Daratumumab for Relapsed/Refractory Primary Effusion Lymphoma

INCLUSION CRITERIA: Participants must have primary effusion lymphoma (PEL), including extracavitary variant and KSHV-associated large cell lymphoma that relapsed and/or is refractory after front-line chemotherapy or be ineligible for front-line chemotherapy. Note: Participants must have pathologic confirmation of the disease diagnosis (at any time) confirmed by NCI Laboratory of Pathology. Age >= 18 years. Any HIV status Those with HIV must have CD4 count >= 100 cells/(micro)L or CD4 >= 50 cells/(micro)L if CD4 was >= 100 cells/(micro)L prior to front-line chemotherapy Participants with HIV must be receiving or willing to initiate an effective combination antiretroviral therapy (ART) regimen Participants with PEL must meet the following criteria: Must have measurable or assessable lymphoma ECOG performance status 0-3 Adequate hematological and renal functions as defined below: Hemoglobin (Hgb) > 7 g/dL Creatinine clearance (CrCl) >= 30 mL/min/1.73 m^2 Must have received first-line curative-intent therapy (anthracycline-containing chemotherapy) for PEL, unless such therapy is contraindicated due to infection that precludes combination chemotherapy (such as progressive multifocal leukoencephalopathy) or if there is a contraindication to receiving CHOP or EPOCH (such as multi-organ failure). For participants with evidence of chronic hepatitis B virus (HBV) infection, participants must be on suppressive therapy with an undetectable viral load. Participants who are seropositive for hepatitis C are eligible only in the setting of a sustained virologic response [SVR], defined as aviremia at least 12 weeks after completion of antiviral therapy. People of child-bearing potential and those who can father children must agree to use dual form of contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation and for 3 months after the last dose. Participants must understand and sign a written informed consent document. EXCLUSION CRITERIA: Participants who have had anticancer treatment within the last 2 weeks unless the cancer treatment is for a malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial, such as local treatment for carcinoma in situ or hormonal therapy for prostate or breast carcinoma. Toxicity related to prior therapies other than hair loss and neuropathy must have resolved to grade 1. Participants may not receive investigational agents on other clinical trials. Kaposi sarcoma requiring urgent treatment with cytotoxic chemotherapy. Bilirubin (total) > 1.5 times the upper limit of normal; AST and/or ALT > 3 times the upper limit of normal; EXCEPTIONS: Total bilirubin >= 5 mg/dL in participants with Gilbert's syndrome as defined by > 80% unconjugated If the elevated total bilirubin or AST/ALT are due to ART or lymphoma ANC < 1000/mm3 and platelets < 75,000/mm3 unless related to lymphoma or prior therapy. Clinically significant cardiac disease, including: Myocardial infarction within 6 months of randomization, or an unstable or uncontrolled disease/condition related to or affecting cardiac function (e.g., unstable angina, congestive heart failure, New York Heart Association Class III-IV). Uncontrolled cardiac arrhythmia Chronic obstructive pulmonary disease (COPD) with a forced expiratory volume in 1 second (FEV1) < 50% of predicted normal. Moderate or severe persistent asthma within the past 2 years, or uncontrolled asthma of any classification. Note that participants who currently have controlled intermittent asthma or controlled mild persistent asthma are allowed to participate in the study. Pregnant people as evaluated by a positive serum or urine Beta-hCG test Participants with severe uncontrolled intercurrent illness, evaluated by history, physical exam and chemistry panel. Participants with severe intercurrent illnesses attributed to lymphoma may be eligible per PI s or designee s discretion.