Patricia K. Coyle, MD: There was an interesting abstract that reported on the OPERA study. Recall that these were the phase 3 trials for relapsing multiple sclerosis where patients were randomized to ocrelizumab 600 mg IV [intravenous] every 6 months or subq [subcutaneous] interferon beta-1a, 44 mcg 3 times a week. So, the pivotal trial was 2 years. There was then an extension study, and we're now looking at 6-year data. This is important because you want to be assured that over 6 years you continue to see good safety and you continue to see some efficacy. What they looked at was the group that was randomized to ocrelizumab initially and then had an additional 4 years of study—so 6 years of ocrelizumab study versus those who were on the comparator, the interferon beta, the first 2 years and then went on ocrelizumab in years 3 through 6. They looked at the annualized relapse rate. The annualized relapse rate was higher initially in the interferon beta arm—it went down when they were switched to ocrelizumab. In the ocrelizumab arm, they continued to have very low annualized relapse rates. In fact, by year 6 we were in the 0.04 to 0.05 range. It was really amazing. They also looked at confirmed disability worsening, and this was the interesting feature. The group that was delayed, that didn't go on ocrelizumab immediately, that had 2 years of a good interferon beta, didn't catch up. There was still a difference. The lowest confirmed disability worsening was in the group that had been on the ocrelizumab for the entire 6-year period compared to the group that had delayed treatment, who were on the interferon beta and then switched over for the last 4 years.
The real-world application is that ocrelizumab is a high efficacy agent, interferon beta is not. It's additional documentation that there seems to be a benefit in starting early with optimized high efficacy treatment.