Patients with large B-cell lymphoma (LBCL) who experience relapsed disease after CD19-directed chimeric antigen receptor (CAR) T-cell (CAR-T) therapy have a poor prognosis. Bispecific antibodies (BsAbs) induce complete remissions in ∼35% of these cases. Hypothesizing overlapping LBCL-intrinsic resistance mechanisms as well as common poor prognosis predictors to CAR-T and BsAb therapy, we conducted a multicenter retrospective analysis including 92 patients with relapsed/refractory (R/R) LBCL treated with BsAbs after CAR-T failure. Overall response rate (ORR) was 43%, with a progression-free survival (PFS) of 2.8 months. Patients receiving BsAbs during early relapse (≤3 months) achieved a significantly worse outcome (ORR, 29%; PFS, 2.2 months) compared with patients with an intermediate (4-6 months; ORR, 54%; PFS, 3.7 months) or a late relapse (>6 months; ORR, 60%; PFS, 10.5 months). The benefit of later relapse was particularly notable in patients receiving BsAbs as first salvage therapy compared with those receiving a BsAb in subsequent lines (PFS not reached vs 2.7 months; overall survival not reached vs 9.1 months, respectively). In addition to early R/R state before BsAbs, elevated lactate dehydrogenase and higher International Prognostic Index score were significant predictors of poor outcomes to BsAb in multivariate Cox regression analyses. The finding that patients with early relapse after CAR-T respond particularly poorly to BsAb highlights the necessity for alternative treatment options in this high-risk patient cohort.

Glofitamab, a bispecific antibody targeting CD20 and CD3, is approved for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL) after at least 2 prior treatment lines, but real-world data are scarce. In this retrospective, multicenter, multinational study, we evaluated the outcomes of 70 patients with r/r DLBCL treated with glofitamab as part of the compassionate use patient program in Germany, Austria, and Switzerland. The median number of prior treatment lines was 4, with 71% of patients refractory to their last treatment. Cytokine release syndrome was observed in 40% of patients (grade 3-4 in 2%), immune effector cell–associated neurotoxicity syndrome in 10% (grade 3 in 1%), and infections in 31% (grade 5 in 3%). The overall response rate was 46%, with 27% achieving complete responses (CR) and 19% partial responses. The median progression-free survival (PFS) was 3.6 months, whereas the median overall survival was 5.7 months. Notably, 13 patients (19%) were in CR 6 months after initiating glofitamab and exhibited durable responses. Elevated lactate dehydrogenase is the most robust predictor of inferior outcome. Patients pretreated with bendamustine within 6 months prior to glofitamab initiation exhibited significantly reduced PFS, suggesting that bendamustine may impair T-cell fitness and hence glofitamab efficacy. In summary, glofitamab demonstrates promising efficacy and a manageable safety profile in heavily pretreated patients with r/r DLBCL in a real-world scenario and the optimal sequence of treatments should use T-cell–depleting agents before glofitamab with caution.

Patients with hematologic malignancies are at high risk of exacerbated condition and higher mortality from coronavirus disease 2019 (COVID-19). Bamlanivimab, casirivimab/imdevimab combination, and sotrovimab are monoclonal antibodies (mABs) that can reduce the risk of COVID-19-related hospitalization. Clinical effectiveness of bamlanivimab and casirivimab/imdevimab combination has been shown for the Delta variant (B.1.617.2), but the effectiveness of the latter treatment against the Omicron variant (B.1.1.529) has been suggested to be reduced. However, the tolerability and clinical usage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific mABs in patients with hematologic malignancies are less specified. We present a retrospective case series analysis of all SARS-CoV-2-infected patients with hematologic malignancies who received SARS-CoV-2-specific mABs at our facility between February and mid-December 2021. A total of 13 COVID-19 patients (pts) with at least one malignant hematologic diagnosis received SARS-CoV-2-specific mABs at our facility, with 3 pts receiving bamlanivimab and 10 pts receiving casirivimab/imdevimab combination. We observed SARS-CoV-2 clearance in five cases. Furthermore, we observed a reduction in the necessity for oxygen supplementation in five cases where the application was administered off-label. To the best of our knowledge, we present the largest collection of anecdotal cases of SARS-CoV-2-specific monoclonal antibody use in patients with hematological malignancies. Potential benefit of mABs may be reduced duration and/or clearance of persistent SARS-CoV-2 infection.

