Author Of 1 Presentation
FC02.03 - Evaluation of T and B lymphocytopenia in patients treated with Ocrelizumab switching from other treatments compared to naive
Abstract
Background
Ocrelizumab (Ocre) is an anti-CD20 monoclonal antibody with a known major depleting effect on B cells and marginal on T cells. It is approved for clinical use in highly-active naïve multiple sclerosis (MS) patients and those not responder to previous treatment. In MS patients switching from other drugs prolonged dysfunction of adaptive immune system may occur after discontinuation, posing the need to carefully investigate the safety profile of treatment sequencing.
Objectives
To investigate the B and T cells subsets longitudinal dynamic during treatment with Ocre in patients with MS switching from Fingolimod (FTY) and other treatments (Dimetylfumarate, Interferon Beta, Glatiramer Acetate, Natalizumab, Teriflunomide) compared to naïve patients.
Methods
A multicenter observational 2-year study was conducted in patients starting treatment with Ocre grouped in three arms: naïve (naïve), switching from FTY (pre-FTY), switching from other treatments (other). Data about lymphocyte subtype count (CD3+, CD4+, CD8+ and CD20+) were collected at baseline and every 6 months after starting Ocre. Slope of reduction and proportion of patients with lymphocytes count below the normal lower limit was calculated.
Results
A sample of 135 patients was analysed (37 pre-FTY, 64 other, 34 naïve). At baseline pre-FTY compared to naïve showed significant decrease of CD3+ (1204.54+675.37 cells/mm3 vs 1735.53+653.56, p=0.0003), CD4+ (551.91+254.42 vs 997.03+352.79, p<0.0001), CD8+ (430.38+379.73 vs 537.75+254.34, p=0.027) and CD20+ (88.25+90.94 vs 191.32+149.62, p=0.021) cells. During Ocre the slope of reduction of CD3+ in naïve patients was 5.45 cells/mm3/week (p=0.003). Compared to naïve, the rate of decrease in CD3+ was -1.2 cells/mm3/week in pre-FTY (p=0.087) and +0.19 (p=0.012) in other. The slope of reduction of CD4+ was 2.00 cells/mm3/week in naïve (p=0.072). Compared to naïve the rate of reduction in CD4+ was +0.91 cells/mm3/week in pre-FTY (p=0.061) and +1.70 cells/mm3/week (p=0.012) in other. CD8+ and CD20+ cells decrease was similar among groups (p for interaction between time and treatment = 0.184 and 0.108, respectively). In pre-FTY group compared to baseline the proportion of patients with CD3+ and CD4+ cells lymphopenia was unchanged (16.22% versus 17.14% ; 32.35% versus 34.29%), while the proportion of CD8+ cells was increased (8.82% versus 25.71%).
Conclusions
Our study confirms that Ocre may induce depletion of T cell subsets beyond B cells. Nevertheless, in pre-FTY we also observed a prolonged T- lymphocytopenia , as carry-over effect of the previous therapy. FTY-induced immunosenescence or slow immunoreconstitution may explain this finding.
Author Of 1 Presentation
P0131 - Predicting long-term sustained disability progression in multiple sclerosis: application in the CLARITY trial (ID 1071)
Abstract
Background
Prevention of disability over the long-term is the main treatment goal in multiple sclerosis (MS), however, randomized clinical trials provide only short-term (3-6-month) treatment effect on disability.
Objectives
To externally validate the previously developed sustained progression score which established 6-month confirmed disability progression events as indicators of long-term disability worsening in randomized double-blind CLARITY (Cladribine Tablets Treating MS Orally) trials. A higher score indicates a greater probability of a progression event to be sustained over the long-term.
Methods
Data from the CLARITY and CLARITY 2-year Extension study were used. The 3-and 6-month confirmed disability progression events and the time over which progression remained sustained were identified. Patient characteristics at the time of progression previously associated with the likelihood of improvement after confirmed progression event (age, primary progressive MS, a relapse in previous month, expanded disability status scale score≥6 and its change from baseline, number of affected functional system domains, and worsening in pyramidal, brainstem and sensory domains) were used to calculate the sustained progression score for each progression event. A Cox proportional hazards model was used to validate the association of the score calculated for each 6-month confirmed disability progression event with time to improvement. To demonstrate application of the score in trial setting, the analysis of the CLARITY study were repeated estimating the effect of therapy on long-term disability outcomes. Effect of cladribine on 3-month confirmed progression events with any score and score˃1.5 was evaluated.
Results
A total of 667 6-month confirmed disability progression events were identified in the combined dataset, of which only 12 were followed by a 6-month confirmed disability improvement. The external validation of the score illustrated a trend towards a decrease in the likelihood of disability improvement in progression events with higher score (Hazard Ratio HR=0.72, 95% CI: 0.21-2.42). Results of the original trial were confirmed in addition to that oral cladribine reduced the risk of disability progression that was likely to be sustained over the long-term (only events with score˃1.5; HR: 0.64; 95% CI: 0.47-0.87).
Conclusions
The sustained progression score, estimated using the characteristics of confirmed progression events, provides important complementary information that will allow future trials to establish the effect of therapy not only on short-term but also on long-term disability accrual.