Immune biomarkers to predict SARS-CoV-2 vaccine effectiveness in patients with hematological malignancies

There is evidence of reduced SARS-CoV-2 vaccine effectiveness in patients with hematological malignancies. We hypothesized that tumor and treatment-related immunosuppression can be depicted in peripheral blood, and that immune profiling prior to vaccination can help predict immunogenicity. We performed a comprehensive immunological characterization of 83 hematological patients before vaccination and measured IgM, IgG, and IgA antibody response to four viral antigens at day +7 after second-dose COVID-19 vaccination using multidimensional and computational flow cytometry. Health care practitioners of similar age were the control group (n = 102). Forty-four out of 59 immune cell types were significantly altered in patients; those with monoclonal gammopathies showed greater immunosuppression than patients with B-cell disorders and Hodgkin lymphoma. Immune dysregulation emerged before treatment, peaked while on-therapy, and did not return to normalcy after stopping treatment. We identified an immunotype that was significantly associated with poor antibody response and uncovered that the frequency of neutrophils, classical monocytes, CD4, and CD8 effector memory CD127low T cells, as well as naive CD21+ and IgM+D+ memory B cells, were independently associated with immunogenicity. Thus, we provide novel immune biomarkers to predict COVID-19 vaccine effectiveness in hematological patients, which are complementary to treatment-related factors and may help tailoring possible vaccine boosters

Safety and efficacy of tafasitamab ± lenalidomide added to first-line R‑CHOP for DLBCL: Phase 1b First-MIND study.

Anti-CD19 immunotherapy tafasitamab in combination with lenalidomide is used in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) ineligible for autologous stem cell transplant. Open-label, phase 1b, First-MIND study assessed safety and preliminary efficacy of tafasitamab + R-CHOP ± lenalidomide as first-line therapy in patients with DLBCL. Adults with newly-diagnosed, untreated DLBCL (ECOG PS 0-2, IPI 2-5), were randomly assigned to R-CHOP+tafasitamab (Arm T) or R-CHOP+tafasitamab+lenalidomide (Arm T/L) for six cycles. Primary endpoint was safety; secondary endpoints included overall response rate (ORR) and complete response (CR) rate at end of treatment (EoT). From Dec2019-Aug2020, 83 patients were screened, 66 treated (n=33 per arm). All patients had ≥1 treatment-emergent adverse event, mostly grade 1/2. Grade ≥3 neutropenia and thrombocytopenia occurred in 57.6% and 12.1% of patients (Arm T), and 84.8% and 36.4% (Arm T/L). Non-hematologic toxicities occurred at similar rates between arms. Mean relative dose intensity of R-CHOP was 89% or higher in both arms. ORR at EoT was 75.8% (CR 72.7%) in Arm T and 81.8% (CR 66.7%) in Arm T/L; best ORR across visits was 90.0% and 93.9%. Eighteen-month duration of response and duration of CR rates were 72.7% and 74.5% (Arm T), and 78.7% and 86.5% (Arm T/L); 24-month progression-free survival and overall survival rates were 72.7% and 90.3% (Arm T), and 76.8% and 93.8% (Arm T/L). Manageable safety and promising signals of efficacy were observed in both arms. Potential benefit of adding tafasitamab+lenalidomide to R-CHOP is being investigated in phase 3 frontMIND (NCT04824092)

High prognostic value of measurable residual disease detection by flow cytometry in chronic lymphocytic leukemia patients treated with front-line fludarabine, cyclophosphamide, and rituximab, followed by three years of rituximab maintenance.

It has been postulated that monitoring measurable residual disease (MRD) could be used as a surrogate marker of progression-free survival (PFS) in chronic lymphocytic leukemia (CLL) patients after treatment with immunochemotherapy regimens. In this study, we analyzed the outcome of 84 patients at 3 years of follow-up after first-line treatment with fludarabine, cyclophosphamide and rituximab (FCR) induction followed by 36 months of rituximab maintenance thearpy. MRD was assessed by a quantitative four-color flow cytometry panel with a sensitivity level of 10-4 Eighty out of 84 evaluable patients (95.2%) achieved at least a partial response or better at the end of induction. After clinical evaluation, 74 patients went into rituximab maintenance and the primary endpoint was assessed in the final analysis at 3 years of follow-up. Bone marrow (BM) MRD analysis was performed after the last planned induction course and every 6 months in cases with detectable residual disease during the 36 months of maintenance therapy. Thirty-seven patients (44%) did not have detectable residual disease in the BM prior to maintenance therapy. Interestingly, 29 patients with detectable residual disease in the BM after induction no longer had detectable disease in the BM following maintenance therapy. After a median followup of 6.30 years, the median overall survival (OS) and PFS had not been reached in patients with either undetectable or detectable residual disease in the BM, who had achieved a complete response at the time of starting maintenance therapy. Interestingly, univariate analysis showed that after rituximab maintenance OS was not affected by IGHV status (mutated vs unmutated OS: 85.7% alive at 7.2 years vs 79.6% alive at 7.3 years, respectively). As per protocol, 15 patients (17.8%), who achieved a complete response and undetectable peripheral blood and BM residual disease after four courses of induction, were allowed to stop fludarabine and cyclophosphamide and complete two additional courses of rituximab and continue with maintenance therapy for 18 cycles. Surprisingly, the outcome in this population was similar to that observed in patients who received the full six cycles of the induction regimen. These data show that, compared to historic controls, patients treated with FCR followed by rituximab maintenance have high-quality responses with fewer relapses and improved OS. The tolerability of this regime is favorable. Furthermore, attaining an early undetectable residual disease status could shorten the duration of chemoimmunotherapy, reducing toxicities and preventing long-term side effects. The analysis of BM MRD after fludarabine-based induction could be a powerful predictor of post-maintenance outcomes in patients with CLL undergoing rituximab maintenance and could be a valuable tool to identify patients at high risk of relapse, influencing further treatment strategies. This trial is registered with EudraCT n. 2007-002733-36 and ClinicalTrials.gov Identifier: NCT00545714