[Small Molecule Therapy for Inflammatory Bowel Disease: JAK Inhibitors and S1PR Modulators].

Small molecules, including Janus kinase (JAK) inhibitors and sphingosine-1-phosphate receptor modulators (S1PRMs), are promising new treatments for inflammatory bowel disease (IBD). Small molecules exhibit more predictable pharmacokinetics than biologics, are less likely to induce immune responses, and can be administered orally. JAK inhibitors function by blocking the activity of JAK enzymes, which prevents the subsequent phosphorylation and activation of signal transducer and activator of transcription (STAT) proteins. Tofacitinib and filgotinib are approved for treating ulcerative colitis (UC), while upadacitinib is approved for UC and Crohn's disease. Nevertheless, JAK inhibitors can increase the risk of herpes zoster, cancer, major adverse cardiovascular events, and venous thromboembolism. S1PRMs bind to S1PRs, particularly S1PR1, on lymphocytes. This interaction inhibits lymphocytes from exiting the lymph nodes and migrating to the gut, thereby reducing inflammation and the immune response in the intestinal mucosa. Ozanimod and etrasimod are S1PRMs approved for the treatment of UC, but they can cause side effects such as bradycardia, conduction disorder, and macular edema. Overall, JAK inhibitors and S1PRMs offer significant benefits in managing IBD, although their potential side effects require careful monitoring.

Siponimod treatment response shows partial BDNF dependency in multiple sclerosis models.

So far, only a small number of medications are effective in progressive multiple sclerosis (MS). The sphingosine-1-phosphate-receptor (S1PR)-1,5 modulator siponimod, licensed for progressive MS, is acting both on peripheral immune cells and in the central nervous system (CNS). So far it remains elusive, whether those effects are related to the neurotrophin brain derived neurotrophic factor (BDNF). We hypothesized that BDNF in immune cells might be a prerequisite to reduce disease activity in experimental autoimmune encephalomyelitis (EAE) and prevent neurotoxicity. MOG35-55 immunized wild type (WT) and BDNF knock-out (BDNFko) mice were treated with siponimod or vehicle and scored daily in a blinded manner. Immune cell phenotyping was performed via flow cytometry. Immune cell infiltration and demyelination of spinal cord were assessed using immunohistochemistry. In vitro, effects on neurotoxicity and mRNA regulation were investigated using dorsal root ganglion cells incubated with EAE splenocyte supernatant. Siponimod led to a dose-dependent reduction of EAE scores in chronic WT EAE. Using a suboptimal dosage of 0.45 µg/day, siponimod reduced clinical signs of EAE independent of BDNF-expression in immune cells in accordance with reduced infiltration and demyelination. Th and Tc cells in secondary lymphoid organs were dose-dependently reduced, paralleled with an increase of regulatory T cells. In vitro, neuronal viability trended towards a deterioration after incubation with EAE supernatant; siponimod showed a slight rescue effect following treatment of WT splenocytes. Neuronal gene expression for CCL2 and CX3CL1 was elevated after incubation with EAE supernatant, which was reversed after siponimod treatment for WT, but not for BNDFko. Apoptosis markers and alternative death pathways were not affected. Siponimod exerts both anti-inflammatory and neuroprotective effects, partially related to BDNF-expression. This might in part explain effectiveness during progression in MS and could be a target for therapy.

Efficacy and Safety of Sphingosine 1-Phosphate Receptor Modulators for Ulcerative Colitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND AND AIMS: Sphingosine 1-phosphate receptor modulators (S1PRMs) are an effective treatment for ulcerative colitis (UC). This review summarizes all available randomized trial data on the efficacy and safety of S1PRM therapy. METHODS: Multiple publication databases were systematically searched for randomized control trials (RCTs) of adults with moderate to severe UC treated with S1PRMs. Random effects meta-analysis was performed. The risk of bias was assessed using the Cochrane Risk-of-Bias 2 tool, and the overall quality of evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. RESULTS: We identified 7 RCTs (1737 patients) involving the use of S1PRMs for moderate to severe UC. During induction, S1PRM therapy was efficacious when compared with placebo for clinical remission [RR: 2.65 (95% CI: 2.00, 3.53)], clinical response [RR: 1.68 (95% CI: 1.48, 1.91)], endoscopic improvement [RR: 2.17 (95% CI: 1.76, 2.68)], endoscopic normalization [RR: 2.56 (95% CI: 1.58, 3.83)], mucosal healing [RR: 2.88 (95% CI: 1.94, 4.26)], and histologic remission [RR: 2.42 (95% CI: 1.60, 3.66)]. Similar results were seen throughout the maintenance peroid, although fewer data were available to pool; notably, both sustained [RR: 3.57 (95% CI: 1.23, 10.35)] and steroid-free [RR: 2.92 (95% CI: 1.35, 6.33)] remission were significantly increased by S1PRM. There were no significant differences in adverse events [RR: 1.02 (95% CI: 0.90, 1.15)] and infections [RR: 1.15 (95% CI: 0.82, 1.60)] between S1PRM and placebo. CONCLUSION: Pooling of RCT data confirms that S1PRM therapy is both effective and safe for patients with moderate to severe UC.

