Loncastuximab tesirine in relapsed/refractory diffuse large B-cell lymphoma: long-term efficacy and safety from the phase II LOTIS-2 study

Outcomes with loncastuximab tesirine following CAR T-cell therapy in patients with relapsed or refractory diffuse large B-cell lymphoma

The efficacy of loncastuximab tesirine (lonca) following chimeric antigen receptor T-cell therapy (CAR-T) progression/failure is unknown. Hence, we sought to examine real-world use and outcomes of lonca following CAR-T in patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in the USA. In this retrospective study, we included adults (age ≥ 18 years) with R/R DLBCL who received lonca monotherapy as third- (3 L) or fourth line (4 L) treatment after progressing on second line (2 L) or 3 L CAR-T, respectively. Post-CAR-T lonca outcomes included response rates (overall response rate [ORR] and complete response [CR] rate), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). A total of 118 patients were included in the analysis with 95 receiving lonca following 2 L CAR-T (median age:66 years; 61% male) and 23 following 3 L CAR-T (median age:57 years; 43% male). Patients with 2 L CAR-T/3 L lonca had an ORR of 73% (CR rate of 34%). With a median follow-up of 8.5 months following lonca initiation, median DOR, PFS, and OS were not reached. The DOR, PFS, and OS at 12 months were 68%, 77%, and 84%, respectively. Patients with 3 L CAR-T/4 L lonca had an ORR of 78% (CR rate of 17%). With a median follow-up of 13 months following lonca initiation, the median DOR and PFS were 7.6 and 12.0 months, while median OS was not reached. OS at 12 months was 95%. In this study, we found that lonca monotherapy was an effective treatment option in R/R DLBCL in 3 L and 4 L settings including those who were resistant to or progressed after CAR-T.

Targeting CD19-positive lymphomas with the antibodydrug conjugate loncastuximab tesirine: preclinical evidence of activity as a single agent and in combination therapy

Antibody-drug conjugates (ADC) represent one of the most successful therapeutic approaches introduced into clinical practice in the last few years. Loncastuximab tesirine (ADCT-402) is a CD19-targeting ADC in which the antibody is conjugated through a protease cleavable dipeptide linker to a pyrrolobenzodiazepine dimer warhead (SG3199). Based on the results of a phase II study, loncastuximab tesirine was recently approved for adult patients with relapsed/refractory large B-cell lymphoma. We assessed the activity of loncastuximab tesirine using in vitro and in vivo models of lymphomas, correlated its activity with levels of CD19 expression, and identified combination partners providing synergy with the ADC. Loncastuximab tesirine was tested across 60 lymphoma cell lines. It had strong cytotoxic activity in B-cell lymphoma cell lines. The in vitro activity was correlated with the level of CD19 expression and intrinsic sensitivity of cell lines to the ADC's warhead. Loncastuximab tesirine was more potent than other anti-CD19 ADC (coltuximab ravtansine, huB4-DGN462), although the pattern of activity across cell lines was correlated. The activity of loncastuximab tesirine was also largely correlated with cell line sensitivity to R-CHOP. Combinatorial in vitro and in vivo experiments identified the benefit of adding loncastuximab tesirine to other agents, especially BCL2 and PI3K inhibitors. Our data support the further development of loncastuximab tesirine for use as a single agent and in combination for patients affected by mature B-cell neoplasms. The results also highlight the importance of CD19 expression and the existence of lymphoma populations characterized by resistance to multiple therapies.

B-cell non-Hodgkin lymphomas

B-cell lymphomas occur with an incidence of 20 new cases per 100 000 people per year in high-income countries. They can affect any organ and are characterised by heterogeneous clinical presentations and courses, varying from asymptomatic, to indolent, to very aggressive cases. Since the topic of B-cell non-Hodgkin lymphomas was last reviewed in The Lancet in 2017, a deeper understanding of the biological background of this heterogeneous group of malignancies, the availability of new diagnostic methods, and the development and implementation of new targeted and immunotherapeutic approaches have improved our ability to treat patients. This Seminar provides an overview of the pathobiology, classification, and prognostication of B-cell non-Hodgkin lymphomas and summarises the current knowledge and standard of care regarding biology and clinical management of the most common subtypes of mature B-cell non-Hodgkin lymphomas. It also highlights new findings in deciphering the molecular background of disease development and the implementation of new therapeutic approaches, particularly those targeting the immune system.

