Department of Research & Evaluation News

A novel treatment algorithm developed and implemented within Kaiser Permanente Southern California increased the use of effective medications for people with multiple sclerosis (MS), and reduced treatment disparities for Hispanic and Black patients.

“Studies show Hispanic and Black people with MS typically have higher levels of disability than white people, but no studies have addressed whether this is because they were less likely to receive highly effective treatments compared to white people,” said study author Annette Langer-Gould, MD, PhD, an affiliated investigator with the Kaiser Permanente Southern California Department of Research & Evaluation, and a neurologist at the Kaiser Permanente Los Angeles Medical Center. “We’re excited that we’ve found a straightforward way to rapidly increase the use of these highly effective medications among all 3 groups, greatly improving health for all people.”

The study was published in April 2025 in Neurology.

Algorithm debuted in 2012

In 2012, Kaiser Permanente Southern California – one of the largest health maintenance organizations in the United States with over 4.7 million members – launched the Multiple Sclerosis Treatment Optimization Program (MSTOP). MSTOP is a novel, multi-faceted health systems-level intervention designed to increase the use of highly efficacious treatments, mostly rituximab, while simultaneously improving access to and affordability of MS specialty care.

Langer-Gould said MSTOP was motivated by research showing that Black and Hispanic people with MS had higher levels of disability and become disabled at younger ages. Also, young Black people with MS were more likely to die from the disease.

Algorithm finds best treatment

The program uses an algorithm developed by Kaiser Permanente’s MS specialist group to find the best disease-modifying treatments for people with MS. The algorithm uses readily available clinical factors such as weakness and bladder dysfunction, and considers social factors such as out-of-pocket costs, transportation barriers, childcare, and work schedules, but not race and ethnicity.

The algorithm offers clear, measurable guidance to clinicians on prescribing MS medications, prioritizing lower-cost medications, and supporting people with MS who have financial or other barriers to medication adherence.

Intervention matched patients to newer treatments

The intervention can match people to newer treatments that are highly effective at reducing MS relapses, including medications like natalizumab, rituximab, and ofatumumab. Relapses are when MS symptoms like numbness, weakness, stiffness, or vision problems appear for at least 24 hours. Because some of these drugs are expensive, not everyone with MS may be able to get them, which can widen health disparities.

The study involved 1,741 Hispanic people, 978 Black people, and 3,400 white people with MS who were being treated with disease-modifying therapies. Three years before the start of the study, Hispanic people, followed by Black people, had a higher annual relapse rate than white people, with 245 and 186 relapses compared to 156 relapses per 1,000 person-years. Person-years represent both the number of people in the study and the amount of time each person spends in the study.

The researchers compared treatments and annual relapse rate by race and ethnicity from 2009 to 2011, before the program was implemented, with types of treatments used and annual relapses from 2012 to 2023. Over the 12-year study, researchers found all 3 groups had an increased use of highly effective therapies, primarily rituximab, which is less expensive and can be given once a year or less. The use of highly effective therapies increased by 89% for Hispanic patients, 87% for Black patients, and 83% for white patients.

MS relapse rates declined

After adjusting for age and sex, researchers reported a decline in the annual relapse rate for each group. The decline was greatest among Hispanic people at 90% fewer relapses per year, white people at 86%, and Black people at 82%. By the end of the study in 2023, there was no longer a significant difference in the annual relapse rate among Hispanic, Black, and white people.

“Our intervention may have been successful in increasing highly efficacious treatments because the algorithm is concrete and relatively simple, relying on medical factors and laboratory tests that are readily available to clinicians,” Dr. Langer-Gould said. “We think it was successful in achieving not only equality but also equity because it incorporates social determinants of health that adversely affect adherence, including social economic status, yet it does not mention race or ethnicity, thereby reducing unconscious bias.”

Study underscores use of rituximab for MS

In addition to improving outcomes for MS patients, the study also adds to the growing literature supporting the real-word effectiveness of rituximab in treating relapsing MS and underscores the importance of removing barriers to accessing rituximab biosimilars, Dr. Langer-Gould said. Rituximab, an anti-CD20 monoclonal antibody, is approved in the United States for the treatment of certain blood cancers and autoimmune diseases including rheumatoid arthritis. While rituximab meets FDA criteria for approval as an MS treatment based on multiple studies showing efficacy in MS, a specific U.S. law intended to benefit manufacturers of very expensive, branded products effectively bars rituximab from becoming FDA-approved for MS.

In the meantime, Dr. Langer-Gould and her colleagues are assessing whether the treatment algorithm improves long-term disability outcomes and whether starting these highly effective treatments at diagnosis is more beneficial than delaying these treatments until later in the disease course.

Authors on this study in addition to Dr. Langer-Gould include Bonnie H Li, MS; Jessica B Smith, MPH; and senior author Stanley Xu, PhD; with the Department of Research & Evaluation; Michael H Kanter, MD, with the Kaiser Permanente Bernard J. Tyson School of Medicine; Kirsten R Choi, with the Department of Research & Evaluation and UCLA. Dr. Langer-Gould and Dr. Xu are also with the Kaiser Permanente Bernard J. Tyson School of Medicine.