AL/MDS, acute leukemia/myelodysplastic syndrome; allo-HSCT, allogeneic hematopoietic stem cell transplantation; ASCT, autologous stem cell transplantation; BTKI, Bruton’s tyrosine kinase inhibitor; CLL, chronic lymphocytic leukemia; HD, Hodgkin disease; mAb, monoclonal antibody; MM, multiple myeloma; MPN, chronic myeloproliferative neoplasm; NT, not tested; TKI, tyrosine kinase inhibitor.

Data are odds ratio (95% confidence interval).

We included 48 patients with CLL. Seventeen (35%) were assigned to the watch-and-wait approach, whereas 5 (10%) were >1 year after allo-HSCT, and 9 (19%) were in complete remission for >1 y before vaccination without active therapy. The remaining 17 patients with CLL were on treatment at the time of vaccination. Four of them received BTKI (n = 2) or venetoclax (n = 2), both in combination with anti-CD20 therapy, whereas 13 patients were on BTKI only. Thus, only 13 of 48 patients with CLL (27%) received rituxan prior to vaccination, and 9 of them received it >1 year before vaccination. This highly heterogenous population of patients with CLL may have precluded our ability to identify poor responders.

We included 90 patients with B-cell NHL, of whom 69 (77%) received anti-CD20 therapy prior to vaccination (including 11 vaccinated after ASCT) and 21 (23%) were vaccinated after allogeneic stem cell transplantation. Thus, a high collinearity (100%) was observed between B-cell NHL not allografted and prior anti-CD20 therapy. In multivariate analyses, if we include rituxan along with the baseline disease, the only significant variable associated with a lower response rate was B-cell NHL. In contrast, after removing baseline disease and including prior anti-CD20 therapy, we observed a significant association with lower response rate. The rest of the significant variables remained unchanged.