In a French retrospective study, researchers studied and compared outcomes between 333 kidney transplant recipients who received intramuscular tixagevimab-cilgavimab injections (150 mg each) for prophylaxis and 97 who did not because a contraindication or patient refused to take medicine. All the study participants had no COVID vaccine response or a weak response. The study was conducted when Omicron variants BA.1 and BA.2 were predominant. 

Following the drug administration, symptomatic COVID 19 developed in a significantly small proportion of the group compared to those who did not receive the test medication. The treatment group also lowered overall hospitalization and intensive care hospitalization rates.

There was one death due to respiratory distress syndrome in the prophylactic treatment group while 2 in the non-treatment group. 

The investigators have suggested that 

• 150 mg tixagevimab/150 mg cilgavimab may not offer full protection.
• Hence, the USFDA has recommended increasing the dose to 300 mg each with repeat dosing every six months. 

Reference:

1. Kaminski H, Gigan M, Vermorel A, et al. COVID-19 morbidity decreases with tixagevimab/cilgavimab preexposure prophylaxis in kidney transplant recipients non/low vaccine responders. Kidney Int. July 20, 2022. DOI: 10.1016/j.kint.2022.07.008  
2. FDA authorizes revisions to Evusheld dosing. US Food and Drug Administration: Updated June 29, 2022. Accessed at https://www.fda.gov/drugs/drug-safety-and-availability/fda-authorizes-revisions-evusheld-dosing