RE-MIND: Comparing Tafasitamab + Lenalidomide (L-MIND) with a Real-world Lenalidomide Monotherapy Cohort in Relapsed or Refractory Diffuse Large B-cell Lymphoma

Tafasitamab for the treatment of patients with diffuse large B-cell lymphoma

Patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) require additional treatments, especially those not eligible or not responding to high dose cytotoxic chemotherapy and stem cell transplantation. Over the last few years, several new treatments have been developed and approved for these patients, among them of particular relevance are those targeting CD19. Tafasitamab is a humanized monoclonal antibody targeting CD19, composed of a modified fragment crystallizable (Fc) region engineered with higher affinity for Fc gamma receptors (FcγR) receptors, leading to increased cytotoxicity through natural killer cells and macrophages (antibody-dependent cellular cytotoxicity and antibody-dependent cell-mediated phagocytosis). In this product review, we will discuss its mechanism of action, safety profile and efficacy results from clinical trials that led to its approval in combination with lenalidomide for patients with R/R DLBCL ineligible for high-dose chemotherapy and autologous transplantation.

Changing Trends in B-Cell Non-Hodgkin Lymphoma Treatment: The Role of Novel Monoclonal Antibodies in Clinical Practice

We are currently witnessing a dramatic shift in our approach to the treatment of B-cell non-Hodgkin lymphoma (B-NHL). In the evolving clinical landscape, novel treatments for this clinically heterogeneous disease span a wide range of interventions, encompassing targeted agents, cell therapy approaches, and novel monoclonal antibodies (NMABs). Among these, the latter are likely to exert the most profound impact due to their distinctive high efficacy and versatile applicability. NMABs represent a heterogeneous group of agents, including naked antibodies, immunotoxins, and T-cell-engaging molecules. In recent times, several NMABs have either gained regulatory approval or are on the verge of introduction into clinical practice, addressing multiple therapeutic indications and treatment regimens. Their anticipated impact is expected to be broad, initially in the context of relapsed/refractory (R/R) disease and subsequently extending to early treatment lines. The scope of this review is to provide a comprehensive overview of the biological characteristics, clinical properties, efficacy, and toxicity profiles of NMABs that have recently been introduced or are nearing integration into clinical practice.

Second-line treatment of diffuse large B-cell lymphoma: Evolution of options

In the era of immunochemotherapy, approximately 60%-70% of diffuse large B-cell lymphoma (DLBCL) patients achieve remission with first-line rituximab-based chemoimmunotherapy. However, 30%-40% relapse after initial response to first-line therapy and, out of them, 20%-50% are refractory or experience early relapse. The second-line therapy algorithm for DLBCL has recently evolved, thanks to the recent approval of new therapeutic agents or their combinations. The new guidelines suggest a stratification of relapsed/refractory (R/R) DLBCL based on the time to relapse. For transplant-eligible patients, autologous stem cell transplant remains the preferred option when the patient relapses after 12 months from diagnosis, while anti-CD19 CART-cell therapy is the current preferred choice for high-risk DLBCL, defined as primary refractory or relapse ≤12 months. For transplant-ineligible or CAR T-cell therapy-ineligible patients, the therapeutic arsenal historically lacked effective options. However, new therapeutic options, including polatuzumab vedotin combined with bendamustine-rituximab and tafasitamab with lenalidomide, have been recently approved, and novel agents such as loncastuximab tesirine, selinexor, anti-CD19 CAR T-cell therapy, and bispecific antibodies have shown promising efficacy and manageable safety in this setting offering new hope to patients in this challenging scenario.

The synergy of the XPO1 inhibitors combined with the BET inhibitor INCB057643 in high-grade B-cell lymphoma via downregulation of MYC expression

High grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBCL-DH) represents an uncommon B-cell lymphoma (BCL) with aggressive clinical courses and poor prognosis. Despite revolutionary therapeutic advances in BCL, there has been limited treatment progress in HGBCL-DH, thus necessitating additional therapeutic strategies for HGBCL-DH. This study demonstrated that the BET antagonist INCB057643 synergized with the XPO1 inhibitors (selinexor and eltanexor) to decrease cell viability and increase cell apoptosis in HGBCL-DH cells with or without TP53 mutations. As anticipated, the combined treatment of INCB057643 with selinexor slowed tumor growth and reduced the tumor burden in TP53-mutated HGBCL-DH xenografts. Mechanistically, MYC functional inhibition was a potential molecular mechanism underlying the synergy of the combined INCB057643 and selinexor treatment in HGBCL-DH cells independent of TP53 mutation status. In TP53 mutated HGBCL-DH cells, inducing DNA damage and impairing the DNA damage response (DDR) were involved in the therapeutic interaction of the combined regimen. In TP53 wild-type cells, the molecular mechanism was linked with upregulation of p53 levels and activation of its targeted pathways, rather than dysregulation of the DDR. Collectively, we might provide a potential promising combination therapy regimen for the management of HGBCL-DH. Clinical evaluations are warranted to confirm this conclusion.

