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

Bispecific Antibodies in Hematologic and Solid Tumors: Current Landscape and Therapeutic Advances

Bispecific antibodies (bsAbs) have emerged as a novel class of therapeutics, offering a dual-targeting strategy to enhance the therapeutic efficacy of monoclonal antibodies, which is often limited by tumor heterogeneity and the occurrence of resistance mechanisms. By simultaneously engaging two distinct antigens or pathways, bsAbs disrupt multiple signaling cascades simultaneously, preventing escape mechanisms and offering a more durable response. Furthermore, they can optimize immune activation, improving immune cell recruitment strategies. In particular, T-cell engager bsAbs facilitate immune cell-mediated tumor destruction by linking T cells to tumor antigens. Instead, dual immune checkpoint inhibitors (CPIs) enhance immune activation by blocking inhibitory signals. Additionally, bsAbs targeting tumor growth factors or receptor tyrosine kinases offer solutions for overcoming drug resistance in solid tumors. Although bsAbs have shown remarkable success in hematologic malignancies, their expansion into solid tumors faces key challenges, including tumor heterogeneity, limited tumor penetration, and the risk of on-target, off-tumor toxicities. Addressing these challenges requires innovative engineering strategies, optimized delivery mechanisms, and careful patient selection to maximize therapeutic benefit while mitigating adverse effects. The efficacy of bsAbs in clinical trials has led to their approval for both hematologic and solid malignancies, with numerous agents in development. Combination strategies with chemotherapy, targeted agents, and immune CPIs could represent a promising strategy to further expand their potential. As research progresses, bsAbs are expected to play a role in reshaping the future of precision oncology, offering more effective and tailored treatment options.

Chidamide, a Histone Deacetylase Inhibitor, Combined With R-GemOx in Relapsed/Refractory Diffuse Large B-Cell Lymphoma (TRUST): A Multicenter, Single-Arm, Phase 2 Trial

BACKGROUND

Histone deacetylase (HDAC) inhibitors demonstrated a synergistic anti-tumor effect with rituximab and chemotherapy in preclinical studies on diffuse large B-cell lymphoma (DLBCL). This phase 2 trial aimed to evaluate the efficacy and safety of chidamide, an orally active HDAC inhibitor, plus the R-GemOx regimen for relapsed/refractory (R/R) DLBCL.

METHODS

Patients with transplantation-ineligible R/R DLBCL received chidamide (20 mg, oral, days 1, 4, 8, 11, 15, and 18), rituximab (375 mg/m2, day 1), gemcitabine (1000 mg/m2, day 2), and oxaliplatin (100 mg/m2, day 2) in a 21-day cycle for 6 cycles (induction phase), followed by chidamide (20 mg, oral, twice weekly on Mondays and Thursdays) until disease progression or intolerable toxicity (maintenance phase). The primary endpoint was overall response rate (ORR).

RESULTS

Between June 19, 2019 and July 5, 2022, 54 patients were enrolled. The ORR was 59.3% (95% CI: 45.0-72.4). With a median follow-up of 38.1 months (interquartile range: 19.5-48.2), the median progression-free survival and overall survival were 7.4 (95% CI: 5.2-14.2) and 23.9 (95% CI: 15.2-not reached) months, respectively. The most common grade 3/4 treatment-emergent adverse events (TEAEs) were neutropenia (40.7%), thrombocytopenia (33.3%), and leukopenia (27.8%). Whole-exome sequencing showed that CREBBP mutations and BTG2 mutations were associated with poor response and survival.

CONCLUSION

Chidamide plus R-GemOx demonstrated promising anti-tumor activity with acceptable toxicities in transplantation-ineligible R/R DLBCL patients. Patients with CREBBP mutations and BTG2 mutations had inferior response and survival.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04022005.

Emerging biomarkers for CD3×CD20 bispecific antibodies in lymphoma

ABSTRACT

Novel CD3×CD20 bispecific antibody (BsAb) immunotherapies have entered the armamentarium for follicular lymphoma and diffuse large B-cell lymphoma based on accelerated approvals. The primary challenge in utilizing BsAbs lies in patient selection due to variable responses, unique toxicity, and health economics. To date, no validated biomarkers of therapy response exist, however data demonstrating potential clinical, imaging, and biological markers relating to BsAbs are growing. This review examines current prognostic and potentially predictive biomarkers and explores future directions for nuanced patient selection.