Immunity in digestive diseases: new drugs for inflammatory bowel disease treatment-insights from Phase II and III trials.

BACKGROUND: Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), continues to challenge treatment paradigms. Advancements in therapeutic options have been have been driven by Phase 2 and 3 clinical trials of new drug classes, particularly sphingosine-1-phosphate (S1P) modulators and interleukin-23 (IL-23) inhibitors. METHODS: This review synthesizes findings from Phase 2 and 3 clinical trials conducted up to early 2024, focusing on the impact of S1P modulators and IL-23 inhibitors on IBD management. Drugs such as ozanimod, etrasimod, risankizumab, mirikizumab, guselkumab, and brasikumab were evaluated for their efficacy and safety profiles. RESULTS: S1P modulators, such as ozanimod and etrasimod, effectively regulate immune cell trafficking to reduce inflammation and several trials highlight their clinical effectiveness in both inducing and maintaining remission in IBD, highlighting its long-term safety and sustained therapeutic effects. Additionally, IL-23 inhibitors including risankizumab, mirikizumab, and guselkumab, which disrupt key inflammatory cytokine pathways, have already shown significant effectiveness in inducing and maintaining remission in both CD and UC, with favorable safety profiles across multiple studies, suggesting their potential as critical components in managing IBD. CONCLUSIONS: The clinical trials indicate that both S1P modulators and IL-23 inhibitors offer promising therapeutic benefits and maintain strong safety profiles, positioning them as potential cornerstone treatments for IBD. Despite these advancements, further exploration into long-term safety and the development of personalized treatment strategies is essential for maximizing clinical outcomes.

Switching disease-modifying therapies from sphingosine-1-phosphate receptor modulators to natalizumab or dimethyl fumarate restores immune responses after SARS-CoV-2 mRNA vaccination in patients with multiple sclerosis.

OBJECTIVES: This study aimed to evaluate whether switching disease-modifying therapies (DMTs) from sphingosine-1 phosphate (S1P) receptor modulators to either natalizumab (NTZ) or dimethyl fumarate (DMF) could restore the effectiveness of SARS-CoV-2 mRNA vaccination in patients with multiple sclerosis (MS). METHODS: This study included 9 controls and 33 patients with MS: 7 patients treated with DMF, 7 patients treated with NTZ, 9 patients treated with S1P receptor modulators, and 10 patients who had switched DMTs from S1P receptor modulators to DMF or NTZ by the second vaccine dose. The patients who had switched DMTs were classified into two groups, based on whether their lymphocyte counts were above or below 1000/µL at the time of vaccination. In addition, relapses within 6 months after switching DMTs were also evaluated in these patients. Six months after the second dose of the vaccination, anti-SARS-CoV-2 spike antibodies were evaluated in all participants, and spike specific CD4+ T cells were also assessed in patients who had switched DMTs from S1P receptor modulators. RESULTS: Patients treated with S1P receptor modulators had lower levels of anti-SARS-CoV-2 spike antibodies than the controls and patients treated with DMF and NTZ. On the other hand, in patients who had switched DMTs from S1P receptor modulators, a recovery of lymphocyte counts above 1000/µL resulted in restored humoral and cellular immune responses to the vaccination. There were no neurological relapses in patients who had switched DMTs from S1P receptor modulators to NTZ. CONCLUSION: SARS-CoV-2 mRNA vaccination is expected to be effective in patients whose lymphocyte counts have recovered due to switching DMTs from S1P receptor modulators. Switching DMTs from S1P receptor modulators to NTZ before vaccination may be beneficial in achieving efficacy for SARS-CoV-2 mRNA vaccination, with a reduced risk of relapse.

