To understand the real-world clinical and economic burden in people with nonrelapsing secondary progressive multiple sclerosis (nrSPMS) in the United States (US).

A portion of people diagnosed with relapsing-remitting MS eventually progress to SPMS overtime. However, many people with SPMS show disability progression in the absence of clinical relapses and can be termed as nrSPMS. Currently, data on the clinical and economic burden of nrSPMS are lacking.

The final cohort comprised 856 people with nrSPMS and 856 matched controls. At index, mean±SD age of nrSPMS cohort was 54.4±10.7 years; majority were female (79.8%). Infections (53.9% vs. 48.8%; P=0.038) and leukopenia (1.3% vs. 0.8%) were more frequent in people with nrSPMS compared to controls. The most frequent MS-related comorbidities in people with nrSPMS versus controls included malaise/fatigue (31.3% vs. 15.3%; P<0.001), depression (28.6% vs. 20.8%; P<0.001), and abnormal gait (16.0% vs. 3.7%; P<0.001). The nrSPMS cohort had higher mortality (2.2% vs. 1.1%; P=0.057), hospitalizations (10.7% vs. 10.3%), emergency visits (30.5% vs. 28.5%) and physician visits (mean: 12.6 vs. 10.1; P<0.001) during the follow-up period; the mean total HCCs were significantly higher versus controls ($58,412 vs. $24,827; P<0.001), which was primarily driven by outpatient pharmacy ($34,830 vs. $4,623; P<0.001) and physician visit ($4,110 vs. $2,072; P<0.001) costs.

Overall, people with nrSPMS had more comorbidities and substantially higher HCCs compared to matched controls, resulting in considerable clinical and economic burden in this population for whom no approved therapies exist.