Association of antibody induction immunosuppression with cancer after kidney transplantation

Clinical and Economic Consequences of Early Cancer After Kidney Transplantation in Contemporary Practice

BACKGROUND

Current clinical and economic consequences of cancer after kidney transplantation are incompletely defined.

METHODS

We examined United States Renal Data System records of Medicare-insured kidney transplant recipients in 2000 to 2011 to determine clinical and economic impacts of cancer diagnosed within the first 3 years posttransplantation. Cancer diagnoses were identified using Medicare billing codes and categorized as nonmelanoma skin cancer (NMSC), viral-linked and "other" cancers. Associations of cancers with mortality and graft loss were estimated by time-varying Cox regression. Impacts of cancer diagnoses on inpatient and outpatient costs within each year were quantified by multivariate linear regression modeling.

RESULTS

Among 67 157 recipients, by 3 years posttransplant, NMSC was diagnosed in 5.7%, viral-linked cancer in 1.9%, and "other" cancers in 6.3%. Viral-linked cancer was associated with more than 3-fold increased risk in subsequent mortality until the third transplant anniversary, and nearly twice the mortality risk after year 3. "Other" cancers had similar associations with death and graft loss, whereas NMSC was associated with 33% higher mortality beyond the third year posttransplant. Viral-linked cancer had the largest inpatient and outpatient cost impacts per case, followed by "other" cancer, whereas NMSC impacted only outpatient costs. Care of new cancer diagnoses was generally more costly than care of previously established diagnoses. Cancer accounted for 3% to 5.5% of total inpatient Medicare expenditures and 1.5% to 3.3% of outpatient expenditures in the first 3 years posttransplant.

CONCLUSIONS

Early posttransplant malignancy is an expensive and morbid condition that warrants attention in efforts to improve pretransplant screening and management protocols before and after transplant.

Cancer-related outcomes in kidney allograft recipients in England versus New York State: a comparative population-cohort analysis between 2003 and 2013

It is unclear whether cancer‐related epidemiology after kidney transplantation is translatable between countries. In this population‐cohort study, we compared cancer incidence and all‐cause mortality after extracting data for every kidney‐alone transplant procedure performed in England and New York State (NYS) between 2003 and 2013. Data were analyzed for 18,493 and 11,602 adult recipients from England and NYS respectively, with median follow up 6.3 years and 5.5 years respectively (up to December 2014). English patients were more likely to have previous cancer at time of transplantation compared to NYS patients (5.6% vs. 3.5%, P < 0.001). Kidney allograft recipients in England versus NYS had increased cancer incidence (12.3% vs. 5.9%, P < 0.001) but lower all‐cause mortality during the immediate postoperative stay (0.7% vs. 1.0%, P = 0.011), after 30‐days (0.9% vs. 1.8%, P < 0.001) and after 1‐year post‐transplantation (3.0% vs. 5.1%, P < 0.001). However, mortality rates among patients developing post‐transplant cancer were equivalent between the two countries. During the first year of follow up, if patients had an admission with a cancer diagnosis, they were more likely to die in both England (Odds Ratio 4.28 [95% CI: 3.09–5.93], P < 0.001) and NYS (Odds Ratio 2.88 [95% CI: 1.70–4.89], P < 0.001). Kidney allograft recipients in NYS demonstrated higher hazard ratios for developing kidney transplant rejection/failure compared to England on Cox regression analysis. Our analysis demonstrates significant differences in cancer‐related epidemiology between kidney allograft recipients in England versus NYS, suggesting caution in translating post‐transplant cancer epidemiology between countries.

Use of polyclonal/monoclonal antibody therapies in transplantation

INTRODUCTION

For over thirty years, antibody (mAb)-based therapies have been a standard component of transplant immunosuppression, and yet much remains to be learned in order for us to truly harness their therapeutic capabilities. Current mAbs used in transplant directly target and destroy graft-destructive immune cells, interrupt cytokine and costimulation-dependent T and B cell activation, and prevent down-stream complement activation. Areas covered: This review summarizes our current approaches to using antibody-based therapies to prevent and treat allograft rejection. It also provides examples of promising novel mAb therapies, and discusses the potential for future mAb development in transplantation. Expert opinion: The broad capability of antibodies, in parallel with our growing ability to synthetically modulate them, offers exciting opportunities to develop better biologic therapeutics. In order to do so, we must further our understanding about the basic biology underlying allograft rejection, and gain better appreciation of how characteristics of therapeutic antibodies affect their efficacy.