Re-emergence of T lymphocyte-mediated synaptopathy in progressive multiple sclerosis.

Background: Secondary progressive multiple sclerosis (SPMS) is defined by the irreversible accumulation of disability following a relapsing-remitting MS (RRMS) course. Despite treatments advances, a reliable tool able to capture the transition from RRMS to SPMS is lacking. A T cell chimeric MS model demonstrated that T cells derived from relapsing patients exacerbate excitatory transmission of central neurons, a synaptotoxic event absent during remitting stages. We hypothesized the re-emergence of T cell synaptotoxicity during SPMS and investigated the synaptoprotective effects of siponimod, a sphingosine 1-phosphate receptor (S1PR) modulator, known to reduce grey matter damage in SPMS patients. Methods: Data from healthy controls (HC), SPMS patients, and siponimod-treated SPMS patients were collected. Chimeric experiments were performed incubating human T cells on murine cortico-striatal slices, and recording spontaneous glutamatergic activity from striatal neurons. Homologous chimeric experiments were executed incubating EAE mice T cells with siponimod and specific S1PR agonists or antagonists to identify the receptor involved in siponimod-mediated synaptic recovery. Results: SPMS patient-derived T cells significantly increased the striatal excitatory synaptic transmission (n=40 synapses) compared to HC T cells (n=55 synapses), mimicking the glutamatergic alterations observed in active RRMS-T cells. Siponimod treatment rescued SPMS T cells synaptotoxicity (n=51 synapses). Homologous chimeric experiments highlighted S1P5R involvement in the siponimod's protective effects. Conclusion: Transition from RRMS to SPMS involves the reappearance of T cell-mediated synaptotoxicity. Siponimod counteracts T cell-induced excitotoxicity, emphasizing the significance of inflammatory synaptopathy in progressive MS and its potential as a promising pharmacological target.

Biologics and targeted synthetic medicines for ulcerative colitis and Crohn's disease.

Ulcerative colitis and Crohn's disease are chronic inflammatory bowel diseases. Recent pivotal phase 3 trials involving treatments like interleukin-23-, sphingosin-1-phosphate- and Janus kinase inhibitors have demonstrated notable effectiveness. However, they have also unveiled significant side effects such as herpes zoster, lymphopenia and bradycardia. The introduction of novel treatments raises valid concerns necessitating increased collaboration with diverse medical specialities to address potentially severe side effects, and this is vital for enhancing the future care of individuals with inflammatory bowel diseases, as argued in this review.

Repurposing the multiple sclerosis drug Siponimod for osteoporosis treatment.

Osteoporosis is the most common bone disorder, in which an imbalance between osteoclastic bone resorption and osteoblastic bone formation disrupts bone homeostasis. Osteoporosis management using anti-osteoclastic agents is a promising strategy; however, this remains an unmet need. Sphingosine-1-phosphate (S1P) and its receptors (S1PRs) are essential for maintaining bone homeostasis. Here, we identified that Siponimod, a Food and Drug Administration-approved S1PR antagonist for the treatment of multiple sclerosis, shows promising therapeutic effects against osteoporosis by inhibiting osteoclast formation and function. We found that Siponimod inhibited osteoclast formation in a dose-dependent manner without causing cytotoxicity. Podosome belt staining and bone resorption assays indicated that Siponimod treatment impaired osteoclast function. Western blot and qPCR assays demonstrated that Siponimod suppressed the expression of osteoclast-specific markers, including C-Fos, Nftac1, and Ctsk. Mechanistically, we validated that Siponimod downregulated receptor activator of nuclear factor kappa B ligand (RANKL)-induced Mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) signaling pathways during osteoclastogenesis. Moreover, in a preclinical mouse model, Siponimod prevented ovariectomy-induced bone loss by suppressing osteoclast activity in vivo. Collectively, these results suggest that Siponimod could serve as an alternative therapeutic agent for the treatment of osteoporosis.

Comprehensive overview of novel chemical drugs for ulcerative colitis: focusing on phase 3 and beyond.

