Clinical Efficacy of BG-12 in Relapsing-Remitting Multiple Sclerosis (RRMS): Data from the Phase 3 CONFIRM Study (S01.003)

Oral Dimethyl Fumarate in Children With Multiple Sclerosis: A Dual-Center Study

BACKGROUND

First-line injectable therapies for multiple sclerosis in children may be ineffective or not well-tolerated. There is therefore an urgent need to explore oral medications for pediatric multiple sclerosis. We review our dual-center experience with oral dimethyl fumarate.

METHODS

This study was a retrospective review of children 18 years of age or less with multiple sclerosis treated with dimethyl fumarate at Yale University and the University of Colorado. Clinical, demographic, and magnetic resonance imaging parameters were analyzed.

RESULTS

We identified 13 children treated with oral dimethyl fumarate for a median of 15.0 months (range, 1 to 25). Dimethyl fumarate was utilized as first-line therapy in five children (38%). Ten children (77%) tolerated dose escalation to the usual adult dose of 240 mg twice daily. Nine children had ≥12 months of follow-up on treatment. Eight of nine (89%) displayed stabilized or reduced relapse rates and disability scores on treatment. Nine children underwent brain magnetic resonance imaging performed after 12 or more months of therapy. New T2 lesions were observed in three children (33%), one of whom had been nonadherent to treatment. Common side effects included facial flushing (8/13, 62%), gastrointestinal discomfort (7/13, 54%), rash (3/13, 23%), and malaise (2/13, 15%). Three children (23%) discontinued treatment because of side effects. No patients displayed laboratory abnormalities including lymphopenia or abnormal liver transaminases. There were no reported infections.

CONCLUSIONS

Oral dimethyl fumarate appears to be safe and generally well tolerated in children with multiple sclerosis. Formal clinical trials to evaluate efficacy are ongoing.

Dimethyl fumarate for multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) often leads to severe neurological disability and a serious decline in quality of life. The ideal target of disease-modifying therapy for MS is to prevent disability worsening and improve quality of life. Dimethyl fumarate is considered to have an immunomodulatory activity and neuroprotective effect. It has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency as a first-line therapy for adult patients with relapsing-remitting MS (RMSS).

OBJECTIVES

To assess the benefit and safety of dimethyl fumarate as monotherapy or combination therapy versus placebo or other approved disease-modifying drugs (interferon beta, glatiramer acetate, natalizumab, mitoxantrone, fingolimod, teriflunomide, alemtuzumab) for patients with MS. 

SEARCH METHODS

The Trials Search Co-ordinator searched the Trials Specialised Register of the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group (4 June 2014). We checked reference lists of published reviews and retrieved articles and searched reports (2004 to June 2014) from the MS societies in Europe and America. We also communicated with investigators participating in trials of dimethyl fumarate and the Biogen Idec Medical Information.

SELECTION CRITERIA

We included randomised, controlled, parallel-group clinical trials (RCTs) with a length of follow-up equal to or greater than one year evaluating dimethyl fumarate, as monotherapy or combination therapy, versus placebo or other approved disease-modifying drugs for patients with MS without restrictions regarding dosage, administration frequency and duration of treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of The Cochrane Collaboration. Two review authors independently assessed trial quality and extracted data. Disagreements were discussed and resolved by consensus among the review authors. We contacted the principal investigators of included studies for additional data or confirmation of data.

MAIN RESULTS

Two RCTs were included, involving 2667 adult patients with RRMS to evaluate the efficacy and safety of two dosages of dimethyl fumarate (240 mg orally three times daily or twice daily) by direct comparison with placebo for two years. Among them, a subsample of 1221 (45.8%) patients were selected to participate in MRI evaluations by each study site with MRI capabilities itself. No powered head-to-head study with an active treatment comparator has been found. Meta-analyses showed that dimethyl fumarate both three times daily and twice daily reduced the number of patients with a relapse (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.50 to 0.66, P < 0.00001 and 0.64, 95% CI 0.54 to 0.77, P < 0.00001, respectively) or disability worsening (RR 0.70, 95% CI 0.57 to 0.87, P = 0.0009 and 0.65, 95% CI 0.53 to 0.81, P = 0.0001, respectively) over two years, compared to placebo. The treatment effects were decreased in the likely-case scenario analyses taking the effect of dropouts into consideration. Both dosages also reduced the annualised relapse rate. Data of active lesions on MRI scans were not combined because there was a high risk of selection bias for MRI outcomes and imprecision of MRI data in both studies, as well as an obvious heterogeneity between the studies. In terms of safety profile, both dosages increased the risk for adverse events and the risk for drug discontinuation due to adverse events. The most common adverse events included flushing and gastrointestinal events (upper abdominal pain, nausea and diarrhoea). Uncommon adverse events included lymphopenia and leukopenia, but they were more likely to happen with dimethyl fumarate than with placebo (high dosage: RR 5.25, 95% CI 2.20 to 12.51, P = 0.0002 and 5.23, 95% CI 2.47 to 11.07, P < 0.0001, respectively; low dosage: RR 5.69, 95% CI 2.40 to 13.46, P < 0.0001 and 6.53, 95% CI 3.13 to 13.64, P < 0.00001, respectively). Both studies had a high attrition bias resulting from the unbalanced reasons for dropouts among groups. Quality of evidence for relapse outcome was moderate, but for disability worsening was low.

AUTHORS' CONCLUSIONS

There is moderate-quality evidence to support that dimethyl fumarate at a dose of 240 mg orally three times daily or twice daily reduces both the number of patients with a relapse and the annualised relapse rate over two years of treatment in comparison with placebo. However, the quality of the evidence to support the benefit in reducing the number of patients with disability worsening is low. There is no high-quality data available to evaluate the benefit on MRI outcomes. The common adverse effects such as flushing and gastrointestinal events are mild-to-moderate for most patients. Lymphopenia and leukopenia are uncommon adverse events but significantly associated with dimethyl fumarate. Both dosages of dimethyl fumarate have similar benefit and safety profile, which supports the option of low-dose administration. New studies of high quality and long-term follow-up are needed to evaluate the benefit of dimethyl fumarate on prevention of disability worsening and to observe the long-term adverse effects including progressive multifocal leukoencephalopathy.

Benefits versus risks of latest therapies in multiple sclerosis: a perspective review

Disease-modifying treatments for multiple sclerosis (MS) have now been available for almost 20 years. Interferon β (IFN-β) products and glatiramer acetate (GA) were the first available options and are now considered first-line agents for the treatment of MS. These medications have several years of favorable safety data, but are not effective in completely controlling disease activity in all patients. Alternate medications with increased efficacy have been developed and identified; however, these newer medications have known or potential safety concerns which have prompted clinicians to view them as second-line agents. Highly efficacious and safe medications are continuously being searched for and developed; however, time is needed to establish the long-term safety of any new therapeutic agent. MS practitioners are faced with the clinical dilemma of treating patients with very safe modestly effective medications or using more efficacious and potentially riskier agents. The risk-benefit profile of every medication will have to be weighed carefully and clinicians will need to gage the risk tolerance of each patient in order to tailor treatment. This review will summarize benefits and risks of recently approved therapies in MS and will provide a perspective view on the placement of these medications within the MS treatment algorithm in the near future.