Epcoritamab plus GemOx in transplant-ineligible relapsed/refractory DLBCL: results from the EPCORE NHL-2 trial

ABSTRACT

Patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) have poor outcomes (complete response [CR] rates with standard salvage therapy gemcitabine plus oxaliplatin [GemOx], ∼30%; median overall survival [OS], 10 to 13 months). Patients with refractory disease fare worse (CR rate with salvage therapy, 7%; median OS, 6 months). Epcoritamab, a CD3×CD20 bispecific antibody approved for R/R DLBCL after ≥2 therapy lines, has shown promising safety and efficacy in various combinations. We report results from the phase 1b/2 EPCORE NHL-2 trial evaluating epcoritamab plus GemOx in autologous stem cell transplant (ASCT)-ineligible R/R DLBCL. Patients received 48 mg subcutaneous epcoritamab after 2 step-up doses until progression or unacceptable toxicity; GemOx was given once every 2 weeks for 8 doses. The primary end point was overall response rate (ORR). As of 15 December 2023, 103 patients were enrolled (median follow-up, 13.2 months; median age, 72 years). Patients had challenging-to-treat disease: ≥2 prior therapy lines, 62%; prior chimeric antigen receptor T-cell therapy, 28%; primary refractory disease, 52%; refractory to last therapy, 70%. ORR and CR rate were 85% and 61%, respectively. Median duration of CR and OS were 23.6 and 21.6 months, respectively. Common treatment-emergent adverse events were cytopenias and cytokine release syndrome (CRS). CRS events had predictable timing, were primarily low grade (52% overall, 1% grade 3), and resolved without leading to discontinuation. Epcoritamab plus GemOx yielded deep, durable responses and favorable long-term outcomes in ASCT-ineligible R/R DLBCL. This trial was registered at www.clinicaltrials.gov as #NCT04663347.

An evaluation of odronextamab for the treatment of multiple subtypes of relapsed/refractory B-cell non-Hodgkin lymphoma

INTRODUCTION

Patients with relapsed/refractory B-cell non-Hodgkin lymphoma (B-NHL) have a poor median survival rate when treated with traditional salvage therapies. Bispecific antibodies (BsAbs) are an emerging class of 'off-the-shelf' immunotherapies that show promising efficacy in this population. Odronextamab is a CD20×CD3 targeting bispecific antibody that is being investigated in multiple subtypes of relapsed/refractory B-NHL.

AREAS COVERED

This article describes the development of odronextamab from pre-clinical work through to ongoing clinical trials in relapsed/refractory B-NHL. The structure, safety, efficacy, and administration of odronextamab are discussed. Studies were selected for inclusion by performing a search in PubMed, EMBASE, Cochrane Library, and relevant conference abstracts from 2014 to 2024. The clinicaltrials.gov website and reference lists of the included studies were also reviewed.

EXPERT OPINION

Odronextamab has demonstrated manageable safety and promising efficacy in multiple subtypes of relapsed/refractory B-NHL. The low rates of immune effector cell-associated neurotoxicity syndrome (ICANS) and high response rates in rare aggressive subtypes of B-NHL are particularly noteworthy. High rates of severe infections remain a challenge with BsAbs, with further prophylactic efforts required to reduce the risk. Clinical trials of combination therapies with odronextamab are required to improve the utility of this BsAb across a wider range of settings and subtypes of B-NHL.

Non-relapse mortality with bispecific antibodies: A systematic review and meta-analysis in lymphoma and multiple myeloma

Bispecific antibodies (BsAb) are associated with distinct immune-related toxicities that impact morbidity and mortality. This systematic review and meta-analysis examined non-relapse mortality (NRM) with BsAb therapy in B-cell non-Hodgkin lymphoma (NHL) and multiple myeloma (MM). A PubMed and Embase search up to October 2024 identified 29 studies (21 NHL, 8 MM) involving 2,535 patients. The overall NRM point estimate was 4.7% (95% confidence interval [CI] 3.4%-6.4%), with a median follow-up of 12.0 months. We noted no significant difference in NRM across disease entities (NHL: 4.2%, MM: 6.2%, p = 0.22). In NHL, prespecified subgroup analyses revealed increased NRM in real-world studies compared to clinical trials. For MM, an association between NRM and higher response rates and longer follow-up was noted. Meta-regression comparing BsAb and CAR-T therapies (n = 8,592) showed no significant NRM difference when accounting for key study-level confounders (p = 0.96). Overall, infections were the leading cause of NRM, accounting for 71.8% of non-relapse deaths. Of the infection-related deaths, 48% were attributed to COVID-19. In a pre-specified sensitivity analysis excluding COVID-19 fatalities, the overall NRM estimate was 3.5% (95% CI 2.6%-4.6%). Taken together, these results provide a benchmark for the estimated NRM with BsAb therapy and highlight the paramount importance of infection reporting, prevention, and mitigation.

