Persistent severe lymphopenia 5 years after dimethyl fumarate discontinuation

Disease-modifying therapies and hematological disorders: a systematic review of case reports and case series

Introduction

Disease modifying therapies (DMTs) used to treat multiple sclerosis (MS) can be associated to the occurrence of hematological disorders. This systematic review aims to provide an overview of these events occurring in real-life conditions, by describing case reports and series published in the literature.

Methods

A literature search of all publications up to January 5th 2024 on the Medline and Embase databases was carried out. The results were presented both in the text and in tables.

Results

Sixty-seven case reports/series were included in this review, of which more than half related to alemtuzumab, natalizumab and ocrelizumab. The publication date of included studies ranged from 2006 to 2024. The majority of case reports and series described the occurrence of late-onset hematological disorders (events that occurred more than 30 days after the first DMT administration), mainly represented by case of neutropenia, autoimmune hemolytic anemia and immune thrombocytopenia. All cases reported a favorable outcome, apart one case report that described a fatal case. Among included cases, 4 articles, all related to natalizumab, described the occurrence of myeloid disorders in 13 newborns from mother receiving the DMT.

Discussion

Considering the limitations identified in the majority of included studies, further ad hoc studies are strongly needed to better evaluate the hematological disorders of DMTs. Meantime, the strict monitoring of treated patients for the occurrence of these toxicities should be highly recommended.

Holistic, Long-Term Management of People with Relapsing Multiple Sclerosis with Cladribine Tablets: Expert Opinion from France

Cladribine tablets (CladT) has been available for therapeutic use in France since March 2021 for the management of highly active relapsing multiple sclerosis (RMS). This high-efficacy disease-modifying therapy (DMT) acts as an immune reconstitution therapy. In contrast to most high-efficacy DMTs, which act via continuous immunosuppression, two short courses of oral treatment with CladT at the beginning of years 1 and 2 of treatment provide long-term control of MS disease activity in responders to treatment, without the need for any further pharmacological treatment for several years. Although the labelling for CladT does not provide guidance beyond the initial treatment courses, real-world data on the therapeutic use of CladT from registries of previous clinical trial participants and patients treated in routine practice indicate that MS disease activity is controlled for a period of years beyond this time for a substantial proportion of patients. Moreover, this clinical experience has provided useful information on how to initiate and manage treatment with CladT. In this article we, a group of expert neurologists from France, provide recommendations on the initiation of CladT in DMT-naïve patients, how to switch from existing DMTs to CladT for patients with continuing MS disease activity, how to manage patients during the first 2 years of treatment and finally, how to manage patients with or without MS disease activity in years 3, 4 and beyond after initiating treatment with CladT. We believe that optimisation of the use of CladT beyond its initial courses of treatment will maximise the benefits of this treatment, especially early in the course of MS when suppression of focal inflammation in the CNS is a clinical priority to limit MS disease progression.

Iatrogenic myelodysplastic syndrome complicating multiple sclerosis: A case report

After 1.5 years of treatment with dimethyl fumarate (DMF) for multiple sclerosis, preceded 8 years earlier by intravenous (IV) cladribine and 1 year earlier by natalizumab, our patient developed myelodysplastic syndrome (MDS). The initial manifestation was a severe drop in absolute neutrophil and lymphocyte counts. Repeat bone marrow biopsy demonstrated a new unbalanced translocation (between the chromosome 1 long arm and chromosome 7 short arm). This case report, to our knowledge, is the first linking iatrogenic MDS to DMF and cladribine, while also suggesting caution with immunosuppressants in multiple sclerosis patients.

Clinical use of dimethyl fumarate in multiple sclerosis treatment: an update to include China, using a modified Delphi method

Dimethyl fumarate (DMF) is a widely used oral disease-modifying therapy for multiple sclerosis (MS). Its efficacy and safety profiles are supported by over a decade of experience. Differences exist between Asia and Europe/United States in the prevalence and characteristics of MS; most data for DMF are derived from populations outside Asia. DMF was recently (2021) approved for use in China. The objectives of this review were to evaluate the evidence for DMF's profile, to provide an update to healthcare providers on current knowledge surrounding its use and to assess the relevance of existing data to use in China. This study used a modified Delphi method based on the insights of a scientific Steering Committee (SC), with a structured literature review conducted to assess the data of DMF. The literature review covered all papers in English (from 01 January 2011 to 21 February 2022) that include 'dimethyl fumarate' and 'multiple sclerosis', and their MeSH terms, on PubMed, supplemented by EMBASE and Citeline searches. Papers were categorized by topic and assessed for relevance and quality, before being used to formulate statements summarizing the literature on each subject. SC members voted on/revised statements, requiring ⩾80% agreement and ⩽10% disagreement for inclusion. Statements not reaching this level were discussed further until agreement was reached or until there was agreement to remove the statement. A total of 1030 papers were retrieved and used to formulate the statements and evidence summaries considered by the SC members. A total of 45 statements were agreed by the SC members. The findings support the positive efficacy and safety profile of DMF in treating patients with MS. Limited Chinese patient data are an ongoing consideration; however, based on current evidence, the statements are considered applicable to both the global and Chinese populations. DMF is a valuable addition to address unmet MS treatment needs in China. Registration: Not applicable.