CAR-T therapy in solid transplant recipients with post-transplant lymphoproliferative disease: case report and literature review

Adoptive Immune Effector Cell Therapies in Cancer and Solid Organ Transplantation: A Review

Cancer is one of the most devastating complications of kidney transplantation and constitutes one of the leading causes of morbidity and mortality among solid organ transplantation (SOT) recipients. Immunosuppression, although effective in preventing allograft rejection, inherently inhibits immune surveillance against oncogenic viral infections and malignancy. Adoptive cell therapy, particularly immune effector cell therapy, has long been a modality of interest in both cancer and transplantation, though has only recently stepped into the spotlight with the development of virus-specific T-cell therapy and chimeric antigen receptor T-cell therapy. Although these modalities are best described in hematopoietic cell transplantation and hematologic malignancies, their potential application in the SOT setting may hold tremendous promise for those with limited therapeutic options. In this review, we provide a brief overview of the development of adoptive cell therapies with a focus on virus-specific T-cell therapy and chimeric antigen receptor T-cell therapy. We also describe the current experience of these therapies in the SOT setting as well as the challenges in their application and future directions in their development.

Efficacy and Toxicity of CD19 Chimeric Antigen Receptor T Cell Therapy for Lymphoma in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis

The safety and efficacy of chimeric antigen receptor (CAR) T cell therapy in solid organ transplant recipients is poorly understood, given the paucity of available data in this patient population. There is a theoretical risk of compromising transplanted organ function with CAR T cell therapy; conversely, organ transplantation-related immunosuppression can alter the function of CAR T cells. Given the prevalence of post-transplantation lymphoproliferative disease, which often can be difficult to treat with conventional chemoimmunotherapy, understanding the risks and benefits of delivering lymphoma-directed CAR T cell therapy in solid organ transplant recipients is of utmost importance. We sought to determine the efficacy of CAR T cell therapy in solid organ transplant recipients as well as the associated adverse effects, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and compromised solid organ transplant function. We conducted a systematic review and meta-analysis of adult recipients of solid organ transplant who received CAR T cell therapy for non-Hodgkin lymphoma. Primary outcomes included efficacy, defined as overall response (OR), complete response (CR), progression-free survival, and overall survival, as well as rates of CRS and ICANS. Secondary outcomes included rates of transplanted organ loss, compromised organ function, and alterations to immunosuppressant regimens. After a systematic literature review and 2-reviewer screening process, we identified 10 studies suitable for descriptive analysis and 4 studies suitable for meta-analysis. Among all patients, 69% (24 of 35) achieved a response to CAR T cell therapy, and 52% (18 of 35) achieved a CR. CRS of any grade occurred in 83% (29 of 35), and CRS grade ≥3 occurred in 9% (3 of 35). Sixty percent of the patients (21 of 35) developed ICANS, and 34% (12 of 35) developed ICANS grade ≥3. The incidence of any grade 5 toxicity among all patients was 11% (4 of 35). Fourteen percent of the patients (5 of 35) experienced loss of the transplanted organ. Immunosuppressant therapy was held in 22 patients but eventually restarted in 68% of them (15 of 22). Among the studies included in the meta-analysis, the pooled OR rate was 70% (95% confidence interval [CI], 29.2% to 100%; I2 = 71%) and the pooled CR rate was 46% (95% CI, 25.4% to 67.8%; I2 = 29%). The rates of any grade CRS and grade ≥3 CRS were 88% (95% CI, 69% to 99%; I2 = 0%) and 5% (95% CI, 0% to 21%; I2 = 0%), respectively. The rates of any grade ICANS and ICANS grade ≥3 were 54% (95% CI, 9% to 96%; I2 = 68%) and 40% (95% CI, 3% to 85%; I2 = 63%), respectively. The efficacy of CAR T cell therapy in solid organ transplant recipients is comparable to that in the general population as reported in prior investigational studies, with an acceptable toxicity profile in terms of CRS, ICANS, and transplanted organ compromise. Further studies are needed to determine long-term effects on organ function, sustained response rates, and best practices peri-CAR T infusion period in this patient population.