Antibody Therapy for Patients with Lymphoid Malignancies: Past and Present

Antibody therapies are a crucial component of modern lymphoid malignancy treatment and an exciting area of active research. We performed a review of modern antibody therapies used in the treatment of lymphoid malignancies, with an emphasis on landmark studies and current directions. We describe the indications for rituximab, obinutuzumab, ADCs, and bispecific antibody therapies. Finally, we summarize early data from ongoing trials on emerging novel therapy combination regimens and discuss the role of machine learning in future therapy development.

Strategies following failure of CAR-T-cell therapy in non-Hodgkin lymphoma

Several CD19 CAR-T-cell drugs are approved for safety and efficacy in advanced B-cell cancers with encouraging results. However, primary refractory and relapse are common. We critically analyze long-term data on efficacy of CD19 CAR-T-cell therapies in B-cell non-Hodgkin lymphomas from clinical trials with those of so-called real world data. We identify co-variates associated with efficacy, discuss mechanisms of relapse, summarize the data on the results of post-failure therapy including allotransplants, monoclonal and bi-specific antibodies, antibody-drug conjugates, immune checkpoint-inhibitors and repeat infusions of CAR-T-cells. We conclude, save for allotransplants, there are few data strongly supporting any of these interventions. Most trial are with few heterogeneously-treated subjects with diverse interventions and brief follow-up. Interventions need to be tailored to the cause(s) of CAR-T-cell failure. Prestly, there is not a convincingly safe and effective therapy of people failing initial CAR-T-cell therapy of B-cell non-Hodgkin lymphoma.

Unlocking Natural Potential: Antibody-Drug Conjugates With Naturally Derived Payloads for Cancer Therapy

Natural compound-derived chemotherapies remain central to cancer treatment, however, they often cause off-target side effects that negatively impact patients' quality of life. In contrast, antibody-drug conjugates (ADCs) combine cytotoxic payloads with antibodies to specifically target cancer cells. Most approved and clinically investigated ADCs utilize naturally derived payloads, while those with conventional synthetic molecular payloads remain limited. This review focuses on approved ADCs that enhance the efficacy of naturally derived payloads by linking them with antibodies. We provide an overview of the core components of ADCs, their working mechanisms, and FDA-approved ADCs featuring naturally derived payloads, such as calicheamicin, camptothecin, dolastatin 10, maytansine, pyrrolbenzodiazepine (PBD), and the immunotoxin Pseudomonas exotoxin A. This review also explores recent clinical advancements aimed at broadening the therapeutic potential of ADCs, their applicability in treating heterogeneously composed tumors and their potential use beyond oncology. Additionally, this review highlights naturally derived payloads that are currently being clinically investigated but have not yet received approval. By summarizing the current landscape, this review provides insights into promising avenues for exploration and contributes to the refinement of treatment protocols for improved patient outcomes.

The potential of antibody-drug conjugates for effective therapy in diffuse large B-cell lymphoma

INTRODUCTION

Antibody-drug conjugates (ADCs) are a rapidly evolving class of anti-cancer drugs with a significant impact on management of hematological malignancies including diffuse large B-cell lymphoma (DLBCL). ADCs combine a cytotoxic drug (a.k.a. payload) attached through a linker to a monoclonal antibody specific to a particular cancer antigen. Payloads include microtubule disruptors or DNA damaging chemicals. After attaching to the antigen, the ADCs are internalized, and the payload is dissociated from ADC by lysozymes and delivered to the intended site for exerting cytotoxic effects. This unique molecular design permits a better balance of efficacy and safety. Loncastuximab tesirine and polatuzumab vedotin are two ADCs approved in the U.S.A. for treatment of DLBCL.

AREAS COVERED

This review covers the efficacy and safety data of these two drugs. We will review new ADC-based combination regimens and novel constructs in development.

