# Key Indications for Passive Immune Prophylaxis Against SARS-CoV-2 Infection in Malignant Hematological Disorders: An Analytic Hierarchy Process by an Ad Hoc Italian Expert Panel

## TL;DR

This study identifies key situations where passive immune protection against SARS-CoV-2 should be used in patients with blood cancers.

## Contribution

The study provides a structured framework for prioritizing passive immune prophylaxis in hematological malignancies using expert consensus.

## Key findings

- HM-related mortality had the highest priority score for PrEP use.
- PrEP is recommended for patients undergoing allogeneic transplants or CAR-T therapy.
- High-risk patients should receive variant-specific PrEP during viral waves.

## Abstract

Background: Pre-exposure passive immune prophylaxis (PrEP) might contribute to improve hematologic malignancy (HM) outcomes; however, there are currently no specific guidelines to inform patient selection. Methods: A literature review and a Delphi consensus process were used to identify COVID-19 risk factors, critical COVID-19 outcomes, and efficacy of PrEP against SARS-CoV-2 in HMs. An analytic hierarchy process was used to assign a priority score to candidate outcomes and to determine the PrEP indications. For these decisions, the experts assumed adequate compliance with anti-COVID-19 vaccination and acknowledged the effectiveness of PrEP in reducing SARS-CoV-2-related mortality and hospital admissions. Results: Based on the literature review, the expert panel identified 80 risk categories among patients with HM and prioritized eight clinical outcomes related to SARS-CoV-2 PrEP. The highest mean priority scores were observed for HM-related mortality (7.0), intensive care unit admission (6.7), and delays in anti-HM treatment (6.6). Based on such a framework, the experts deemed that if there was a variant-specific PrEP promptly available, it would be considered mandatory for all candidates receiving allogeneic hematopoietic cell transplantation, CAR-T therapy, or bispecific antibodies, regardless of local viral epidemiology. During epidemiological waves, variant-specific PrEP would also be recommended for patients with HMs at high risk of unfavorable COVID-19 clinical outcomes. Conclusions: This study identified PrEP indications for patients with HM receiving appropriate active immunization against COVID-19.