Treatment regimen for the treatment of autoimmune disorders

A method for treating Relapsing-Remitting Multiple Sclerosis (RRMS) or Secondary Progressive Multiple Sclerosis (SPMS) in a patient in need thereof, the method comprising:

• (a) identifying whether the patient is at risk of reactivation of latent varicella zoster virus (VZV),
• (b) vaccinating said patient at risk of reactivation varicella zoster virus (VZV) with a vaccine against said varicella zoster virus (VZV) reactivation within a timeframe of about 4 weeks prior to a first treatment period wherein cladribine is orally administered to said patient, and
• (c) administering cladribine during said first treatment period and one or more additional treatment periods orally to the patient at fixed dose per patient, per body weight and per treatment period, wherein said fixed dose is selected from the range of 1.75 mg/kg plus/minus 0.25 mg/kg,
• i) wherein said first treatment period and said one or more additional treatment periods in which cladribine is administered each have a duration from 1 to 3 months,
• ii) wherein each of said treatment periods in which cladribine is orally administered are separated by a period in which no cladribine is administered to said patient, and
• iii) wherein each of the periods in which no cladribine is administered to said patient has a duration of at least 9 months,
• with the proviso that said fixed dose per patient is about the same in all of the first treatment period and said one or more additional treatment periods wherein cladribine is administered, and wherein (a), (b) and (c) are performed in the order given above,
• thereby treating said patient against said autoimmune disorder and limiting the risk of said patient of reactivation of varicella zoster virus (VZV).