Curative intent therapy for DLBCL in the elderly

Older patients with aggressive lymphoma are extremely heterogeneous due to the high frequency of functional limitations and comorbidities and to the different biological profiles and clinical behavior of the disease. The stratification in three geriatric categories (fit-unfit-frail) based on multidimensional geriatric assessment (GA) helps physicians tailor a potentially curative treatment.While an intensive approach with the standard R-CHOP regimen is feasible in fit patients, leading to similar long-term response and survival rates compared to younger ones, in unfit patients a balance between treatment toxicity and curative intent can be obtained through the reduction of dose intensity. Frail patients, treated with best supportive care so far, could benefit from a chemo-free approach with new target drugs. These novel agents, either alone or in combination with chemo-immunotherapy, are changing the therapeutic landscape of older patients with aggressive lymphoma, both in first-line therapy and in the setting of the relapsed/refractory disease.

More than a lonca-shot: beating the odds in relapsed/ refractory diffuse large B-cell lymphoma

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A review of the clinical efficacy of FDA-approved antibody‒drug conjugates in human cancers

While strategies such as chemotherapy and immunotherapy have become the first-line standard therapies for patients with advanced or metastatic cancer, acquired resistance is still inevitable in most cases. The introduction of antibody‒drug conjugates (ADCs) provides a novel alternative. ADCs are a new class of anticancer drugs comprising the coupling of antitumor mAbs with cytotoxic drugs. Compared with chemotherapeutic drugs, ADCs have the advantages of good tolerance, accurate target recognition, and small effects on noncancerous cells. ADCs occupy an increasingly important position in the therapeutic field. Currently, there are 13 Food and Drug Administration (FDA)‒approved ADCs and more than 100 ADC drugs at different stages of clinical trials. This review briefly describes the efficacy and safety of FDA-approved ADCs, and discusses the related problems and challenges to provide a reference for clinical work.

Mosunetuzumab with polatuzumab vedotin in relapsed or refractory aggressive large B cell lymphoma: a phase 1b/2 trial

Relapsed/refractory aggressive large B cell lymphoma (LBCL) remains an area of unmet need. Here we report the primary analysis of a phase 1b/2 trial of outpatient mosunetuzumab (a CD20xCD3 T-cell-engaging bispecific antibody) plus polatuzumab vedotin (an anti-CD79B antibody-drug conjugate) in relapsed/refractory LBCL. The phase 2 component is a single arm of an ongoing multi-arm trial. The primary endpoint during dose expansion was independent review committee (IRC)-assessed best overall response rate. Secondary endpoints included investigator-assessed overall response rate, complete response, duration of response, progression-free survival and overall survival. At data cutoff, 120 patients were enrolled (22 dose escalation, 98 dose expansion). The primary endpoint was met during dose expansion, with IRC-assessed best overall response rate and complete response rates of 59.2% (58/98; 95% confidence interval (CI): 48.8-69.0) and 45.9% (45/98; 95% CI: 35.8-56.3), respectively (median follow-up, 23.9 months). Median duration of complete was not reached (95% CI: 20.5-not estimable (NE)). Median progression-free survival was 11.4 months (95% CI: 6.2-18.7). Median overall survival was 23.3 months (95% CI: 14.8-NE). Across dose escalation and expansion, the most common grade 3 or higher adverse events were neutropenia (25.0%, 30/120) and fatigue (6.7%, 8/120). Any-grade cytokine release syndrome occurred in 16.7% of patients. These data demonstrate that mosunetuzumab plus polatuzumab vedotin has a favorable safety profile with highly durable responses suitable as second-line therapy in transplant-ineligible relapsed/refractory LBCL. ClinicalTrials.gov identifier: NCT03671018 .