Catastrophic outcome of patients with a rebound after Natalizumab treatment discontinuation

Treatment switches of disease-modifying therapies in people with multiple sclerosis: long-term experience from the German MS Registry

Background

The spectrum of disease-modifying therapies (DMTs) for people with multiple sclerosis (PwMS) has expanded over years, but data on treatment strategies is largely lacking. DMT switches are common clinical practice.

Objective

To compare switchers and non-switchers, characterize the first DMT switch and identify reasons and predictors for switching the first DMT.

Methods

Data on 2722 PwMS from the German MS Registry were retrospectively analyzed regarding sociodemographic/clinical differences between 1361 switchers (PwMS discontinuing the first DMT) and non-switchers matched according to age, sex, and observation period. Frequencies of first and second DMTs were calculated and switch reasons identified. Predictors for DMT switches were revealed using univariable and multivariable regression models.

Results

Switchers and non-switchers differed significantly regarding time to first DMT, education, calendar period of the first DMT start (2014-2017 versus 2018-2021), first DMT class used [mild-to-moderate efficacy (MME) versus high-efficacy (HE) DMT], time on first DMT, and disease activity at first DMT start or cessation/last follow-up. The majority of PwMS started with MME DMTs (77.1%), with the most common being glatiramer acetate, dimethyl/diroximel fumarate, and beta-interferon variants. Switchers changed treatment more often to HE DMTs (39.6%), most commonly sphingosine-1-phosphate receptor modulators, anti-CD20 monoclonal antibodies, and natalizumab. Fewer PwMS switched to MME DMTs (35.9%), with the most common being dimethyl/diroximel fumarate, teriflunomide, or beta-interferon. Among 1045 PwMS with sufficient data (76.8% of 1361 switchers), the most frequent reasons for discontinuing the first DMT were disease activity despite DMT (63.1%), adverse events (17.1%), and patient request (8.3%). Predictors for the first DMT switch were MME DMT as initial treatment [odds ratio (OR) = 2.83 (1.76-4.61), p < 0.001; reference: HE DMT], first DMT initiation between 2014 and 2017 [OR = 11.55 (6.93-19.94), p < 0.001; reference: 2018-2021], and shorter time on first DMT [OR = 0.22 (0.18-0.27), p < 0.001].

Conclusion

The initial use of MME DMTs was among the strongest predictors of DMT discontinuation in a large German retrospective MS cohort, arguing for the need for prospective treatment strategy trials, not only but also on the initial broad use of HE DMTs in PwMS.

Integrinβ-1 in disorders and cancers: molecular mechanisms and therapeutic targets

Integrinβ-1 (ITGB1) is a crucial member of the transmembrane glycoprotein signaling receptor family and is also central to the integrin family. It forms heterodimers with other ligands, participates in intracellular signaling and controls a variety of cellular processes, such as angiogenesis and the growth of neurons; because of its role in bidirectional signaling regulation both inside and outside the membrane, ITGB1 must interact with a multitude of substances, so a variety of interfering factors can affect ITGB1 and lead to changes in its function. Over the past 20 years, many studies have confirmed a clear causal relationship between ITGB1 dysregulation and cancer development and progression in a wide range of benign diseases and solid tumor types, which may imply that ITGB1 is a prognostic biomarker and a therapeutic target for cancer treatment that warrants further investigation. This review summarizes the biological roles of ITGB1 in benign diseases and cancers, and compiles the current status of ITGB1 function and therapy in various aspects of tumorigenesis and progression. Finally, future research directions and application prospects of ITGB1 are suggested. Video Abstract.

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.

Rituximab De-escalation in Patients With Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVES

Exit strategies such as de-escalations have not been evaluated for rituximab in patients with neuromyelitis optica spectrum disorder (NMOSD). We hypothesized that they are associated with disease reactivations and aimed to estimate this risk.

METHODS

We describe a case series of real-world de-escalations from the French NMOSD registry (NOMADMUS). All patients met the 2015 International Panel for NMO Diagnosis (IPND) diagnostic criteria for NMOSD. A computerized screening of the registry extracted patients with rituximab de-escalations and at least 12 months of subsequent follow-up. We searched for 7 de-escalation regimens: scheduled discontinuations or switches to an oral treatment after single infusion cycles, scheduled discontinuations or switches to an oral treatment after periodic infusions, de-escalations before pregnancies, de-escalations after tolerance issues, and increased infusion intervals. Rituximab discontinuations motivated by inefficacy or for unknown purposes were excluded. The primary outcome was the absolute risk of NMOSD reactivation (one or more relapses) at 12 months. AQP4+ and AQP4- serotypes were analyzed separately.

