REGEN-Cov antibody combination to prevent COVID-19 infection in kidney transplant recipient without detectable antibody response to optimal vaccine scheme

Safety and efficacy of tixagevimab/cilgavimab for pre-exposure prophylaxis in kidney transplant recipients: a multicenter retrospective cohort study

BACKGROUND

Immunocompromised patients show an impaired vaccine response and remain at high risk of severe COVID-19, despite vaccination. Neutralizing monoclonal antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed for prophylaxis and treatment. The combination tixagevimab/cilgavimab (AZD7442) has been authorized for emergency use as pre-exposure prophylaxis for COVID-19, but data on safety and efficacy in kidney transplant recipients during the Omicron period are limited.

METHODS

We conducted a multicenter retrospective cohort study including 253 kidney transplant recipients, of whom 98 were treated with tixagevimab/cilgavimab 150 mg/150 mg and 155 who received only four doses of the BNT162b2 mRNA vaccine.

RESULTS

Only 13.3% of patients developed SARS-CoV-2 infection after the administration of tixagevimab/cilgavimab; in comparison, 34.2% of patients had been infected after the fourth dose of vaccine (p = 0.00013). Most infected patients in the AZD7442 group remained asymptomatic (92.3% vs 54.7%), 7.7% had mild symptoms and none had severe disease, need for hospitalization or died, while in the control group, 9.4% of patients had moderate or severe disease (p = 0.04). Using Kaplan-Meier curves we demonstrated that the controls presented early infection compared to the AZD7442 group (p = 0.000014). No changes in eGFR or proteinuria, assessed before and after the administration, were observed.

CONCLUSIONS

In conclusion, our study showed that tixagevimab/cilgavimab 150/150 mg is effective and safe in preventing infection and severe disease when administered to patients with weak or no response to COVID-19 vaccine.

Prevention and treatment strategies for kidney transplant recipients in the context of long-term existence of COVID-19

The sudden outbreak of coronavirus disease 2019 (COVID-19) in early 2020 posed a massive threat to human life and caused an economic upheaval worldwide. Kidney transplant recipients (KTRs) became susceptible to infection during the COVID-19 pandemic owing to their use of immunosuppressants, resulting in increased hospitalization and mortality rates. Although the current epidemic situation is alleviated, the long-term existence of COVID-19 still seriously threatens the life and health of KTRs with low immunity. The Omicron variant, a highly infectious but less-pathogenic strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised concerns among transplant physicians regarding managing KTRs diagnosed with this variant. However, currently, there are no clear and unified guidelines for caring for KTRs infected with this variant. Therefore, we aimed to summarize the ongoing research on drugs that can treat Omicron variant infections in KTRs and explore the potential of adjusting immunotherapy strategies to enhance their responsiveness to vaccines. Herein, we discuss the situation of KTRs since the emergence of COVID-19 and focus on various prevention and treatment strategies for KTRs since the Omicron variant outbreak. We hope to assist physicians in managing KTRs in the presence of long-term COVID-19 variants.

COVID-19 Breakthrough Infections in Vaccinated Kidney Transplant Recipients

Coronavirus disease 2019 (COVID-19) is associated with increased morbidity and mortality among kidney transplant recipients (KTRs). The administration of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is the only reliable strategy to prevent COVID-19 and alleviate the severity of COVID-19 in this particular population. The aim of this article was to evaluate the clinical protection by vaccines (breakthrough infections, deaths, and hospitalizations) in KTRs. There were 135 KTRs with COVID-19 breakthrough infections for whom patient-level data were available in PubMed and Web of Science. There was a male predominance (61.4%), 97 were given the standard vaccination regimen, and 38 received three or four doses of the vaccine. The median age was 59.0 (IQR: 49.0−69.0) years. A total of 67 patients were hospitalized, and 10 patients died. In 72.6% of cases, triple-maintenance immunosuppression was employed. The deceased patients were older than the survivors (p < 0.05); an age over 60 years was a risk factor for death (p < 0.05). The KTRs with booster vaccines had a longer time interval from the last vaccine to COVID-19 infection and lower hospitalization rates than the individuals who received the standard vaccination regimen (33.3% vs. 54.8%, p < 0.05). The hospitalized patients were older than the outpatients (p < 0.05). Among 16,820 fully vaccinated or boosted KTRs from 14 centers, there were 633 breakthrough infections (3.58%) and 73 associated deaths (0.41%). The center-level breakthrough infection rates varied from 0.21% to 9.29%. These findings highlight the need for booster doses for KTRs. However, more research is needed to define the long-term effectiveness and immunogenicity of booster doses and to identify methods to boost the protective response to vaccination in these immunocompromised patients.

