Velde NV, et al. - Via this systematic literature review, current clinical evidence for treatment of patients with stem-cell transplant ineligible R/R DLBCL were summarized. In addition, researchers investigated the possibility of completing an indirect treatment comparison or network meta-analysis (NMA). Among 36 identified studies, 19 studies (53 publications) met the eligibility criteria. Six of the 19 studies were randomized controlled trials (RCTs), and 13 were prospective, observational or single-arm trials. Ten of 19 studies used the IWG 1999-NHL guidelines. Given the variations in studies regarding response criteria and progression-free survival definitions, limitations in conducting cross-study comparisons were experienced. Using data from RCTs or the broader post-hoc analysis, it was identified as impossible to construct a connected network of evidence. Thus, suggesting unfeasibility of conducting an NMA.