RESULTS

We identified 137 rituximab de-escalations between 2006 and 2019 that corresponded to a predefined group: 13 discontinuations after a single infusion cycle, 6 switches to an oral treatment after a single infusion cycle, 9 discontinuations after periodic infusions, 5 switches to an oral treatment after periodic infusions, 4 de-escalations before pregnancies, 9 de-escalations after tolerance issues, and 91 increased infusion intervals. No group remained relapse-free over the whole de-escalation follow-up (mean: 3.2 years; range: 0.79-9.5), except pregnancies in AQP+ patients. In all groups combined and within 12 months, reactivations occurred after 11/119 de-escalations in patients with AQP4+ NMOSD (9.2%, 95% CI [4.7-15.9]), from 0.69 to 10.0 months, and in 5/18 de-escalations in patients with AQP4- NMOSD (27.8%, 95% CI [9.7-53.5]), from 1.1 to 9.9 months.

DISCUSSION

There is a risk of NMOSD reactivation whatever the rituximab de-escalation regimen.

TRIAL REGISTRATION INFORMATION

Registered on ClinicalTrials.gov: NCT02850705.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that de-escalation of rituximab increases the probability of disease reactivation.

Natalizumab treatment during pregnancy in multiple sclerosis-clinical and bioethical aspects of an ongoing debate

BACKGROUND

Natalizumab is an approved treatment for relapsing remitting multiple sclerosis; however, its safety during pregnancy is not formally proven.

CASE PRESENTATION

We report a woman with multiple sclerosis being treated with natalizumab before pregnancy. After withdrawal of natalizumab, she suffered a severe, disabling rebound. In agreement with the patient, natalizumab was restarted during pregnancy. Our patient improved substantially and gave birth to a healthy boy.

CONCLUSION

Use of natalizumab during pregnancy may be an option in highly active multiple sclerosis.

Integrins regulate stemness in solid tumor: an emerging therapeutic target

Integrins are the adhesion molecules and transmembrane receptors that consist of α and β subunits. After binding to extracellular matrix components, integrins trigger intracellular signaling and regulate a wide spectrum of cellular functions, including cell survival, proliferation, differentiation and migration. Since the pattern of integrins expression is a key determinant of cell behavior in response to microenvironmental cues, deregulation of integrins caused by various mechanisms has been causally linked to cancer development and progression in several solid tumor types. In this review, we discuss the integrin signalosome with a highlight of a few key pro-oncogenic pathways elicited by integrins, and uncover the mutational and transcriptomic landscape of integrin-encoding genes across human cancers. In addition, we focus on the integrin-mediated control of cancer stem cell and tumor stemness in general, such as tumor initiation, epithelial plasticity, organotropic metastasis and drug resistance. With insights into how integrins contribute to the stem-like functions, we now gain better understanding of the integrin signalosome, which will greatly assist novel therapeutic development and more precise clinical decisions.

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

Background It is still controversial whether the relapse experienced after discontinuation of fingolimod treatment is a rebound. Increasing cases of rebound have been reported in the literature. The rate of fingolimod rebound in patients after fingolimod cessation is reported between 5% and 52%. The present study aims to determine the rate of rebound after discontinuation of fingolimod treatment and the factors affecting the rebound. Methods This retrospective cohort study consists of adult MS patients who have been admitted to the Hacettepe University Hospital Neurology MS Center outpatient clinic between 2012 and 2020. Results During the study period, 642 patients received fingolimod and 23.1% discontinued the fingolimod treatment. Thirteen of 126 patients had a rebound (10.3%) after fingolimod discontinuation. The patients in the rebound group were significantly younger and washout period were significantly longer than those in the non-rebound group. After discontinuation of fingolimod treatment, the EDSS score of the rebound group was significantly higher than the non-rebound group, while Annualized Relapse Rates were similar. Conclusion Younger age, longer washout time, and previous treatment preferences may increase the occurrence probability of rebound. It is recommended that patients should be closely monitored after fingolimod discontinuation and appropriate disease-modifying therapy should be initiated as soon as possible.

