Inebilizumab Efficacy for Neuromyelitis Optica Spectrum Disorder Not Affected by Previous Rituximab Exposure
Post hoc analysis of the N-MOmentum phase 2/3 trial (NCT02200770) suggests that prior rituximab exposure does not affect the efficacy of (Uplinza; Horizon Therapeutics; Deerfield, IL) for treating neuromyelitis optica spectrum disorder (NMOSD). Rates of annualized attack in those who previously had rituximab were similar to those who had not (annualized attack rate per person 0.08 vs 0.10).
Among those who previously took rituximab and were then treated with inebilizumab during the placebo-controlled portion of the trial (n=13), 92% had no NMOSD attacks (hazard ratio [HR] vs all placebo, 0.16; 95% CI, 0.02-1.20). Freedom from relapse continued throughout the open-label extension period for these individuals.
Among those who had previously taken rituximab and were treated with placebo in the controlled portion of the trial (n=4), 50% had attacks in the open-label period while receiving inebilizumab. All 7 participants who had experienced attacks while taking rituximab before the trial (annualized attack rate, 0.78 attacks per person year) did not experience any attacks while being treated with Uplinza.
“It is encouraging to see that in this analysis, none of the 7 patients who experienced breakthrough attacks while previously being treated with rituximab went on to experience an attack while taking Uplinza,” said Eoin P. Flanagan, MB, BCh, neurology specialist, Mayo Clinic. “Although Uplinza and rituximab both target B cells, Uplinza targets a broader range of B cells, and may explain why patients in the study who had attacks while being treated with rituximab did not experience attacks with Uplinza.”
The safety profile of inebilizumab for people was similar with or without prior rituximab treatment. Serious adverse events occurred in 2 participants previously treated with rituximab and 3 experienced serious infections. Uplinza is a B-cell-depleting humanized monoclonal antibody approved by the Food and Drug Administration (FDA) for treatment of NMOSD in adults with antibodies to aquaporin-4 (AQP4).