Amgen, the sponsor of the clinical trial evaluating ABP 959, an eculizumab biosimilar, in subjects with paroxysmal nocturnal hemoglobinuria (PNH), has recently provided updated information on study status, document section, and outcome measures as published on

The randomized, double-blind, active-controlled phase 3 study enrolled 42 participants aged 18 years or older with a diagnosis of PNH.

Participants were randomized to receive ABP 959 and eculizumab (Soliris®), both intravenously, in 1 of 2 treatment sequences: ABP 959 every 14±2 days for 52 weeks in period 1 followed by eculizumab every 14±2 days for 26 weeks in period 2, or eculizumab every 14±2 days for 52 weeks in period 1 followed by ABP 959 every 14±2 days for 26 weeks in period 2. There was no washout between periods 1 and 2.

The primary outcome measures of the study were lactate dehydrogenase (LDH) level at week 27 (parallel comparison) and time-adjusted area under the effect curve of LDH (crossover comparison per assigned treatment).

Read more about PNH experimental therapies

Secondary objectives of the study were mean total complement, mean total hemoglobin levels, mean serum-free hemoglobin levels, mean haptoglobin levels, mean bilirubin levels, degree of hemoglobinuria, mean percentage of type III erythrocytes, LDH levels, mean LDH levels, mean number of packed red blood cell units transfused per month, total and unbound pharmacokinetics area under the curve of ABP 959 and eculizumab, total and unbound trough serum concentrations of ABP 959 and eculizumab, number of participants with treatment-emergent adverse events, and number of participants with antidrug antibodies.

Two participants, one from each study arm, have not completed the study. One of them (eculizumab/ABP 959 group) discontinued the study due to an adverse event during period 1.

The study began on January 22, 2019. The results were first submitted on March 23, 2023 and were first posted on May 23, 2023.


A study evaluating the efficacy and safety of ABP 959 compared with eculizumab in adult participants with PNH (DAHLIA). January 28, 2019. Updated May 23, 2023. Accessed May 30, 2023.