EXPERT OPINION

ADCs have made a significant impact in improving outcomes of DLBCL patients. Both polatuzumab vedotin and loncastuximab tesirine are established as useful therapeutics options, with polatuzumab vedotin currently approved in first line and relapsed/refractory setting, while loncastuximab tesirine is approved in relapsed setting. ADCs are effective with tolerable safety profile and currently many more ADCs are undergoing clinical trials.

Bispecific Antibodies for Lymphoid Malignancy Treatment

BACKGROUD

The introduction of highly active immunotherapies has changed the outcome of B-cell non-Hodgkin lymphomas (B-NHLs) in the last two decades. Since then, important progress has been shown using newer and more active immunotherapies, including chimeric antigen receptor T-cell therapy (CAR-T), conjugated monoclonal antibodies, and bispecific antobodies, which currently plays a significant role in the treatment of diffuse large B-cell (DLBCL), follicular (FL), and mantle cell (MCL) lymphoma.

PURPOSE

In this review, we provide an updated overview of recently completed and ongoing BsAb trials in patients with relapsed/refractory(R/R) B-NHL and Hodgkin's lymphoma, including single-agent results, emerging combinations, safety data, and novel constructs.

CONCLUSIONS

Bispecific antibodies (BsAbs) are a novel class of "off-the-shelf" T-cell-redirecting drugs capable of targeting various cell-surface antigens. New antigen targets are currently under investigation, such as CD19 × CD3 and CD30 × CD3 or CD30 × CD16, in different settings. BsAbs are among the most promising therapeutic options for lymphoma today since they have demonstrated significant single-agent activity, along with a manageable toxicity profile, in patients with heavily pretreated B-NHL.

Impact of immunological aging on T cell-mediated therapies in older adults with multiple myeloma and lymphoma

The treatment landscape for lymphoma and multiple myeloma, which disproportionally affect older adults, has been transformed by the advent of T cell-mediated immunotherapies, including immune checkpoint inhibition, T cell-engaging bispecific antibodies, and chimeric antigen receptor (CAR) T cell therapy, during the last decade. These treatment modalities re-enable the patient's own immune system to combat malignant cells and offer the potential for sustained remissions and cure for various diseases.Age profoundly affects the physiological function of the immune system. The process of biological aging is largely driven by inflammatory signaling, which is reciprocally fueled by aging-related alterations of physiology and metabolism. In the T cell compartment, aging contributes to T cell senescence and exhaustion, increased abundance of terminally differentiated cells, a corresponding attrition in naïve T cell numbers, and a decrease in the breadth of the receptor repertoire. Furthermore, inflammatory signaling drives aging-related pathologies and contributes to frailty in older individuals. Thus, there is growing evidence of biological aging modulating the efficacy and toxicity of T cell-mediated immunotherapies.Here, we review the available evidence from biological and clinical studies focusing on the relationship between T cell-mediated treatment of hematologic malignancies and age. We discuss biological features potentially impacting clinical outcomes in various scenarios, and potential strategies to improve the safety and efficacy of immune checkpoint inhibitors, T cell-engaging bispecific antibodies, and CAR-T cell therapy in older patients.

Bispecific Antibodies, Immune Checkpoint Inhibitors, and Antibody-Drug Conjugates Directing Antitumor Immune Responses: Challenges and Prospects

Tumor immunotherapy includes bispecific antibodies (BsAbs), immune checkpoint inhibitors (ICIs), vaccines, and adoptive cell immunotherapy. BsAbs belong to the family of antibodies that can specifically target two or more different antigens and are a promising option for tumor immunotherapy. Immune checkpoints are antibodies targeting PD-1, PD-L1, and CTLA4 and have demonstrated remarkable therapeutic efficacy in the treatment of hematological and solid tumors, whose combination therapies have been shown to synergistically enhance the antitumor effects of BsAbs. In addition, the clinical efficacy of existing monoclonal antibodies targeting PD-1 (e.g., ipilimumab, nivolumab, pembrolizumab, and cemiplimab) and PD-L1 (e.g., atezolizumab, avelumab, and durvalumab) could also be enhanced by conjugation to small drugs as antibody-drug conjugates (ADCs). The development of truly effective therapies for patients with treatment-resistant cancers can be achieved by optimizing the various components of ADCs.

