Factors associated with fingolimod rebound: A single center real-life experience

A case of early disease rebound after fingolimod discontinuation in a patient with multiple sclerosis and SARS-CoV-2 infection

Fingolimod is approved in Italy as a second-line therapy for relapsing-remitting multiple sclerosis (RRMS). Discontinuation of fingolimod may elevate the risk of relapses, typically manifesting after a relatively prolonged drug-free interval and often necessitating high doses of intravenous steroids for management. Similar to other viruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can act as a trigger for MS relapses. In this context, we present a case of rebound following fingolimod discontinuation during a SARS-CoV-2 infection. Notably, the rebound occurred shortly after stopping the medication and responded effectively to low doses of oral steroids. Our case is discussed in light of existing literature, with speculation on potential mechanisms governing this unconventional disease course rebound. We also consider the possibility that SARS-CoV-2 infection might have contributed to or even triggered the MS relapse.

An integrative mechanistic model of thymocyte dynamics

Background

The thymus plays a central role in shaping human immune function. A mechanistic, quantitative description of immune cell dynamics and thymic output under homeostatic conditions and various patho-physiological scenarios are of particular interest in drug development applications, e.g., in the identification of potential therapeutic targets and selection of lead drug candidates against infectious diseases.

Methods

We here developed an integrative mathematical model of thymocyte dynamics in human. It incorporates mechanistic features of thymocyte homeostasis as well as spatial constraints of the thymus and considerations of age-dependent involution. All model parameter estimates were obtained based on published physiological data of thymocyte dynamics and thymus properties in mouse and human. We performed model sensitivity analyses to reveal potential therapeutic targets through an identification of processes critically affecting thymic function; we further explored differences in thymic function across healthy subjects, multiple sclerosis patients, and patients on fingolimod treatment.

Results

We found thymic function to be most impacted by the egress, proliferation, differentiation and death rates of those thymocytes which are most differentiated. Model predictions also showed that the clinically observed decrease in relapse risk with age, in multiple sclerosis patients who would have discontinued fingolimod therapy, can be explained mechanistically by decreased thymic output with age. Moreover, we quantified the effects of fingolimod treatment duration on thymic output.

Conclusions

In summary, the proposed model accurately describes, in mechanistic terms, thymic output as a function of age. It may be further used to perform predictive simulations of clinically relevant scenarios which combine specific patho-physiological conditions and pharmacological interventions of interest.

Risk of T2 lesions when discontinuing fingolimod: a nationwide predictive and comparative study

Fingolimod is a frequently used disease-modifying therapy in relapsing-remitting multiple sclerosis. However, case reports and small observational studies indicate a highly increased risk of disease reactivation after discontinuation. We aimed to investigate the risk of radiological disease reactivation in patients discontinuing fingolimod. We performed a nationwide cohort study in Denmark, including patients who discontinued fingolimod between January 2014 and January 2023. Eligibility was a diagnosis with relapsing-remitting multiple sclerosis and two MRIs performed respectively within 1 year before and after discontinuing fingolimod. The included patients were compared with those discontinuing dimethyl fumarate with the same eligibility criteria in an unadjusted and matched propensity score analysis. Matching was done on age, sex, Expanded Disability Status Scale, MRI data, cause for treatment discontinuation, treatment duration and relapse rate. The main outcome was the presence of new T2 lesions on the first MRI after treatment discontinuation. To identify high-risk patients among those discontinuing fingolimod, we made a predictive model assessing risk factors for obtaining new T2 lesions. Of 1324 patients discontinuing fingolimod in the study period, 752 were eligible for inclusion [mean age (standard deviation), years, 41 (10); 552 females (73%); median Expanded Disability Status Scale (Q1-Q3), 2.5 (2.0-3.5); mean disease duration (standard deviation), years, 12 (8)]. Of 2044 patients discontinuing dimethyl fumarate in the study period, 957 were eligible for inclusion, presenting similar baseline characteristics. Among patients discontinuing fingolimod, 127 (17%) had 1-2 new T2 lesions, and 124 (17%) had ≥3 new T2 lesions compared with 114 (12%) and 45 (5%), respectively, for those discontinuing dimethyl fumarate, corresponding to odds ratios (95% confidence interval) of 1.8 (1.3-2.3) and 4.4 (3.1-6.3). The predictive model, including 509 of the 752 patients discontinuing fingolimod, showed a highly increased risk of new T2 lesions among those with disease activity during fingolimod treatment and among females under 40 years. This nationwide study suggests that discontinuing fingolimod in some cases carries a risk of developing new T2 lesions, emphasizing the importance of clinical awareness. If feasible, clinicians should prioritize the prompt initiation of new disease-modifying therapies, particularly among young females.

