Selumetinib in Treating Patients With Relapsed or Refractory Diffuse Large B-cell Lymphoma

PRIMARY OBJECTIVES: I. To evaluate the overall response rate (combined complete remission \[CR\] and partial remission \[PR\]) of AZD6244 hyd-sulfate anti-MEK (selumetinib) therapy for patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). SECONDARY OBJECTIVES: I. To evaluate the safety and tolerability of MEK inhibitor therapy. II. To determine the progression-free survival, time to treatment failure, duration of response, and overall survival with AZD6244 hyd-sulfate therapy. III. To examine biomarkers through down-regulation of phosphorylated extracellular signal-related kinase (pERK) and several relevant target substrates (e.g., monocarboxylate transporter-1 \[MCT-1\], Menkes disease-associated protein \[MNK\], ELK, c-v-myc avian myelocytomatosis viral oncogene homolog \[c-MYC\], and hypoxia-inducible factor-1alpha \[HIF-1a\]) in peripheral blood studies. OUTLINE: This is a multicenter study. Patients receive selumetinib orally (PO) twice daily (BID) on days 1-28. Treatment repeats every 28 days for 8 courses in the absence of disease progression or unacceptable toxicity. Patients undergo blood sample and tumor tissue collection at baseline and at day 15 of course 1 for biomarker studies. After completion of study therapy, patients are followed up every 3 months for up to 3 years.