Real-world evidence of the safety and survival with CD19 CAR-T cell therapy for relapsed/refractory solid organ transplant-related PTLD

The use of CD19 chimeric antigen receptor T-cell (CAR-T) therapy for relapsed/refractory solid organ transplantation (SOT)-related post-transplant lymphoproliferative disorder (PTLD) is not well studied. We conducted a multicentre, retrospective analysis of adults with relapsed/refractory SOT-associated PTLD. Among 22 relapsed/refractory SOT-PTLD patients, the pathology was monomorphic B cell. Prior SOTs included 14 kidney (64%), three liver (14%), two heart (9%), one intestinal (5%), one lung (5%), and one pancreas after kidney transplant (5%). The median time from SOT to PTLD diagnosis was 107 months. Pre-CAR-T bridging therapy was used in 55% of patients, and immunosuppression was stopped completely before CAR-T infusion in 64%. Eighteen (82%) patients experienced cytokine release syndrome: one (5%) each grade (G) 3 and G4. The immune effector cell-associated neurotoxicity syndrome was observed in 16 (73%) patients: six (27%) G3 and two (9%) G4. The overall response rate was 64% (55% complete response). Three patients (14%) experienced allograft rejection after CAR-T. The two-year progression-free survival and overall survival rates were 35% and 58%, respectively. Additionally, the achievement of CR post-CAR-T was strongly associated with survival. Collectively, the safety and efficacy of CD19 CAR-T therapy in relapsed/refractory SOT-related PTLD appeared similar to pivotal CAR-T data, including approximately one-third of patients achieving sustained remission.

CD19 CAR-T therapy in solid organ transplant recipients: case report and systematic review

Post-transplant lymphoproliferative disorder (PTLD) is a leading cause of cancer death in solid organ transplant recipients (SOTRs). Relapsed or refractory (R/R) PTLD portends a high risk of death and effective management is not well established. CD19-targeted CAR-T cell therapy has been utilized, but the risks and benefits are unknown. We report the first case of diffuse large B-cell lymphoma (DLBCL) PTLD treated with lisocabtagene maraleucel and present a systematic literature review of SOTRs with PTLD treated with CD19 CAR-T therapy. Our patient achieved a complete response (CR) with limited toxicity but experienced a CD19+ relapse 8 months after infusion despite CAR-T persistence. Literature review revealed 14 DLBCL and 2 Burkitt lymphoma PTLD cases treated with CD19 CAR-T cells. Kidney (n = 12), liver (n = 2), heart (n = 2), and pancreas after kidney (n = 1) transplant recipients were analyzed. The objective response rate (ORR) was 82.4% (14/17), with 58.5% (10/17) CRs and a 6.5-month median duration of response. Among kidney transplant recipients, the ORR was 91.7% (11/12). Allograft rejection occurred in 23.5% (4/17). No graft failure occurred. Our analysis suggests that CD19 CAR-T therapy offers short-term effectiveness and manageable toxicity in SOTRs with R/R PTLD. Further investigation through larger datasets and prospective study is needed.

Post-transplant lymphoproliferative disorder: Update on treatment and novel therapies

Post-transplant lymphoproliferative disorder (PTLD) is rare and heterogeneous lymphoid proliferations that occur as a result of immunosuppression following solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT) with the majority being driven by EBV. Although some histologies are similar to lymphoid neoplasms seen in immunocompetent patients, treatment of PTLD may be different due to difference in pathobiology and higher risk of treatment complications. The most common treatment approach in SOT PTLD after failing immunosuppression reduction (RIS) takes into consideration a risk-stratified sequential algorithm with rituximab +/- chemotherapy based on phase 2 studies. In HSCT PTLD, RIS alone and chemotherapy are usually ineffective making rituximab +/- RIS as the gold standard of frontline treatment. In this review, we give an update on the treatment of PTLD beyond RIS. We highlight the most recent studies that attempted to incorporate more aggressive chemotherapy regimens and novel treatments into the traditional risk-stratified sequential approach. We also discuss the role of EBV-cytotoxic T lymphocytes in treatment of EBV-driven PTLD. Other novel agents with potential role in PTLD will be discussed in addition to the challenges that could arise with chimeric antigen receptor T-cell therapy and immune checkpoint inhibitors in this population.