Targeted Treatment of Adults with Relapsed or Refractory Diffuse Large B-Cell Lymphoma (DLBCL): Tafasitamab in Context

The outcomes of Relapsed/Refractory (R/R) Diffuse Large B-cell lymphoma have been historically poor. The recent development of several novel therapies including CD19 directed agents has improved the prognosis of this disease significantly. Chimeric antigen receptor (CAR) T-cell therapy has drastically changed the treatment of R/R DLBCL, but it is still associated with significant barriers and limited access. Tafasitamab (an anti-CD19 engineered monoclonal antibody), in addition to lenalidomide, has shown significant efficacy with exceptionally durable responses in patients with R/R DLBCL who are ineligible for autologous stem cell transplantation (ASCT). Tafasitamab-lenalidomide and certain other therapies (ie, antibody-drug conjugates and bispecific antibodies) are important treatment options for patients who are ineligible for CAR-T due to co-morbidities or lack of access, and patients with rapid progression of disease who are unable to wait for manufacturing of CAR-T. This review will thus discuss currently approved and recently studied targeted treatment options for patients with R/R DLBCL with an emphasis on CAR-T alternative options, particularly Tafasitamab-lenalidomide.

Redefining Precision Management of r/r Large B-Cell Lymphoma: Novel Antibodies Take on CART and BMT in the Quest for Future Treatment Strategies

The treatment paradigms for patients with relapsed large B-cell lymphoma are expanding. Chimeric antigen receptor technology (CAR-T) has revolutionized the management of these patients. Novel bispecific antibodies and antibody-drug conjugates, used as chemotherapy-free single agents or in combination with other novel therapeutics, have been quickly introduced into the real-world setting. With such a paradigm shift, patients have an improved chance of better outcomes with unpredictable complete remission rates. Additionally, the excellent tolerance of new antibodies targeting B-cell lymphomas is another motivation to broaden its use in relapsed and refractory patients. With the increasing number of approved therapy approaches, future research needs to focus on optimizing the sequence and developing new combination strategies for these antibodies, both among themselves and with other agents. Clinical, pathological, and genetic risk profiling can assist in identifying which patients are most likely to benefit from these costly therapeutic options. However, new combinations may lead to new side effects, which we must learn to deal with. This review provides a comprehensive overview of the current state of research on several innovative antibodies for the precision management of large B-cell lymphoma. It explores various treatment strategies, such as CAR-T vs. ASCT, naked antibodies, antibody-drug conjugates, bispecific antibodies, and bispecific T-cell engagers, as well as discussing the challenges and future perspectives of novel treatment strategies. We also delve into resistance mechanisms and factors that may affect decision making. Moreover, each section provides a detailed analysis of the available literature and ongoing clinical trials.

HBV-associated DLBCL of poor prognosis: advance in pathogenesis, immunity and therapy

Advanced studies have shown a biological correlation between hepatitis B virus (HBV) and B-cell lymphoma, especially diffuse large B-cell lymphoma (DLBCL). Patients with DLBCL infected with HBV (HBV-associated DLBCL) are clinically characterized by an advanced clinical stage, poor response to front-line immunochemotherapy regimens, and worse clinical prognosis. HBV-associated DLBCL often exhibits abnormal activation of the nuclear factor kappa B pathway as well as mutations in oncogenes, including Myc and BCL-6. Currently, there is no consensus on any specific and effective treatment for HBV-associated DLBCL. Therefore, in this review, we comprehensively and mechanistically analyzed the natural history of HBV infection and immunity, including HBV-mediated oncogenes, immune escape, epigenetic alterations, dysregulated signaling pathways, and potential therapeutic approaches for HBV-associated DLBCL. We hope that an improved understanding of the biology of HBV-associated DLBCL would lead to the development of novel therapeutic approaches, enhance the number of effective clinical trials, and improve the prognosis of this disease.

