OBJECTIVES: In 2021, the French Health Authority recommended new guidelines for use of Early Access Programs (EAPs) linked with the French national claims database (SNDS, for ‘Système National des données de santé’), which covers 99% of the French population. Few studies have been conducted so far. Here, we describe challenges and opportunities of this innovative approach, using the EAP for AZD7442, a combination of 2 neutralizing antibodies authorized in 2021 for the prevention of COVID-19 in immunocompromised individuals.

METHODS: Two databases will be linked:

• The EAP database which includes the identification of patients who were treated with AZD7442 and the description of patients.
• The SNDS claims database to be used to identify outcomes of interest (e.g., overall deaths and hospitalizations and due to COVID-19 infection)

RESULTS: Out of the 27,782 patients enrolled in the EAP, treatment administration forms were completed for 13,387 (47.8%).

AZD7442 was mostly prescribed by onco-hematologists (24.2%), followed by nephrologists (19.9%), internal medicine specialists (15.6%), and rheumatologists (6.5%). The majority (96.7%) had received at least three vaccine doses at inclusion. Most common comorbidities were cancer (34.9%), chronic kidney disease (23.7%), hypertension (23.2%), cardiovascular disease (19.4% >2 CV factors), and diabetes (9.2%).

A matched control cohort will be extracted from SNDS. The matching will be based on 2 variables:

• A Propensity based on calendar time, immune category, and confounding clinical characteristics.
• Comorbidities for which AZD7442 was prescribed.

CONCLUSIONS: The study will assess the effectiveness of AZD7442 using an innovative, large observational comparative study combining EAP data and SNDS. The reuse and enrichment of the EAP database linked to SNDS will provide valuable insights for future recommendations on COVID-19 prophylaxis in immunocompromised patients and this method could set the path for new RWE effectiveness studies.