Frequency and risk factors of rebound after fingolimod discontinuation - A retrospective study

BACKGROUND

Fingolimod (FTY) rebound, a phenomenon of unexpectedly severe disease activity following FTY discontinuation, has been reported to occur in 5-43 % of patients. Only a few larger cohorts have been analyzed. We aimed to determine the frequency and risk factors of FTY rebound in our hospital district in Southern Finland with a population of 1.7 million.

METHODS

We searched the Finnish MS-register for patients who were previous or current users of FTY for at least 6 months by November 2020. We assessed medical records and collected basic demographic data for the whole cohort. Criteria for a rebound were: (i) the most severe relapse in patient's history and an increase of at least 2 EDSS points during the relapse occurring within 6 months from FTY cessation, or (ii) more than one relapse within 6 months after FTY discontinuation, this being the highest relapse rate observed during the patient's lifetime.

RESULTS

Among 3496 MS patients, we found 331 patients ever starting FTY and 283 of them had used FTY for at least 6 months. Among these 283 patients we discovered a total of 114 discontinuation events in 110 patients. Of the discontinuations, 32 (28 %) were followed by a relapse: 20 (17.5 %) were ordinary relapses not fulfilling rebound criteria, and 12 (10.5 %) were rebounds. The median time to an ordinary relapse and rebound were similar: 8.5 weeks (range 1.3-23) and 9.9 weeks (range 5.9-15.9), respectively. The rebound group was younger at diagnosis (p = 0.034) and had used FTY for a longer time (p = 0.048) before discontinuation compared to the group without a relapse. After discontinuation, rebound group had lower lymphocyte values as compared to both ordinary relapse group (p = 0.027) and no-relapse group (p = 0.006) and neutrophil to lymphocyte ratio (NLR) was increased compared to the no-relapse group (p = 0.019).

CONCLUSION

In this study, 10.5 % of patients experienced a rebound, which is similar to the frequencies (10.3-12.5 %) obtained in other larger studies with >100 discontinuations. Relapses of any severity occurred in 28 % of patients discontinuing FTY, and therefore initiation of subsequent disease modifying therapies should occur promptly after discontinuation. Younger age at diagnosis, longer exposure to FTY and lower lymphocyte count as well as higher NLR after discontinuation were identified as risk factors for a rebound. The differences in blood leukocytes indicate that rebound might be a distinct pathophysiological phenomenon compared to an ordinary relapse.

Multiple faces of multiple sclerosis in the era of highly efficient treatment modalities: Lymphopenia and switching treatment options challenges daily practice

The expanded treatment landscape in relapsing-remitting multiple sclerosis (MS) has resulted in highly effective treatment options and complexity in managing disease- or drug-related events during disease progression. Proper decision-making requires thorough knowledge of the immunobiology of MS itself and an understanding of the main principles behind the mechanisms that lead to secondary autoimmunity affecting organs other than the central nervous system as well as opportunistic infections. The immune system is highly adapted to both environmental and disease-modifying agents. Immune reconstitution following cell depletion or cell entrapment therapies eliminates pathogenic aspects of the disease but can also lead to distorted immune responses with harmful effects. Atypical relapses occur with second-line treatments or after their discontinuation and require appropriate clinical decisions. Lymphopenia is a result of the mechanism of action of many drugs used to treat MS. However, persistent lymphopenia and cell-specific lymphopenia could result in disease exacerbation, secondary autoimmunity, or the emergence of opportunistic infections. Clinicians treating patients with MS should be aware of the multiple faces of MS under novel, efficient treatment modalities and understand the intricate brain-immune cell interactions in the context of an altered immune system. MS relapses and disease progression still occur despite the current treatment modalities and are mediated either by failure to control effector mechanisms inherent to MS pathophysiology or by new drug-related mechanisms. The multiple faces of MS due to the highly adapted immune system of patients impose the need for appropriate switching therapies that safeguard disease remission and further clinical improvement.

