Background: Alemtuzumab (ALZ) belongs to the immune reconstitution therapies for relapsing-remitting multiple sclerosis (RRMS). ALZ is used as second or third line treatment in clinical practise, thus the real-world population treated with ALZ is markedly different from the populations in the pivotal trials of ALZ.
Objectives: To assess basic characteristics and therapeutic effects on clinical and imaging parameters of disease activity for RRMS patients selected for ALZ.
Methods: RRMS patients were consecutively included at the MS Centre, Gothenburg. Patients were clinically assessed with Expanded Disability Status Scale (EDSS), occurrence of clinical relapses and with cerebral MRI at baseline, month 12, 24, 36 and 48.
Resluts: 51 (31 females) RRMS patients, mean age and mean disease duration of 35.5 (±7.1) respectively 7.1 (±5.4) years were included. Prior to baseline 6 patients had first line treatment, 38 had second line and 7 were naïve. Reasons to switch to ALZ; break through disease activity despite disease modifying treatment (DMT) (n=23), side effects (n=3), positive JC virus antibody test during natalizumab (n=18), highly active disease from disease onset (n=7). All patients received the first course of ALZ, 50 the second, 14 a third, and 2 a fourth course. At baseline, month 12, 24, 36 and 48 median EDSS was 2 (0-7.5), 1.5 (0-7), 1.5 (0-7.5), 1.5 (0-7.5) and 1.5 (0-7), respectively. At 48 months 34 patients were relapse free, and the annual relapse rate was 0.12. Baseline MRI revealed high lesion load; T2 lesions >20 (n=35), T2 lesions 10-20 (n=12), T2 lesions 1-9 (n=4), 36 patients had no contrast enhancement. Upon follow-up at 12, 24 , 36 and 48 months, 39 patients, 42, 45 and 38 had no new or enlarged T2 lesions respectively, corresponding number with no contrast enhancement was 43, 45, 47, and 40. Mean brain parenchymal fraction at baseline was 0.862 (±0.037, n=43) and was unchanged at follow-up. 23 patients met No Evidence of Disease Activity (NEDA) at 48 months. 9 (18%) patients have switched from ALZ to another DMT (rituximab n=6, autologous hematopoietic stem cell transplantation n=3) due to disease activity.
Conclusions: This real-world population confirms that ALZ as second or third line treatment effectively reduced disease activity. Although most of our patients had previously failed on DMT the proportion of progression free survival (82%) and NEDA (45%) were of similar magnitude as those reported from the pivotal trials CARE-MS I&II.