Tixagevimab and Cilgavimab Administration for Hemodialysis Patients at Community-Based Dialysis Centers in Singapore as Pre-Exposure Prophylaxis for SARS-CoV-2 Infection.

INTRODUCTION

Hemodialysis patients are deemed to be immunosuppressed and may not be able to mount an adequate response to vaccination against the SARS-CoV-2 virus. Due to the higher morbidity and mortality in this vulnerable group, pre-exposure prophylaxis with monoclonal antibodies was introduced as an additional measure for protection in selected community-based hemodialysis patients in Singapore. Tixagevimab and cilgavimab, available as Evusheld, were used for this purpose.

METHODS

A government-sponsored clinical administration program with the provision of 200 doses of Evusheld at no cost to the patients was implemented. Patient selection criteria to further risk-stratify this vulnerable hemodialysis patient cohort was developed and 200 patients were finally selected. Evusheld administration was done over a period of two months, as two consecutive injections were given at two separate intramuscular sites, which constituted one administration. Data were collected as part of a retrospective clinical audit, as part of a routine quality monitoring process for this patient care program. Real-world evidence was generated to assess the impact on mortality, hospitalization rate, reason for hospitalization, and any associated morbidity.

RESULTS

No adverse events from the Evusheld administration were noted. All recipients had received COVID-19 vaccinations prior to Tixa-Cilga, with a range of one to five doses. A total of 198 (99%) completed two doses and 189 (95%) completed three doses, out of which, 14 (7%) patients contracted COVID-19 infection over three months. The overall hospitalization rate was 2% (four out of 200 patients). Severe illness that required intensive care unit stay was therefore seen in only 2 (1%) out of 200 patients. None of the infected patients died.

DISCUSSION

A significant reduction in severity of illness, hospitalization rate, and mortality was found with pre-exposure prophylaxis with tixagevimab and cilgavimab, in this real-world experience from Singapore. Evusheld administration reduced the hospitalization rate from 42.5% to 2%, which is a reduction of 95.3% (p<0.0001). Symptoms in infected patients were mild, with only 1% being admitted to the intensive care unit. The mortality rate from COVID-19 infection was reduced from 2.5% to 0% with Evusheld.  Conclusion: Mass administration of prophylactic treatments for vulnerable populations can be challenging in community-based settings and the successful implementation of such a program has been described. The findings can have health policy implications for the protection of such immunocompromised patients in the future. The combination of tixagevimab and cilgavimab, available as Evusheld in Singapore, was safe to use in hemodialysis patients, with no adverse events noted. There was a significant reduction in hospitalization rates and intensive care unit admissions with a zero-mortality rate due to COVID-19 infection, after pre-exposure prophylaxis.