Real World Lab Data: Patterns of Lymphocyte Counts in Fingolimod Treated Patients

Objective:Fingolimod is approved for the treatment of highly active relapsing remitting multiple sclerosis (MS) patients and acts by its unique mechanism of action via sphingosine-1-phosphate receptor-modulation. Although fingolimod-associated lymphopenia is a well-known phenomenon, the exact cause for the intra- and inter-individual differences of the fluctuation of lymphocyte count and its subtypes is still subject of debate. In this analysis, we aim to estimate the significance of the individual variation of distinct lymphocyte subsets for differences in absolute lymphocyte decrease in fingolimod treated patients and discuss how different lymphocyte subset patterns are related to clinical presentation in a long-term real life setting.Methods/Design:One hundred and thirteen patients with MS were characterized by complete blood cell count and immune cell phentopying of peripheral lymphocyte subsets before, at month 1 and every 3 months up to 36 months of fingolimod treatment. In addition, patients were monitored regarding clinical parameters (relapses, disability, MRI).Results:There was no significant association of baseline lymphocyte count and lymphocyte subtypes with lymphocyte decrease after fingolimod start. The initial drop of the absolute lymphocyte count could not predict the level of lymphocyte count during steady state on fingolimod. Variable CD8+ T cell and NK cell counts account for the remarkable intra- and inter-individual differences regarding initial drop and steady state level of lymphocyte count during fingolimod treatment, whereas CD4+ T cells and B cells mostly present a quite uniform decrease in all treated patients. Selected patients with lymphocyte count >1.0 GPT/l differed by higher CD8+ T cells and NK cell counts compared to lymphopenic patients but presented comparable clinical effectiveness during treatment.Conclusion:Monitoring of the absolute lymphocyte count at steady state seems to be a rough estimate of fingolimod induced lymphocyte redistribution. Our results suggest, that evaluation of distinct lymphocyte subsets as CD4+ T cells allow a more detailed evaluation to weigh and interpret degree of lymphopenia and treatment response in fingolimod treated patients

New insights into the pharmacokinetics and pharmacodynamics of natalizumab treatment for patients with multiple sclerosis, obtained from clinical and in vitro studies

Background The monoclonal antibody natalizumab (NAT) inhibits the migration of lymphocytes throughout the blood–brain barrier by blocking very late antigen (VLA)-4 interactions, thereby reducing inflammatory central nervous system (CNS) activity in patients with multiple sclerosis (MS). We evaluated the effects of different NAT treatment regimens. Methods We developed and optimised a NAT assay to measure free NAT, cell-bound NAT and VLA-4 expression levels in blood and cerebrospinal fluid (CSF) of patients using standard and prolonged treatment intervals and after the cessation of therapy. Results In paired CSF and blood samples of NAT-treated MS patients, NAT concentrations in CSF were approximately 100-fold lower than those in serum. Cell-bound NAT and mean VLA-4 expression levels in CSF were comparable with those in blood. After the cessation of therapy, the kinetics of free NAT, cell-bound NAT and VLA-4 expression levels differed. Prolonged intervals greater than 4 weeks between infusions caused a gradual reduction of free and cell-bound NAT concentrations. Sera from patients with and without NAT-neutralising antibodies could be identified in a blinded assessment. The NAT-neutralising antibodies removed NAT from the cell surface in vivo and in vitro. Intercellular NAT exchange was detected in vitro. Conclusions Incorporating assays to measure free and cell-bound NAT into clinical practice can help to determine the optimal individual NAT dosing regimen for patients with MS

Letter to the editor on the paper: “The majority of natalizumab-treated MS patients have high natalizumab concentrations at time of re-dosing”

Van Kempen et al. described high natalizumab concentrations in their natalizumab-treated multiple sclerosis (MS) patients at time of re-dosing. Based on the literature research the authors consider a natalizumab concentration above 2 μg/mL to be sufficient for an adequate alpha-4 integrin receptor saturation of above 70%. Recently, we have demonstrated similar results using our new cell-based immunoassay to evaluate free natalizumab concentration, cell-bound natalizumab, and alpha-4 integrin receptor saturation as the key pharmacokinetic/pharmacodynamic parameters of natalizumab treatment in different in vivo settings. We investigated the effects of treatment interval extension or treatment cessation