What Is New in Prophylaxis and Treatment of COVID-19 in Renal Transplant Patients? A Report from an ESOT Meeting on the Topic

I should highlight that this manuscript is not a formal review on the topic, but a report from an ESOT meeting held on 22 June 2022. The assumption of immunosuppressants exposes kidney transplant recipients to the risk of infections, including COVID-19 infection. A transplant patient having COVID-19 infection raises several questions, including whether the immunosuppressive therapy should be reduced with the consequent risk of favoring acute rejections. Patient vaccination before transplantation is probably the gold standard to avoid the risk of COVID-19 infection after transplantation. In the case of transplant patients, three measures may be undertaken: vaccination, use of monoclonal antibodies and use of therapeutic antiviral small molecules. Concerning vaccination, it is still debated which one is the best and how many doses should be administered, particularly considering the new variants of the virus. The onset of virus variants has stimulated researchers to find new active vaccines. In addition, not all transplant patients develop antibodies. An alternative prophylactic measure to be principally used for patients that do not develop antibodies after vaccination is the use of monoclonal antibodies. These drugs may be administered as prophylaxis or in the early stage of the disease. Finally, the small antiviral molecules may be used again as prophylaxis or treatment. Their major drawbacks are their interference with immunosuppressive drugs and the fact that some of them cannot be administered to patients with low eGFR.

Breakthrough COVID-19 cases despite prophylaxis with 150 mg of tixagevimab and 150 mg of cilgavimab in kidney transplant recipients

The cilgavimab-tixagevimab combination retains a partial in vitro neutralizing activity against the current SARS-CoV-2 variants of concern (omicron BA.1, BA.1.1, and BA.2). Here, we examined whether preexposure prophylaxis with cilgavimab-tixagevimab can effectively protect kidney transplant recipients (KTRs) against the omicron variant. Of the 416 KTRs who received intramuscular prophylactic injections of 150 mg tixagevimab and 150 mg cilgavimab, 39 (9.4%) developed COVID-19. With the exception of one case, all patients were symptomatic. Hospitalization and admission to an intensive care unit were required for 14 (35.9%) and three patients (7.7%), respectively. Two KTRs died of COVID-19-related acute respiratory distress syndrome. SARS-CoV-2 sequencing was carried out in 15 cases (BA.1, n = 5; BA.1.1, n = 9; BA.2, n = 1). Viral neutralizing activity of the serum against the BA.1 variant was negative in the 12 tested patients, suggesting that this prophylactic strategy does not provide sufficient protection against this variant of concern. In summary, preexposure prophylaxis with cilgavimab-tixagevimab at the dose of 150 mg of each antibody does not adequately protect KTRs against omicron. Further clarification of the optimal dosing can assist in our understanding of how best to harness its protective potential.

Can the COVID-19 Pandemic Improve the Management of Solid Organ Transplant Recipients?

Increased mortality due to SARS-CoV-2 infection was observed among solid organ transplant patients. During the pandemic, in order to prevent and treat COVID-19 infections in this context, several innovative procedures and therapies were initiated within a short period of time. A large number of these innovations can be applied and expanded to improve the management of non-COVID-19 infectious diseases in solid organ transplant patients and in the case of a future pandemic. In this vein, the present paper reviews and discusses medical care system adaptation, modification of immunosuppression, adjuvant innovative therapies, the role of laboratory expertise, and the prevention of infections as examples of such innovations.

