Treatment of Hairy Cell Leukaemia Variant and Relapsing Hairy Cell Leukaemia With Cladribine Plus Rituximab

Inclusion Criteria: * Patients with histologically verified hairy cell leukaemia (HCL) Hairy cell leukaemia variant (HCLv) or * Relapse of hairy cell leukaemia after therapy with cladribine or pentostatin * Need for treatment is indicated (see 4.3 below) * Age at least 18 years * General state of health according to WHO 0-2 * Written declaration of consent by the patient * Current histology, which should not be older than 6 months, is necessary Exclusion Criteria: * Patients, who do not fulfil the above-mentioned inclusion criteria. * Patients with severe functional limitations of the heart according to New York Heart Association III / IV, of the lung according to WHO degree III / IV, the liver (bilirubin \> 2mg/dl, alkaline phosphatase, raised GOT and GPT (glutamate- pyruvate transaminase) values more than twice normal), diseases of the central nervous system, including psychoses. Creatinine \> 2 mg/dl, or creatinine clearance \< 50 mg/min * Patients with proven HIV infections * Patients with active hepatitis * Patients with other florid infections * Patients with anamnesis / diagnosis of another malignant disease (other than nonmelanoma associated skin tumours or stage 0 in situ carcinoma of the cervix) * Pregnant or lactating women