Using Monoclonal Antibody Therapies for Multiple Sclerosis: A Review

Monoclonal antibody therapies have secured an important role in the therapeutic landscape for the treatment of both relapsing and progressive forms of multiple sclerosis due to their potent efficacy, convenient dosing schedules, and well-defined side effect profiles. Each therapy has unique risks and benefits associated with its specific mechanism of action which ultimately guides clinical decision-making for individual patients. This review will summarize the mechanisms of action, evidence leading to their approval, and clinically relevant considerations for each of the current monoclonal antibody therapies approved for the treatment of multiple sclerosis.

Update on treatment in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. In recent years, many disease-modifying therapies (DMT) have been approved for MS treatment. For this reason, a profound knowledge of the characteristics and indications of the available compounds is required to tailor the therapeutic strategy to the individual patient characteristics. This should include the mechanism of action and pharmacokinetic of the drug, the safety and efficacy profile provided by clinical trials, as well as the understanding of possible side effects. Moreover, the evolving knowledge of the disease is paving the way to new and innovative therapeutic approaches, as well as the development of new biomarkers to monitor the therapeutic response and to guide the clinician's therapeutic choices. In this review we provide a comprehensive overview on currently approved therapies in MS and the emerging evidence-based strategies to adopt for initiating, monitoring, and eventually adapting a therapeutic regimen with DMT.

Natalizumab in Multiple Sclerosis Treatment: From Biological Effects to Immune Monitoring

Multiple sclerosis is a chronic demyelinating disease of the central nervous system (CNS) with an autoimmune component. Among the recent disease-modifying treatments available, Natalizumab, a monoclonal antibody directed against the alpha chain of the VLA-4 integrin (CD49d), is a potent inhibitor of cell migration toward the tissues including CNS. It potently reduces relapses and active brain lesions in the relapsing remitting form of the disease. However, it has also been associated with a severe infectious complication, the progressive multifocal leukoencephalitis (PML). Using the standard protocol with an injection every 4 weeks it has been shown by a close monitoring of the drug that trough levels soon reach a plateau with an almost saturation of the target cell receptor as well as a down modulation of this receptor. In this review, mechanisms of action involved in therapeutic efficacy as well as in PML risk will be discussed. Furthermore the interest of a biological monitoring that may be helpful to rapidly adapt treatment is presented. Indeed, development of anti-NAT antibodies, although sometimes unapparent, can be detected indirectly by normalization of CD49d expression on circulating mononuclear cells and might require to switch to another drug. On the other hand a stable modulation of CD49d expression might be useful to follow the circulating NAT levels and apply an extended interval dose scheme that could contribute to limiting the risk of PML.

Managing Disease-Modifying Therapies and Breakthrough Activity in Multiple Sclerosis Patients During the COVID-19 Pandemic: Toward an Optimized Approach

The emergence of the novel coronavirus disease 2019 (COVID-19) pandemic has become a major public health challenge of global concern since December 2019, when the virus was recognized in Wuhan, the capital city of Hubei province in China and epicenter of the COVID-19 epidemic. Given the novelty of COVID-19 and the lack of specific anti-virus therapies, the current management is essentially supportive. There is an absence of consensus on guidelines or treatment strategies for complex disorders such as multiple sclerosis (MS), in which the risk of infections is higher than in the general population. This is due to the overall impairment of the immune system typical of autoimmune diseases, in addition to accumulation of disabilities, and the iatrogenic effect generated by corticosteroids and the recommended disease-modifying therapies (DMTs). DMTs have different modes of action, but all modulate and interfere with the patient's immune response, thereby raising concerns about adverse effects, such as an increased susceptibility to infections. In this review, we analyze the evidence for use of DMTs during the current critical period and ratify an algorithmic approach for management to optimize care between keeping DMTs, with their infection hazards, or coming off them, with the risk of disease activation. We also provide an algorithmic approach to the management of breakthrough activity during the COVID-19 pandemic.

COVID-19 and MS disease-modifying therapies

OBJECTIVE

To address concerns regarding the effect of MS disease-modifying therapies (DMTs) on the expression of coronavirus 2019 (COVID-19).

METHODS

Review of the current state of knowledge regarding the viral etiology of COVID-19, mechanisms of injury by SARS-CoV-2 infection, and the effect of individual DMTs on the risk of infection and COVID-19 disease expression.

