DMT Alone Not a Good Predictor of COVID-19 Among Patients With MS

A new study from a team of investigators at the NYU Langone Multiple Sclerosis Center and the University of Alabama School of Public Health shows that higher risk of COVID-19 among individuals with multiple sclerosis (MS) cannot be predicted by disease-modifying therapy (DMT) alone. Their findings indicate that being on public insurance, younger age, and Hispanic ethnicity are better predictors of COVID-19 and related hospitalization for persons with MS.

An abstract showing these results is being presented at this year’s American Academy of Neurology 73rd Annual Meeting, held virtually April 17-22, 2021.

“We wanted to determine whether the frequency and severity of COVID-19 in patients with MS differ by DMT,” the authors stated. “To more accurately estimate whether the risk of COVID-19 varies by DMT, one need to know both the number of COVID-19 cases (numerator) and the number of patients on the given DMT (denominator). Studies thus far compared the frequency of DMTs among COVID-19 cases using numerator data only.”

Their study, which took place between March 2020 and February 2021 encompassed 1635 patients from NYU’s MS Care Center who were on any of these DMTs: rituximab, ocrelizumab, dimethyl fumarate, siponimod, or natalizumab. Either the CDC’s case definition or lab testing (polymerase chain reaction or immunoglobulin G) determined positive/negative COVID-19 status.

There were 203 cases of COVID-19 among the 66% of patients for whom lab-confirmed results were available. By DMT, most of these patients (mean [SD] age, 41.6 [12.6] years; 72% female; 84.7%, relapsing-remitting MS) were on ocrelizumab (n = 69), followed by dimethyl fumarate (n = 41), natalizumab (n = 34), siponimod (n = 30), and rituximab (n = 29). There were 3 deaths and 19 hospitalizations. Fifty-nine percent also had at least 1 comorbidity, with the most common being current or former smoker (31%). A majority were White and fully ambulatory.

However, when considering all of the patients with MS included in this study, COVID-19 was shown to happen most often among those on rituximab (18.2%) or dimethyl fumarate (15.2%), followed by natalizumab (13.2%), ocrelizumab (10.5%), and siponimod (10.2%). In addition, more of those on rituximab or dimethyl fumarate were hospitalized because of COVID-19 (17.2% and 14.6%, respectively) vs patients on ocrelizumab, siponimod, or natalizumab (7.2%, 6.7%, and 2.9%, respectively). A majority of hospitalizations were seen among Hispanic (14.3%) and Black (13.0%) patients.

Broken down by age, most COVID-19 cases were seen among patients younger than 29 years, aged 50 to 64 years, and aged 65 years and older on dimethyl fumarate and patients aged 30 to 49 years on rituximab.

Analysis also found the following:

• When just looking at COVID-19 infection, being on public insurance (odds ratio [OR], 6.1; 95% CI, 4.29-8.78), having a younger age (OR, 4.7; 95% CI, 1.73-12.76), and being Hispanic (OR, 1.7; 95% CI, 1.03-2.71) were the most significant predictors
• When looking at just COVID-19–related hospitalization, being Hispanic (OR, 4.8; 95% CI, 1.08-21.45) was the most significant predictor

The authors attributed their findings to certain socioeconomic conditions.

“Younger patients may be more likely to travel, and there are more crowded living conditions and higher COVID-19 prevalence in neighborhoods of patients on public insurance and Hispanics,” they concluded. “DMT did not predict either infection or hospitalization.”

Limitations on their results include the 34% of patients for whom lab-confirmed COVID-19 results were not available, loss of follow-up, selection bias, and limited sample size

Reference

Smith TE, Madhavan M, Gratch D, et al. Does frequency of COVID-19 differ by disease modifying therapy in MS patients? Presented at: Presented at: American Academy of Neurology 73rd Annual Meeting; April 17-22, 2021; Virtual. Accessed April 18, 2021. https://cattendee.abstractsonline.com/meeting/10429/Presentation/9014