Statistical Considerations on the Use of RWD/RWE for Oncology Drug Approvals: Overview and Lessons Learned

Despite increasing utilization of real-world data (RWD)/real-world evidence (RWE) in regulatory submissions, their application to oncology drug approvals has seen limited success. Real-world data is most commonly summarized as a benchmark control for a single arm study or used to augment the concurrent control in a randomized clinical trial (RCT). While there has been substantial research on usage of RWD/RWE, our goal is to provide a comprehensive overview of their use in oncology drug approval submissions to inform future RWD/RWE study design. We will review examples of applications and summarize the strengths and weaknesses of each example identified by regulatory agencies. A few noteworthy case studies will be reviewed in detail. Operational aspects of RWD/RWE study design/analysis will be also discussed.

A non-randomized risk-adjusted comparison of lenalidomide + R-CHOP versus R-CHOP for MYC-rearranged DLBCL patients

Patients with MYC rearranged (MYC-R) diffuse large B-cell lymphoma (DLBCL) have a poor prognosis. Previously, we demonstrated in a single-arm phase II trial (HOVON-130) that addition of lenalidomide to R-CHOP (R2CHOP) is well-tolerated and yields similar complete metabolic remission rates as more intensive chemotherapy regimens in literature. In parallel with this single-arm interventional trial, a prospective observational screening cohort (HOVON-900) was open in which we identified all newly diagnosed MYC-R DLBCL patients in the Netherlands. Eligible patients from the observational cohort that were not included in the interventional trial served as control group in the present risk-adjusted comparison. R2CHOP treated patients from the interventional trial (n = 77) were younger than patients in the R-CHOP control cohort (n = 56) (median age 63 versus 70 years, p = 0.018) and they were more likely to have a lower WHO performance score (p = 0.013). We adjusted for differences at baseline using 1:1 matching, multivariable analysis, and weighting using the propensity score to reduce treatment-selection bias. These analyses consistently showed improved outcome after R2CHOP with HRs of 0.53, 0.51, and 0.59, respectively, for OS, and 0.53, 0.59, and 0.60 for PFS. Thus, this non-randomized risk-adjusted comparison supports R2CHOP as an additional treatment option for MYC-R DLBCL patients.

Navigating the Evolving Treatment Landscape of Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma, the most common subtype of non-Hodgkin lymphoma, comprises a heterogenous group of morphologically, genetically, and clinically distinct diseases. Several recent advances have affected the treatment landscape, which had been mostly stagnant for the past few decades. We will review the practice-changing studies in frontline (POLARIX), early relapse (ZUMA-7 and TRANSFORM), and multiple recurrent (ZUMA-1, JULIET, TRANSCEND, L-MIND, and LOTIS-2) stages and discuss how the treatment landscape may evolve with the emergence of bispecific antibodies.

Primary CNS lymphoma: update on molecular pathogenesis and therapy

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin lymphoma that as a brain tumor poses a unique set of challenges in diagnosis and management. With the advent of next-generation sequencing, we review updates in the understanding of its molecular and genomic pathogenesis. We also highlight key issues in management, with a focus on emerging technologies and new biological therapies including monoclonal antibodies, IMiDs, BTK inhibitors, PD-1 inhibitors, and CAR-T therapy. Integration of these approaches will likely enhance induction and consolidation strategies to suppress NF-κB activation and the anti-tumor immune response, while minimizing the often noxious effects of genotoxic approaches.

Targeting CD19 for diffuse large B cell lymphoma in the era of CARs: Other modes of transportation

CD19 is nearly ubiquitously expressed on B-lymphocytes and in B-cell malignancies. Although CD19-directed CAR T cells have greatly improved outcomes in B-cell malignancies, there are significant limitations with this therapy. CD19 can also be effectively targeted by other drug classes, such as monoclonal antibodies, antibody-drug conjugates, and bispecific T cell engagers or antibodies. However, the optimal patient selection and sequencing of these novel therapies has not yet been established. In this review, we discuss the utilization of CD19 as a target for the treatment of DLBCL, focusing on tafasitamab, loncastuximab tesirine, and blinatumomab. We provide a comprehensive review of the pivotal clinical trials, discussing the strength and limitations of the data for each agent. We explore the emerging evidence that CD19 expression is retained following exposure to these agents and that patients can be successfully re-challenged with anti-CD19 therapies of a different drug class upon disease relapse post-CAR T cells. Finally, we discuss how these drugs potentially fit into the most current treatment paradigm for DLBCL.

