New imaging confirms ocrelizumab’s impact on lesion activity in multiple sclerosis

Key takeaways:

• Ocrelizumab reduced the number and size of MS-related cortical lesions.
• Data synthesis featuring a mix of traditional and AI methods may be the path forward to improved analysis of lesion activity.

WEST PALM BEACH, Fla. — Ocrelizumab significantly reduced the number and volume of cortical lesions associated with multiple sclerosis at 120 weeks, findings confirmed by data from a series of new imaging techniques and presented at ACTRIMS.

“Gray matter is increasingly recognized as a key component in MS despite the focus on white matter, and we know that cortical lesions commonly occur very early and are very prevalent,” Michael G. Dwyer, III, PhD, associate professor of neurology and bioinformatics in the department of neurology in the Jacobs School of Medicine at the University of Buffalo, said in his presentation. “They associate very strongly with disability and cognition.”

Dwyer and colleagues evaluated the impact of ocrelizumab (Ocrevus, Roche) on cortical lesion activity in patients with primary progressive MS (PPMS) enrolled in the phase 3 ORATRIO clinical trial by conducting a secondary analysis using recently introduced imaging technologies.

The double-blind, placebo-controlled study included 732 individuals with PPMS randomly assigned in a 2:1 ratio to either 60 mg IV ocrelizumab or placebo. Patients underwent MRI at baseline, 24, 48 and 120 weeks to measure lesion amount and level of brain atrophy.

Lesion activity was examined by fluid attenuated inversion recovery (FLAIR), as well as T1/T2 ratio and AI double inversion recovery (AI-DIR) methods. Multimodal contrast enhanced image (MMCLE) was additionally generated to combine FLAIR2 and AI-DIR, with the researchers subsequently examining all lesions via MMCLE while referencing the other three methods.

From baseline to 120 weeks, results showed that new or enlarging cortical lesions were reduced by 74.8% for those given ocrelizumab compared with the placebo group, with lesion volume reduced by 86.6% for the treatment group vs. placebo.

These data suggest, Dwyer said, that cortical lesion analysis by simultaneous employment of contrasts is a key factor in accurate synthesis.

“We really should be using these methods, cortical lesion analysis, on retrospective medical data, to ask whether the treatments we have right now, are affecting these lesions,” he said.