Real-world experience of tixagevimab-cilgavimab pre-exposure prophylaxis in orthotopic heart transplant recipients.

BACKGROUND: Pre-exposure prophylaxis with tixagevimab-cilgavimab (tix-cil) may be associated with cardiovascular adverse events. Also, in vitro studies have reported a reduced activity of tix-cil against emerging SARS-CoV-2 Omicron subvariants. Our study aimed to report the real-world outcomes of tix-cil prophylaxis in orthotopic heart transplant (OHT) recipients METHODS: We retrospectively studied all OHT recipients who received one dose of tix-cil (150-150 mg or 300-300 mg) at Mayo Clinic in Arizona, Florida, and Minnesota, between February 5, 2022 and September 8, 2022. We collected data on cardiovascular adverse events and breakthrough COVID-19 following tix-cil administration. RESULTS: One hundred sixty-three OHT recipients were included. The majority were male (65.6%), and the median age was 61 years (IQR 48, 69). During the median follow-up of 164 days (IQR 123, 190), one patient presented an episode of asymptomatic hypertensive urgency that was managed with outpatient antihypertensive treatment optimization. Twenty-four patients (14.7%) experienced breakthrough COVID-19 at the median of 63.5 days (IQR 28.3, 101.3) after tix-cil administration. The majority (70.8%) completed the primary vaccine series and received at least one booster dose (70.8%). Only one patient with breakthrough COVID-19 required hospitalization. All patients survived. CONCLUSIONS: In this cohort of OHT recipients, no patients developed severe cardiovascular events related to tix-cil. The high incidence of breakthrough COVID-19 could be due to the reduced activity of tix-cil against current circulating SARS-CoV-2 Omicron variants. These results emphasize the need for a multimodal prevention strategy against SARS-CoV-2 in these high-risk patients.

Genotypic and predicted phenotypic analysis of SARS-COV-2 Omicron subvariants in immunocompromised patients with COVID-19 following tixagevimab-cilgavimab prophylaxis.

BACKGROUND: Tixagevimab-cilgavimab is used for pre-exposure prophylaxis of COVID-19 in immunocompromised patients, though in vitro data has shown reduced neutralizing activity against SARS-CoV-2 Omicron subvariants. METHODS: We performed genomic sequencing of SARS-CoV-2 isolated from patients diagnosed with COVID-19 following tixagevimab-cilgavimab. Resistance-associated substitutions were used to generate a predicted phenotypic susceptibility analysis to tixagevimab-cilgavimab and bebtelovimab. Clinical data collected from these patients included SARS-CoV-2 immunization status, COVID-19-directed therapies, and outcomes. RESULTS: SARS-CoV-2 genome sequencing was performed in 25 patients. SARS-CoV-2 Omicron BA.2 was the most common identified subvariant. All patients had viral isolates with spike codon substitutions associated with reduced susceptibility to tixagevimab-cilgavimab; their predicted phenotypic analysis showed a >2-fold reduced susceptibility to tixagevimab-cilgavimab. Two patients had viral isolates with spike codon substitutions (K444N and G446D) associated with highly reduced susceptibility to bebtelovimab, although all the viral isolates had <2-fold reduced susceptibility based on predicted phenotypic analysis. Sixteen patients received rescue therapy with bebtelovimab, but one patient with BA.2 subvariant harboring K444N mutation died of COVID-19-related complications. Five patients received other COVID-19 therapies and survived. Four had mild or asymptomatic COVID-19 with an uncomplicated course despite not receiving any additional therapy. DISCUSSION: Multiple SARS-CoV-2 Omicron spike codon substitutions that correlated with reduced susceptibility to tixagevimab-cilgavimab were identified in patients with COVID-19 after receiving this monoclonal antibody. Most patients had an uncomplicated course. The identification of spike codon substitutions conferring resistance to bebtelovimab highlights the importance of performing genomic surveillance to identify new resistant SARS-CoV-2 variants.

Characterization of Early-Onset Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Immunocompromised Patients Who Received Tixagevimab-Cilgavimab Prophylaxis.

Tixagevimab-cilgavimab is authorized for preexposure prophylaxis against coronavirus disease 2019 (COVID-19) in immunocompromised hosts. Herein, we report the clinical characteristics of 8 patients who developed COVID-19 soon after receiving tixagevimab-cilgavimab. This study emphasizes the need to maintain additional measures to prevent COVID-19 during periods of high severe acute respiratory syndrome coronavirus 2 transmission.

Characterization of early-onset SARS-CoV-2 infection in immunocompromised patients who received tixagevimab-cilgavimab prophylaxis

Tixagevimab-cilgavimab is authorized for pre-exposure prophylaxis against coronavirus disease 2019 (COVID-19) in immunocompromised hosts. Herein, we report the clinical characteristics of eight patients who developed COVID-19 soon after receiving tixagevimab-cilgavimab. This study emphasizes the need to maintain additional measures to prevent COVID-19 during periods of high SARS-CoV-2 transmission.