NEW ORLEANS—Two-year analyses show that fewer patients required treatment with alemtuzumab than ocrelizumab to prevent one relapse, to prevent relapse in one patient, and to prevent six-month confirmed disability worsening in one patient versus subcutaneous interferon beta-1a, according to a report presented at the 31st Annual Meeting of the Consortium of Multiple Sclerosis Centers.
In the absence of head-to-head trials, researchers can use the number needed to treat to indirectly assess the comparative efficacy of disease-modifying therapies. Aaron L. Boster, MD, and colleagues analyzed the number needed to treat to prevent clinical disease events in studies of alemtuzumab and ocrelizumab in relapsing-remitting multiple sclerosis (MS). Dr. Boster is a clinical neuroimmunologist at the OhioHealth MS Clinic in Columbus.
Aaron L. Boster, MD
Number needed to treat values were derived from post hoc analyses of two-year data from studies of alemtuzumab (12 mg) and ocrelizumab (600 mg). Alemtuzumab data were of pooled treatment-naive patients from the CAMMS223 and CARE-MS I studies (n = 786), and separately, patients with inadequate response to prior therapy from CARE-MS II (n = 628). Ocrelizumab data were derived from the OPERA I and II studies (n = 821 and n = 835, respectively). Alemtuzumab was administered as two annual courses; ocrelizumab was administered at baseline and weeks 24, 48, and 72. Number needed to treat was based on inverse of absolute risk differences versus subcutaneous interferon beta-1a 44 μg three times per week (common comparator) for annualized relapse rate and proportion of patients experiencing relapse, and the Altman method for six-month confirmed disability worsening. Lower number needed to treat values reflect greater efficacy.
Baseline mean Expanded Disability Status Scale (EDSS) scores were 2.0 for CAMMS223 and CARE-MS I, 2.7 for CARE-MS II, 2.9 for OPERA I, and 2.8 for OPERA II. Mean MS duration was 1.9 years in CAMMS223 and CARE-MS I, 4.5 years in CARE-MS II, and 6.7 years in OPERA I and II. Mean number of relapses in the previous two years was 2.5 for CAMMS223 and CARE-MS I, 2.8 for CARE-MS II, and 1.8 in OPERA I and II.
Alemtuzumab and ocrelizumab significantly reduced annualized relapse rates and confirmed disability worsening versus subcutaneous interferon beta-1a. Number needed to treat values to prevent one relapse versus subcutaneous interferon beta-1a were lower with alemtuzumab (CAMMS223/CARE-MS I: five; CARE-MS II: four) than with ocrelizumab (OPERA I/II: eight in each study), as were number needed to treat values to prevent one patient from experiencing relapse (CAMMS223/CARE-MS I and CARE-MS II: six in each study; OPERA I and II: eight in each study), and to prevent one patient from experiencing six-month confirmed disability worsening (CAMMS223/CARE-MS I: 15; CARE-MS II: 13; OPERA I: 23; OPERA II: 21).
Although the populations in the available datasets differ, these findings suggest a benefit of alemtuzumab over ocrelizumab.
This study was supported by Sanofi Genzyme.