Human Regulatory T Cells: Understanding the Role of Tregs in Select Autoimmune Skin Diseases and Post-Transplant Nonmelanoma Skin Cancers

Regulatory T cells (Tregs) play an important role in maintaining immune tolerance and homeostasis by modulating how the immune system is activated. Several studies have documented the critical role of Tregs in suppressing the functions of effector T cells and antigen-presenting cells. Under certain conditions, Tregs can lose their suppressive capability, leading to a compromised immune system. For example, mutations in the Treg transcription factor, Forkhead box P3 (FOXP3), can drive the development of autoimmune diseases in multiple organs within the body. Furthermore, mutations leading to a reduction in the numbers of Tregs or a change in their function facilitate autoimmunity, whereas an overabundance can inhibit anti-tumor and anti-pathogen immunity. This review discusses the characteristics of Tregs and their mechanism of action in select autoimmune skin diseases, transplantation, and skin cancer. We also examine the potential of Tregs-based cellular therapies in autoimmunity.

Recent Advances in Adult Post-Transplant Lymphoproliferative Disorder

PTLD is a rare but severe complication of hematopoietic or solid organ transplant recipients, with variable incidence and timing of occurrence depending on different patient-, therapy-, and transplant-related factors. The pathogenesis of PTLD is complex, with most cases of early PLTD having a strong association with Epstein-Barr virus (EBV) infection and the iatrogenic, immunosuppression-related decrease in T-cell immune surveillance. Without appropriate T-cell response, EBV-infected B cells persist and proliferate, resulting in malignant transformation. Classification is based on the histologic subtype and ranges from nondestructive hyperplasias to monoclonal aggressive lymphomas, with the most common subtype being diffuse large B-cell lymphoma-like PTLD. Management focuses on prevention of PTLD development, as well as therapy for active disease. Treatment is largely based on the histologic subtype. However, given lack of clinical trials providing evidence-based data on PLTD therapy-related outcomes, there are no specific management guidelines. In this review, we discuss the pathogenesis, histologic classification, and risk factors of PTLD. We further focus on common preventive and frontline treatment modalities, as well as describe the application of novel therapies for PLTD and elaborate on potential challenges in therapy.

Transplant Onconephrology: An Update

Transplant onconephrology is a growing specialty focused on the health care of kidney transplant recipients with cancer. Given the complexities associated with the care of transplant patients, along with the advent of novel cancer therapies such as immune checkpoint inhibitors and chimeric antigen-receptor T cells, there is a dire need for the subspecialty of transplant onconephrology. The management of cancer in the setting of kidney transplantation is best accomplished by a multidisciplinary team, including transplant nephrologists, oncologists, and patients. This review addresses the current state and future opportunities for transplant onconephrology, including the roles of the multidisciplinary team, and related scientific and clinical knowledge.

Epstein-Barr virus-associated posttransplant lymphoproliferative disorders: new insights in pathogenesis, classification and treatment

PURPOSE OF REVIEW

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication following transplantation from an allogeneic donor. Epstein-Barr Virus (EBV) is involved in a substantial number of cases. In this review, we aim to summarize recent knowledge on pathogenesis, classification and treatment of EBV + PTLD.

RECENT FINDINGS

New insights in the complex oncogenic properties of EBV antigens noncoding Ribonucleic acids (RNAs), especially EBV MicroRNA (miRNAs), have increased our knowledge of the pathogenesis of EBV + PTLD. In addition the potential influence of EBV on the tumor microenvironment is becoming clearer, paving the way for new types of immunotherapy. Currently PTLD is classified according to the World Health Organization classification together with other lymphoproliferative disorders, based on the specific immunosuppression. However, a new framework integrating all types of lymphoproliferative disorders in all different settings of immune deficiency and dysregulation is needed. Although treatment of EBV + and EBV - PTLD was largely similar in the past, EBV-directed therapies are currently increasingly used.

SUMMARY

The use of EBV-directed therapies and new agents, based on better understanding of pathogenesis and classification of PTLD, will change the treatment landscape of EBV + PTLD in the next era.