Investigators are using checkpoint inhibitors (CPIs) to treat aggressive hematologic malignancies in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) and in some patients with relapsed disease after allo-HSCT. CTLA-4 inhibitors and PD-1 inhibitors are 2 main types of CPIs, which work through activation of the immune system. On one hand, CPIs can achieve graft-versus-tumor effect, and on the other hand, there is a risk of graft-versus-host disease (GVHD). After a comprehensive literature review, we included data (n = 283) from 24 studies (11 original manuscripts and 13 case reports or case series) and evaluated the results to assess the safety and efficacy of CPI use in conjunction with allo-HSCT. Among the 283 patients, 107 received CPI before allo-HSCT, and 176 received CPI after allo-HSCT. The most common indication for CPI use was for Hodgkin lymphoma. The CPIs used in various studies included ipilimumab, nivolumab, and pembrolizumab. Among the patients exposed to CPI before allo-HSCT, 56% developed acute GVHD and 29% developed chronic GVHD. Investigators reported 20 deaths, 60% of which were GVHD-related. The overall mortality risk with GVHD is 11%. In this group, investigators noted an objective response rate (ORR) in 68% of patients, with complete remission (CR) in 47%, partial remission (PR) in 21%, and stable disease in 11%. Among the patients who received a CPI after allo-HSCT for disease relapse, 14% developed acute GVHD and 9% developed chronic GVHD. Investigators reported 40 deaths, 28% of which were GVHD-related. The mortality risk with GVHD is approximately 7%. Investigators reported ORR in 54% of patients, with CR in 33%, PR in 21%, and disease stabilization in 5%. After careful evaluation of collective data, we found that CPI use both before and after allo-HSCT can be highly effective, but exposure can lead to a significantly increased risk of GVHD-related morbidity and mortality in this patient population. Despite limited availability of data, there is need for extreme caution while making decisions regarding the use of CPIs. Detailed discussions and prospective well-designed clinical trials are needed to explore this issue further.

Primary immunodeficiencies and immune dysregulatory disorders (PIDDs; now referred to as inborn errors in immunity) are rare disorders with a prevalence of 41. 4 or 50.5 per 100,000 persons ( 1 ). The incidence of malignancy in PIDD patents is the second-highest cause of death in children as well as adults, after infection, and is higher in certain PIDDs compared to others. We performed a systematic review of the literature to identify reports of B cell and T cell neoplasias in PIDDs and clustered them based on their classification in the IUIS schema. As would be expected, higher susceptibility to malignancies are typically reported in patients with Common Variable Immunodeficiency (CVID), combined immunodeficiencies affecting cellular immunity, in particular, DNA repair defects, or in the context of impaired immune regulatory control. There is not much evidence of increased risk for cancer in patients with innate immune defects, indicating that not all types of infection or genetic susceptibility predispose equally to cancer risk. Viral infections, in particular EBV, HHV and HPV, have been shown to increase susceptibility to developing cancer, but also patients with defects in immune regulation, such as Autoimmune Lymphoproliferative Syndrome (ALPS), activated p110delta syndrome (APDS type 1) and IL-10 receptor deficiency among others have a higher incidence of neoplastic disease, particularly lymphomas. In fact, lymphomas account for two-thirds of all malignancies reported in PIDD patients ( 2 ), with either a combined immunodeficiency or DNA repair defect predominating as the underlying immune defect in one registry, or antibody deficiencies in another ( 3 ). The vast majority of lymphomas reported in the context of PIDDs are B cell lymphomas, though T cell lymphomas have been reported in a few studies, and tend to largely be associated with chromosomal breakage disorders ( 4 ) or Cartilage Hair Hypoplasia ( 5 ). There appears to be a much higher prevalence of T cell lymphomas in patients with secondary immunodeficiencies ( 6 ), though this could reflect treatment bias. We reviewed the literature and summarized the reports of B and T cell lymphoma in PIDD patients to survey the current state of knowledge in this area.

Blinatumomab and donor lymphocyte infusion (DLI) combination is a promising cancer therapy, whereby blinatumomab might achieve an initial reduction in leukemic-cell burden using T cells, and after tumor clearance, DLI can potentially stimulate the donor immune system to achieve longer lasting remission. Here, we present a 51-year-old female with mixed phenotype acute leukemia who had a hematologic relapse 3 months after she received total body irradiation-based myeloablative allogeneic hematopoietic stem cell transplantation from an unrelated human leukocyte antigen matched (10/10) donor and achieved complete remission with minimal residual disease negativity by multi-parameter flow cytometry using the combination of blinatumomab and DLI. To the best of our knowledge, this is the first report to describe the use of blinatumomab and DLI combination therapy in the treatment of B/myeloid mixed phenotype acute leukemia.

Key PointsQuestionWhat is the risk of serious infections, opportunistic infections, and cancer in patients with rheumatologic diseases treated with interleukin inhibitors?FindingsIn this systematic review and meta-analysis of 74 randomized clinical trials comprising 29 214 patients, pooled results suggest that risk of serious infections, opportunistic infections, and cancer is increased in patients with rheumatologic diseases who are treated with interleukin inhibitors compared with placebo.MeaningThis analysis suggests estimates of risk for infections and cancer associated with the use of interleukin inhibitors that can inform shared decision-making when patients and clinicians are contemplating the use of interleukin inhibitors for rheumatologic diseases.

R-CHOP has been the standard of care for diffuse large B cell lymphoma (DLBCL), curing approximately 60% of patients for more than 2 decades. However, the optimal treatment of patients who are too frail to tolerate this regimen and/or are not candidates for anthracycline therapy continues to be debated. MInT and GELA trials established addition of rituximab to CHOP in DLBCL but excluded patients older than 80 years. Multiple regimens have been tried with varying success in the very elderly, including R-mini-CHOP, R-mini CEOP, R-split CHOP, pre-phase strategies, and R-GCVP. However, there has not been a randomized trial among these strategies. Although addition of novel agents including ibrutinib, brentuximab vedotin, lenalidomide, and many others on the horizon holds promise in this population, none have been tested in a randomized setting or have results awaited. There is also a lack of a validated and easy to use clinical tool in this population to predict patients who will not tolerate R-CHOP. Identifying patients who will not tolerate R-CHOP early with the help of tools like CGA, along with integrating biology-based treatment (ibrutinib, lenalidomide in activated B cell type DLBCL) is being investigated in this population.