Hypersensitivity to the active substance or to any of the excipients listed in Description.
Infection with human immunodeficiency virus (HIV).
Active chronic infection (tuberculosis or hepatitis).
Initiation of cladribine treatment in immunocompromised patients, including patients currently receiving immunosuppressive or myelosuppressive therapy (see Interactions).
Moderate or severe renal impairment (creatinine clearance <60 mL/min) (see Pharmacology: Pharmacokinetics under Actions).
Pregnancy and breast-feeding (see Use in Pregnancy & Lactation).