The efficacy and safety of teriflunomide based therapy in patients with relapsing multiple sclerosis: A meta-analysis of randomized controlled trials

Is it ethical to use teriflunomide as an active comparator in phase 3 trials?

Ethical concerns have been raised about the practice of using teriflunomide, an oral licensed disease-modifying therapy, as an active comparator in phase 3 multiple sclerosis (MS) trials. The assumption is based on the perceived low efficacy of teriflunomide as judged by its effect on relapses and focal MRI activity. However, when you look beyond focal inflammation, teriflunomide has a robust impact on disability progression and a similar effect to the anti-CD20 monoclonal antibody therapies on slowing down the accelerated brain volume loss associated with MS. Teriflunomide is also more effective when used second or third line. The other classes of disease-modifying therapies have problems with their use as active comparators in clinical trials. Using a non-inferiority or equivalence trial design has its own unique set of regulatory and ethical challenges and is not necessarily a solution. There are also economic, altruistic and pragmatic reasons for continuing to use teriflunomide as an active comparator in MS clinical trials. An online survey indicates that the majority of the MS community feels it is still ethical to randomise subjects to teriflunomide and that procedures can be put in place to protect trial subjects randomised to teriflunomide. Therefore, we still have equipoise, and teriflunomide comparator trials are ethical.

In vivo detection of teriflunomide-derived fluorine signal during neuroinflammation using fluorine MR spectroscopy

Background: Magnetic resonance imaging (MRI) is indispensable for diagnosing neurological conditions such as multiple sclerosis (MS). MRI also supports decisions regarding the choice of disease-modifying drugs (DMDs). Determining in vivo tissue concentrations of DMDs has the potential to become an essential clinical tool for therapeutic drug monitoring (TDM). The aim here was to examine the feasibility of fluorine-19 (¹⁹F) MR methods to detect the fluorinated DMD teriflunomide (TF) during normal and pathological conditions.

Methods: We used ¹⁹F MR spectroscopy to detect TF in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis (MS) in vivo. Prior to the in vivo investigations we characterized the MR properties of TF in vitro. We studied the impact of pH and protein binding as well as MR contrast agents.

Results: We could detect TF in vivo and could follow the ¹⁹F MR signal over different time points of disease. We quantified TF concentrations in different tissues using HPLC/MS and showed a significant correlation between ex vivo TF levels in serum and the ex vivo¹⁹F MR signal.

Conclusion: This study demonstrates the feasibility of ¹⁹F MR methods to detect TF during neuroinflammation in vivo. It also highlights the need for further technological developments in this field. The ultimate goal is to add ¹⁹F MR protocols to conventional ¹H MRI protocols in clinical practice to guide therapy decisions.

Efficacy and Safety of Oral Therapies for Relapsing-Remitting Multiple Sclerosis

Disease-modifying therapies have now become standard treatment for multiple sclerosis. These include five oral therapies for relapsing-remitting multiple sclerosis, namely fingolimod, dimethyl fumarate, teriflunomide, cladribine, and siponimod, although there is some discrepancy on the relative efficacy and safety of these agents. To gain further insight on these oral agents in relapsing-remitting multiple sclerosis, we performed a narrative review of fingolimod, dimethyl fumarate, teriflunomide, cladribine, and siponimod. We limited the analysis to randomized clinical studies in which a comparator was used (i.e., placebo or other disease-modifying therapy). As relapsing-remitting multiple sclerosis is a chronic disease and treatment is lifelong, long-term outcomes were an additional focus. A total of 37 studies met inclusion criteria: 15 for fingolimod, 8 for dimethyl fumarate, 7 for teriflunomide, 4 for cladribine, and 3 for siponimod. All drugs showed some functional and magnetic resonance imaging benefit in nearly all clinical studies. The reduction in annual relapse rate was similar for fingolimod, dimethyl fumarate, and cladribine, and somewhat greater than for teriflunomide; there is limited information on the annual relapse rate for siponimod. For all drugs, the benefits reported at short follow-up times are broadly consistent with those seen at longer follow-up times. For fingolimod and dimethyl fumarate, there was a definite trend towards a progressively lower annual relapse rate with continuing treatment. The safety profile of all five drugs was considered to be acceptable, even after extended treatment. While these results should be treated with caution, they highlight that future head-to-head studies are needed to better understand the long-term benefits of disease-modifying therapies. Such information will be of value when considering the risk-benefit profile of these oral therapies.

The Effect of Disease Modifying Therapies on Disability Progression in Multiple Sclerosis: A Systematic Overview of Meta-Analyses

Background: Disease modifying therapy (DMT) efficacy trials make an essential contribution to the development of evidence-based clinical treatments and practices for people with multiple sclerosis (MS). Meta-analysis is a critical part of this process and provides a powerful tool to assess the effects of DMT on MS progression. However, although there have been several meta-analyses on the effect of DMT on MS disease progression, they often do not reach the same conclusions.

Objective: Our aim was to better understand and contextualize the results of meta-analyses evaluating DMT, identify differences in methodology that might explain their differing conclusions, and highlight areas for future research that will improve our ability to develop clinical recommendations.

Methods: We conducted an overview of systematic reviews with meta-analyses assessing the efficacy of DMT on disability progression in people with MS in PubMed (Medline) and the Cochrane Database of Systematic Reviews.