Bispecific antibody therapy for lymphoma

The rapid development of novel therapeutics in B-cell Non-Hodgkin's lymphoma (B-NHL) over the past decade has presented a critical inflection point for the field. Bispecific antibodies are one such therapeutic class emerging as an effective, off-the-shelf option for B-NHL. In this review, we focus primarily on Diffuse Large B-cell Lymphoma (DLBCL), highlighting the evolution, comparison, tolerability, ongoing challenges, and future potential of bispecific antibodies that are currently approved or in clinical trials for B-NHL. With the number of anti-lymphoma drugs increasing every year, it is important to optimize clinical trial analysis and design so that outcomes, toxicities, and predictors thereof can be understood and compared amongst therapeutic classes to ensure that patients get the safest and most effective treatments for them at the most appropriate line of therapy.

SOHO State of the Art Updates and Next Questions | Diffuse Large B-Cell Lymphoma in Older Adults: A Comprehensive Review

Older adults (OA) with DLBCL are a heterogenous population with suboptimal outcomes. In this review, we identify and address the unique challenges encountered in the care of OA with DLBCL. We elaborate on the role and limitations of current geriatric assessment (GA) tools and ways to incorporate fitness in therapeutic decision making. We suggest best practices to implement GA in routine practice and clinical trials. The most widely used tool is simplified GA (sGA) which categorizes patients into fit, unfit and frail groups. Patients who are fit benefit from full dose/curative approach, whereas consideration should be made to reduce the intensity of chemotherapy for unfit patients. Frail patients with DLBCL are a major unmet need without any satisfactory treatment options. Ongoing investigations combining novel therapies into chemotherapy-free regimens are underway with promising early results. In the relapsed/refractory (R/R) setting, anti-CD19 CAR-T cell therapy (CART) is now the standard of care for primary refractory disease or relapse within 12 months of completing therapy. Autologous stem cell transplant is still a consideration for fit OA with relapse >12 months after completing therapy. The recent approval of bispecific antibodies is a welcome advance that will greatly benefit OA not eligible for CART. Other regimens available for patients ineligible for CART or for those who experience progression post-CART include polatuzumab-rituximab±bendamustine, tafasitamab-lenalidomide, loncastuximab or chemotherapy-based approaches such as rituximab-gemcitabine-oxaliplatin. We discuss the changing paradigm in R/R DLBCL and spotlight emerging data from recent congresses that can improve outcomes in this vulnerable population.

Novel Bispecific T-Cell Engagers for the Treatment of Relapsed B Cell Non-Hodgkin Lymphomas: Current Knowledge and Treatment Considerations

This article provides an overview of the novel treatments focusing on the class of bispecific T cell engagers (BiTEs) for the treatment of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), the two most prevalent subtypes of B cell non-Hodgkin lymphomas (B-NHL). After a brief outline of these diseases, the difficulties in the management of relapsed or refractory (R/R) disease are highlighted. There are currently 4 main BiTEs showing promise in treating R/R B-NHL-glofitamab, epcoritamab, mosunetuzumab, and odronextamab. Although the rational of their mechanism of action is similar, there are significant differences in their respective clinical trial design, reported outcomes, and the final FDA approvals. Considerations for selecting a specific BiTE therapy, including treatment duration, cost, administration route, adverse effects, and impact on quality of life, are also discussed. Patient preferences and shared decision making should be acknowledged by healthcare providers. Finally, the importance of personalized treatment strategies and ongoing research to optimize outcomes in the evolving landscape of R/R B-NHL therapy cannot be overstated.

Safety and Efficacy of Bispecific Antibodies in Adults with Large B-Cell Lymphomas: A Systematic Review of Clinical Trial Data