Induction Therapy for Kidney Transplant Recipients: Do We Still Need Anti-IL2 Receptor Monoclonal Antibodies?

Induction therapy with antilymphocyte biological agents is widely used after kidney transplantation, most commonly T lymphocyte-depleting rabbit-derived antithymocyte globulin (rATG) or an IL-2 receptor antagonist (IL2RA). Early randomized trials showed that rATG or IL2RA induction reduces early acute rejection, prompting recommendations by Kidney Disease Improving Global Outcomes that IL2RA induction be used routinely in first-line therapy after kidney transplantation, with lymphocyte-depleting induction reserved for high-risk cases. These studies, however, mainly used outdated maintenance regimens. No large randomized trial has examined the effect of IL2RA or rATG induction versus no induction in patients receiving tacrolimus, mycophenolic acid and steroids. With this triple maintenance therapy, the addition of induction may achieve an absolute risk reduction for acute rejection of only 1-4% in standard-risk patients without improving graft or patient survival. In contrast, rATG induction lowers the relative risk of acute rejection by almost 50% versus IL2RA in patients with high immunological risk. These recent data raise questions about the need for IL2RA in kidney transplantation, as it may no longer be beneficial in standard-risk transplantation and may be inferior to rATG in high-risk situations. Updated evidence-based guidelines are necessary to support clinicians deciding whether and what induction therapy is required for their transplant patients today.

Differential risks for adverse outcomes 3 years after kidney transplantation based on initial immunosuppression regimen: a national study

We examined integrated national transplant registry, pharmacy fill, and medical claims data for Medicare-insured kidney transplant recipients in 2000-2011 (n = 45 164) from the United States Renal Data System to assess the efficacy and safety endpoints associated with seven early (first 90 days) immunosuppression (ISx) regimens. Risks of clinical complications over 3 years according to IS regimens were assessed with multivariate regression analysis, including the adjustment for covariates and propensity for receipt of a nonreference ISx regimen. Compared with the reference ISx (thymoglobulin induction with tacrolimus, mycophenolate, and prednisone maintenance), sirolimus-based ISx was associated with significantly higher three-year risks of pneumonia (adjusted hazard ratio, aHR 1.45; P < 0.0001), sepsis (aHR 1.40; P < 0.0001), diabetes (aHR 1.21; P < 0.0001), acute rejection (AR; adjusted odds ratio, aOR 1.33; P < 0.0001), graft failure (aHR 1.78; P < 0.0001), and patient death (aHR 1.40; P < 0.0001), but reduced skin cancer risk (aHR 0.71; P < 0.001). Cyclosporine-based IS was associated with increased risks of pneumonia (aHR 1.17; P < 0.001), sepsis (aHR 1.16; P < 0.001), AR (aOR 1.43; P < 0.001), and graft failure (aHR 1.39; P < 0.001), but less diabetes (aHR 0.83; P < 0.001). Steroid-free ISx was associated with the reduced risk of pneumonia (aHR 0.89; P = 0.002), sepsis (aHR 0.80; P < 0.001), and diabetes (aHR 0.77; P < 0.001), but higher graft failure (aHR 1.35; P < 0.001). Impacts of ISx over time warrant further study to better guide ISx tailoring to balance the efficacy and morbidity.