Radiotherapy (RT) is an established treatment modality in the management of patients with multiple myeloma (MM), aiming at analgesia and stabilization of osteolytic lesions. As a multifocal disease, the combined use of RT, systemic chemotherapy, and targeted therapy (ST) is pivotal to achieve better disease control. However, adding RT to ST may lead to increased toxicity. The aim of this study was to evaluate the tolerability of ST given concurrently with RT. Overall, 82 patients treated at our hematological center with a median follow-up of 60 months from initial diagnosis and 46.5 months from the start of RT were evaluated retrospectively. Toxicities were recorded from 30 days before RT up to 90 days after RT. 54 patients (65.9%) developed at least one non-hematological toxicity, with 50 patients (61.0%) showing low-grade (grade I or II) and 14 patients (17.1%) revealing high-grade (grade III and IV) toxicities. Hematological toxicities were documented in 50 patients (61.0%) before RT, 60 patients (73.2%) during RT, and 67 patients (81.7%) following RT. After RT, patients who had received ST during RT showed a significant increase in high-grade hematological toxicities (p = 0.018). In summary, RT can be safely implemented into modern treatment regimens for MM, but stringent monitoring of potential toxicities even after completion of RT has to be ensured.

Background: Two-dose COVID-19 vaccination often results in poor humoral response rates in patients with hematologic malignancies (HMs); yet responses to COVID-19 booster vaccines and the risk of COVID-19 infection post-booster are mostly uncertain. Methods: We included 200 outpatients with HMs and predominantly lymphoid neoplasms (96%, 191/200) in our academic center and reported on the humoral responses, which were assessed by measurement of anti-spike IgG antibodies in peripheral blood as early as 14 days after mRNA-based prime-boost vaccination, as well as factors hampering booster efficacy. Previous basic (double) immunization was applied according to the local recommendations with mRNA- and/or vector-based vaccines. We also report on post-booster COVID-19 breakthrough infections that emerged in the Omicron era and the prophylaxis strategies that were applied to poor and non-responders to booster vaccines. Results: A total of 55% (110/200) of the patients achieved seroconversion (i.e., anti-spike protein IgG antibody titer > 100 AU/mL assessed in median 48 days after prime-boost vaccination) after prime-boost vaccination. Multivariable analyses revealed age, lymphocytopenia, ongoing treatment and prior anti-CD20 B-cell depletion to be independent predictors for booster failure. With each month between anti-CD20-mediated B-cell depletion and booster vaccination, the probability of seroconversion increased by approximately 4% (p < 0.001) and serum–antibody titer (S-AbT) levels increased by 90 AU/mL (p = 0.011). Notably, obinutuzumab treatment was associated with an 85% lower probability for seroconversion after prime-boost vaccination compared to rituximab (p = 0.002). Of poor or non-responders to prime-boost vaccination, 41% (47/114) underwent a second booster and 73% (83/114) underwent passive immunization. COVID-19 breakthrough infections were observed in 15% (29/200) of patients after prime-boost vaccination with predominantly mild courses (93%). Next to seroconversion, passive immunization was associated with a significantly lower risk of COVID-19 breakthrough infections after booster, even in vaccine non-responders (all p < 0.05). In a small proportion of analyzed patients with myeloid neoplasms (9/200), the seroconversion rate was higher compared to those with lymphoid ones (78% vs. 54%, accordingly), while the incidence rate of COVID-19 breakthrough infections was similar (22% vs. 14%, respectively). Following the low frequency of myeloid neoplasms in this study, the results may not be automatically applied to a larger cohort. Conclusions: Patients with HMs are at a high risk of COVID-19 booster vaccine failure; yet COVID-19 breakthrough infections after prime-boost vaccination are predominantly mild. Booster failure can likely be overcome by passive immunization, thereby providing immune protection against COVID-19 and attenuating the severity of COVID-19 courses. Further sophistication of clinical algorithms for preventing post-vaccination COVID-19 breakthrough infections is urgently needed.