Bispecific antibodies (bsAbs) are an emerging therapy in the treatment of large B-cell lymphomas (LBCLs). There is a gap in the research on the safety and efficacy of bsAbs in adults with LBCL, with current research focusing on the wider non-Hodgkin's lymphoma population. To address this research gap, we conducted a systematic review aiming to evaluate the safety and efficacy outcomes of bsAbs in adults with LBCL. A systematized search was conducted in PubMed, EMBASE, and CENTRAL on 10 April 2024. Interventional clinical trials were eligible for inclusion. Observational studies, reviews, and meta-analyses were excluded. According to the Revised Risk of Bias Assessment Tool for Nonrandomized Studies, the included studies were largely of a high quality for safety outcome reporting, but of mixed quality for efficacy outcome reporting. Due to the heterogeneity of the included studies, the results were discussed as a narrative synthesis. Nineteen early phase studies were evaluated in the final analysis, with a pooled sample size of 1332 patients. Nine bsAbs were investigated across the studies as monotherapy (nine studies) or in combination regimes (10 studies). The rates of cytokine release syndrome were variable, with any grade events ranging from 0 to 72.2%. Infection rates were consistently high across the reporting studies (38-60%). Cytopenias were found to be common, in particular, anemia (4.4-62%), thrombocytopenia (3.3-69%), and neutropenia (4.4-70%). Immune effector cell-associated neurotoxicity syndrome (ICANS) and grade ≥3 adverse events were not commonly reported. Promising efficacy outcomes were reported, with median overall response rates of 95-100% in the front-line and 36-91% in terms of relapsed/refractory disease. The results of this systematic review demonstrate that bsAbs are generally well-tolerated and effective in adults with LBCL. BsAbs appear to have superior tolerability, but inferior efficacy to CAR T-cell therapies in adults with LBCL. Future research on safety and efficacy should focus on evaluating adverse event timing and management, the impact on the patient's quality of life, the burden on the healthcare system, and overall survival outcomes.

Spotlight on polatuzumab vedotin: new standards for diffuse large B-cell lymphoma?

Despite continuous improvements in the management and treatment of diffuse large B-cell lymphoma (DLBCL), approximately 35% of affected patients experience relapse or are refractory to frontline chemotherapy. For these patients, outcomes are far from satisfactory, and a real unmet need exists both to improve frontline treatment and to create better options for relapsed/refractory disease. Polatuzumab vedotin is an anti-CD79b antibody conjugated to the monomethyl auristatin E microtubule inhibitor. The molecule has recently been under the spotlight for the promising results of the frontline combination with rituximab, cyclophosphamide, doxorubicin and prednisone in the phase III POLARIX study, demonstrating improved progression-free survival over standard rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. Remarkable improvements in terms of complete response rate and overall survival have also been achieved with polatuzumab vedotin by combining the antibody with the standard rituximab and bendamustine regimen for relapsed/refractory patients. Based on the results of these studies, health authorities in several countries granted approval for polatuzumab vedotin to be used as treatment both for patients with previously untreated DLBCL and for those with relapsed/refractory DLBCL. In this review, we summarize the data of major studies recently concluded with polatuzumab vedotin, and we provide an overview of the ongoing combination trials for frontline and relapsed/refractory DLBCL, outlining reported toxicities.

Update of antibody-drug conjugates for hematological malignancies

PURPOSE OF REVIEW

Antibody-drug conjugates (ADCs), consisting of monoclonal antibodies (mAbs) covalently linked to cytotoxic drugs via chemical linkers, are a kind of promising tumor immunotherapy. ADCs also face a number of challenges, including unavoidable adverse effects, drug resistance, tumor targeting and payload release. To address these issues, in addition to optimizing the individual components of ADCs, such as new payloads, linkage sites and new targets, and using bispecific antibodies to increase precision, attention should be paid to optimizing the dosage of ADCs.

RECENT FINDINGS

There are currently 7 ADCs approved for marketing by the Food and Drug Administration (FDA) for hematological malignancies, and dozens of other ADCs are either in clinical trials or in the process of applying for marketing. In recent clinical studies targeting ADCs in hematologic malignancies, in addition to validating effectiveness in different indications, researchers have attempted to combine ADCs with other chemotherapeutic agents in anticipation of increased therapeutic efficacy. Furthermore, the availability of bispecific antibodies may increase the safety and efficacy of ADCs.

SUMMARY

This review summarized the progress of research on ADCs in hematological malignancies, the challenges being faced, and possible future directions to improve the efficacy of ADCs, which can provide novel insight into the future exploration of ADCs in the treatment of hematological malignancies.

Bispecific antibodies and autologous chimeric antigen receptor T cell therapies for treatment of hematological malignancies

In recent years, the therapeutic landscape for hematological malignancies has markedly advanced, particularly since the inaugural approval of autologous chimeric antigen receptor T cell (CAR-T) therapy in 2017 for relapsed/refractory acute lymphoblastic leukemia (ALL). Autologous CAR-T therapy involves the genetic modification of a patient's T cells to specifically identify and attack cancer cells, while bispecific antibodies (BsAbs) function by binding to both cancer cells and immune cells simultaneously, thereby triggering an immune response against the tumor. The subsequent approval of various CAR-T therapies and BsAbs have revolutionized the treatment of multiple hematological malignancies, highlighting high response rates and a subset of patients achieving prolonged disease control. This review explores the mechanisms underlying autologous CAR-T therapies and BsAbs, focusing on their clinical application in multiple myeloma, ALL, and non-Hodgkin lymphoma. We provide comprehensive insights into their individual efficacy, limitations concerning broad application, and the potential of combination therapies. These upcoming strategies aim to propel the field forward, paving the way for safer and more effective therapeutic interventions in hematological malignancies.

