Antibody–Drug Conjugates for the Treatment of Hematological Malignancies: A Comprehensive Review

Synergistic antitumor activity between HER2 antibody-drug conjugate and chemotherapy for treating advanced colorectal cancer

Colorectal cancer (CRC) is the third most common cancer associated with a poor prognosis. Effective targeted therapy alone or in combination for treating advanced CRC remains to be a major clinical challenge. Here, we propose the therapeutic efficacy and molecular mechanism underlying RC48, a FDA-approved anti-HER2 antibody conjugate via a cleavable linker to the microtubule inhibitor monomethyl auristatin E (MMAE), either alone or in combination with gemcitabine (GEM) in various models of HER2-positive advanced CRC. Our findings demonstrated that HER2 was widely expressed and located on the plasma membrane of CRC patient specimens, PDX xenograft tumors and cell lines. It confirmed that RC48 alone significantly targeted and eradicated HER2 positive CRC tumor in these models. Moreover, we screened a panel of FDA-approved first-line chemotherapy drugs in vitro. We found that GEM exhibited stronger antiproliferative activity compared to the other first-line anti-cancer agents. Furthermore, combination therapy of RC48 and GEM significantly showed synergetic antitumor activity in vitro and in vivo. To gain further mechanistic insights into the combination therapy, we performed RNA-seq analysis. The results revealed that combination treatment of RC48 and GEM regulated multiple signaling pathways, such as PI3K-AKT, MAPK, p53, Foxo, apoptosis, cell cycle and cell senescence, etc., to exert its antitumor activity in CRC cells. Collectively, these preclinical findings demonstrated that RC48 alone or combinational therapy exerted promising antitumor activity, and meriting the preclinical framework for combinational therapy of anti-HER2 drug conjugate drug and chemotherapy drugs for HER2-positive patients with advanced CRC.

Nanoparticle-Based Approaches for Treatment of Hematological Malignancies: a Comprehensive Review

Blood cancer, also known as hematological malignancy, is one of the devastating types of cancer that has significantly paved its mortality mark globally. It persists as an extremely deadly cancer type and needs utmost attention owing to its negligible overall survival rate. Major challenges in the treatment of blood cancer include difficulties in early diagnosis, as well as severe side effects resulting from chemotherapy. In addition, immunotherapies and targeted therapies can be prohibitively expensive. Over the past two decades, scientists have devised a few nanoparticle-based drug delivery systems aimed at overcoming this challenge. These therapeutic strategies are engineered to augment the cellular uptake, pharmacokinetics, and effectiveness of anticancer drugs. However, there are still numerous types of nanoparticles that could potentially improve the efficacy of blood cancer treatment, while also reducing treatment costs and mitigating drug-related side effects. To the best of our knowledge, there has been limited reviews published on the use of nano-based drug delivery systems for the treatment of hematological malignancies. Therefore, we have made a concerted effort to provide a comprehensive review that draws upon recent literature and patents, with a focus on the most promising results regarding the use of nanoparticle-based approaches for the treatment of hematological malignancies. All these crucial points covered under a common title would significantly help researchers and scientists working in the area.

Antibody-Drug Conjugates for the Treatment of Renal Cancer: A Scoping Review on Current Evidence and Clinical Perspectives

Antibody-drug conjugates (ADCs) are complex chemical structures composed of a monoclonal antibody, serving as a link to target cells, which is conjugated with a potent cytotoxic drug (i.e., payload) through a chemical linker. Inspired by Paul Ehrlich's concept of the ideal anticancer drug as a "magic bullet", ADCs are also highly specific anticancer agents, as they have been demonstrated to recognize, bind, and neutralize cancer cells, limiting injuries to normal cells. ADCs are among the newest pharmacologic breakthroughs in treating solid and hematologic malignancies. Indeed, in recent years, various ADCs have been approved by the Food and Drug Administration and European Medicines Agency for the treatment of several cancers, resulting in a "practice-changing" approach. However, despite these successes, no ADC is approved for treating patients affected by renal cell carcinoma (RCC). In the present paper, we thoroughly reviewed the current literature and summarized preclinical studies and clinical trials that evaluated the activity and toxicity profile of ADCs in RCC patients. Moreover, we scrutinized the potential causes that, until now, hampered the therapeutical success of ADCs in those patients. Finally, we discussed novel strategies that would improve the development of ADCs and their efficacy in treating RCC patients.

