Among patients with paroxysmal nocturnal hemoglobinuria (PNH), SB12 appears to be clinically equivalent to eculizumab for improving lactate dehydrogenase (LDH) levels, according to research presented at the EHA 2022 Hybrid Congress.
SB12 is a proposed biosimilar to eculizumab. Previous study suggests that the drug — a humanized monoclonal antibody targeting complement C5 cleavage — blocks terminal complement-mediated intravascular hemolysis.
For this randomized phase 3 study (ClinicalTrials.gov Identifier: NCT04058158), researchers compared the LDH levels, safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity after SB12 treatment with those of eculizumab among patients with PNH.
Overall, 50 patients with PNH, all at least 18 years of age, were included. Patients had LDH levels of at least 1.5 more than the upper limit of normal; none had received prior complement therapy.
Out of the 50 enrolled patients, 46 completed the study protocol. At week 26, the mean difference in LDH levels between SB12 and eculizumab were within the researchers’ pre-defined margin of equivalence (difference, 34.48; 95% CI, -47.66-116.61). The time-adjusted area of under the effect curve of LDH levels, similarly, was within the equivalence margin (1.08; 90% CI, 0.95-1.23).
No significant difference, furthermore, was noted in the number of transfused units of packed red blood cells, and PK and PD appeared similar.
Treatment-related adverse events occurred in 72.3% and 68.1% of patients in the SB12 and eculizumab groups, respectively. No cases of anti-drug antibody development were observed.
“SB12 showed clinical equivalence to [eculizumab] measured by LDH,” the authors wrote. “SB12 and [eculizumab] were comparable in terms of safety, PK, PD, and immunogenicity.”
Jang JH, Gomez RD, Bumbea H, et al. A phase III randomized clinical trial comparing SB12 (proposed eculizumab biosimilar) with reference eculizumab in patients with paroxysmal nocturnal hemoglobinuria. Presented at EHA 2022; June 9-12, 2022. Abstract P829.