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

Loncastuximab Tesirine Versus Polatuzumab Vedotin Plus Bendamustine and Rituximab in Relapsed/Refractory DLBCL After ≥ 2 Lines of Therapy: Matching-Adjusted Indirect Comparison

INTRODUCTION

Despite recent approvals of new treatments, relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) remains challenging to treat, with limited durable responses and a high proportion of patients relapsing after two or more lines of therapy. Loncastuximab tesirine (Lonca) is a highly potent CD19-targeted antibody drug conjugate with convenient dosing for patients with third-line R/R DLBCL.

METHODS

In the absence of head-to-head trials, unanchored matching-adjusted indirect comparisons (MAICs) were conducted to compare the relative efficacy and safety of Lonca with polatuzumab vedotin + bendamustine and rituximab (Pola + BR).

RESULTS

Four studies included in the MAICs were identified via systematic review and hand-searching. Lonca (LOTIS-2) was compared with three comparator studies for Pola + BR (GO29365 extension study, COTA database, Dal et al. 2023). Overall, there was no evidence of a difference in overall response and complete response (CR) rates. Despite Pola + BR demonstrating a higher CR rate in the GO29365 extension study, this did not translate into significant improvements in progression-free or overall survival. Survival analyses indicated similar efficacy between treatments across studies, with most comparisons/meta-analyses showing no statistically significant differences. Lonca had significantly lower odds of Grade 3-4 infections, any serious adverse event (SAE), and specific SAEs including febrile neutropenia, pneumonia and pyrexia. Of the safety endpoints analyzed, none indicated significant differences in favor of Pola + BR.

CONCLUSION

These results suggest no evidence of a difference in efficacy between the two treatments and potentially more favorable safety profile for Lonca compared with Pola + BR in patients with R/R DLBCL after two or more lines of treatment.

Immunotherapy in chronic lymphocytic leukemia: advances and challenges

Chronic lymphocytic leukemia (CLL) is characterized as a clonal proliferation of mature B lymphocytes with distinct immunophenotypic traits, predominantly affecting the middle-aged and elderly population. This condition is marked by an accumulation of lymphocytes within the peripheral blood, bone marrow, spleen, and lymph nodes. The associated immune dysregulation predisposes CLL patients to a higher risk of secondary malignancies and infections, which significantly contribute to morbidity and mortality rates. The advent of immunotherapy has revolutionized the prognosis of CLL, advancing treatment modalities and offering substantial benefits to patient outcomes. This review endeavors to synthesize and scrutinize the efficacy, merits, and limitations of the current immunotherapeutic strategies for CLL. The aim is to inform the selection of optimal treatment regimens tailored to individual patient needs. Furthermore, the review juxtaposes various therapeutic combinations to elucidate the comparative advantages of each approach, with the ultimate objective of enhancing patient prognosis and quality of life.

Loncastuximab tesirine in Chinese patients with relapsed or refractory diffuse large B-cell lymphoma: a multicenter, open-label, single-arm, phase II trial

Patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) have a poor prognosis. Loncastuximab tesirine (Lonca), an antibody conjugate targeting CD19, has demonstrated significant clinical benefit in R/R DLBCL in a global phase II LOTIS-2 study. In the China bridging pivotal phase II OL-ADCT-402-001 study, eligible patients aged ≥18 years with R/R DLBCL who had failed ≥2 lines of systemic therapies were enrolled and treated every 3 weeks with 150 μg/kg Lonca for two cycles; then 75 μg/kg for subsequent cycles (up to 1 year). The primary endpoint was overall response rate (ORR) assessed by an independent review committee. Primary analyses for efficacy and safety were performed on the patients who received at least one treatment and had at least 6 months of follow-up following an initial documented response. As of data cutoff, 64 patients received Lonca (median 4.0 cycles; range, 1-17). The median number of prior lines of therapies was 3.0 (range, 2-12). The ORR was 51.6% (95% confidence interval [CI]: 38.7-64.2), and the complete response rate was 23.4%. Hematological events accounted for the majority of the most common (≥15%) grade ≥3 treatment-emergent adverse events (TEAE), in which increased γ-glutamyltransferase (25.0%), and hypokalaemia (18.8%) also were reported. Serious TEAE were reported in 35 of 64 patients with four fatal TEAE. In conclusion, Lonca monotherapy demonstrated clinically meaningful efficacy and was well-tolerated in heavily pretreated Chinese patients with R/R DLBCL, which was consistent with the results of the LOTIS-2 study in Caucasian patients.

Loncastuximab in high-risk and heavily pretreated relapsed/refractory diffuse large B-cell lymphoma: a realworld analysis from 21 US centers

Outcomes in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) are poor. Loncastuximab- teserine (Lonca) is an antibody-drug conjugate which was approved by the Food and Drug Administration for the treatment of patients with R/R DLBCL who have received at least two prior lines of therapy, based on the results of the LOTIS-2 trial. However, there are limited data regarding its efficacy in the real-world setting. This retrospective study included 21 US centers and evaluated outcomes of patients with R/R DLBCL treated with Lonca. Our analysis comprises 187 patients with notably higher-risk baseline features compared to those of the LOTIS-2 population, including a higher proportion of patients with bulky disease (17% vs. 0%), high-grade B-cell histology (22% vs. 8%), and increased number of prior lines of therapy (median 4 vs. 3). The complete response rate was 14% and overall response rate was 32%. The median event-free survival and overall survival were 2.1 and 4.6 months, respectively. Those with bulky disease and high-grade B-cell histology had significantly worse outcomes, and those with non-germinal center cell of origin and a complete response to the most recent line of therapy demonstrated superior outcomes. In summary, in this largest retrospective cohort study of Lonca in the real-world setting, the response rates, event-free survival and overall survival were lower than those reported in LOTIS-2, which is likely reflective of its use in higher risk and more heavily pre-treated patients in the real world compared to the patients enrolled on a clinical study.

Improving access to chimeric antigen receptor T-cells for refractory or relapsing diffuse large B cell lymphoma therapy in Asia

Chimeric antigen receptor T-cell (CAR-T)-mediated therapies have shown promising clinical benefit in patients with refractory or relapsing (R/R) diffuse large B-cell lymphoma (DLBCL). However, CAR-T treatment presents challenges such as lack of drug accessibility, financial barriers, variable physician preference or experience, and risk assessment based on patient-specific characteristics. This article thus aims to provide an overview of the CAR-T landscape for R/R DLBCL in Asia, with a focus on identifying barriers to access, from the perspective of Asian and international lymphoma experts. Presently, existing clinical data indicate that CAR-T therapy is a potentially curative strategy for R/R DLBCL in addition to stem cell transplantation, provided the patient's disease profile and treatment history have been thoroughly considered. However, longer-term follow-up data from large-scale studies are needed to confirm curative potential and define optimal sequencing of CAR-T in the context of novel emerging treatments, such as bi-specific antibodies, in the management of R/R DLBCL. Consequently, further research into CAR-T would benefit from collaboration between institutions. Furthermore, there is a wide disparity in CAR-T accessibility across regions due to complicated logistics and cost, which represent a significant barrier to patients in Asia. Hence, there is a need to increase representation and engagement across different stakeholders such as policymakers, payers, and the industry to arrive at a consensus on patient selection, establish clear guidelines, and develop strategies to lower CAR-T costs. Ultimately, data can support a multi-stakeholder approach when devising strategies to make CAR-T feasible and sustainable for patients.

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 .