RESULTS

Although data are limited, MS DMTs do not obviously increase the risk of acquiring symptomatic SARS-CoV-2 infection. The severe morbidity and mortality of SARS-CoV-2 appear to be largely the consequence of an overly robust immune response rather than the consequence of unchecked viral replication. The effects of specific MS DMTs on the immune response that may increase the risk of impaired viral clearance and their potential counterbalancing beneficial effects on the development of COVID-19-associated acute respiratory distress syndrome are reviewed.

CONCLUSION

Although there is currently insufficient real-world experience to definitively answer the question of the effect of a specific MS DMT on COVID-19, registries presently in nascent form should provide these answers. This review provides an approach to addressing these concerns while the data are being accumulated. Early insights suggest that the risk of infection and associated morbidity of COVID-19 in this population is little different than that of the population at large.

Effectiveness of fingolimod in real-world relapsing-remitting multiple sclerosis Italian patients: the GENIUS study

Background

Fingolimod is the first oral agent approved for treatment of relapsing-remitting multiple sclerosis (RRMS). We aimed to evaluate fingolimod effectiveness in a real-world sample of RRMS patients.

Methods

A retrospective, multicentre study in patients treated with fingolimod, whom clinical and radiological data were collected in the 2 years preceding and following the initiation of fingolimod.

Results

Out of 414 patients, 56.8% received prior first-line injectable disease-modifying therapies, 25.4% were previously treated with natalizumab, 1.2% with immunosuppressant agents, and 16.7% were treatment naive. The annualized relapse rate decreased by 65% in the first year and by 70% after two years of treatment. Age ≤ 40 years, ≥ 1 relapse in the 24 months before fingolimod initiation and previous treatment with natalizumab were risk factors for relapses. Overall, 67.9% patients had no evidence of disease activity (NEDA-3) after 1 year and 54.6% after 2 years of treatment. A higher proportion of naïve (81.2% in 1 year and 66.7% after 2 years) or first-line injected patients (70.2% and 56.6%) achieved NEDA-3 than those previously treated with natalizumab (54.3% and 42.9%).

Conclusions

Fingolimod appeared to be effective in naive patients and after first-line treatment failure in reducing risk of relapse and disease activity throughout the 2-year follow-up.

Electronic supplementary material

The online version of this article (10.1007/s10072-020-04380-y) contains supplementary material, which is available to authorized users.

Extending the Interval of Natalizumab Dosing: Is Efficacy Preserved?

Extending the natalizumab interval after the 24th administration could reduce the risk of progressive multifocal leukoencephalopathy (PML). The objective is to evaluate the noninferiority of the efficacy of an extended interval dosing (EID) compared with the standard interval dosing (SID) of natalizumab. It is an observational, multicenter (14 Italian centers), retrospective cohort study, starting from the 24th natalizumab infusion to the loss of follow-up or 2 years after baseline. Patients were grouped in 2 categories according to the mean number of weeks between doses: < 5 weeks, SID; ≥ 5 weeks, EID. Three hundred and sixty patients were enrolled. Median dose interval (MDI) following 24th infusion was 4.7 weeks, with a bimodal distribution (modes at 4 and 6 weeks). Two hundred and sixteen patients were in the SID group (MDI = 4.3 weeks) and 144 in the EID group (MDI 6.2 weeks). Annualized relapse rate was 0.060 (95% CI = 0.033-0.087) in the SID group and 0.039 (95% CI = 0.017-0.063) in the EID group. The non-inferiority of EID versus SID was satisfied. In conclusion, there is no evidence of a reduced efficacy of natalizumab in an EID setting. This observation confirms previous results and together with the emerging evidence of a reduced risk of PML associated to an EID, supports the need of a randomized study to assess the need to change the standard of the natalizumab dosing schedule.

Multiple sclerosis

Multiple sclerosis is a chronic, unpredictable, and disabling disease. Significant advances have been made in recent years supporting an earlier, more accurate, diagnosis and have led to more than 15 disease-modifying therapies approved by the Food and Drug Administration for relapsing forms of multiple sclerosis. Disease-modifying therapies are now being classified into categories based on level of efficacy. Strategies to use disease-modifying therapies earlier and in a more customizable manner are also emerging. A clinical case study will be used throughout this pearl to review the disease-modifying therapies and use patient-specific factors to develop and provide recommendations on therapeutic strategies for individuals with relapsing forms of multiple sclerosis.