Pembrolizumab for patients with non-Hodgkin lymphoma: phase 1b KEYNOTE-013 study

The multicohort phase 1b KEYNOTE-013 study (NCT01953692) evaluated the safety and efficacy of pembrolizumab in patients with relapsed or refractory NHL who were ineligible for or failed hematopoietic cell transplantation (HCT). Patients received pembrolizumab (cohort 4) or pembrolizumab plus lenalidomide (cohort 5). Primary end points were safety and objective response rate (ORR) per IWG 2007 criteria. Cohort 4 included 89 patients. ORR was 22% (19/86; 90% CI 15-31; 10 CR, nine PR); ORRs by disease type were 48% (10/21), 10% (2/20), 12% (5/41), and 50% (2/4), for PMBCL, FL, DLBCL, and 'other' NHL, respectively. Toxicity was as predicted. Cohort 5 included 19 patients. ORR was 39% (90% CI 20-61; four CR, three PR). Hematologic toxicities were the most common treatment-related AEs. In conclusion, pembrolizumab following HCT ineligibility/failure confirms prior experience in PMBCL but not with NHL subtypes in this study. Additional analyses in DLBCL may not be warranted.

Utilization of real-world data in assessing treatment effectiveness for diffuse large B-cell lymphoma

Direct comparisons of the effectiveness of the numerous novel therapies in the diffuse large B-cell lymphoma (DLBCL) treatment landscape in a range of head-to-head randomized phase 3 trials would be time-consuming and costly. Comparative effectiveness studies using real-world data (RWD) represent a complementary approach. Recently, several studies of relapsed/refractory (R/R) DLBCL have used RWD to create observational cohorts to compare patient outcomes with cohorts derived from single-arm phase 2 trials. Using propensity score methods to balance clinically and prognostically relevant baseline covariates, closely matched patient-level cohorts can be generated. By incorporating appropriate measures to assess covariate balance and address potential bias in comparative effectiveness study designs, robust comparative analyses can be performed. Results from such studies have been used to supplement regulatory approval of therapies assessed in single-arm trials. While RWD studies have a greater susceptibility to bias compared to randomized controlled trials, well-designed and appropriately analyzed studies can provide complementary real-world evidence on treatment effectiveness.

Tafasitamab and lenalidomide for relapsed/refractory diffuse large B-cell lymphoma in a patient on chronic intermittent hemodialysis

INTRODUCTION

Tafasitamab is an anti-CD19 monoclonal antibody indicated for the treatment of relapsed/refractory diffuse large B-cell lymphoma to be given in combination with lenalidomide. Experiences with tafasitamab in the setting of hemodialysis are limited and the efficacy and safety of this agent in this setting are unknown.

CASE REPORT

We describe a patient with relapsed/refractory diffuse large B-cell lymphoma with hemodialysis-dependent end-stage renal disease who successfully received tafasitamab/lenalidomide.

MANAGEMENT AND OUTCOME

Tafasitamab and reduced dose lenalidomide were initiated for relapsed diffuse large B-cell lymphoma. Tafasitamab was administered on non-dialysis days. Follow-up imaging for disease response assessment demonstrated a complete response. Therapy was well tolerated; the only major toxicity experienced was grade 4 neutropenia that resolved with dose adjustment to lenalidomide. Over a year from initiating therapy, the patient remains in a complete response.

DISCUSSION/CONCLUSION

The combination of tafasitamab and dose-reduced lenalidomide produced a complete response in the treatment of relapsed/refractory diffuse large B-cell lymphoma in the setting of chronic intermittent hemodialysis.

Sequencing therapy in relapsed DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy worldwide, comprising approximately 30% of all lymphomas. Currently, 50% to 60% of patients diagnosed with DLBCL are alive at 5 years and cured with modern therapy, but about 10% to 15% of patients are refractory to first-line therapy, and an additional 20% to 30% relapse following a complete response. Patients who have relapses beyond 2 years may experience more favorable outcomes and have forms of DLBCL that can be distinguished biologically. Patients who experience early relapse or who have primary refractory disease (less than a complete response or relapse within 3 to 6 months of initial therapy) have worse outcomes. For decades, the standard of care treatment strategy for fit patients with relapsed DLBCL has been salvage therapy with non-cross-resistant combination chemoimmunotherapy regimens followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) as stem cell rescue for patients with chemosensitive disease. Recent data suggest that certain patients may benefit from chimeric antigen receptor T-cell therapy (CAR T) in the second-line setting. Additional novel therapies exist for patients who are ineligible, who are unable to access these therapies, or who fail ASCT and/or CAR T. Despite the advent of new therapies for DLBCL and improved outcomes, DLBCL remains a life-threatening illness. Thus, it is essential for clinicians to engage in serious illness conversations with their patients. Goals-of-care communication can be improved through skills-based training and has been demonstrated to have an impact on patient experiences.

