The US Food and Drug Administration (FDA) has approved oral cladribine for the treatment of adults with relapsing forms of MS and active secondary progressive MS.

Clinical trials show cladribine could decrease the number of relapses and slow the accumulation of physical disability caused by MS, when compared to placebo. This approval provides a new treatment option for people living with secondary progressive MS who are continuing to experience active disease.

In 2017, the European Medicines Agency (EMA) – the body responsible for drug licensing in Europe – authorised cladribine for use by people with highly active relapsing remitting MS, but not for those with active secondary progressive MS.

Cladribine is a treatment that targets certain types of white blood cells (lymphocytes) that drive the immune attack in MS. It temporarily reduces the number of both T and B lymphocytes without continuous suppression of the immune system. Because of its safety profile, cladribine is generally recommended in people with MS who either have a highly active form of MS or  who have had an inadequate response to, or are unable to tolerate, another MS therapy.

In the FDA approval, Mavenclad has a boxed warning due to an increased risk of cancers and risk of fetal (unborn baby) harm. Potential safety issues identified by the FDA include decrease in white blood cells, and increased risk of infections and liver injury. The most common adverse reactions reported during clinical trials included upper respiratory tract infections, headache, and low white blood counts. The EMA approval included similar warnings.

Cladribine is taken by mouth in two treatment courses, twelve months apart.