Alemtuzumab improves long-term clinical and radiological outcomes in black patients with relapsing-remitting multiple sclerosis, according to data presented at the 69th Annual Meeting of the American Academy of Neurology in Boston, MA.
The new findings were seen in a small cohort of patients enrolled in phase III studies comparing alemtuzumab with subcutaneous interferon beta-1a (SC IFNB-1a), all of whom had relapsing-remitting multiple sclerosis (RRMS) and were either treatment-naïve at enrolment or had responded inadequately to prior therapy.
Importantly, the results in black patients were on a par with those previously reported in the overall study population, said principal investigator Dr. Annette Okai, from the Multiple Sclerosis Treatment Center of Dallas in Texas.
Black patients typically have more severe MS than white patients, characterized by more rapid disability accumulation, greater MRI lesion volumes, increased risk for secondary progression, accelerated retinal nerve fiber layer and ganglion cell/inner plexiform layer thinning, and the potential for a poorer response to disease-modifying therapies (DMTs).
Limited published data are available on response to DMTs among black patients.
Subjects received two 12-milligram courses of alemtuzumab (baseline: 5 days; month 12: 3 days), or SC IFNB-1a (44 micrograms three times weekly for 2 years) in the core studies, and as-needed alemtuzumab for relapse or MRI activity or another DMT per investigator discretion in the extension study.
Low relapse rate for alemtuzumab-treated patients
Overall, 46 black patients were enrolled in the core studies (alemtuzumab, n=35; SC IFNB-1a, n=11). Most alemtuzumab patients entering extension did not receive alemtuzumab retreatment (53 percent) or other DMT (88 percent).
Alemtuzumab-treated patients maintained a low annualized relapse rate (ARR) throughout the core and extension studies, with a cumulative ARR over years 0 to 6 of 0.19 (95 percent CI, 0.11-0.30). Fifty-two percent were relapse-free during years 3 to 6.
Over 6 years, the mean change in Expanded Disability Status Scale (EDSS) score was +0.52 among patients receiving alemtuzumab.
Overall, 72 percent of alemtuzumab-treated patients were free of 6-month confirmed disability worsening through year 6, and 50 percent experienced 6-month confirmed disability improvement.
At year 6, 64 percent of the alemtuzumab cohort had improved or had stable EDSS scores, compared with baseline (improved, 20 percent; stable, 44 percent).
Alemtuzumab slowed brain volume loss (BVL) by 58 percent versus SC IFNB-1a at year 2. The median yearly BVL decreased over 2 years and remained low in years 3 to 6.
Over 6 years, alemtuzumab demonstrated a safety profile in the patient population that was consistent with the overall CARE-MS and extension study population, with the overall incidence of adverse events decreasing over time.
Dr. Okai said that findings in this small cohort need confirmation in a larger study or real-world setting.