New research has found that MS patients treated with anti-CD20 antibodies, such as Roche’s Ocrevus, do not experience significantly slower progression of disability.
Anti-CD20 therapies might not significantly slow the progression of disability in patients with primary progressive multiple sclerosis, according to a study published Wednesday in the journal Neurology.
Researchers conducted a retrospective study of 1,184 patients, of whom 758 had never been treated with anti-CD20 antibodies, while the remaining 426 had. Of those with prior anti-CD20 exposure, 131 were given Roche’s Ocrevus (ocrelizumab), while the other 295 were treated with Roche and Biogen’s Rituxan (rituximab), which is not approved for primary progressive multiple sclerosis (PPMS) but is often used off-label in this indication.
Results showed no significant difference between treated and untreated patients across several clinical efficacy endpoints. The time to first confirmed disability progression was statistically comparable between patient groups, with a p-value of 0.2113, according to the paper.
Anti-CD20 therapies demonstrated a “trend toward fewer patients relapsing” versus untreated patients, but this effect also fell short of statistical significance. Magnetic resonance imaging found no difference in disease activity between the groups.
“Anti-CD20 therapies are widely prescribed, in part because there are few alternate treatments. However, our study suggests they may not slow disability from worsening for people with primary progressive MS,” study author Laure Michel said in a statement, noting that the findings suggest there should be “constant evaluation” for MS treatments to accurately determine if their “benefits outweigh the risks.”
Further studies—in a larger group of patients and with more well-controlled designs—are needed to confirm these findings, according to the paper’s authors.
Anti-CD20 therapies like Ocrevus work by targeting and binding to the cell surface protein CD20, which is commonly found on immature and mature B lymphocytes. After binding to its target, anti-CD20 antibodies trigger the destruction of the cell.
Several other FDA-approved therapies use this mechanism of action for MS, including Novartis’ Kesimpta (ofatumumab) and TG Therapeutics’ Briumvi (ublituximab). Unlike Ocrevus, however, these treatments are indicated for relapsing forms of the disease, and not specifically for PPMS.
Ocrevus was approved in March 2017 for both relapsing and primary progressive MS. Roche backed Ocrevus with several late-stage studies, including the Phase III ORATORIO trial in PPMS. Results from this study showed that Ocrevus could significantly delay the progression of disability and reduce disease activity in the brain, compared with placebo.
Since hitting the market, Ocrevus has become one of Roche’s top-selling assets, earning around $7.5 billion in 2023. According to the company, Ocrevus was one of its “main growth drivers” last year.
