Rituximab is Associated with Limiting Progression in Individuals with Stiff Person Syndrome Spectrum Disorders
Kimystian Harrison1, Chen Hu1, Salman Aljarallah2, Yujie Wang3, Kathryn Fitzgerald1, Scott Newsome1
1Department of Neurology, Johns Hopkins University, School of Medicine, 2Department of Medicine, King Saud University, 3Department of Neurology, University of Washington
Objective:
To assess if rituximab minimizes disease progression in people with Stiff Person Syndrome Spectrum Disorders (SPSD).
Background:
Rituximab has been used to treat many autoimmune conditions including SPSD. However, there is a lack of long-term data assessing rituximab in a large cohort of people with SPSD. We previously analyzed the effects of rituximab in a small group of people with SPSD and focused on improvement of function. The purpose of this study was to evaluate the effects of rituximab in a larger cohort of patients over a longer duration of time and assess how this therapy minimizes disease progression.
Design/Methods:
Demographic and clinical data from 235 SPSD patients evaluated at the Johns Hopkins SPS Center were obtained as part of an ongoing longitudinal observational study. Data analysis was performed in patients who met the following inclusion criteria: confirmed diagnosis of SPSD, exposure to rituximab therapy, and >1 follow-up visit with adequate clinical information for outcome measure comparisons. The main outcomes were change in relevant symptoms, objective findings, and global score (combined subjective and objective data).
Results:
Of 69 SPSD patients with rituximab exposure (81% female, age M±SD=49y±13.6y), data analysis was performed in 63 patients who met the inclusion criteria. The median (IQR) years between symptom onset and rituximab exposure was 9.17y (4.46y, 13.26y). At baseline, 97% self-reported gait difficulties, 88% had objective gait abnormalities, and mean (SD) modified Rankin score was 3.0 (0.83). The median and maximum follow-up times were 1.1y and 9.4y, respectively. Based on global scores over the follow-up period, 37 (58.7%) improved, 21 (33.3%) stabilized, and 5 (7.9%) worsened after rituximab exposure.
Conclusions:
The findings of this study suggest that many patients with SPSD may experience plateauing of worsening disability with chronic rituximab treatment. Specific factors associated with treatment response remain unclear and warrant further studies.