Pemetrexed and Temozolomide in Treating Patients With Relapsed Primary Central Nervous System Lymphoma （PCNSL）

Phase II Trial of Pemetrexed and Temozolomide in Treating Patients With Relapsed PCNSL

In this trial, we will treat relapsed PCNSL with temozolomide, pemetrexed. Our objective was to assess our treatment strategies' availability based on response rates, progression-free survival (PFS), median PFS, and toxicity.

The best reported outcomes of PCNSL treatment are high-dose methotrexate-based chemotherapy combined with whole-brain radiation therapy (WBRT). Despite aggressive therapy, however, nearly 50% of patients will relapse within 24 months of diagnosis. Furthermore, the application of high-dose methotrexate-based regimen is complex, needing be hydrated, alkalified and detoxified, and treatment-related toxicity mortality is severe. In an attempt to improve upon these poor results and reduce treatment-related side effects, we will treat about 15-20 relapsed PCNSL patients who was fail in high-dose methotrexate-based chemotherapy. Our objective is to assess our treatment strategies' availability based on response rates, progression-free survival (PFS), median PFS, and toxicity.

Inclusion Criteria:

• Histologically confirmed primary CNS lymphoma.
• ECOG (Eastern Cooperative Oncology Group) Performance status of 0-1.
• Positive cerebrospinal fluid (CSF) cytology or immunohistochemical diagnosis of CSF monoclonality with or without measurable intracranial disease.
• Measurable (greater than 1 cm in diameter) tumor by CT scan or MRI.
• Progressed during first-line chemotherapy and/or radiotherapy OR relapsed after initial successful treatment.
• No systemic lymphoma by CT scan of the chest, abdomen, and pelvis with contrast.
• No leptomeningeal lymphoma by lumbar puncture for CNS cytology/flow cytometry.
• No ocular lymphoma by slit lamp examination.
• Must have adequate organ function as defined by the protocol: Adequate renal function: serum creatinine ≤ 1.5 mg/dl and/or calculated creatinine clearance ≥ 60 ml/min; Adequate hepatic function: bilirubin level ≤ 1.5 x ULN, ASAT & ALST ≤ 1.5 x ULN.Adequate bone marrow reserves: neutrophil (ANC) count ≥ 1500 /mm^3, platelet count ≥ 100,000 /mm^3, hemoglobin ≥ 9 g/dl.
• Age >/= 18 and </= 75 years.
• Signed written informed consent prior to study entry.

Exclusion Criteria:

• Patients with human immunodeficiency virus seropositivity and systemic lymphoma manifestation.
• Serious uncontrolled concurrent illness.
• Previous brain radiotherapy, systemic chemotherapy.
• Concurrent chronic systemic immune therapy, targeted therapy not indicated in this study protocol.
• Any evidence of prior exposure to Hepatitis B virus.
• Unable to comprehend the study requirements or who are not likely to comply with the study parameters.
• Pregnant (confirmed by serum or urine β-HCG) or lactating.