Therapeutic efficacy of a MMAE-based anti-DR5 drug conjugate Oba01 in preclinical models of pancreatic cancer

Pancreatic cancer (PC) is among the most aggressive malignancies associated with a 5-year survival rate of <9%, and the treatment options remain limited. Antibody-drug conjugates (ADCs) are a new class of anticancer agents with superior efficacy and safety profiles. We studied the antitumor activity of Oba01 ADC and the mechanism underlying the targeting of death receptor 5 (DR5) in preclinical PC models. Our data revealed that DR5 was highly expressed on the plasma membrane of PC cells and Oba01 showed potent in vitro antitumor activity in a panel of human DR5-positive PC cell lines. DR5 was readily cleaved by lysosomal proteases after receptor-mediated internalization. Monomethyl auristatin E (MMAE) was then released into the cytosol to induce G2/M-phase growth arrest, cell death via apoptosis induction, and the bystander effect. Furthermore, Oba01 mediated cell death via antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. For improved potency, we investigated the synergetic effect of Oba01 in combination with approved drugs. Oba01 combined with gemcitabine showed better antiproliferative activity than either standalone treatment. In cell- and patient-derived xenografts, Oba01 showed excellent tumoricidal activity in mono- or combinational therapy. Thus, Oba01 may provide a novel biotherapeutic approach and a scientific basis for clinical trials in DR5-expressing patients with PC.

Education and Empowering Special Forces to Eradicate Secret Defectors: Immune System-Based Treatment Approaches for Mature T- and NK-Cell Malignancies

Mature T- and NK-cell leukemia/lymphoma (MTCL/L) constitute a heterogeneous group of, currently, 30 distinct neoplastic entities that are overall rare, and all present with a challenging molecular markup. Thus, so far, the use of first-line cancer treatment modalities, including chemotherapies, achieve only limited clinical responses associated with discouraging prognoses. Recently, cancer immunotherapy has evolved rapidly, allowing us to help patients with, e.g., solid tumors and also relapsed/refractory B-cell malignancies to achieve durable clinical responses. In this review, we systematically unveiled the distinct immunotherapeutic approaches available, emphasizing the special impediments faced when trying to employ immune system defense mechanisms to target 'one of their own-gone mad'. We summarized the preclinical and clinical efforts made to employ the various platforms of cancer immunotherapies including antibody-drug conjugates, monoclonal as well as bispecific antibodies, immune-checkpoint blockades, and CAR T cell therapies. We emphasized the challenges to, but also the goals of, what needs to be done to achieve similar successes as seen for B-cell entities.

Advances in antibody-based therapy in oncology

Monoclonal antibodies are a growing class of targeted cancer therapeutics, characterized by exquisite specificity, long serum half-life, high affinity and immune effector functions. In this review, we outline key advances in the field with a particular focus on recent and emerging classes of engineered antibody therapeutic candidates, discuss molecular structure and mechanisms of action and provide updates on clinical development and practice.

Antibodies and bispecifics for multiple myeloma: effective effector therapy

The therapeutic landscape in multiple myeloma (MM) has changed dramatically over the last 2 decades. With the introduction of novel immunotherapies, patients with MM can expect deeper responses, longer remissions, and improved overall survival. Since its approval by the US Food and Drug Administration in 2015, the monoclonal antibody specific for CD38, daratumumab, has been incorporated into both frontline and relapsed treatment regimens. Its role as a maintenance therapy is currently being explored. Subsequently, a variety of novel antibody therapeutics have evolved from the success of daratumumab, using similar concepts to target the malignant plasma cell clone. Noteworthy naked monoclonal antibodies include isatuximab, another agent directed against CD38, and elotuzumab, an agent directed against SLAM family member 7. Antibody-drug conjugates, complex molecules composed of an antibody tethered to a cytotoxic drug, target malignant cells and deliver a lethal payload. The first to market is belantamab mafodotin, which targets B-cell maturation antigen (BCMA) on malignant plasma cells and delivers a potent microtubule inhibitor, monomethyl auristatin F. Additionally, bispecific T-cell antibodies are in development that engage the immune system directly by simultaneously binding CD3 on T cells and a target epitope-such as BCMA, G-protein coupled receptor family C group 5 member D (GPRC5d), and Fc receptor homologue 5 (FcRH5)-on malignant cells. Currently, teclistamab, an anti-BCMA bispecific, is closest to approval for commercial use. In this review, we explore the evolving landscape of antibodies in the treatment of MM, including their role in frontline and relapse settings.

