COVID-19 antibody titers after tixagevimab-cilgavimab injection in patients with hematologic diseases; a single-center, prospective study

Knowledge of the SARS-CoV-2 antibody titers induced by tixagevimab-cilgavimab in patients with hematologic diseases remains insufficient. Here, we performed a single-center, prospective study to reveal the changes in antibody titer after administration of tixagevimab-cilgavimab in 78 patients with hematologic diseases. The median peak titer was 155.4 U/mL, and the median AUC was 46556 days·U/mL. First, we compared several characteristics between patients with low titers (peak titer ≤ 155.4 U/mL) and high titers (peak titer > 155.4 U/mL). We extracted 6 factors (patient age, sex, ECOG-PS, serum albumin level, and cross-sectional area and computed tomographic number of the psoas major muscle) as candidates influencing the antibody titers. Multiple regression analysis revealed that antibody titer was closely associated with these 6 factors (contribution rate = 0.76, p = 0.02). Our data support the inability of tixagevimab-cilgavimab to induce sufficient antibody titers against SARS-CoV-2, especially in older, frailer, female patients.

Allogeneic stem cell transplantation achieves long-term remissions in mantle cell lymphoma, including in TP53-mutated disease

Cytarabine-containing chemoimmunotherapy followed by autologous transplantation and rituximab maintenance achieves durable remissions for most patients with mantle cell lymphoma (MCL). However, patients with TP53-mutated disease have poor outcomes with standard approaches. We previously reported that allogeneic stem cell transplantation (alloSCT) achieved durable remissions in MCL, however follow-up among patients with TP53-mutated disease was limited. Here we report extended follow-up of the overall cohort (n = 36) and TP53-mutated subset (n = 13) (median follow-up 10.8 and 4.2 years, respectively). Estimated overall survival was 56% at 10 years for the overall cohort and 59% at 4 years for the TP53-mutated subset. Among patients with TP53-mutated disease, no relapses occurred beyond 6 months post-transplant. Survival after post-alloSCT disease relapse was poor (median 2.1 years). These data confirm that alloSCT can be curative in MCL, including patients with TP53-mutated disease, and should be considered for earlier utilization in this subgroup for whom conventional chemoimmunotherapy is ineffective.