Uplizna effective in patients with NMOSD previously treated with rituximab

Uplizna appeared to benefit patients with neuromyelitis optica spectrum disorder who were previously treated with rituximab, according to study results published in Multiple Sclerosis and Related Disorders.

“Rituximab is an anti-CD20 B-cell-depleting agent that has historically been used to help prevent attacks in neuromyelitis optica spectrum disorder (NMOSD),” Eoin P. Flanagan, MB, BCh, a neurologist at Mayo Clinic, told Healio Neurology. “Uplizna (inebilizumab; Horizon Therapeutics) is a recently approved medicine that targets and depletes CD19-expressing B cells, including plasmablasts and some plasma cells not targeted by anti-CD20 therapies like rituximab. Because of their closely related mechanisms of action, it is important to understand the effects of inebilizumab in patients with prior rituximab exposure to determine whether it may be a suitable treatment option.”

Flanagan and colleagues conducted a post hoc analysis of data from the N-MOmentum study to examine the efficacy and tolerability of inebilizumab among 17 patients who previously received rituximab. They randomly assigned 13 patients to receive inebilizumab. They assessed adjudicated attacks, secondary efficacy outcomes and treatment-emergent adverse events by previous use of rituximab during a 6-month randomized control period and open-label period.

A total of seven participants had breakthrough attacks before enrollment despite rituximab use, for an annualized attack rate of 0.78 attacks per person-year. While receiving inebilizumab in the randomized control period, one of 13 patients with prior rituximab use had an attack (HR vs. all placebo, 0.16; 95% CI, 0.02-1.2). Two other participants with prior rituximab use had attacks on inebilizumab during the open-label period, for an overall annualized attack rate of 0.08 attacks per person-year, which was similar to that of participants without prior rituximab use. No participants who had attacks while taking rituximab had an attack while taking inebilizumab. Two participants with prior rituximab use had serious treatment-emergent adverse events associated with inebilizumab, with serious or grade 3 or higher infections occurring among three participants each. The researchers reported no deaths or opportunistic infections among this cohort.

“It is positive to see that in this analysis, inebilizumab appeared to be effective among patients previously treated with rituximab, and that all seven patients who had experienced attacks while being treated with rituximab were attack-free after being treated with inebilizumab,” Flanagan said. “There was a potential for infection and reduced IgG levels in those treated with both inebilizumab and rituximab and that will require further study in larger numbers of patients. The findings of this analysis are important in helping clinicians make more informed decisions when considering transitioning their patients from rituximab to inebilizumab.”