Dependence, withdrawal and rebound of CNS drugs: an update and regulatory considerations for new drugs development

The purpose of this article is to describe dependence and withdrawal phenomena related to CNS drugs discontinuation and to clarify issues related to the evaluation of clinical drug withdrawal and rebound as they relate to safety in new drug development. The article presents current understanding and definitions of drug dependence and withdrawal which are also relevant and important features of addiction, though not the same. Addiction, called substance use disorder in DSM-5, affects an individual’s brain and behaviour, represents uncontrollable drug abuse and inability to stop taking a drug regardless of the harm it causes. Characteristic withdrawal syndromes following abrupt discontinuation of CNS-active drugs from numerous drug classes are described. These include drugs both scheduled and non-scheduled in the Controlled Substances Act, which categorizes drugs in five schedules based on their relative abuse potentials and dependence liabilities and for regulatory purposes. Schedules 1 and 2 contain drugs identified as those with the highest abuse potential and strictest regulations. Less recognized aspects of drug withdrawal, such as rebound and protracted withdrawal syndromes for several drug classes are also addressed. Part I presents relevant definitions and describes clinical withdrawal and dependence phenomena. Part II reviews known withdrawal syndromes for the different drug classes, Part III describes rebound and Part IV describes protracted withdrawal syndromes. To our knowledge, this is the first compilation of withdrawal syndromes for CNS drugs. Part V provides details of evaluation of dependence and withdrawal in the clinical trials for CNS drugs, which includes general design recommendations, and several tools, such as withdrawal questionnaires and multiple scales that are helpful in the systematic evaluation of withdrawal. The limitations of different aspects of this method of dependence and withdrawal evaluation are also discussed.

An Overview of High-Efficacy Drugs for Multiple Sclerosis: Gulf Region Expert Opinion

This article discusses the opinions of the multiple sclerosis (MS) experts in the Gulf region on the use of high-efficacy disease-modifying drugs (DMDs; natalizumab, fingolimod, alemtuzumab, cladribine tablets, and ocrelizumab) in clinical practice. The experts reviewed the current literature including pivotal clinical trials and meta-analyses for high-efficacy DMDs, supplemented by the expert opinions on the usage of these DMDs in clinical practice. Several criteria were discussed by the panel based on different efficacy, safety, and convenience attributes. The panel concluded that all the DMDs available for the treatment of MS have benefits and risks, which should be considered while discussing the treatment plan with the patient. It is important to have a personalized approach based on the risk-benefit assessment for each case. Common considerations while choosing treatments include effectiveness, side effects/safety, and convenience/route of administration.

Funding: Merck Serono Middle East FZ LTD.

Alemtuzumab as rescue therapy in case of multiple sclerosis rebound following Natalizumab break: Clinical case and literature review

INTRODUCTION

Natalizumab break exposes multiple sclerosis (MS) patients to a high risk of disease reactivation or rebound, whose prevention and treatment constitute a clinical challenge.

CASE PRESENTATION

We describe a dramatic case of MS rebound, characterized by the development of severe neurological and psychiatric symptoms, following natalizumab break. Alemtuzumab rapidly and completely suppressed brain inflammation as demonstrated by clinical and radiological findings.

CONCLUSIONS

Our case further adds to the available literature evidence on Alemtuzumab as first-choice rescue therapy following Natalizumab discontinuation.

Cladribine tablets' potential role as a key example of selective immune reconstitution therapy in multiple sclerosis

Multiple sclerosis (MS) is one of the most important, disabling, and prevalent neurological disorders of young adults. It is a chronic inflammatory and neurodegenerative disease when autoreactive B and T cells have downstream effects that result in demyelination and neuronal loss. Anti-inflammatory disease-modifying therapies do have proven efficacy in delaying disease and disability progression in MS. While the progress in MS treatments has already improved the prognosis and quality of patients’ lives overall, there are some clear shortcomings and unmet needs in the current MS treatment landscape. The most promising means of MS treatment is selective immune reconstitution therapy (SIRT). This therapy is given in short-duration courses of immunosuppression, producing durable effects on the immune system and preventing nervous tissue loss. This review discusses the mechanisms of action and the data of clinical trials of cladribine tablets as an example of SIRT in MS. The clinical benefits of cladribine tablets in these studies include decreased relapse rate and disability progression with large reductions in lesion activity, and protection against brain volume loss. Whether all of these neurological findings are direct results of lymphocyte depletion, or if there are downstream effects on other, unknown, neurodegenerative processes are yet to be determined, but these clearly point to an interesting area of research.

