One-year efficacy and safety of ravulizumab in adults with paroxysmal nocturnal hemoglobinuria naïve to complement inhibitor therapy: open-label extension of a randomized study
Hubert Schrezenmeier, Austin Kulasekararaj, Lindsay Mitchell, Flore Sicre de Fontbrune, Timothy Devos, Shinichiro Okamoto, Richard A. Wells, Scott T. Rottinghaus, Peng Liu, Stephan Ortiz, Jong Wook Lee, Gèrard Socié
Abstract
BACKGROUND: Ravulizumab, the only long-acting complement C5 inhibitor for adults with paroxysmal nocturnal hemoglobinuria (PNH), demonstrated non-inferiority to eculizumab after 26 weeks of treatment in complement inhibitor-naïve patients during a phase III randomized controlled trial. We present open-label extension results with up to 52 weeks of treatment. METHODS: Patients assigned to ravulizumab every 8 weeks (q8w) or eculizumab every 2 weeks during the randomized primary evaluation period received ravulizumab q8w during the 26-week extension. Efficacy endpoints were lactate dehydrogenase (LDH) normalization, transfusion avoidance, breakthrough hemolysis (BTH), LDH levels, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale, and stabilized hemoglobin. Serum free C5 levels and safety were assessed. Outcomes as of the data cut-off (4 September 2018) were summarized using descriptive statistics. RESULTS: Overall, 124 patients continued ravulizumab, and 119 switched from eculizumab to ravulizumab. During the extension, 43.5% and 40.3% of patients in the ravulizumab-ravulizumab and eculizumab-ravulizumab arms, respectively, achieved LDH normalization; 76.6% and 67.2% avoided transfusion. BTH decreased in the eculizumab-ravulizumab arm; no events were associated with free C5 ⩾0.5 μg/mL while receiving ravulizumab. Overall, 73.4% and 65.5% of patients in the ravulizumab-ravulizumab and eculizumab-ravulizumab arms, respectively, achieved stabilized hemoglobin. Similar proportions of patients achieved ⩾3-point improvement in FACIT-Fatigue at week 52 (ravulizumab-ravulizumab, 64.5%; eculizumab-ravulizumab, 57.1%). All patients maintained free C5 <0.5 μg/mL during the ravulizumab extension, including those who experienced C5 excursions ⩾0.5 μg/mL while receiving eculizumab during the primary evaluation period. Adverse events were comparable between groups and decreased over time. CONCLUSION: In adult, complement inhibitor-naïve patients with PNH, ravulizumab q8w for up to 52 weeks demonstrated durable efficacy and was well tolerated, with complete and sustained free C5 inhibition and a decreased incidence of BTH with no events associated with loss of free C5 control. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02946463.