Natalizumab during pregnancy and lactation

Background: Managing medication during pregnancy and lactation in multiple sclerosis (MS) patients needs to balance potential risks to the newborn with the substantial risks of ongoing disease activity. Objective: To evaluate the potential transfer of natalizumab (NAT) into breast milk and into the serum of newborn babies in women who continued NAT treatment during pregnancy and lactation. Methods: Serum samples of 11 mother–infant pairs and mother milk samples of a further 4 women were analyzed for free NAT using a HL60 cell-based fluorescence-activated cell sorting (FACS) assay. Two mother–baby pairs were analyzed for cell-bound NAT, very-late-antigen (VLA)-4 expression, and saturation with NAT on immune cells by FACS analysis. Results: In the majority of the mother–infant serum pairs (6/11) and in all breast milk samples, free NAT was detectable. Cell-bound NAT was measurable in both mother–baby pairs with significant higher levels in babies. VLA-4 expression seems to be higher in newborns. Saturation with NAT was comparable between newborns and mothers. Conclusion: NAT can pass placental barrier before delivery and into breast milk. Measurable NAT on neonatal lymphocytes may have functional impact. Further investigations are needed to clarify safety and risk of NAT exposure during pregnancy and lactation

Fingolimod additionally acts as immunomodulator focused on the innate immune system beyond its prominent effects on lymphocyte recirculation

Background Growing evidence emphasizes the relevance of sphingolipids for metabolism and immunity of antigen-presenting cells (APC). APCs are key players in balancing tolerogenic and encephalitogenic responses in immunology. In contrast to the well-known prominent effects of sphingosine-1-phosphate (S1P) on lymphocyte trafficking, modulatory effects on APCs have not been fully characterized. Methods Frequencies and activation profiles of dendritic cell (DC) subtypes, monocytes, and T cell subsets in 35 multiple sclerosis (MS) patients were evaluated prior and after undergoing fingolimod treatment for up to 24 months. Impact of fingolimod and S1P on maturation and activation profile, pro-inflammatory cytokine release, and phagocytotic capacity was assessed in vitro and ex vivo. Modulation of DC-dependent programming of naïve CD4+ T cells, as well as CD4+ and CD8+ T cell proliferation, was also investigated in vitro and ex vivo. Results Fingolimod increased peripheral slanDC count—CD1+ DC, and monocyte frequencies remained stable. While CD4+ T cell count decreased, ratio of Treg/Th17 significantly increased in fingolimod-treated patients over time. CD83, CD150, and HLADR were all inhibited, but CD86 was upregulated in DCs after incubation in the presence of fingolimod. Fingolimod but not S1P was associated with reduced release of pro-inflammatory cytokines from DCs and monocytes in vitro and ex vivo. Fingolimod also inhibited phagocytic capacity of slanDCs and monocytes. After fingolimod, slanDCs demonstrated reduced potential to induce interferon–gamma-expressing Th1 or IL-17-expressing Th17 cells and DC-dependent T cell proliferation in vitro and in fingolimod-treated patients. Conclusions We present the first evidence that S1P-directed therapies can act additionally as immunomodulators that decrease the pro-inflammatory capabilities of APCs, which is a crucial element in DC-dependent T cell activation and programming

Fampridine response in MS patients with gait impairment in a real-world setting: Need for new response criteria?

Objective: The primary objective of this real-world study was to describe the response to fampridine and changes of gait parameters in multiple sclerosis (MS) patients’ walking disability (Expanded Disability Status Scale (EDSS): 4–7) after treatment with fampridine for 2 weeks as recommended by the European Medicines Agency (EMA) and compare it with the overall physician’s judgement. Methods: A total of 211 adult MS patients were analyzed using a multimodal gait assessment including the timed 25-foot walk test (T25FW), 2-minute walking test (2-MWT), 12-item Multiple Sclerosis Walking Scale (MSWS-12), the GAITRite electronic walkway system, and the patients’ clinical global impression (CGI). Multimodal gait assessment was compared with the clinician’s impression of overall improvement after 2 weeks. Results: In total, 189 subjects were included, of which 133 (70.37%) were responders to fampridine (RF), according to physician’s judgement. Looking at independent multimodal gait assessment, RFs showed improvement of 12.60% in the T25FW, 19.25% in the 2-MWT, 21.12% in the MSWS-12, and 6.54% in their Functional Ambulation Profile (FAP) score. The combination of the T25FW and the MSWS-12 would offer the best sensitivity and specificity for determining response to fampridine according to both neurologists’ and patients’ classification. Conclusion: This study provides new information on the use of fampridine in a real-world setting with a large patient sample on the potential benefit of using more definitive responder criteria to fampridine for the clinical setting