Perspective on COVID-19 vaccination in patients with immune-mediated kidney diseases: consensus statements from the ERA-IWG and EUVAS

Patients with immune-mediated kidney diseases are at increased risk of severe coronavirus disease 2019 (COVID-19). The international rollout of COVID-19 vaccines has provided varying degrees of protection and enabled the understanding of vaccine efficacy and safety. The immune response to COVID-19 vaccines is lower in most patients with immune-mediated kidney diseases; either related to immunosuppression or comorbidities and complications caused by the underlying disease. Humoral vaccine response, measured by the presence of antibodies, is impaired or absent in patients receiving rituximab, mycophenolate mofetil (MMF), higher doses of glucocorticoids and likely other immunosuppressants, such as cyclophosphamide. The timing between the use of these agents and administration of vaccines is associated with the level of immune response: with rituximab, vaccine response can only be expected once B cells start to recover and patients with transient discontinuation of MMF mount a humoral response more frequently. The emergence of new COVID-19 variants and waning of vaccine-induced immunity highlight the value of a booster dose and the need to develop mutant-proof vaccines. COVID-19 vaccines are safe, exhibiting a very low risk of de novo or relapsing immune-mediated kidney disease. Population-based studies will determine whether this is causal or coincidental. Such cases respond to standard management, including the use of immunosuppression. The Immunonephrology Working Group and European Vasculitis Society recommend that patients with immune-mediated kidney diseases follow national guidance on vaccination. Booster doses based on antibody measurements could be considered.

Issues regarding COVID-19 in kidney transplantation in the era of the omicron variant: a commentary by the era descartes working group

The Omicron variant, which has become the dominant strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide, brings new challenges to preventing and controlling the infection. Moreover, the widespread implementation of vaccination policies before and after transplantation, and the development of new prophylactic and treatment strategies for coronavirus disease 2019 (COVID-19) over the past 12–18 months, has raised several new issues concerning kidney transplant recipients. In this special report, the ERA DESCARTES (Developing Education Science and Care for Renal Transplantation in European States) Working Group addresses several questions related to everyday clinical practice concerning kidney transplant recipients and to the assessment of deceased and live kidney donors: what is the current risk of severe disease and of breakthrough infection, the optimal management of immunosuppression in kidney transplant recipients with COVID-19, the role of passive immunization and the efficacy of antiviral drugs in ambulatory patients, the management of drug-to-drug interactions, safety criteria for the use of SARS-CoV-2-positive donors, issues related to the use of T cell depleting agents as induction treatment, and current recommendations for shielding practices.

Monoclonal Antibody Therapy in Kidney Transplant Recipients With Delta and Omicron Variants of SARS-CoV-2: A Single-Center Case Series

Rationale & Objective

Study Design

Setting & Participants

Results

Limitations

Conclusions

Heterologous high dose SARS-CoV-2 mRNA vaccine booster may improve immune response in seronegative kidney transplant recipients

INTRODUCTION

Three-dose mRNA vaccination against COVID-19 is unable to elicit a sufficient immune response in immunocompromised subjects.

METHODS

The aim of the study was to conduct a retrospective evaluation of the efficacy of a heterologous mRNA booster with mRNA-1273 in constantly seronegative kidney transplant recipients (KTRs) after three doses of the BNT162b2 mRNA vaccine. Twelve seronegative KTRs received a mRNA-1273 booster 5 months after the third dose of BNT162b2.

RESULTS

A total of 5 out of 12 patients (41.7%) seroconverted, with a mean titer of 353 BAU/ml.

CONCLUSIONS

The administration of a heterologous mRNA vaccine as a booster may be an effective alternative for achieving post-vaccination immunity in seronegative KTRs.