Antibody-drug conjugate as targeted therapeutics against hepatocellular carcinoma: preclinical studies and clinical relevance

An antibody-drug conjugate (ADC) is an advanced chemotherapeutic option with immense promises in treating many tumor. They are designed to selectively attack and kill neoplastic cells with minimal toxicity to normal tissues. ADCs are complex engineered immunoconjugates that comprise a monoclonal antibody for site-directed delivery and cytotoxic payload for targeted destruction of malignant cells. Therefore, it enables the reduction of off-target toxicities and enhances the therapeutic index of the drug. Hepatocellular carcinoma (HCC) is a solid tumor that shows high heterogeneity of molecular phenotypes and is considered the second most common cause of cancer-related death. Studies show enormous potential for ADCs targeting GPC3 and CD24 and other tumor-associated antigens in HCC with their high, selective expression and show potential outputs in preclinical evaluations. The review mainly highlights the preclinical evaluation of different antigen-targeted ADCs such as MetFab-DOX, Anti-c-Met IgG-OXA, Anti CD 24, ANC-HN-01, G7mab-DOX, hYP7-DCand hYP7-PC, Anti-CD147 ILs-DOX and AC133-vcMMAF against hepatocellular carcinoma and its future relevance.

A Decade of FDA-Approved Drugs (2010-2019): Trends and Future Directions

A total of 378 novel drugs and 27 biosimilars approved by the U.S. Food and Drug Administration (FDA) between 2010 and 2019 were evaluated according to approval numbers by year, therapeutic areas, modalities, route of administration, first-in-class designation, approval times, and expedited review categories. From this review, oncology remains the top therapy area (25%), followed by infection (15%) and central nervous system disorders (11%). Regulatory incentives have been effective as evidenced by an increase in orphan drugs as well as antibacterial drugs approved under the GAIN act. Clinical development times may be increasing, perhaps as a result of the increase in orphan drug indications. Small molecules continue to mostly adhere to "Rule of 5" (Ro5) parameters, but innovation in new modalities is rapidly progressing with approvals for antisense oligonucleotides (ASO), small-interfering RNA (siRNAs), and antibody-directed conjugates (ADCs). Finally, novel targets and scientific breakthroughs that address areas of unmet clinical need are discussed in detail.

Antibody-drug conjugates for previously treated aggressive lymphomas: focus on polatuzumab vedotin

INTRODUCTION

Antibody-drug conjugates (ADCs) are immunoconjugates and comprise a monoclonal antibody that is chemically attached to a cytotoxic drug (or payload) via a stable chemical linker. Since the approval of the first ADC in 2000, there are now nine different approved agents and over 100 ADCs in the drug-development pipeline.

AREAS COVERED

This review briefly describes the ADCs approved for treatment of lymphoma and their distinguishing factors in terms of target, linker and payload. The clinical implications of the use of ADCs are also considered. Here, we focus on polatuzumab vedotin, an ADC targeted to CD79b, which is approved for the treatment of patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) who have received at least one (EU approval) or two (US approval) prior therapies and are not eligible for bone marrow transplantation. The characteristics of polatuzumab vedotin are discussed and clinical data are presented. The future of polatuzumab vedotin clinical development, and ADCs in general, are also considered.

EXPERT OPINION

ADCs represent a significant advance in the treatment of lymphoma. Polatuzumab vedotin has shown clinical efficacy and a tolerable safety profile in both first-line and R/R DLBCL; future studies are planned to further investigate this ADC.