Switch from Anti-CD20 to Fumarate May Be a Viable Treatment Option for MS

Patients with stable MS who switched from anti-CD20 to fumarate experienced reductions in infection-related health resource utilization.

Among patients with multiple sclerosis (MS) who switch from anti-CD20 monoclonal antibody (mAb) therapy to treatment with fumarate, reductions in infection-related health resource utilization (HRU) have been reported. These are the findings of a study presented at the 2023 Consortium of Multiple Sclerosis Centers (CMSC) Annual Meeting, held from May 31 to June 3 in Aurora, Colorado.

A variety of disease-modifying therapies (DMTs) with different modes of action are used to treat individuals with MS. In the United States, the most frequently used classes of DMTs are anti-CD20 mAbs and fumarates.

Researchers conducted a secondary data analysis of a retrospective, comparative case-control study of the Komodo Health Sentinel Claims Database, in which they sought to estimate infection-associated HRU, disease relapses, and costs among patients with stable MS who switched from an anti-CD20 mAb to a fumarate.

All participants were age 18 and older and had a claim during the study period between January 1, 2015 and August 31, 2022. Patients who switched from an anti-CD20 mAb to a fumarate from January 1, 2016 to May 31, 2022, who experienced no relapses in either the prior year on anti-CD20 therapy or during the washout period, and who had
3 or more months’ exposure to a fumarate following the switch in treatment were included in the analysis.

These outcomes suggest that FUM may be a reasonable treatment option in patients who are stable on anti-CD20 but are considering transition for nonefficacy reasons.

A total of 47 individuals (74% women; mean age, 47.0) with MS fulfilled eligibility criteria and were enrolled in the study.

The participants used the following anti-CD20 mAbs: ocrelizumab (85%); rituximab (11%); and ocrelizumab to rituximab (4%).

The fumarates used in the switch included the following: dimethyl fumarate (64%); diroximel fumarate (34%); and dimethyl fumarate to diroximel fumarate (2%).

Among 40 participants with data available at 1-year prior to receiving anti-CD20 mAb therapy, these were the following findings:

  • Mean annualized relapse rate prior to receiving anti-CD20 therapy: 0.08±0.27
  • Mean duration on anti-CD20 therapy: 21.2±9.2 months
  • Mean duration from last anti-CD20 dose to fumarate switch: 7.2±3.3 months

One patient experienced a relapse following the fumarate switch; this individual had started fumarate at 27.4 weeks after the last anti-CD20 dose, relapsed at 6.4 weeks after the switch, and remained on fumarate following the relapse.

From baseline (ie, at 1-year prior to fumarate initiation) to after the start of fumarate (mean exposure: 10.2±7.8 months), the outcomes reported to date are as follows:

  • Reductions in annualized infection-linked health care encounters (HCEs) from a
    mean of 0.74±1.34 to a mean of 0.41±0.96
  • Infection-related HCEs: 38% of patients at baseline vs 26% following switch in DMT

All-cause HRU, all-cause and infection-associated health care costs, and outcomes vs matched controls who remained on anti-CD20 mAbs all remain to be reported.

“These outcomes suggest that FUM [fumarate] may be a reasonable treatment option in patients who are stable on anti-CD20 but are considering transition for nonefficacy reasons,” the researchers concluded.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Ben-Zaccharia AB, Feng J, Moss B, et al. Clinical characteristics and treatment outcomes in MS patients treated with anti-CD20s who switched to fumarates. Abstract presented at: CMSC 2023; May 31-June 3, 2023; Aurora, CO. Abstract DMT09.