Temsirolimus in Recurrent Primary Central Nervous System (CNS) Lymphoma

Inclusion Criteria: * Primary CNS lymphoma diagnosed histologically or by cerebrospinal fluid cytology; absence of systemic lymphoma manifestations * Relapse or lymphoma progression after/during high-dose methotrexate containing first-line chemotherapy or alternative therapy in the case of contraindications against high-dose methotrexate * ECOG performance score ≤ 2 * Age ≥18 years and ≤ 75 years * Life expectancy of at least 3 months * Absence of active infection * Negative HIV serology * Adequate renal function (GFR \>30ml/h) * Adequate bone marrow reserve (neutrophils \> 1500/µl, platelets \> 80,000/µl) * Bilirubin \<1.5x upper limit of normal (ULN), ALT and AST \<3x ULN * At least 3 weeks interval from prior cytostatic treatment * Negative pregnancy test * Patient accessible for treatment and follow-up * Patient compliance * Signed informed consent Exclusion Criteria: * Secondary CNS lymphoma * Primary intraocular lymphoma * Patient eligible for high-dose chemotherapy and autologous stem-cell transplantation * Concurrent treatment within another clinical trial * Concurrent other malignant disease * Symptomatic congestive heart failure (≥NYHA II) * Active or uncontrolled chronic infection * Severe concomitant disease incompatible with study conduct * History of cerebral bleeding * Concomitant treatment with strong CYP3A4/5-inductors or -inhibitors * Premenopausal women without highly effective contraception (defined as Pearl index \<1) * Pregnant or lactating women * Refusal to record and pass on pseudonymized disease and treatment related data as part of the treatment protocol * Concurrent admission to a psychiatric institution by public order