Dimethyl fumarate: a novel oral front-line therapy for multiple sclerosis treatment

Dimethyl fumarate therapy reduces memory T cells and the CNS migration potential in patients with multiple sclerosis

BACKGROUND

Dimethyl fumarate (DMF) is a disease-modifying therapy for patients with relapsing-remitting multiple sclerosis (RRMS). T cells are major contributors to the pathogenesis of RRMS, where they regulate the pathogenic immune response and participate in CNS lesion development.

OBJECTIVES

In this study we evaluate the therapeutic effects of DMF on T cell subpopulations, their CNS migration potential and effector functions.

METHODS

Blood and CSF from untreated and DMF-treated patients with RRMS and healthy donors were analyzed by flow cytometry.

RESULTS

DMF reduced the prevalence of circulating proinflammatory CD4+ and CD8+ memory T cells, whereas regulatory T cells were unaffected. Furthermore, DMF reduced the frequency of CD4+ T cells expressing CNS-homing markers. In coherence, we found a reduced recruitment of CD4+ but not CD8+ T cells to CSF. We also found that monomethyl fumarate dampened T cell proliferation and reduced the frequency of TNF-α, IL-17 and IFN-γ producing T cells.

CONCLUSION

DMF influences the balance between proinflammatory and regulatory T cells, presumably favoring a less proinflammatory environment. DMF also reduces the CNS migratory potential of CD4+ T cells whereas CD8+ T cells are less affected. Altogether, our study suggests an anti-inflammatory effect of DMF mainly on the CD4+ T cell compartment.

Dimethyl fumarate therapy suppresses B cell responses and follicular helper T cells in relapsing-remitting multiple sclerosis

Background:

Dimethyl fumarate (DMF) is a disease-modifying therapy used for patients with relapsing-remitting multiple sclerosis (RRMS). B cells are important contributors to the pathogenesis of RRMS, where they regulate the inflammatory immune responses and participate in development of lesions in the central nervous system (CNS). The impact of DMF on B cell subpopulations remains incompletely understood.

Objectives:

In this study, we evaluated the effects of DMF on B cell subpopulations and their effector functions.

Methods:

Blood from 21 DMF-treated and 18 untreated patients with RRMS was analyzed by flow cytometry.

Results:

We found that DMF reduces the frequency of circulating antigen–experienced B cells, a reduction likely related to a reduced frequency of follicular helper T (TFH) cells and an increased frequency of follicular regulatory T (TFR) cells. Studying the impact of monomethyl fumarate (MMF), the primary metabolite of DMF, on B cell effector function in vitro showed that MMF increased the frequency of transforming growth factor (TGF)-β-producing B cells and decreased the frequency of B cells secreting lymphotoxin (LT)-α, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and to a lesser extent IL-10.

Conclusion:

In summary, these data suggest an anti-inflammatory role of DMF and its metabolite MMF on the B cell compartment.

Dimethyl fumarate: a review of its use in patients with relapsing-remitting multiple sclerosis

Dimethyl fumarate (Tecfidera®) is a novel oral therapy that has recently been approved for the treatment of relapsing forms of multiple sclerosis (MS) and relapsing-remitting MS (RRMS). In preclinical studies, dimethyl fumarate exhibited anti-inflammatory and cytoprotective properties that are generally thought to be mediated via activation of the nuclear factor (erythroid-derived 2)-like 2 transcriptional pathway, which is involved in the cellular response to oxidative stress. In the large, double-blind, multinational, 2-year DEFINE and CONFIRM trials conducted in over 2,600 adult patients with RRMS, twice-daily oral dimethyl fumarate 240 mg was effective in reducing the proportion of patients with MS relapse at 2 years (primary endpoint of DEFINE) and the annualized relapse rate (primary endpoint of CONFIRM) compared with placebo, with reduced disability progression also observed with the drug versus placebo in DEFINE. Dimethyl fumarate also reduced disease activity measures relative to placebo in these trials, as assessed by magnetic resonance imaging. Dimethyl fumarate was generally well tolerated in patients with RRMS; adverse events that occurred more frequently in dimethyl fumarate than in placebo recipients included flushing and gastrointestinal events. The long-term efficacy and tolerability of dimethyl fumarate is currently being investigated in the ENDORSE trial, with interim results demonstrating that dimethyl fumarate was associated with continued efficacy for up to 4 years of treatment, with no new tolerability concerns. In conclusion, although more comparative data are needed to fully establish the relative efficacy and tolerability of dimethyl fumarate compared with other therapies, oral dimethyl fumarate is an important addition to the therapeutic options available for RRMS.

Tecfidera®: an approach for repurposing

As a case study of patent coverage for a repurposed drug, Biogen Idec’s approach for Tecfidera®, an oral formulation of dimethyl fumarate, was analyzed. While mixtures of fumarates have been used for over 50 years to treat psoriasis, Tecifidera is approved for the treatment of relapsing-remitting multiple sclerosis. Biogen pursued claims to pharmaceutical formulations and useful doses for treating multiple sclerosis, an approach that is relevant to pharmaceutical lifecycle management in general. A survey of recent US, EP, and PCT patent applications indicate other companies are developing competing fumarate formulations. While it is possible to pursue secondary patents for compounds without composition of matter coverage, regulatory data exclusivity provides additional protection to delay competitors.