Looking ahead to CD3, T-cell engager bispecific antibodies for hematological malignancies

INTRODUCTION

Since the approval of the bispecific antibody blinatumomab in 2017 for the treatment of acute lymphoblastic leukemia in relapse, the development of numerous bispecific antibody constructs has dramatically expanded in hematologic malignancies. Many have recently received Food Drug Administration and European Medicines Agency approvals in various stages of treatment for lymphomas, leukemias, and multiple myeloma.

AREAS COVERED

The purpose of this review is to provide an overview of bispecific antibody treatment including the mechanisms leading to effector T cells targeting tumor-associated antigens, the treatment indications, efficacies, toxicities, and challenges of the different constructs. A literature search was performed through access to PubMed and clinicaltrials.gov.

EXPERT OPINION

While there has been substantial success in the treatment of NHL, MM, and ALL, there are still hematologic malignancies such as AML where there has been limited progress. It is important to continue to investigate new designs, tumor antigen targets, and further refine where current approved bispecific antibodies fit in terms of sequencing of therapy. Hopefully, with the knowledge gained in recent years and the explosion of these therapies, patients with blood cancers will continue to benefit from these treatments for years to come.

Cancer organoids 2.0: modelling the complexity of the tumour immune microenvironment

The development of neoplasia involves a complex and continuous interplay between malignantly transformed cells and the tumour microenvironment (TME). Cancer immunotherapies targeting the immune TME have been increasingly validated in clinical trials but response rates vary substantially between tumour histologies and are often transient, idiosyncratic and confounded by resistance. Faithful experimental models of the patient-specific tumour immune microenvironment, capable of recapitulating tumour biology and immunotherapy effects, would greatly improve patient selection, target identification and definition of resistance mechanisms for immuno-oncology therapeutics. In this Review, we discuss currently available and rapidly evolving 3D tumour organoid models that capture important immune features of the TME. We highlight diverse opportunities for organoid-based investigations of tumour immunity, drug development and precision medicine.

Bispecific antibody drug conjugates: Making 1+1>2

Bispecific antibody‒drug conjugates (BsADCs) represent an innovative therapeutic category amalgamating the merits of antibody‒drug conjugates (ADCs) and bispecific antibodies (BsAbs). Positioned as the next-generation ADC approach, BsADCs hold promise for ameliorating extant clinical challenges associated with ADCs, particularly pertaining to issues such as poor internalization, off-target toxicity, and drug resistance. Presently, ten BsADCs are undergoing clinical trials, and initial findings underscore the imperative for ongoing refinement. This review initially delves into specific design considerations for BsADCs, encompassing target selection, antibody formats, and the linker-payload complex. Subsequent sections delineate the extant progress and challenges encountered by BsADCs, illustrated through pertinent case studies. The amalgamation of BsAbs with ADCs offers a prospective solution to prevailing clinical limitations of ADCs. Nevertheless, the symbiotic interplay among BsAb, linker, and payload necessitates further optimizations and coordination beyond a simplistic "1 + 1" to effectively surmount the extant challenges facing the BsADC domain.

Beyond Chemotherapy: Present and Future Perspectives in the Treatment of Lymphoproliferative Disorders

Over the past three decades, the treatment of lymphoproliferative disorders has undergone profound changes, notably due to the increasing availability of innovative therapies with the potential to redefine clinical management paradigms. A major impact is related to the development of monoclonal antibodies, checkpoint inhibitors, bispecific antibodies, and chimeric antigen receptor T (CAR-T) cell therapies. This review discusses the current landscape of clinical trials targeting various hematological malignancies, highlighting promising early-phase results and strategies to overcome resistance. Lymphoproliferative disorders encompass a range of conditions: while in Hodgkin lymphoma (HL) the goal is to reduce chemotherapy-related toxicity by integrating immunotherapy into the frontline setting, peripheral T cell lymphoma (PTCL) lacks effective targeted therapies. The review emphasizes a shifting therapeutic landscape towards precision medicine and treatment modalities that are less toxic yet more effective.

