Summary
Health Canada has recently approved EMD Serono’s disease modifying therapy, Mavenclad™ (oral cladribine). Mavenclad™ selectively targets and accumulates in certain types of white blood cells (lymphocytes), such as disease-causing T cells. By interfering with a target cell’s ability to process DNA, the therapy leads to the depletion of disease-causing lymphocytes and results in reduced inflammation. Mavenclad™ was previously approved by Health Canada in an injectable form for the treatment of hairy cell leukemia. Mavenclad™ is the only second-line, short-course oral treatment indicated for MS that does not cause continuous immunosuppression.
Approval of Mavenclad™ by Health Canada is based on results from the phase III clinical trial called CLARITY. The trial tested the safety and efficacy of Mavenclad™ in 1,326 participants living with relapsing remitting MS (RRMS) by comparing two doses of Mavenclad™ (3.5 mg/kg, and 5.25 mg/kg) against dummy treatment (placebo). The study followed the participants for up to two years. Treatment with Mavenclad™ led to a 58% reduction in annualized relapse rate compared to placebo at the 3.5mg/kg dosage. Participants taking Mavenclad™ also had a lower risk of sustained disability progression at three months and had fewer brain lesions as seen on imaging scans.
In clinical trials, the most common serious adverse effects were low levels of white blood cells (called lymphopenia), herpes zoster (shingles), oral herpes and skin and tissue disorders.
An extension study evaluated the long-term safety and efficacy of Mavenclad™ over two additional years. In this extension study, 806 patients received either placebo or a low-dose of Mavenclad™ (in a regimen similar to that used in CLARITY) over a 96-week study period. The safety outcomes were consistent with the safety profile observed for the CLARITY study.
Comment:
The approval of Mavenclad™ provides another second-line option for people with active RRMS who have had an inadequate response to, or are unable to tolerate, one or more therapies indicated for the treatment of MS.
With the approval of Mavenclad™, there are now 14 disease-modifying therapies available for Canadians diagnosed with RRMS. Selecting an MS therapy should be done in consultation with a health care team. The MS Society of Canada will provide updates on availability and public coverage of Mavenclad™ as they become available.
Full drug information is available on the MS Society website.