Anti-CD20 maintenance strategies to face the challenge of COVID-19 pandemic in follicular lymphoma: results from the R-FolSTOP multicentre Italian study

The SARS-CoV2 pandemic has posed unprecedented challenges between temporary or permanent discontinuation of immunosuppressive treatment to protect patients, or disease control prioritization by not interrupting treatment. Maintenance treatment with anti-CD20 monoclonal antibodies (MoAbs) improves progression-free survival (PFS) in follicular lymphoma (FL), but also impairs anti-SARS-CoV2 immune response. This challenge has been addressed in Italy by temporary, definitive or no discontinuation of anti-CD20 treatment. We report the outcome of 539 FL patients receiving anti-CD20 MoAbs (rituximab in 431, obinutuzumab in 108), which were temporarily discontinued in 150 patients (group A), definitively discontinued in 166 (group B), or uninterrupted in 223 (group C). In the overall cohort, the 3-year progression-free survival (3y PFS) and 3-year overall survival (3y OS) rates were 80% and 88%. PFS and OS were significantly better in group A compared to group B and C (p = 0.01). Induction chemoimmunotherapy significantly influenced OS: the 3y OS was 91% vs 85% in CHOP vs bendamustine treated patients (p = 0.04), while the 3y OS was 90% vs 77% in rituximab vs obinutuzumab treated patients (p = 0.002). SARS-Cov2 infection was the main cause of death (67% of cases). Vaccination with multiple doses demonstrated to be clinically helpful, with impact on OS.