INTRODUCTION: Despite the growing number of highly efficacious biologics and chemical drugs for ulcerative colitis (UC), steroid-free disease control is still difficult to achieve in subgroups of patients due to refractoriness, adverse events, primary or secondary failure. New treatments are therefore still required in order to optimize clinical management of patients with UC. AREAS COVERED: The efficacy and safety of both currently available and newly developed small molecules have been summarized. The PubMed database and clinicaltrials.gov were considered in order to search for phase 2b and 3 trials on new chemical drugs for UC. The study drugs reviewed included Janus kinases (JAK) and sphingosine-1-phosphate receptor (S1Pr) inhibitors, α4 integrin antagonist, and micro-RNA-124 upregulators. EXPERT OPINION: Rapidity of onset, low immunogenicity, and safety are the main characteristics of small molecules currently available or under evaluation for treatment patients with UC. Among the currently available chemical drugs, the selective JAK and the S1Pr inhibitors are characterized by a good safety profile combined with the ability to induce clinical remission in UC. A relatively low frequency of endoscopic improvement and healing currently appears associated with their use, being higher in UC patients treated with S1Pr inhibitor Etrasimod. Overall, additional new safe and effective drugs are still required in order to optimize disease control in a larger majority of UC patients.

Preventing and managing cardiovascular events in patients with inflammatory bowel diseases treated with small-molecule drugs, an international Delphi consensus.

Janus kinase (JAK) inhibitors and sphingosine 1 phosphate (S1P) receptor modulators are small molecule drugs (SMDs) approved for IBD treatment. Their use in clinical practice might be limited due to cardiovascular concerns. We aimed to provide guidance on risk assessment, monitoring, and management strategies, aiming to minimize potential cardiovascular risks of SMDs and to facilitate an adequate shared decision-making. A systematic literature search was conducted, and proposed statements were prepared. A virtual consensus meeting was held, in which eleven IBD physicians and two cardiovascular specialists from ten countries attended. Proposed statements were voted upon in an anonymous manner. Agreement was defined as at least 75 % of participants voting as 'agree' with each statement. Consensus was reached for eighteen statements. Available evidence does not show a higher risk of cardiovascular events with JAK inhibitors in the overall IBD population, although it might be increased in patients with an unfavorable cardiovascular profile. S1P receptor modulators may be associated with a risk of bradycardia, atrioventricular blocks, and hypertension. Cardiovascular risk stratification should be done before initiation of SMDs. Although the risk of cardiovascular events in patients with IBD on SMDs appears to be low overall, caution should still be taken in certain scenarios.

Ozanimod Differentially Impacts Circulating Lymphocyte Subsets in Patients with Moderately to Severely Active Crohn's Disease.

BACKGROUND: Ozanimod showed efficacy and safety in the phase 2 STEPSTONE study conducted in patients with moderately to severely active Crohn's disease. AIMS: This analysis assessed the effects of ozanimod on circulating lymphocytes in Crohn's disease. METHODS: Patients received ozanimod 0.92 mg for 12 weeks. Lymphocyte subtypes were evaluated using multicolor flow analysis on blood samples collected before treatment and on Week 12. Absolute lymphocyte count changes were analyzed by Wilcoxon signed rank tests. Disease activity changes and efficacy outcomes were evaluated at Week 12, and associations with lymphocyte subtype levels were assessed using Spearman's correlation and logistic regression. RESULTS: Reductions in median total T, Th, and cytotoxic T cells occurred at Week 12 (45.4%-76.8%), with reductions in most subtypes of 47.5% to 91.3% (P < 0.001). CD8+ terminally differentiated effector memory cells were largely unaffected (median change, - 19%; P = 0.44). Reductions in median total B cells occurred at Week 12 (76.7%), with reductions in subtypes of 71.4% to 81.7% (P < 0.001). Natural killer and monocyte cell counts were unchanged. Greater baseline levels and changes in nonswitched memory B cells were significantly associated with clinical, endoscopic, and histologic efficacy (P < 0.05, all comparisons). CONCLUSIONS: Ozanimod reduced circulating levels of all B-cell and most T-cell subsets but not monocytes or natural killer cells. Key subsets relevant to immune surveillance were not reduced, supporting the low risk of infection and malignancy with ozanimod in chronic inflammatory diseases. Levels of nonswitched memory B cells were associated with efficacy, providing a potential marker for ozanimod response. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02531113, EudraCT: 2015-002025-19.

Clinical effectiveness of coronavirus disease 2019 vaccination in patients with multiple sclerosis stratified by disease-modifying treatment.

