Subgroup analysis revealed a greater improvement for patients with baseline visual impairment.
Laura Balcer, MD
Ocrelizumab was found to be associated with a greater mean improvement in low-contrast letter acuity (LCLA) in patients with relapse-remitting multiple sclerosis (RMS), especially in patients with visual impairment at baseline, according to data presented at MS Paris 2017, the 7th annual joint meeting of the European and Americas Committees for Treatment and Research in Multiple Sclerosis.
The OPERA I and II trials conducted binocular LCLA testing (1.25% and 2.5% contrast) and reported data for an intent-to-treat (ITT) patient group randomized to either ocrelizumab 600 mg (n=827) or interferon beta-1a 44µg (IFN ß-1a; n=829) every 12 weeks for 96 weeks, and a subgroup analysis of patients with visual impairment at baseline (ocrelizumab: n=375; IFN ß-1a: n=373).
“LCLA was able to capture the treatment benefiit of ocrelizumab versus IFN ß-1a on visual outcomes in patients with MS,” Laura Balcer, MD, lead author and professor of neurology and ophthalmology at New York University at Langone. “Evidenced by significantly greater mean improvement in LCLA score from baseline to Week 96, and a significantly higher proportion of patients with sustained improvement in LCLA scores, confirmed after 12 weeks.”
Improvement was seen particularly in the patients with visual impairment subgroup at 2.5% contrast, as 14.7% of patients in the ocrelizumab arm experienced 12-week confirmed visual improvement in at least 5 out of 7 visits, compared with 6.4% in the IFN ß-1a arm (Odds Ratio [OR] 2.72 [1.60-6.64], 95% CI; p≤0.001).
In the ITT population, the ocrelizumab arm experienced visual improvement at 2.5% contact in at least 5 of 7 visits at a rate of 10.4% compared with 7.1% in the IFN ß-1a group (OR 1.50 [1.04-3.17], 95% CI; p=0.030). The threshold of response was defined as a ≥7 letter improvement confirmed after ≥12 weeks of initial improvement.
“The association of low-contrast acuity with other metrics of disease activity and progression, such as relapse activity and OCT metrics of the retinal fiber layer, is under further investigation,” Balcer added.
The change from baseline in the number of correct letters in LCLA testing at 2.5% contrast in the ITT population was a mean of 1.355 letters for the ocrelizumab arm compared with 0.012 in the IFN ß-1a arm (p=0.026). That change was more pronounced in the subgroup analysis, with the ocrelizumab arm improving 3.440 letters compared to a -0.470 decrease in the IFN ß-1a group (p<0.001).
By Week 96 in the ITT population, 31.7% of patients in the ocrelizumab arm had achieved 12-week confirmed visual improvement, compared to 26.6% in the IFN ß-1a arm (adjusted hazard ratio [HR] 1.190 [0.981-1.445], 95% CI; p=0.078). In the subgroup analysis, a similar improvement was experienced in the ocrelizumab arm (36.6%) compared to the IFN ß-1a arm (25.5%) (HR 1.556-2.046, 95% CI; p=0.003).