Novel and multiple targets for chimeric antigen receptor-based therapies in lymphoma

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 in B-cell non-Hodgkin lymphoma (NHL) validates the utility of CAR-based therapy for lymphomatous malignancies. Despite the success, treatment failure due to CD19 antigen loss, mutation, or down-regulation remains the main obstacle to cure. On-target, off-tumor effect of CD19-CAR T leads to side effects such as prolonged B-cell aplasia, limiting the application of therapy in indolent diseases such as chronic lymphocytic leukemia (CLL). Alternative CAR targets and multi-specific CAR are potential solutions to improving cellular therapy outcomes in B-NHL. For Hodgkin lymphoma and T-cell lymphoma, several cell surface antigens have been studied as CAR targets, some of which already showed promising results in clinical trials. Some antigens are expressed by different lymphomas and could be used for designing tumor-agnostic CAR. Here, we reviewed the antigens that have been studied for novel CAR-based therapies, as well as CARs designed to target two or more antigens in the treatment of lymphoma.

Advancements in cancer immunotherapies targeting CD20: from pioneering monoclonal antibodies to chimeric antigen receptor-modified T cells

CD20 located predominantly on the B cells plays a crucial role in their development, differentiation, and activation, and serves as a key therapeutic target for the treatment of B-cell malignancies. The breakthrough of monoclonal antibodies directed against CD20, notably exemplified by rituximab, revolutionized the prognosis of B-cell malignancies. Rituximab, approved across various hematological malignancies, marked a paradigm shift in cancer treatment. In the current landscape, immunotherapies targeting CD20 continue to evolve rapidly. Beyond traditional mAbs, advancements include antibody-drug conjugates (ADCs), bispecific antibodies (BsAbs), and chimeric antigen receptor-modified (CAR) T cells. ADCs combine the precision of antibodies with the cytotoxic potential of drugs, presenting a promising avenue for enhanced therapeutic efficacy. BsAbs, particularly CD20xCD3 constructs, redirect cytotoxic T cells to eliminate cancer cells, thereby enhancing both precision and potency in their therapeutic action. CAR-T cells stand as a promising strategy for combatting hematological malignancies, representing one of the truly personalized therapeutic interventions. Many new therapies are currently being evaluated in clinical trials. This review serves as a comprehensive summary of CD20-targeted therapies, highlighting the progress and challenges that persist. Despite significant advancements, adverse events associated with these therapies and the development of resistance remain critical issues. Understanding and mitigating these challenges is paramount for the continued success of CD20-targeted immunotherapies.

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.

Trial watch: bispecific antibodies for the treatment of relapsed or refractory large B-cell lymphoma

Immunotherapy has shaped the treatment approach to diffuse large B-cell lymphoma (DLBCL), with rituximab leading to remarkable improvements in outcomes for both relapsed and treatment-naïve patients. Recently, groundbreaking immunotherapies like chimeric antigen receptor T-cells have entered the treatment arena for relapsed/refractory (R/R) DLBCL and gained regulatory approval in several countries. The concept of harnessing a patient's own T-cells to combat cancer has been further explored through the development of bispecific antibodies (BsAbs), a class of engineered antibody products designed to simultaneously target two different antigens. These novel drugs have demonstrated impressive single-agent activity and manageable toxicity in patients with heavily pretreated B-cell non-Hodgkin lymphoma. In this review, we provide an up-to-date overview of recently completed or ongoing BsAbs trials in patients with R/R DLBCL, including single-agent results, emerging combination data, and novel constructs.

Innovations in Antibody-Drug Conjugate (ADC) in the Treatment of Lymphoma

Chemoimmunotherapy and cellular therapy are the mainstay of the treatment of relapsed/refractory (R/R) lymphomas. Development of resistance and commonly encountered toxicities of these treatments limit their role in achieving desired response rates and durable remissions. The Antibody-Drug Conjugate (ADC) is a novel class of targeted therapy that has demonstrated significant efficacy in treating various cancers, including lymphomas. To date, three ADC agents have been approved for different lymphomas, marking a significant advancement in the field. In this article, we aim to review the concept of ADCs and their application in lymphoma treatment, provide an analysis of currently approved agents, and discuss the ongoing advancements of ADC development.