Combination therapy for the treatment of multiple sclerosis: challenges and opportunities

An update on combination therapies for multiple sclerosis: where are we now?

INTRODUCTION

In theory, combination of two agents, which are suboptimal when given individually, may result in a significant increase in therapeutic effect. Combination therapies have proven particularly effective against infections such as HIV, cancer, and also chronic autoimmune diseases such as rheumatoid arthritis.

AREAS COVERED

The authors review the literature, searching for randomized placebo-controlled or comparative, double-blind or investigator-blinded clinical trials, not including open label clinical trials, of treatment of multiple sclerosis (MS) with combination therapy or add-on therapy, including trials of induction therapy, trials for prevention of disease activity or worsening, amelioration of adverse effects, and treatment of relapses, and trials to increase remyelination.

EXPERT OPINION

Combination of two platform therapies (Interferon-beta or glatiramer acetate) was without additional effect. Clinical trials with add-on, often applying repurposed drugs (e.g. simvastatin, atorvastatin, minocycline, estriol, cyclophosphamide, azathioprine, albuterol, vitamin D), have been negative, apart from monthly methylprednisolone that, however, had low tolerability. Combination therapy for neuroprotection/remyelination showed some interesting results, though we are still awaiting results of phase III trials. The results of combination of anti-inflammatory therapies have in general been disappointing. In the future, combination of new effective neuroprotective/remyelinating drugs and highly effective anti-inflammatory treatments may benefit people with MS.

Rapamycin Augments Immunomodulatory Properties of Bone Marrow-Derived Mesenchymal Stem Cells in Experimental Autoimmune Encephalomyelitis

The immunomodulatory and anti-inflammatory properties of bone marrow-derived mesenchymal stem cells (BM-MSCs) have been considered as an appropriate candidate for treatment of autoimmune diseases. Previous studies have revealed that treatment with BM-MSCs may modulate immune responses and alleviate the symptoms in experimental autoimmune encephalomyelitis (EAE) mice, an animal model of multiple sclerosis. Therefore, the present study was designed to examine immunomodulatory effects of BM-MSCs in the treatment of myelin oligodendrocyte glycoprotein (MOG) 35-55-induced EAE in C57BL/6 mice. MSCs were obtained from the bone marrow of C57BL mice, cultured with DMEM/F12, and characterized with flow cytometry for the presence of cell surface markers for BM-MSCs. Following three passages, BM-MSCs were injected intraperitoneally into EAE mice alone or in combination with rapamycin. Immunological and histopathological effects of BM-MSCs and addition of rapamycin to BM-MSCs were evaluated. The results demonstrated that adding rapamycin to BM-MSCs transplantation in EAE mice significantly reduced inflammation infiltration and demyelination, enhanced the immunomodulatory functions, and inhibited progress of neurological impairments compared to BM-MSC transplantation and control groups. The immunological effects of rapamycin and BM-MSC treatments were associated with the inhibition of the Ag-specific lymphocyte proliferation, CD8+ cytolytic activity, and the Th1-type cytokine (gamma-interferon (IFN-γ)) and the increase of Th-2 cytokine (interleukin-4 (IL-4) and IL-10) production. Addition of rapamycin to BM-MSCs was able to ameliorate neurological deficits and provide neuroprotective effects in EAE. This suggests the potential of rapamycin and BM-MSC combined therapy to play neuroprotective roles in the treatment of neuroinflammatory disorders.

Tolerability and Safety of Combined Glatiramer Acetate and N-Acetylcysteine in Relapsing-Remitting Multiple Sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an autoimmune disorder of the central nervous system where inflammation and neurodegeneration play key roles. Mounting evidence implicates oxidative stress in the development of irreversible neuronal and glial injury in this condition. N-acetylcysteine (NAC) is a sulfhydryl amino acid derivative with antioxidant and antiapoptotic properties. Administration of NAC to mice attenuated the induction of or improved experimental autoimmune encephalomyelitis (an MS model).

METHODS

We performed an open-label study to explore the tolerability and safety of the combination of glatiramer acetate (GA) and NAC in patients with relapsing-remitting multiple sclerosis at the outpatient MS clinics of the Jewish General Hospital and Hôpital Charles Lemoyne, Montreal, Canada. Seven patients with relapsing-remitting multiple sclerosis with at least one T1 gadolinium-enhancing lesion on screening magnetic resonance imaging were recruited. Treatment consisted of a 10-week run-in period followed by 36-week treatment with a combination of GA 20 mg subcutaneously once daily plus NAC 2.5 g orally twice daily. Outcome measures included safety and tolerability, redox biochemistry, and magnetic resonance imaging effect.

RESULTS

Treatment with the combination of GA and NAC was safe and well tolerated.

CONCLUSIONS

In light of the favorable safety profile, an efficacy-demonstrating study may be considered.

A multimodal intervention for patients with secondary progressive multiple sclerosis: feasibility and effect on fatigue

BACKGROUND

Multiple sclerosis is an autoimmune disease influenced by environmental factors.

OBJECTIVES

The feasibility of a multimodal intervention and its effect on perceived fatigue in patients with secondary progressive multiple sclerosis were assessed.

DESIGN/SETTING

This was a single-arm, open-label intervention study in an outpatient setting.

INTERVENTIONS

A multimodal intervention including a modified paleolithic diet with supplements, stretching, strengthening exercises with electrical stimulation of trunk and lower limb muscles, meditation, and massage was used.

OUTCOME MEASURES

Adherence to each component of the intervention was calculated using daily logs. Side-effects were assessed from a monthly questionnaire and blood analyses. Fatigue was assessed using the Fatigue Severity Scale (FSS). Data were collected at baseline and months 1, 2, 3, 6, 9, and 12.

RESULTS

Ten (10) of 13 subjects who were enrolled in a 2-week run-in phase were eligible to continue in the 12-month main study. Of those 10 subjects, 8 completed the study and 6 subjects fully adhered to the study intervention for 12 months. Over a 12-month period, average adherence to diet exceeded 90% of days, and to exercise/muscle stimulation exceeded 75% of days. Nutritional supplements intake varied among and within subjects. Group daily average duration of meditation was 13.3 minutes and of massage was 7.2 minutes. No adverse side-effects were reported. Group average FSS scores decreased from 5.7 at baseline to 3.32 (p=0.0008) at 12 months.

CONCLUSIONS

In this small, uncontrolled pilot study, there was a significant improvement in fatigue in those who completed the study. Given the small sample size and completer rate, further evaluation of this multimodal therapy is warranted.

Current approaches to the identification and management of breakthrough disease in patients with multiple sclerosis

Disease-modifying drugs (DMDs) for relapsing-remitting multiple sclerosis (RRMS) are only partly effective -- breakthrough disease commonly occurs despite treatment. Breakthrough disease is predictive of continued disease activity and a poor prognosis. Availability of several DMDs offers the possibility of tailoring treatment to individual patients with RRMS and altering treatment in patients with breakthrough disease. However, no biological or imaging markers have been validated to guide initial treatment, markers of individual responsiveness to DMDs are scarce, and there is no class 1 evidence to guide alternative therapy in patients with breakthrough disease. In this Review, we discuss proposed strategies to monitor patients with RRMS being treated with DMDs, outline approaches to identifying therapeutic response in individual patients, review MRI and biological markers of treatment response, and summarise the role of antibodies in biological therapies. We also outline possible strategies for the management of patients with breakthrough disease and highlight areas in which research is needed.