Pre-exposure prophylaxis for COVID-19 with Tixagevimab/Cilgavimab in immunocompromised patients has reduced the risk of breakthrough infection, disease, hospitalization, and COVID-19 related mortality. However, the advent of the Kraken variant (XBB.1.5) has limited the use of this monoclonal antibody, based on poor efficacy in in vitro studies The objective of the study was to evaluate the risk of breakthrough infection, symptomatic disease, hospitalization, intensive care admission and COVID-19 related death in kidney transplanted recipients receiving pre-exposure prophylaxis with Tixagevimab/Cilgavimab for COVID-19 in the era of the Kraken variant (XBB.1.5). In a prospective, observational study, we enrolled kidney transplant patients undergoing pre-exposure prophylaxis for COVID-19 with Tixagevimab/Cilgavimab at the Division of Infectious Diseases of Federico II University of Naples between February 2023 and August 2023. Each patient subsequently underwent a six-month follow-up with symptom monitoring and surveillance nasopharyngeal swab for SARS-CoV-2 RNA detection every 30 days, regardless of symptoms. Thirty-four kidney transplant patients were enrolled and in the follow-up period, only one tested positive for the nasopharyngeal swab for SARS-CoV-2 research with asymptomatic infection and virological recovery on the eighth day from the diagnosis of infection. Therefore, no patient developed disease and no patient needed hospitalization and no death occurred. No adverse drug reaction to Tixagevimab/Cilgavimab occurred. Our data, although derived from a limited and uncontrolled sample, show the potential of Tixagevimab/Cilgavimab as a valid and viable therapeutic strategy in pre-exposure prophylaxis for immunocompromised patients. These findings highlight the importance of conducting clinical studies on this topic.

(1) Background: Immunosuppressed patients, especially those receiving B-cells depleting therapies (BCDT), are at major risk to develop reduced vaccine seroconversion and contract severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. The aim of our study is to assess safety and efficacy of the pre-exposure prophylactic combination of Tixagevimab and Cilgavimab (TGM-CGM) in a cohort of rheumatic patients diagnosed with Autoimmune Rheumatic Diseases; (2) Methods: We performed a prospective study using the clinical medical charts of 25 patients treated with Rituximab and received a single injection of TGM/CGM. The cohort was followed for 6 months from the injection and compared to a control group of 25 immunosuppressed patients who did not receive TGM-CGM. We assessed the incidence and the severity of Covid-19 in both groups, as well as early and late adverse events; (3) Results: Despite the small sample, we noticed a downward trend in the incidence and severity of symptomatic infection in the group treated with TGM/CGM. In the experimental cohort, one patient was completely asymptomatic, four patients were oligosymptomatic infection, and just one had mild-moderate infection versus 4 oligosymptomatic and 5 mild-moderate infection in the control group. We observed also a reduction in time to nasopharyngeal swab negativization. No adverse events were reported in our data. We collected the dosage of anti-Receptor-Binding Domain (RBD) SARS-CoV2 spike protein for 21 patients, revealing adequate seroconversion in 12 patients out of 21; (4) Conclusions: Even though the study was conducted during the Omicron wave, notably known to be less responsive to monoclonal antibodies, we proved that TGM-CGM could be a risk-free additional tool to prevent SARS-Cov2 infection in rheumatic immunosuppressed patients.

Tixagevimab/cilgavimab (TIXA/CILGA) was introduced in early 2022 as a promising new drug for pre-exposure prophylaxis against COVID-19 in immunocompromised patients. The aim of our study was to evaluate the efficacy and safety of TIXA/CILGA in a Slovenian national cohort of kidney transplant recipients as pre-exposure prophylaxis in the Omicron era. Demographic, clinical, laboratory, and therapeutic data were collected from electronic and paper medical rec-ords. Of the 106 patients who received TIXA/CILGA, 6 patients (5.7%) subsequently acquired SARS-CoV-2 breakthrough infection. The incidence of SARS-CoV-2 infection was only slightly lower compared with patients who did not receive TIXA/CILGA (7.0%). All patients who re-ceived TIXA/CILGA had a mild disease course, whereas 20% of patients who did not receive TIXA/CILGA required hospitalization and two patients died. Adverse effects most likely related to TIXA/CILGA occurred in 12% of patients, one of whom experienced deep vein thrombosis. None of the patients suffered acute myocardial infarction or cerebrovascular insult. Overall, the benefit of added protection for kidney transplant patients appears to outweigh the potential risk of adverse events and provide additional protection against severe COVID-19 protection.

Objectives: Monoclonal antibodies (mAbs) have proven to be a valuable tool against COVID-19, mostly among subjects with risk factors for progression to severe illness. Tixagevimab/cilgavimab (TIX/CIL), a combination of two Fc-modified human monoclonal antibodies, has been recently approved to be employed as early treatment. Methods: Two groups of immunocompromised patients exposed to different early treatments (i.e., TIX/CIL vs. other mAbs [casirivimab/imdevimab, bamlanivimab/etesevimab, sotrovimab]) were compared in terms of clinical outcomes (hospitalization and mortality within 14 days from administration) and time to the negativity of nasal swabs. We used either Pearson’s chi-square or Fisher’s exact test for categorical variables, whereas the Wilcoxon rank–sum test was employed for continuous ones. Kaplan–Meier curves were produced to compare the time to nasopharyngeal swab negativity. Results: Early treatment with TIX/CIL was administered to 19 immunocompromised patients, while 89 patients received other mAbs. Most of them were solid organ transplant recipients or suffering from hematologic or solid malignancies. Overall, no significant difference was observed between the two groups in terms of clinical outcomes. In the TIX/CIL group, one patient (1/19, 5.3%), who was admitted to the emergency room within the first 14 days from treatment and was hospitalised due to COVID-19 progression, died. Regarding the time to nasal swab negativity, no significant difference (p=0.088) emerged. Conclusions: Early treatment of SARS-CoV-2 infection with TIX/CIL shows favourable outcomes in a small group of immunocompromised patients, reporting no significant difference when compared to similar patients treated with other mAbs.

Tixagevimab–cilgavimab are effective for treatment of early COVID-19 among outpatients with risk factors for progression to severe illness, as well as for primary prevention and post-exposure prophylaxis. We aimed to retrospectively evaluate the hospital stay (expressed in days), prognosis, and negativity rate for COVID-19 after treatment with tixagevimab–cilgavimab. We enrolled 42 patients who were nasal swab positive for SARS-CoV-2 (antigenic and molecular), both vaccinated and not vaccinated for COVID-19, hospitalized at the first division of the Cotugno Hospital in Naples and who received intramuscular single dose of tixagevimab-cilgavimab (300 mg / 300 mg). All patients candidates for tixagevimab-cilgavimab had immunocompromised immune system either for chronic degenerative disorders (Group A: 27 patients) or onco-hematological diseases (Group B: 15patients). Patients enrolled in group A came to our observation after 10 days from the detection of positivity to COVID-19 unlike the other types of patients enrolled in this study. The mean stay in hospital of patients in Group A was 21±5 days vs 25±5 days in Group B. Twenty patients resulted negative after a median of hospitalization stay of 16 days (IQR: 18-15.25), of them 5 (25%) patients belonged to group B. Therefore, patients with active hematological malignancy had the lower negativization rate.