Based on overall reporting in low tumor burden FL and MZL, CR rate of at least 30% was achieved when single agent rituximab was used in these subsets. The investigators assume that by administering ublituximab (both as a single agent and in combination with umbralisib for individuals who fail to achieve a CR [Complete response] with the single agent), the CR rate will increase to 50%. Efficacy will be assessed using the proportion of patients treated with ublituximab alone or with ublituximab administered in combination who have a complete response. Thus, the investigators will test the efficacy of ublituximab using a difference in proportions design by comparing an expected study population control rate of 50% to the comparison proportion being determined by the historical control CR rate of 30%. In other words, the null hypothesis is that the true response rate is 30%, and it will be formally tested against a one-sided alternative that the response rate is 50%.
This is an open-label, Phase II interventional study in order to assess efficacy and safety of single agent ublituximab as initial therapy for FL (Follicular lymphoma) and MZL (Marginal zone lymphoma ) with response driven addition of umbralisib for suboptimal response.