Laquinimod for multiple sclerosis.

BACKGROUND

Multiple sclerosis (MS) is a chronic immune-mediated, inflammatory, demyelinating, neurodegenerative disorder of the central nervous system, and it causes major socioeconomic burden for the individual patient and for society. An inflammatory pathology occurs during the early relapsing stage of MS and a neurodegenerative pathology dominates the later progressive stage of the disease. Not all MS patients respond adequately to currently available disease-modifying drugs (DMDs). Alternative MS treatments with new modes of action are required to expand the current options for disease-modifying therapies (DMTs) and to aim for freedom from relapses, inflammatory lesions, disability progression and neurodegeneration. Laquinimod has dual properties of immunomodulation and neuroprotection and is a potentially promising new oral DMD in the treatment of relapsing MS.

OBJECTIVES

To assess the effectiveness and safety profile of laquinimod as monotherapy or combination therapy versus placebo or approved DMDs (interferon-β, glatiramer acetate, natalizumab, mitoxantrone, fingolimod, teriflunomide, dimethyl fumarate) for modifying the disease course in patients with MS.

SEARCH METHODS

The Review Group Trials Search Co-ordinator searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Specialised Register which, among other sources, contains trials from CENTRAL (The Cochrane Library 2013, Issue 2), MEDLINE, EMBASE, CINAHL, LILACS, PEDro and Clinical trials registries (29 April 2013). We checked references in identified trials and manually searched the reports (2004 to March 2013) from neurological associations and MS societies. We also communicated with researchers participating in trials on laquinimod and contacted Teva Pharmaceutical Industries.

SELECTION CRITERIA

All randomised, double-blind, controlled, parallel group clinical trials (RCTs) with a length of follow-up of at least one year evaluating laquinimod, as monotherapy or combination therapy, versus placebo or approved DMDs for patients with MS.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. Disagreements were discussed and resolved by consensus among review authors. Principal investigators of included studies were contacted for additional data or confirmation of information.

MAIN RESULTS

Only one study met our inclusion criteria, involving 1106 adult patients with relapsing-remitting MS (RRMS) and an entry Expanded Disability Status Scale (EDSS) score of ≤ 5.5 and an entry disease duration of ≥ 6 months. Five hundred and fifty patients treated with laquinimod at a dose of 0.6 mg orally administered once daily in a capsule were compared with 556 patients treated with a matching placebo capsule. The study had a high risk for attrition bias (21.9%). Laquinimod had potential benefits in reducing relapse rates and was safe for most patients with RRMS in the short term. The most common adverse events included headache, back pain, arthralgia, diarrhoea, cough, urinary tract infection, elevated alanine aminotransferase, insomnia, nausea, abdominal pain and sinusitis. One ongoing trial was identified.

AUTHORS' CONCLUSIONS: We found low-level evidence for the use of laquinimod as a disease-modifying therapy for MS because only one study with limited quality (high risk of attrition bias) was included. The published study suggests that laquinimod at a dose of 0.6 mg orally administered once daily may be safe and have potential benefits for most patients with RRMS in the short term. We are waiting for the publication of ongoing trials.