Severe disease reactivation in seropositive neuromyelitis optica spectrum disorders patients after stopping eculizumab treatment

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune, inflammatory disease of the central nervous system affecting the optic nerves and spinal cord. Most NMOSD patients have autoantibodies against the astrocyte water channel protein aquaporin-4 (AQP4). Eculizumab treatment is used effectively and safely in AQP4-IgG+ NMOSD. Our study evaluated the prognosis and outcomes of all clinical trial (PREVENT) patients from Turkey who received eculizumab treatment for AQP4-IgG+ NMOSD.

METHOD

Clinical and demographic data of all patients enrolled in the PREVENT and OLE clinical trial in Turkey were analyzed during the study period and after the study ended. Clinical follow-up results were recorded in detail in patients who had to discontinue eculizumab treatment.

RESULTS

The study included 10 patients who participated in PREVENT and OLE. Seven patients completed the studies, three patients did not continue the study and were switched to other treatments. Only one of the seven patients was able to continue treatment after eculizumab was approved in AQP4-IgG+NMOSD. The other six patients could not continue treatment due to reimbursement conditions. Four of the six patients who could not continue eculizumab treatment experienced early relapse (within the first three months after stopping the drug). All of these patients had high disease activity before eculizumab and had never relapsed under eculizumab treatment over the long term.

CONCLUSION

Eculizumab was used effectively and safely in Turkish AQP4-IgG+NMOSD patients with high disease activity. Disease reactivation and relapse may occur after discontinuation of eculizumab treatment in patients with a long-term stable course. In these cases, close monitoring for disease reactivation is recommended.

An update on the use of sphingosine 1-phosphate receptor modulators for the treatment of relapsing multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated disorder of the CNS manifested by recurrent attacks of neurological symptoms (related to focal inflammation) and gradual disability accrual (related to progressive neurodegeneration and neuroinflammation). Sphingosine-1-phosphate-receptor (S1PR) modulators are a class of oral disease-modifying therapies (DMTs) for relapsing MS. The first S1PR modulator developed and approved for MS was fingolimod, followed by siponimod, ozanimod, and ponesimod. All are S1P analogues with different S1PR-subtype selectivity. They restrain the S1P-dependent lymphocyte egress from lymph nodes by binding the lymphocytic S1P-subtype-1-receptor. Depending on their pharmacodynamics and pharmacokinetics, they can also interfere with other biological functions.

AREAS COVERED

Our narrative review covers the PubMed English literature on S1PR modulators in MS until August 2022. We discuss their pharmacology, efficacy, safety profile, and risk management recommendations based on the results of phase II and III clinical trials. We briefly address their impact on the risk of infections and vaccines efficacy.

EXPERT OPINION

S1PR modulators decrease relapse rate and may modestly delay disease progression in people with relapsing MS. Aside their established benefit, their place and timing within the long-term DMT strategy in MS, as well as their immunological effects in the new and evolving context of the post-COVID-19 pandemic and vaccination campaigns warrant further study.

Expert opinion on the long-term use of cladribine tablets for multiple sclerosis: Systematic literature review of real-world evidence

BACKGROUND

Treatment with cladribine tablets (CladT), an immune reconstitution therapy for relapsing multiple sclerosis (RMS), involves two short courses of treatment in Year 1 and Year 2. Most patients achieve sustained efficacy with CladT, but a small proportion may experience new disease activity (DA). Following completion of the indicated dose, physicians may have questions relating to the long-term management of these patients. Since the EU approval of CladT over 5 years ago, real-world evidence (RWE) is increasing and may provide some insights and guidance for clinical practice. We describe a systematic literature review (SLR) of RWE and provide expert opinions relating to six questions regarding the long-term use of CladT.

METHODS

Pertinent clinical questions were developed by a steering committee (SC) of 14 international multiple sclerosis (MS) experts regarding breakthrough DA in Year 1, new DA after 2 years or more of treatment, long-term management of stable patients, and whether additional courses of CladT may be required or safe. An SLR was performed in EMBASE and PubMed using the population, intervention, comparators, outcomes, study design (PICOS) framework to identify relevant studies within the last 15 years. Searches of key congress proceedings for the last 2-3 years were also performed. Following review of the results and RWE, the SC drafted and agreed on expert opinion statements for each question.

