# Successful 30-Day Nirmatrelvir/Ritonavir Treatment of a Patient Who Developed Multi-relapsed COVID-19 After Receiving R-CHOP Against Follicular Lymphoma

## TL;DR

A 58-year-old man with a history of follicular lymphoma experienced multiple relapses of COVID-19, but a 30-day treatment with nirmatrelvir/ritonavir successfully cleared the virus.

## Contribution

This case demonstrates the effectiveness of extended nirmatrelvir/ritonavir treatment in managing prolonged SARS-CoV-2 infection in immunocompromised patients.

## Key findings

- A 30-day nirmatrelvir/ritonavir course resolved symptoms and achieved sustained RT-qPCR negativity.
- Genome analysis confirmed the Omicron BA.5 sublineage BF.13 in cultured and swab samples.
- The patient maintained high neutralizing antibody levels against BA.5 throughout the infection.

## Abstract

A 58-year-old male developed three coronavirus disease 2019 (COVID-19) relapses within three months after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemoimmunotherapy against relapsed follicular lymphoma. Five- and 10-day remdesivir courses failed to achieve viral clearance. A 30-day nirmatrelvir/ritonavir course provided symptom resolution and sustained reverse transcription and quantitative polymerase chain reaction (RT-qPCR) negativity. Genome analyses identified cultured live virus (day 59) and nasopharyngeal-swab viral RNA (days 74, 82, 95) as Omicron BA.5 sublineage BF.13. Normal immunoglobulin (Ig)G levels and high neutralizing activities against BA.5 were maintained throughout the infection's course. Extended nirmatrelvir/ritonavir antiviral treatment may be effective for patients administered anti-CD20 therapy who develop prolonged/relapsed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection despite possessing high neutralizing activities.