Acute Rejection Rates and Graft Outcomes According to Induction Regimen among Recipients of Kidneys from Deceased Donors Treated with Tacrolimus and Mycophenolate

BACKGROUND AND OBJECTIVES

IL-2 receptor antagonist (IL2-RA) is recommended as a first-line agent for induction therapy in renal transplantation. However, this remains controversial in deceased donor renal transplantation (DDRT) maintained on tacrolimus (TAC)/mycophenolic acid (MPA) with or without steroids.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied the United Network for Organ Sharing Registry for patients receiving DDRT from 2000 to 2012 maintained on TAC/MPA at transplantation hospital discharge (n=74,627) to compare outcomes of IL2-RA and other induction agents. We initially divided the cohort into two groups on the basis of steroid use at the time of discharge: steroid (n=59,010) versus no steroid (n=15,617). Each group was stratified into induction categories: IL2-RA, rabbit antithymocyte globulin (r-ATG), alemtuzumab, and no induction. The main outcomes were incidence of acute rejection within the first year and overall graft failure (defined as graft failure and/or death) post-transplantation. Propensity score (PS), specifically inverse probability of treatment weight, analysis was used to minimize selection bias caused by nonrandom assignment of induction therapies.

RESULTS

Median (25th, 75th percentiles) follow-up times were 3.9 (1.1, 5.9) and 3.2 (1.1, 4.9) years for steroid and no steroid groups, respectively. Acute rejection within the first year and overall graft failure within 5 years of transplantation were more common in the no induction category (13.3%; P<0.001 and 28%; P=0.01, respectively) in the steroid group and the IL2-RA category (11.1%; P=0.16 and 27.4%; P<0.001, respectively) in the no steroid group. Compared with IL2-RA, PS-weighted and covariate-adjusted multivariable logistic and Cox analyses showed that outcomes in the steroid group were similar among induction categories, except that acute rejection was significantly lower with r-ATG (odds ratio [OR], 0.68; 95% confidence interval [95% CI], 0.62 to 0.74). In the no steroid group, compared with IL2-RA, odds of acute rejection with r-ATG (OR, 0.80; 95% CI, 0.60 to 1.00) and alemtuzumab (OR, 0.68; 95% CI, 0.53 to 0.88) were lower, and r-ATG was associated with better graft survival (hazard ratio, 0.86; 95% CI, 0.75 to 0.99).

CONCLUSIONS

In DDRT, compared with IL2-RA induction, no induction was associated with similar outcomes when TAC/MPA/steroids were used. r-ATG seems to offer better graft survival over IL2-RA in steroid avoidance protocols.

Posttransplant solid organ malignancies in lung transplant recipients: a single-center experience and review of the literature

PURPOSE

Solid-organ tumor incidences are higher in solid organ transplant patients than in the general population. The aim of this study was to analyze solid-organ tumor frequency and characteristics in a population of lung transplant patients and provide a brief review of the literature.

METHODS

A retrospective analysis was conducted of all patients who underwent a lung transplant in the Lung Transplant Program at the University Hospital of Siena, Italy, from 2001 to 2014 (n = 119). Patients' demographics, pretransplant characteristics, immunosuppressive therapy, and infectious factors were recorded.

RESULTS

Nine patients with a median age of 59.0 years (range 50-63) of our cohort developed a solid-organ tumor (7.5%). Most of the patients experienced nonmelanoma skin cancer (44.4%); the others were diagnosed with lung cancer (22.2%), breast cancer (22.2%), and colon-rectal cancer (11.2%). The median time from transplantation to tumor diagnosis was 895.0 days (range 321-2046). No differences in pretransplant characteristics, immunosuppressive therapy, or infectious factors were found between patients who developed solid organ tumors and those who did not.

CONCLUSIONS

The present study confirmed that de novo malignancies are a major issue in lung transplant patients; in particular, skin and lung cancers demonstrated a higher incidence rate. Oncologic treatment of these patients is complex, requiring close collaboration between the transplant team and oncologist. Strict screening programs are key factors for an early diagnosis and to allow for prompt treatment resulting in a better outcome.

Effects of anti-human T lymphocyte immune globulins in patients: new or old

Multiple studies demonstrated that anti‐human T lymphocyte immune globulins (ATG) can decrease the incidence of acute and chronic graft rejection in cell or organ transplants. However, further in‐depth study indicates that different subgroups may benefit from either different regimes or alteration of them. Studies among renal transplant patients indicate that low immunological risk patients may not gain the same amount of benefit and thus tilt the risk versus benefit consideration. This may hold true for low immunological risk patients receiving other organ transplants and would be worth further investigation. The recovery time of T cells and natural killer (NK) cells also bears consideration and the impact that it has on the severity and incidence of opportunistic infections closely correlated with the dosage of ATG. The use of lower doses of ATG in combination with other induction medications may offer a solution. The finding that ATG may lose efficacy in cases of multiple transplants or re‐transplants in the case of heart transplants may hold true for other transplantations. This may lead to reconsideration of which induction therapies would be most beneficial in the clinical setting. These studies on ATG done on different patient groups will naturally not be applicable to all, but the evidence accrued from them as a whole may offer us new and different perspectives on how to approach and potentially solve the clinical question of how to best reduce the mortality associated with chronic host‐versus‐graft disease.