RESULTS

A total of 35 publications reporting RWE for CladT were included in this review. In the real world, breakthrough DA in Year 1 is of low incidence (1.1-21.9%) but can occur, particularly in patients switching from anti-lymphocyte trafficking agents. In most patients, this DA did not lead to treatment discontinuation. Reported rates of DA after the full therapeutic effect of CladT has been achieved (end of Year 2, 3 or 4) range from 12.0 to 18.7% in the few studies identified. No RWE was identified to support management decisions for stable patients in Year 5 or later. Views among the group were also diverse on this question and voting on expert opinion statements was required. Only two studies reported the administration of additional courses of CladT, but detailed safety outcomes were not provided.

CONCLUSIONS

RWE for the long-term use of CladT in the treatment of RMS is increasing, however, gaps in knowledge remain. Where possible, the RWE identified through the SLR informed expert statements, but, where RWE is still lacking, these were based solely on experiences and opinion, providing some guidance on topics and questions that occur in daily clinical practice. More real-world studies with longer-term follow-up periods are needed and highly anticipated.

Rebound of clinical disease activity after fingolimod discontinuation? A nationwide cohort study of patients in Denmark

OBJECTIVE

We investigated whether clinical rebound occurred after fingolimod discontinuation in a complete population of patients with relapsing-remitting multiple sclerosis (RRMS) in Denmark. We further identified clinical and demographical factors associated with disease reactivation after fingolimod discontinuation.

METHODS

The population comprised 992 RRMS patients treated with fingolimod for 6 months or more. We estimated annualised relapse rates (ARR) before, during and after treatment. We estimated overall ARRs and ARRs stratified by disease activity before discontinuation. We calculated the proportion of patients with a higher clinical disease activity after discontinuation than before treatment start. Finally, we analysed the association between variables at discontinuation and time to first relapse after discontinuation.

RESULTS

The ARR 3 months after discontinuation (ARR=0.56; 95% CI=0.47 to 0.66) was statistically significantly lower (p<0.01) than the ARR 1 year before treatment (ARR=0.74; 95% CI=0.69 to 0.80). Results were similar when repeating analyses in patients with and without disease activity before discontinuation. In total, 124 patients (12.5%) had clinical rebound. Of those, 36 had no disease breakthrough before discontinuation (3.6% of total population). On treatment disease activity (HR=1.98, p<0.01), lower age (HR=0.98, p=0.01) and female sex (HR=1.68, p=0.02) were associated with a higher relapse risk after discontinuation.

CONCLUSIONS

Based on average ARR levels, there was no evidence of clinical rebound after fingolimod discontinuation. In total, 12.5% of patients had clinical rebound. Only 3.6%, however, had clinical rebound without disease activity before discontinuation. Disease activity before discontinuation, female sex and younger age were statistically significantly associated with a higher relapse risk after discontinuation.

High-Efficacy Therapies for Treatment-Naïve Individuals with Relapsing-Remitting Multiple Sclerosis

There are > 18 distinct disease-modifying therapy (DMT) options covering 10 mechanisms of action currently approved by the US Food and Drug Administration for the treatment of relapsing-remitting multiple sclerosis (RRMS). Given the multitude of available treatment options, and recent international consensus guidelines offering differing recommendations, there is broad heterogeneity in how the DMTs are used in clinical practice. Choosing a DMT for newly diagnosed patients with MS is currently a topic of significant debate in MS care. Historically, an escalation approach to DMT was used for newly diagnosed patients with RRMS. However, the evidence for clinical benefits of early treatment with high-efficacy therapies (HETs) in this population is emerging. In this review, we provide an overview of the DMT options and MS treatment strategies, and discuss the clinical benefits of HETs (including ofatumumab, ocrelizumab, natalizumab, alemtuzumab, and cladribine) in the early stages of MS, along with safety concerns associated with these DMTs. By minimizing the accumulation of neurological damage early in the disease course, early treatment with HETs may enhance long-term clinical outcomes over the lifetime of the patient.