Results: We included 22 meta-analyses in this overview: eight general (on >3 DMT), 11 specific (on ≤3 DMT), 2 that evaluated subsets, and 1 that evaluated long-term effects. We found that there is good evidence that DMT improve short-term (≤2–3 years) disability progression outcomes relative to placebo in people with relapsing-remitting MS. However, results varied substantially between meta-analyses, and there is little evidence of their efficacy in other populations or over longer periods. The relative effects of individual DMT also remain unclear. The variance in results between meta-analyses may be related to the substantial differences in inclusion criteria, which was reflected in the limited overlap in included studies, as well as the year of meta-analysis publication. Of the 123 total unique studies included in the general meta-analyses, 77 (62.6%) were included in only one meta-analysis. This incongruence was also evident in the included DMT. Six of the 16 (37.5%) DMT evaluated in the general meta-analyses were only included in one meta-analysis.

Conclusions: Translating DMT efficacy studies into evidence-based clinical practice requires greater methodological consistency in meta-analyses, more data on the relative effects of DMT through head-to-head clinical trials, and better reporting of adverse events.

Efficacy and Safety of Teriflunomide in Chinese Patients with Relapsing Forms of Multiple Sclerosis: A Subgroup Analysis of the Phase 3 TOWER Study

Background

Disease-modifying therapy is the standard treatment for patients with multiple sclerosis (MS) in remission. The primary objective of the current analysis was to assess the efficacy and safety of two teriflunomide doses (7 mg and 14 mg) in the subgroup of Chinese patients with relapsing MS included in the TOWER study.

Methods

TOWER was a multicenter, multinational, randomized, double-blind, parallel-group (three groups), placebo-controlled study. This subgroup analysis includes 148 Chinese patients randomized to receive either teriflunomide 7 mg (n = 51), teriflunomide 14 mg (n = 43), or placebo (n = 54).

Results

Of the 148 patients in the intent-to-treat population, adjusted annualized relapse rates were 0.63 (95% confidence interval [CI]: 0.44, 0.92) in the placebo group, 0.48 (95% CI: 0.33, 0.70) in the teriflunomide 7 mg group, and 0.18 (95% CI: 0.09, 0.36) in the teriflunomide 14 mg group; this corresponded to a significant relative risk reduction in the teriflunomide 14 mg group versus placebo (-71.2%, P = 0.0012). Teriflunomide 14 mg also tended to reduce 12-week confirmed disability worsening by 68.1% compared with placebo (hazard ratio: 0.319, P = 0.1194). There were no differences across all treatment groups in the proportion of patients with treatment-emergent adverse events (TEAEs; 72.2% in the placebo group, 74.5% in the teriflunomide 7 mg group, and 69.8% in the teriflunomide 14 mg group); corresponding proportions for serious adverse events were 11.1%, 3.9%, and 11.6%, respectively. The most frequently reported TEAEs with teriflunomide versus placebo were neutropenia, increased alanine aminotransferase, and hair thinning.

Conclusions

Teriflunomide was as effective and safe in the Chinese subpopulation as it was in the overall population of patients in the TOWER trial. Teriflunomide has the potential to meet unmet medical needs for MS patients in China.

Trial Registration

ClinicalTrials.gov, NCT00751881; https://clinicaltrials.gov/ct2/show/NCT00751881?term=NCT00751881&rank=1.

Teriflunomide for multiple sclerosis in real-world setting

OBJECTIVES

Teriflunomide 14 mg is a once-daily oral disease-modifying treatment for relapsing-remitting multiple sclerosis. We examined adverse event (AE) profile and efficacy in real life.

MATERIALS AND METHODS

In this observational cohort study, we retrospectively examined 1521 blood samples and data of 102 patients followed for up to 28 months.

RESULTS

The number of female patients starting teriflunomide peaked in the fifth decade, 10 years later compared to male patients (P<.001), reflecting pregnancy concerns. Seventy-six percentages of patients shifted to teriflunomide from treatment with interferon-beta. Expanded disability status scale improved in 11% of patients (18.2±3.6 months follow-up) and remained constant in 67.5% (15±5.3 months follow-up). Of ten relapses, three occurred within 6 months after starting treatment. Seventeen patients (16.5%) discontinued teriflunomide: 53% because of AEs and 29% because of relapse. Levels of alanine aminotransferase (ALT) remained normal in 95.3% of the blood samples and remained below 1.5 times the upper limit of normal in 91% of the 4.7% abnormal samples. One-third of the patients had abnormal ALT values at least once. Haematological abnormalities were found in <4% of the blood samples, but at least one abnormal value was observed in up to 21% of the patients.

CONCLUSIONS

Efficacy and safety of teriflunomide in real-life setting support data obtained by the pivotal trials. Laboratory abnormalities are rare among the large number of samples, but patients may commonly have a single mild, abnormal value if frequently tested.

Should We Stop Saying 'Glia' and 'Neuroinflammation'?

Central nervous system (CNS) therapeutics based on the theoretical framework of neuroinflammation have only barely succeeded. We argue that a problem may be the wrong use of the term 'neuroinflammation' as a distinct nosological entity when, based on recent evidence, it may not explain CNS disease pathology. Indeed, the terms 'neuroinflammation' and 'glia' could be obsolete. First, unbiased molecular profiling of CNS cell populations and individual cells reveals striking phenotypic heterogeneity in health and disease. Second, astrocytes, microglia, oligodendrocytes, and NG2 cells may contribute to higher-brain functions by performing actions beyond housekeeping. We propose that CNS diseases be viewed as failed circuits caused in part by disease-specific dysfunction of cells traditionally called 'glia', and hence, favor therapies promoting their functional recovery.