BACKGROUND AND PURPOSE: Coronavirus disease 2019 (COVID-19) vaccination has been associated with a dampened humoral and/or cellular immune response in patients with multiple sclerosis (MS) who were concurrently on disease-modifying treatment (DMT) with B-cell depleting agents or sphingosine-1-phosphate receptor modulators (S1PRMs). Our main goal was to investigate the impact of these DMT classes on the clinical effectiveness of COVID-19 vaccination. METHODS: Since March 2020, demographics and clinical data of patients with MS who developed COVID-19 have been collected at the Belgian National MS Centre in Melsbroek. Patients were considered to be 'protected by vaccination' if they were (i) fully vaccinated and (ii) tested positive for COVID-19 in the period ranging from 14 days to 6 months after the last administered vaccine. RESULTS: On 19 December 2022, 418 COVID-19 cases were retrospectively identified in 389 individual patients. Hospitalization and mortality rates resulting from the infection were 10.8% and 2.4%, respectively. Being 'unprotected by vaccination' was significantly associated with a worse COVID-19 outcome (i.e., hospitalization and/or death) in the total cohort (N = 418, odds ratio [OR] 3.96), in patients on ongoing DMT other than anti-CD20 agents or S1PRMs (N = 123, OR 31.75) and in patients without DMT (N = 182, OR 5.60), but not in those receiving anti-CD20 agents (N = 91, OR 0.39); the S1PRMs subgroup was considered too small (22 infections) for any meaningful analysis. CONCLUSIONS: Coronavirus disease 2019 vaccination protects against severe infection in patients with MS but it was not possible to confirm this effect in those on DMT with B-cell depleting agents.

Efficacy and Safety of Etrasimod in Patients with Moderately to Severely Active Isolated Proctitis: Results From the Phase 3 ELEVATE UC Clinical Programme.

BACKGROUND AND AIMS: Pivotal trials in ulcerative colitis have historically excluded patients with isolated proctitis. Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis. This post hoc analysis assessed efficacy and safety of etrasimod 2 mg once daily in patients with isolated proctitis (centrally read) from the phase 3 ELEVATE UC 52 and ELEVATE UC 12 trials. METHODS: Patients, including those with isolated proctitis (<10 cm rectal involvement) who met all other inclusion criteria in ELEVATE UC 52 and ELEVATE UC 12, were randomised 2:1 to receive etrasimod or placebo. Primary, secondary and other identified efficacy endpoints and safety were assessed. RESULTS: We analysed data from 64 and 723 patients at Week 12 (both trials pooled), and 36 and 397 patients at Week 52 (ELEVATE UC 52 only) with isolated proctitis and more extensive colitis (≥10 cm rectal involvement), respectively. Patients with isolated proctitis receiving etrasimod demonstrated significant improvements versus placebo, including clinical remission rates at Weeks 12 (42.9% vs 13.6%) and 52 (44.4% vs 11.1%), endoscopic improvement (52.4% vs 22.7%) at Week 12 and bowel urgency numerical rating scale score at Week 12 (all p < 0.01). Generally similar trends were observed in patients with more extensive colitis. Safety was consistent across subgroups, with no new findings. CONCLUSIONS: Etrasimod demonstrated significant improvements versus placebo in patients with isolated proctitis, and those with more extensive disease, in most efficacy endpoints at Week 12 and 52. Clinicaltrials.gov: NCT03945188; NCT03996369.

Achievement of Clinical, Endoscopic, and Histological Outcomes in Patients with Ulcerative Colitis Treated with Etrasimod, and Association with Faecal Calprotectin and C-reactive Protein: Results From the Phase 2 OASIS Trial.