Alemtuzumab (Campath-1H) experience in kidney transplantation what we have learned; current practices; and scope for the future?

PURPOSE OF REVIEW

Alemtuzumab (Campath) usage as a preconditioning agent in kidney transplantation has gained considerable interest in the recent future. Alemtuzumab is currently available only by special request from Sanofi through its Campath distribution program. It is restricted to transplant programs with prior and continued experience with the agent. There may be a resurgence of interest for the utilization of this agent because of its ease of administration, and less cost and comparable or improved outcome in comparison to other induction agents.

RECENT FINDINGS

Alemtuzumab when combined with standard calcineurin inhibitor and mycophenolate mofetil is well tolerated and efficacious as an induction therapy and allows for long-term steroid avoidance in high-risk renal transplant recipients.

SUMMARY

The transplant community has advanced through a learning curve with the use of alemtuzumab over time; starting from an agent that was tried out to induce proper tolerance, minimization of nephrotoxic calcineurin inhibitors, and currently as a comparable depletional therapy that can reduce acute rejection in high-risk kidney transplant recipients.

Induction by anti-thymocyte globulins in kidney transplantation: a review of the literature and current usage

Context: Preventing acute rejection (AR) after kidney transplantation is of utmost importance because an AR can have a negative impact on long-term allograft survival.

Evidence Acquisition: Directory of Open Access Journals (DOAJ), Google Scholar, PubMed, EBSCO, and Web of Science have been searched.

Results: At the moment this can be done by using rabbit anti-thymocyte globulins (rATGs) as an induction therapy. However, because rATGs are associated with some deleterious side-effects, such as the opportunistic infections cytomegalovirus (CMV) and de novo post-transplant cancer, it is very important they are used optimally, i.e., at minimal doses that avoid many side-effects but still retain optimal treatment efficacy. Recent data show that the risk of CMV infection can be minimized using tacrolimus plus everolimus, and not tacrolimus plus mycophenolic acid, as the maintenance immunosuppression. The use of rATG is particularly valuable in; (a) sensitized patients; (b) in recipients from an expanded-criteria donor, thus enabling the introduction of calcineurin inhibitors at reduced doses; and (c) for patients where steroid avoidance is contemplated. However, we also need to consider that rATG may increase the risk of de novo cancer, even though recent data indicate this is unlikely and that any risk can be reduced by using mammalian target of rapamycin (mTOR) inhibitors instead of mycophenolic acid combined with low-dose calcineurin inhibitors.

Conclusions: Even though rATGs do not improve long-term kidney-allograft survival, they may help reduce calcineurin-inhibitor dosage during the early post-transplant period and minimize the risk of AR.

A multistate additive relative survival semi-Markov model

Medical researchers are often interested to investigate the relationship between explicative variables and times-to-events such as disease progression or death. Such multiple times-to-events can be studied using multistate models. For chronic diseases, it may be relevant to consider semi-Markov multistate models because the transition intensities between two clinical states more likely depend on the time already spent in the current state than on the chronological time. When the cause of death for a patient is unavailable or not totally attributable to the disease, it is not possible to specifically study the associations with the excess mortality related to the disease. Relative survival analysis allows an estimate of the net survival in the hypothetical situation where the disease would be the only possible cause of death. In this paper, we propose a semi-Markov additive relative survival (SMRS) model that combines the multistate and the relative survival approaches. The usefulness of the SMRS model is illustrated by two applications with data from a French cohort of kidney transplant recipients. Using simulated data, we also highlight the effectiveness of the SMRS model: the results tend to those obtained if the different causes of death are known.