Biosimilar Found Equivalent to Natalizumab for Relapsing-Remitting MS

Biosimilar natalizumab PB006 (biosim-NTZ; Polpharma Biologics SA, Warsaw, Poland) is comparable in safety, immunogenicity, and efficacy for treatment of relapsing-remitting multiple sclerosis (RMMS) when compared with reference natalizumab (ref-NTZ), according to a study published in JAMA Neurology. The study met its primary endpoint with a similar cumulative number of new active lesions reported in both treatment groups and no differences in secondary outcomes among groups, including disability. PB006 is the first biosimilar antibody developed for MS.

In this phase 3, parallel-group, randomized, active-controlled study (Antelope, NCT04115488), 264 participants aged 18 to 60 years diagnosed with RRMS were enlisted. Participants had 1 or more MS relapse within the prior year, evidence of brain lesions on MRI, and were ambulatory according to Kurtzke Expanded Disability Status Score (EDSS of 0 to 5.0). Participants were randomized to receive intravenous infusions every 4 weeks of either biosim-NTZ 300 mg or ref-NTZ 300 mg for 44 weeks. At the 24th week, the ref-NTZ group was rerandomized, and 30 patients received ref-NTZ for the duration of the study. The primary endpoint was to evaluate the number of new active lesions, either new gadolinium-enhancing T1-weighted or new/enlarging T2-weighted lesions, visualized through MRI. The study took place in 48 healthcare centers in Croatia, Belarus, Georgia, Moldova, Poland, Serbia, and Ukraine. 

Treatment-emergent adverse event rates per 100 patient-years were similar across all treatment groups (biosim-NTZ, 85 [64.9%]; ref-NTZ, 71 [68.9%]; ref-NTZ/biosim-NTZ switch, 22 [73.3%]). At week 24, 79.4% in the biosim-NTZ cohort and 74% in the ref-NTZ treatment group were positive for treatment-emergent antidrug antibodies. The model-based mean difference in the cumulative number of new active lesions between treatment groups at week 24 was 0.17 (least square means [SE]: biosim-NTZ, 0.34 [0.34]; ref-NTZ, 0.45 [0.28], 95% CI, –0.61 to 0.94). Both medications had similar immunogenicity, safety, and efficacy points for the duration of the trial.