Reshaping the tumor microenvironment: The versatility of immunomodulatory drugs in B-cell neoplasms

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide are antitumor compounds that have direct tumoricidal activity and indirect effects mediated by multiple types of immune cells in the tumor microenvironment (TME). IMiDs have shown remarkable therapeutic efficacy in a set of B-cell neoplasms including multiple myeloma, B-cell lymphomas and chronic lymphocytic leukemia. More recently, the advent of immunotherapy has revolutionized the treatment of these B-cell neoplasms. However, the success of immunotherapy is restrained by immunosuppressive signals and dysfunctional immune cells in the TME. Due to the pleiotropic immunobiological properties, IMiDs have shown to generate synergetic effects in preclinical models when combined with monoclonal antibodies, immune checkpoint inhibitors or CAR-T cell therapy, some of which were successfully translated to the clinic and lead to improved responses for both first-line and relapsed/refractory settings. Mechanistically, despite cereblon (CRBN), an E3 ubiquitin ligase, is considered as considered as the major molecular target responsible for the antineoplastic activities of IMiDs, the exact mechanisms of action for IMiDs-based TME re-education remain largely unknown. This review presents an overview of IMiDs in regulation of immune cell function and their utilization in potentiating efficacy of immunotherapies across multiple types of B-cell neoplasms.

Broadening the MIND: Tafasitamab and Lenalidomide versus Synthetic Controls

Tafasitamab and lenalidomide were approved for second-line treatment of diffuse large B-cell lymphoma (DLBCL) based on a single-arm phase II study. This combination was superior to routine immunochemotherapy regimens when comparing matched observational cohorts. "Synthetic" control groups may support use of novel DLBCL therapies in the absence of randomized studies. See related article by Nowakowski et al., p. 4003.

Comparative effectiveness of ZUMA-5 (axi-cel) vs SCHOLAR-5 external control in relapsed/refractory follicular lymphoma

In the pivotal ZUMA-5 trial, axicabtagene ciloleucel (axi-cel; an autologous anti-CD19 chimeric antigen receptor T-cell therapy) demonstrated high rates of durable response in relapsed/refractory (r/r) follicular lymphoma (FL) patients. Here, outcomes from ZUMA-5 are compared with the international SCHOLAR-5 cohort, which applied key ZUMA-5 trial eligibility criteria simulating randomized controlled trial conditions. SCHOLAR-5 data were extracted from institutions in 5 countries, and from 1 historical clinical trial, for r/r FL patients who initiated a third or higher line of therapy after July 2014. Patient characteristics were balanced through propensity scoring on prespecified prognostic factors using standardized mortality ratio (SMR) weighting. Time-to-event outcomes were evaluated using weighted Kaplan-Meier analysis. Overall response rate (ORR) and complete response (CR) rate were compared using weighted odds ratios. The 143 ScHOLAR-5 patients reduced to an effective sample of 85 patients after SMR weighting vs 86 patients in ZUMA-5. Median follow-up time was 25.4 and 23.3 months for SCHOLAR-5 and ZUMA-5. Median overall survival (OS) and progression-free survival (PFS) in SCHOLAR-5 were 59.8 months and 12.7 months and not reached in ZUMA-5. Hazard ratios for OS and PFS were 0.42 (95% confidence interval [CI], 0.21-0.83) and 0.30 (95% CI, 0.18-0.49). The ORR and CR rate were 49.9% and 29.9% in SCHOLAR-5 and 94.2% and 79.1% in ZUMA-5, for odds ratios of 16.2 (95% CI, 5.6-46.9) and 8.9 (95% CI, 4.3-18.3). Compared with available therapies, axi-cel demonstrated an improvement in meaningful clinical endpoints, suggesting axi-cel addresses an important unmet need for r/r FL patients. This trial was registered at www.clinicaltrials.gov as #NCT03105336.

