Experience of bortezomib use in refractory autoimmune neurological disorders

Bortezomib (BTZ) is a proteasome inhibitor depleting plasma cells. We share experience of BTZ use in patients with refractory autoimmune-mediated neurological disorders and its safety characteristics.

This single-center (AIMS, Kochi, India) retrospective cohort study included 29 patients (aged 44±21 years, 15 males) with refractory and aggressive course of autoimmune encephalitis (anti-NMDAR (n = 8), seronegative (n = 2), anti-DR2 (n = 1), Hashimoto encephalopathy (n = 1)), neuromyelitis optica spectrum disorder (n = 2), seronegative optic neuritis (n = 1), myasthenia gravis (n = 2), myelitis (n = 3), postinfectious demyelination (n = 1), vasculitic peripheral neuropathy (n = 1), autoimmune atypical parkinsonism (n = 5), autoimmune ataxia (n = 1), cramp-fasciculation syndrome (n = 1). We used Wilcoxon signed rank test and univariate binary logistic regression to assess outcomes.

The median mRS-9Q score was 4 at BTZ initiation; 3 at 60 days after (z=-3.59; p< .001) and the last documented mRS-9Q score in patients having a longer follow-up (n = 27 [93 %]; z=-2.40; p=.016). Out of 28 patients who had a follow-up, 13 (46 %) patients had no registered adverse events (AE), 4 (14 %) had mild and moderate AE, 8 (29 %) had severe but not immediately life-threatening AE, 1 (4 %) - life-threatening AE, and 2 died of SARS-CoV2 infection. However, this could not be attributed to BTZ use alone, as the number of BTZ doses and the duration on active treatment including BTZ did not correlate with having any grade of an adverse event.

In our cohort bortezomib appeared to improve mRS-9Q scores, especially in the cohort of anti-NMDAR encephalitis; infection was the most common side effect which, however, could not be attributed to bortezomib use alone.