Chemotherapy and HAART to Treat AIDS-related Primary Brain Lymphoma

Background: Acquired Immunodeficiency Syndrome (AIDS)-related primary central nervous system lymphoma (AR-PCNSL) is an Epstein-Barr virus (EBV)-driven lymphoproliferative process that typically results in death within a few months. Essentially all of the cases are immunoblastic cluster of differentiation 20 (CD20+) tumors, and occur once the cluster of differentiation 4 (CD4+) cells have fallen to below 50 cells/mm\^3. Highly active antiretroviral therapy (HAART) can result in immune reconstitution that decreases the risk of AR-PCNSL. However, a subset of human immunodeficiency virus (HIV)-infected patients still develops ARPCNSL, often because they are unaware that they are HIV infected, or they do not take HAART. Treatment options for such patients are limited. In the non-AIDS setting, chemotherapy has become the standard of care for primary central nervous system lymphoma (PCNSL) and late neurocognitive decline consequent to radiotherapy can be avoided by such approaches. In the pre-HAART era, AR-PCNSL was generally treated with whole brain radiotherapy, however death due to recurrent lymphoma or to other AIDS complications occurred prior to the potential manifestations of late occurring radiation-related neurotoxicity. Radiation-sparing approaches have not been studied in AR-PCNSL in the HAART era, where advances in antiretroviral therapy have made curative intent chemotherapy feasible for most patients with HIV infection. Objectives: The primary objective of this study is to estimate the fraction of patients with AR-PCNSL receiving experimental treatment consisting of HAART, combined with rituximab, high-dose methotrexate and leucovorin (R-HD-MTX) who are alive and without recurrent lymphoma or severe cognitive problems at two years. . Eligibility: HIV-infected, age 18 years or older, AR-PCSNL that has not previously been treated, and be able to give informed consent or have a durable power of attorney who can provide informed consent, HIV profile that makes them likely to respond to HAART. There are a number of other specific inclusion and exclusion criteria, in part to exclude patients who would be unlikely to tolerate the therapy. Design: Phase II pilot study investigating R-HD-MTX given with leucovorin rescue and HAART as a treatment for AR-PCNSL. Evaluation will include quantitative measurement of lymphocyte subsets, quantitative polymerase chain reaction (PCR) of HIV and EBV viral loads (including both blood and cerebrospinal fluid in the case of EBV) to assess immune response and anti-viral effects. Tumor evaluation with brain magnetic resonance imaging (MRI) and brain fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET scans) will be used for staging and response assessment. Longitudinal neuropsychologic testing after complete responses are documented will serve to evaluate neurocognitive parameters post therapy. a separate cohort for additional secondary endpoints.