Relapsed Hodgkin lymphoma remains a clinical challenge, with few non-cytotoxic treatment options. CD80 is a surface antigen that normally functions as a co-stimulatory molecule but is aberrantly and uniformly expressed on Reed-Sternberg cells. Galiximab is a primatized monoclonal antibody against CD80, with a favorable toxicity profile demonstrated in other lymphomas. Cancer and Leukemia Group B (CALGB) 50602 (Alliance) tested single-agent galiximab in a highly refractory group of patients with Hodgkin lymphoma (median 3 prior regimens, 83% failing after prior stem cell transplant) to determine the efficacy. The overall response rate was 10.3% and the median progression-free survival was 1.6 months. Galiximab was well-tolerated, with minimal grade 3 or 4 toxicities. Despite this preclinical rationale, single-agent galiximab had limited activity in heavily pretreated Hodgkin lymphoma.