis (BTH) demonstrated by raised LDH (black line) on 11th January 2021 and pegcetacoplan 1080 mg s/c daily for 3 days on 20th April 2021 (P). P2 represents increase to three times a week pegcetacoplan 1080 mg s/c. Subsequent BTH 20th April 2022 due to severe skin reaction resolved with pegcetacoplan 1080 mg s/c daily for 3 days (P). Single dose eculizumab 1200 mg IV given prior to laminectomy September 2022 (E). LDH, Lactate dehydrogenase.