Rituximab before and during pregnancy: A systematic review, and a case series in MS and NMOSD

OBJECTIVE

To evaluate the safety of rituximab treatment before and during pregnancy in women with MS and neuromyelitis optica spectrum disorders (NMOSDs) who may be at risk of relapses by performing a systematic literature review combined with a retrospective single-center case series.

METHODS

Studies were systematically identified in the PubMed, Google Scholar, and EMBASE using the key terms "pregnancy" and "rituximab"; 22 articles were included for review (>17,000 screened). Then, patients with MS and NMOSD from 1 center (University of California, San Francisco) exposed to rituximab before conception were identified through medical record review.

RESULTS

Systematic review: We identified 102 pregnancies with rituximab use within 6 months of conception: 78 resulted in live births and 12 in spontaneous abortions. Of 54 live births with reported gestational age, 31 occurred at term (37 weeks+) and 2 before 32 weeks. When checked, B-cell counts were low in 39% of newborns and normalized within 6 months. Case series: we identified 11 pregnancies (1 ongoing) in 10 women (7 MS and 3 NMOSD) treated with rituximab within 6 months of conception. All completed pregnancies resulted in term live births of healthy newborns (1 lost to follow-up at term). No maternal relapses occurred before/during pregnancy; 1 occurred postpartum (NMOSD).

CONCLUSION

No major safety signal was observed with rituximab use within 6 months of conception. Beyond the need for monitoring neonatal B cells, these observations support prospectively monitoring a larger patient cohort to determine whether rituximab may safely protect women with MS and NMOSD who are planning a pregnancy against relapses.

Integrins as Therapeutic Targets: Successes and Cancers

Integrins are transmembrane receptors that are central to the biology of many human pathologies. Classically mediating cell-extracellular matrix and cell-cell interaction, and with an emerging role as local activators of TGFβ, they influence cancer, fibrosis, thrombosis and inflammation. Their ligand binding and some regulatory sites are extracellular and sensitive to pharmacological intervention, as proven by the clinical success of seven drugs targeting them. The six drugs on the market in 2016 generated revenues of some US$3.5 billion, mainly from inhibitors of α4-series integrins. In this review we examine the current developments in integrin therapeutics, especially in cancer, and comment on the health economic implications of these developments.

Catastrophic outcome of patients with a rebound after Natalizumab treatment discontinuation

INTRODUCTION

Natalizumab (NTZ) is an effective drug for the treatment of relapsing-remitting multiple sclerosis. In some patients discontinuation is mandatory due to the risk of progressive multifocal leukoencephalopathy. However, severe clinical and radiological worsening has been described after drug cessation. Our aim was to describe the clinical and radiological features of the rebound phenomenon.

MATERIAL AND METHODS

Patients switched from NTZ to Fingolimod (FTY) who had presented a rebound after discontinuation were selected. Clinical and magnetic resonance imaging (MRI) data were collected.

RESULTS

Four JC virus positive patients were included. The mean disease duration was 9.5 years (SD: 4.12) with a mean time of 3.1 years on NTZ. All patients started FTY within 3-4 months. Neurological deterioration started in a mean time of 3.5 months (SD: 2.08) with multifocal involvement: 75% motor disturbances, 50% cognitive impairment, 25% seizures. The average worsening in Expanded Disability Status Scale [EDSS] was of 3.25 points (SD: 2.33). The MRI showed a very large increase in T2 and gadolinium-enhanced lesions (mean: 23.67, SD: 18.58). All patients received 5 days of IV methylprednisolone, one patient required plasma exchange. All the patients presented neurological deterioration with an EDSS worsening of 1.13 points (SD: 0.48). After the rebound three patients continued treatment with FTY, only one patient restarted NTZ.

CONCLUSION

Discontinuation of NTZ treatment may trigger a severe rebound with marked clinical and radiological worsening. A very careful evaluation of benefit-risk should be considered before NTZ withdrawal, and a close monitoring and a short washout period is recommended after drug withdrawal.