BACKGROUND AND AIMS: Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis [UC]. This post-hoc analysis of the phase 2 OASIS trial [NCT02447302] evaluated its efficacy for endoscopic improvement-histologic remission [EIHR] and assessed correlation between faecal calprotectin [FCP] and C-reactive protein [CRP] levels with efficacy outcomes. METHODS: In total, 156 adults with moderately to severely active UC received once-daily etrasimod (1 mg [n = 52]; 2 mg [n = 50]) or placebo [n = 54] for 12 weeks. Clinical, endoscopic, and histologic variables were evaluated at baseline and Week 12. EIHR was defined as achievement of endoscopic improvement [endoscopic subscore ≤ 1, without friability] and histologic remission [Geboes score < 2.0]. Outcomes included the relationships between FCP and CRP concentration and clinical, endoscopic, and histologic variables. RESULTS: Achievement of EIHR was significantly higher in patients who received etrasimod 2 mg versus placebo [19.5% vs 4.1%; Mantel-Haenszel estimated difference, 15.4%; p = 0.010]. In the etrasimod 2 mg group, median FCP and CRP levels at Week 12 were significantly lower in patients who achieved clinical remission, endoscopic improvement, histologic remission, and EIHR versus patients who did not [all p < 0.05]. An FCP concentration cutoff of 250 µg/g achieved optimum sensitivity and specificity for efficacy, including EIHR [0.857 and 0.786, respectively; κ coefficient, 0.3584]. Higher proportions of patients with FCP ≤ 250 µg/g achieved efficacy outcomes at Week 12 versus patients with FCP > 250 µg/g. CONCLUSIONS: Etrasimod was effective for inducing EIHR in patients with UC. FCP and CRP may be useful, noninvasive biomarkers to monitor treatment response. CLINICALTRIALS.GOV NUMBER: NCT02447302.

Sphingosine 1-phosphate (S1P) receptor modulators as an induction and maintenance therapy for ulcerative colitis: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVE: One sphingosine-1-phosphate (S1P) receptor modulator is approved (ozanimod) and another (etrasimod) is under investigation for the induction and maintenance of remission of ulcerative colitis (UC). We aim to evaluate the efficacy and safety of S1P modulators in patients with active UC. METHODS: We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching: PubMed, Web of Science, SCOPUS, and Cochrane through May 13th, 2023. We used the fixed-effect model to pool dichotomous data using risk ratio (RR) with a 95% confidence interval (CI). RESULTS: Five RCTs with a total of 1990 patients were included. S1P receptor modulators were significantly associated with increased clinical response during both the induction (RR 1.71 with 95% CI [1.50, 1.94], P = 0.00001) and maintenance phases (RR 1.89 with 95% CI [1.33, 2.69], P = 0.0004); clinical remission rates during both induction (RR 2.76 with 95% CI [1.88, 4.05], P = 0.00001) and maintenance phases (RR 3.34 with 95% CI [1.41, 7.94], P = 0.006); endoscopic improvement during both induction (RR 2.15 with 95% CI [1.71, 2.70], P = 0.00001) and maintenance phases (RR 2.41 with 95% CI [1.15, 5.05], P = 0.02); and histologic remission during both induction (RR 2.60 with 95% CI [1.89, 3.57] [1.17, 2.10], P = 0.00001) and maintenance phases (RR 2.52 with 95% CI [1.89, 3.37], P = 0.00001). Finally, there was no difference regarding safety outcomes as compared to placebo in both the induction and maintenance phases. CONCLUSION: S1P receptor modulators are effective in inducing and maintaining remission in patients with moderate to severe UC.

[Siponimod (BAF312): General Characteristics and Clinical Implications of Pharmacogenomic Dosage in the Treatment of Active Secondary Progressive Multiple Sclerosis]. / Siponimod (BAF312): Características generales e implicancias clínicas de la dosificación farmacogenómica en el tratamiento de la Esclerosis Múltiple secundaria progresiva.

Siponimod is a selective immunosuppressive medication, developed as the first oral therapy for active secondary progressive multiple sclerosis. This medication acts by modulating the sphingosine 1 phosphate (S1P) receptor, as an antagonist of S1P1 and S1P5, thus preventing the egress of lymphocytes from lymph nodes and preventing inflammatory processes in the Central Nervous System that trigger demyelination. There is extensive scientific knowledge regarding the administration of the medication to patients, which will depend on their pharmacogenetic characteristics. Therefore, the FDA strongly recommends conducting a genotyping study of the enzyme that metabolizes siponimod, CYP2C9, whose genetic variants *2 and *3 classify patients as poor, extensive, or rapid metabolizers. Siponimod is completely contraindicated for patients who are homozygous for CYP2C9*3. Additionally, before prescribing it, an electrocardiogram, assessments of antibody status, ophthalmic evaluation, varicella vaccination status, and peripheral lymphocyte count should be conducted, as the medication's effect is dose-dependent. Therefore, a titration process is carried out starting from 0.25mg up to 2 mg. The pharmacotherapeutic protocol of siponimod is a reliable reflection of the utility of pharmacogenetics in personalized medicine.