Study Questions Anti-CD20 Therapy Benefits in Multiple Sclerosis

New research indicates that patients with multiple sclerosis (MS) treated with anti-CD20 antibodies, such as Roche's Ocrevus, do not experience a significantly slower progression of disability. The study, published in the journal Neurology, suggests that anti-CD20 therapies might not considerably slow the progression of disability in patients with primary progressive multiple sclerosis (PPMS).

The researchers carried out a retrospective study involving 1,184 patients, where 758 patients had never received anti-CD20 antibodies, and 426 had been treated with them. Among the treated group, 131 patients received Roche’s Ocrevus (ocrelizumab), while 295 were treated with Roche and Biogen’s Rituxan (rituximab), which is not officially approved for PPMS but is often used off-label for this condition.

The study revealed no significant differences in clinical efficacy endpoints between those treated with anti-CD20 antibodies and those who were not. Specifically, the time to the first confirmed disability progression was statistically similar between the two groups, with a p-value of 0.2113. Additionally, there was no significant difference in disease activity as observed through magnetic resonance imaging (MRI) scans.

Anti-CD20 therapies did show a trend toward fewer relapses compared to untreated patients, yet this effect did not reach statistical significance. According to the study’s lead author, Laure Michel, anti-CD20 therapies are commonly prescribed due to the limited availability of alternative treatments. However, the findings suggest that these therapies may not effectively slow the worsening of disability in people with primary progressive MS. Michel emphasized the need for continuous evaluation of MS treatments to ensure their benefits outweigh the risks.

The authors of the study called for further research involving a larger pool of patients and better-controlled study designs to confirm these preliminary findings.

Anti-CD20 therapies like Ocrevus work by targeting the cell surface protein CD20, found on immature and mature B lymphocytes. Once bound, these antibodies initiate the destruction of the cell. Other FDA-approved therapies using this mechanism include Novartis’ Kesimpta (ofatumumab) and TG Therapeutics’ Briumvi (ublituximab). However, unlike Ocrevus, these treatments are prescribed for relapsing forms of MS rather than specifically for PPMS.

Ocrevus received FDA approval in March 2017 for both relapsing and primary progressive MS. Roche supported Ocrevus' approval with several late-stage trials, including the Phase III ORATORIO trial for PPMS. This study indicated that Ocrevus could significantly delay disability progression and reduce disease activity in the brain compared to a placebo.

Since its market entry, Ocrevus has become one of Roche’s top-selling products, generating approximately $7.5 billion in 2023. According to Roche, Ocrevus was one of the company's main growth drivers last year.