Did you know that there are multiple forms of multiple sclerosis (MS)? The most common form of MS is relapsing-remitting, meaning patients go through symptomatic periods and periods of remission. However, patients with primary progressive multiple sclerosis (PPMS) experience continued and progressive worsening of symptoms with no relapses or periods of remission. According to MedPage Today, researchers recently evaluated whether ocrelizumab inhibited disease progression and improved patient outcomes through the Phase 3 ORATORIO trial’s extension period. Ultimately, they discovered that ocrelizumab did benefit patients by reducing disease progression. Check out the full results published in The Lancet Neurology.

Ocrelizumab

Developed by Genentech, ocrelizumab, also known as Ocrevus, is designed to treat patients with multiple sclerosis. Multiple Sclerosis News Today suggests that ocrelizumab is a humanized monoclonal antibody. According to the National Cancer Institute (NCI), a humanized monoclonal antibody is:

A type of antibody made in the laboratory by combining a human antibody with a small part of a mouse or rat monoclonal antibody. The mouse or rat part of the antibody binds to the target antigen, and the human part makes it less likely to be destroyed by the body’s immune system.

In this case, ocrelizumab binds to CD20-positive B-cells, which are believed to play a role in the destruction of myelin sheaths. Currently, ocrelizumab is the only FDA-approved modification treatment for patients with both forms of MS. This approval hinged on data from the Phase 3 OPERA I, Phase 3 OPERA II, and Phase 3 ORATORIO clinical trials. Patients in the ORATORIO trial received 600mg ocrelizumab every 6 months. The drug is administered intravenously. Compared to a placebo, the treatment significantly improved disease progression.

ORATORIO Extension Trial

Altogether, 732 participants enrolled in the ORATORIO trial. Of these, 488 initially received ocrelizumab (2 infusions, 2 weeks apart, of 300mg each) while 244 received a placebo every 24 weeks (5.5 months) for 2.3 years. After completing the double-blind part of the clinical trial, patients were able to join the extension trial. Altogether, 527 of the initial 732 participants enrolled in the extension. To this day, 451 participants are still enrolled. Once in the extension phase, all patients were administered ocrelizumab.

During the extension trial, researchers determined:

• Patients with PPMS who began ocrelizumab in the ORATORIO trial had better outcomes than those who started with a placebo and switched to ocrelizumab.
• Ocrelizumab offered a significant advantage to patients in relation to maintaining balance, coordination, and muscle strength.
• Altogether, the therapy was fairly safe and well-tolerated. Adverse reactions included infections, such as Candida.
• While these results were promising, there was no control group. Additionally, researchers consider that bias may have played a role in the results. However, moving forward, additional testing can be done to determine the efficacy of the findings.

Ocrelizumab: Looking to the Future

While the open-label extension study offered insight into the impact of early ocrelizumab treatment, researchers still have some questions. First, could early ocrelizumab treatment also benefit patients with secondary progressive multiple sclerosis (SPMS)? As SPMS typically occurs after relapses and remitting, would this treatment still be worthwhile? Additionally, are there any adverse reactions experienced by patients that haven’t been seen or documented yet?

For now, these questions do not have answers. But one day, we may be able to definitively say whether ocrelizumab is the ideal treatment for all forms of MS.