Real-world data in drug development strategies for orphan drugs: tafasitamab in B cell lymphoma, a case study for approval based on a single-arm combination trial

Tafasitamab (TAF) plus lenalidomide (LEN) is a novel treatment option for patients with relapsed/refractory diffuse large B cell lymphoma (rrDLBCL) who are not eligible for autologous stem cell transplantation. The initial US/EU approvals for TAF represent precedents because this is the first time that approval of a novel combination therapy was granted based on a pivotal single-arm trial (SAT). Matching real world-data (RWD) helped to disentangle the contribution of individual agents. In this review, we present the TAF development strategy, the prospective incorporation of RWD within the clinical development plan, the corresponding regulatory hurdles of this strategy, and the prior regulatory actions for other cancer drugs that previously incorporated RWD and propensity score matching in EU and US regulatory submissions. We also outline how RWD could further advance and impact orphan drug development.

Efficacy and Safety of Lenalidomide Monotherapy for Relapsed/Refractory Diffuse Large B Cell Lymphoma: Systematic Review and Meta-Analysis

INTRODUCTION

Several maintenance therapies are available for treatment of patients with relapsed/refractory (R/R) diffuse large B cell lymphoma (DLBCL). The objective of this review was to assess the efficacy and safety of lenalidomide monotherapy in these patients.

METHODS

MEDLINE, EMBASE, and the Cochrane Library databases were searched for publications up to April 7, 2021. Original studies that had information on lenalidomide monotherapy for DLBCL patients with R/R status were included. Meta-analyses of response rates, adverse events (AEs), overall survival (OS), and progression-free survival (PFS) were performed. The pooled event rates were calculated using a double arcsine transformation to stabilize the variances of the original proportions. Subgroup analysis was used to compare patients with different germinal center B-cell-like (GCB) phenotypes.

RESULTS

We included 11 publications that examined DLBCL patients with R/R status. These studies were published from 2008 to 2020. The cumulative objective response rate (ORR) for lenalidomide monotherapy was 0.33 (95% CI: 0.26, 0.40), and the ORR was better in patients with the non-GCB phenotype (0.50; 95% CI: 0.26, 0.74) than the GCB phenotype (0.06; 95% CI: 0.03, 0.11). The major serious treatment-related AEs were neutropenia, thrombocytopenia, respiratory disorders, anemia, and diarrhea. The median PFS ranged from 2.6 to 34 months and the median OS ranged from 7.8 to 37 months.

CONCLUSION

This study provides evidence that lenalidomide monotherapy was active and tolerable in DLBCL patients with R/R status. Patients in the non-GCB subgroup had better responsiveness.

Anti-CD19 monoclonal antibodies for the treatment of relapsed or refractory B-cell malignancies: a narrative review with focus on diffuse large B-cell lymphoma

PURPOSE

CD19 is a cell surface protein that is found on both healthy and malignant B cells. Accordingly, it has become an important target for novel treatments for non-Hodgkin lymphomas and B-cell leukaemia. Three anti-CD19 monoclonal antibodies with distinct mechanisms of action have been developed for the treatment of B-cell malignancies.

METHODS

We reviewed the preclinical and clinical data on the development of the newly approved anti-CD19 monoclonal antibodies blinatumomab, tafasitamab and loncastuximab tesirine, and consider their place in the treatment of relapsed or refractory B-cell malignancies.

RESULTS

Blinatumomab is a bispecific T-cell engager that binds to both CD19 on B cells and CD3 on T cells, facilitating antibody-dependent cytotoxicity. Blinatumomab significantly prolongs overall survival in patients with relapsed or refractory B-cell acute lymphoblastic leukaemia, although cytokine release syndrome and severe neurotoxicity may necessitate discontinuation. Tafasitamab, which has modified anti-CD19 Fab and Fc regions, has significantly enhanced affinity for both CD19 and effector cell receptors compared with unmodified anti-CD19. In L-MIND, tafasitamab plus lenalidomide provided an overall response rate (ORR) of 57.5% in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) in patients non-transplant eligible. Loncastuximab tesirine is an antibody-drug conjugate that has been studied as monotherapy and in combination with ibrutinib in 3L + relapsed or refractory DLBCL. The ORR was 48.3% in a phase II trial of loncastuximab tesirine. The optimal place of anti-CD19 monoclonal antibodies in therapy has yet to be determined, but the prospect of improved outcomes for at least some patients with treatment-resistant B-cell malignancies appears likely, particularly in those with limited therapeutic options and poor prognosis.