Alemtuzumab, Ocrelizumab Prove Better Against Relapsing MS in Indirect Study

In an indirect comparison of clinical trials for relapsing-remitting multiple sclerosis (RRMS) disease-modifying therapies, researchers found alemtuzumab and ocrelizumab were both more efficient in certain long-term effects over interferon SC IFNB-1a (Rebif).

The research, presented at the 2017 Consortium of Multiple Sclerosis Centers (CMSC) this week, was led by Aaron Boster, MD, systems medical chief of neuroimmunology and director of the Multiple Sclerosis Center at OhioHealth.

Though there is no head-to-head trial readily available for the 3 US Food and Drug Agency (FDA) approved multiple sclerosis (MS) treatments, Boster and researchers found comparable connections the treatments’ number needed to treat (NNT) totals in clinical trials.

“In 2017 we now have 3 highly effective therapies in our MS armamentarium,” Boster said. “It’s fascinating that we’re starting to dive into, “How do we think about them, how do we sequence them, how do we compare them?””

Boster called it “statistical heresy” to compare across trials, but modern techniques such as NNT — though not statistically perfect — allow for such comparisons when available.

NNT values were derived from the analyses of 2-year data from studies of alemtuzumab at 12 mg dosage and ocrelizumab at 600 mg dosage. While alemtuzumab was administered as 2 annual courses in its trial, ocrelizumab was administered at baseline, then weeks 24, 48, and 72 of its study.

Boster and researchers based the NNT on inverse of absolute risk differences versus Rebif for annualized relapse rate (ARR) and proportion of patients experiencing relapse, according to the study presented. They also compared for the Altman method of 6-month confirmed disability worsening (CDW). Lower NNT values reflected greater efficacy.

The results showed both drugs were “clearly superior” to Rebif in regards to ARR and CDW, Boster said.

It also showed that fewer patients required less alemtuzumab treatment than ocrelizumab to prevent one relapse, relapse in one patients, and CDW in one patient versus Rebif. These results are despite differing trial populations, and recommend further clinical trials to confirm.

Alemtuzumab, initially only a prominent antibody used to treat particular B-cell chronic lymphocytic leukemia patients, underwent about 5 years of clinical trials before being FDA approved for MS treatment.

Ocrelizumab was only FDA-approved for MS treatment this March, though has become a popularized RRMS drug quickly. Earlier at the CMSC, Stephen Krieger, MD, associate professor at Mount Sinai Hospital, said the new treatment has been “very substantial” against relapsing MS.

Imperfect statistical comparison aside, Boster said the research should be found to be beneficial at a time when MS treatment is accelerating like never before.

“This information is valuable to me as a MS clinician treater as it starts to help flesh out my understanding how these drugs work and how these drugs compare,” Boster said. “I hope that it’s well-received and others found it resourceful as well.”

The study was supported by Sanofi Genzyme and Bayer HealthCare Pharmaceuticals.