Crovalimab treatment in patients with paroxysmal nocturnal haemoglobinuria: Long‐term results from the phase I/II COMPOSER trial
Alexander Röth, Satoshi Ichikawa, Yoshikazu Ito, Jin Seok Kim, Zsolt Nagy, Naoshi Obara, Jens Panse, Hubert Schrezenmeier, Simona Sica, Juliette Soret, Kensuke Usuki, Sung‐Soo Yoon, Nadiesh Balachandran, Muriel Buri, Pontus Lundberg, Himika Patel, Kenji Shinomiya, Alexandre Sostelly, Jun‐ichi Nishimura
Abstract
OBJECTIVES: This study reports long-term outcomes from the open-label extension (OLE) period of the Phase I/II COMPOSER trial (NCT03157635) that evaluated crovalimab in patients with paroxysmal nocturnal haemoglobinuria, who were treatment-naive or switched from eculizumab at enrolment. METHODS: COMPOSER consists of four sequential parts followed by the OLE. The primary OLE objective was to assess long-term crovalimab safety, with a secondary objective to assess crovalimab pharmacokinetics and pharmacodynamics. Exploratory efficacy endpoints included change in lactate dehydrogenase (LDH), transfusion avoidance, haemoglobin stabilisation and breakthrough haemolysis (BTH). RESULTS: A total 43 of 44 patients entered the OLE after completing the primary treatment period. Overall, 14 of 44 (32%) experienced treatment-related adverse events. Steady state exposure levels of crovalimab and terminal complement inhibition were maintained over the OLE. During the OLE, mean normalised LDH was generally maintained at ≤1.5× upper limit of normal, transfusion avoidance was achieved in 83%-92% of patients and haemoglobin stabilisation was reached in 79%-88% of patients across each 24-week interval. Five BTH events occurred with none leading to withdrawal. CONCLUSIONS: Over a 3-year median treatment duration, crovalimab was well tolerated and sustained C5 inhibition was achieved. Intravascular haemolysis control, haemoglobin stabilisation and transfusion avoidance were maintained, signifying long-term crovalimab efficacy.