Phase I study of IMGN901, a CD56-targeting antibody-drug conjugate, in patients with CD56-positive solid tumors

Antibody-drug conjugates treatment of small cell lung cancer: advances in clinical research

Small cell lung cancer (SCLC) is an extremely aggressive cancer with a relatively low median survival rate after diagnosis. Treatment options such as chemotherapy or combination immunotherapy have shown clinical benefits, but resistance and relapse can occur. Antibody-drug conjugates (ADCs), as a novel class of biopharmaceutical compounds, have broad application prospects in the treatment of SCLC. ADCs consist of monoclonal antibodies that specifically target cancer cells and are attached to cytotoxic drugs, allowing for targeted killing of cancer cells while sparing healthy tissues. Current clinical studies focus on Delta-like protein 3 (DLL3), CD56, Trophoblast cell surface antigen 2 (Trop-2), B7-H3, and SEZ6. Although toxicities exceeding expectations have been observed with Rova-T, drugs targeting TROP-2 (Sacituzumab Govitecan), B7-H3 (DS-7300), and SEZ6 (ABBV-011) have shown exciting clinical benefits. In this review, we collect the latest clinical evidence to describe the therapeutic efficacy and safety of ADCs in SCLC and discuss prospects and challenges.

Merkel cell carcinoma: updates in tumor biology, emerging therapies, and preclinical models

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma thought to arise via either viral (Merkel cell polyomavirus) or ultraviolet-associated pathways. Surgery and radiotherapy have historically been mainstays of management, and immunotherapy has improved outcomes for advanced disease. However, there remains a lack of effective therapy for those patients who fail to respond to these established approaches, underscoring a critical need to better understand MCC biology for more effective prognosis and treatment. Here, we review the fundamental aspects of MCC biology and the recent advances which have had profound impact on management. The first genetically-engineered mouse models for MCC tumorigenesis provide opportunities to understand the potential MCC cell of origin and may prove useful for preclinical investigation of novel therapeutics. The MCC cell of origin debate has also been advanced by recent observations of MCC arising in association with a clonally related hair follicle tumor or squamous cell carcinoma in situ. These studies also suggested a role for epigenetics in the origin of MCC, highlighting a potential utility for this therapeutic avenue in MCC. These and other therapeutic targets form the basis for a wealth of ongoing clinical trials to improve MCC management. Here, we review these recent advances in the context of the existing literature and implications for future investigations.

Novel Therapeutic Options for Small Cell Lung Cancer

PURPOSE OF REVIEW

The aim of this review is to focus on the recent advances in the molecular knowledge of small cell lung cancer (SCLC) and potential promising new treatment strategies, like targeting the DNA damage pathway, epigenetics, angiogenesis, and oncogenic drivers.

RECENT FINDINGS

In the last few years, the addition of immunotherapy to chemotherapy has led to significant improvements in clinical outcomes in this complex neoplasia. Nevertheless, the prognosis remains dismal. Recently, numerous genomic alterations have been identified, and they may be useful to classify SCLC into different molecular subtypes (SCLC-A, SCLC-I, SCLC-Y, SCLC-P). SCLC accounts for 10-20% of all lung cancers, most patients have an extensive disease at the diagnosis, and it is characterized by poor prognosis. Despite the progresses in the knowledge of the disease, efficacious targeted treatments are still lacking. In the near future, the molecular characterisation of SCLC will be fundamental to find more effective treatment strategies.

Orchestrating smart therapeutics to achieve optimal treatment in small cell lung cancer: recent progress and future directions

Small cell lung cancer (SCLC) is a recalcitrant malignancy with elusive mechanism of pathogenesis and dismal prognosis. Over the past decades, platinum-based chemotherapy has been the backbone treatment for SCLC. However, subsequent chemoresistance after initial effectiveness urges researchers to explore novel therapeutic targets of SCLC. Recent years have witnessed significant improvements in targeted therapy in SCLC. New molecular candidates such as Ataxia telangiectasia and RAD3-related protein (ATR), WEE1, checkpoint kinase 1 (CHK1) and poly-ADP-ribose polymerase (PARP) have shown promising therapeutic utility in SCLC. While immune checkpoint inhibitor (ICI) has emerged as an indispensable treatment modality for SCLC, approaches to boost efficacy and reduce toxicity as well as selection of reliable biomarkers for ICI in SCLC have remained elusive and warrants our further investigation. Given the increasing importance of precision medicine in SCLC, optimal subtyping of SCLC using multi-omics have gradually applied into clinical practice, which may identify more drug targets and better tailor treatment strategies to each individual patient. The present review summarizes recent progress and future directions in SCLC. In addition to the emerging new therapeutics, we also focus on the establishment of predictive model for early detection of SCLC. More importantly, we also propose a multi-dimensional model in the prognosis of SCLC to ultimately attain the goal of accurate treatment of SCLC.

Current and preclinical treatment options for Merkel cell carcinoma

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare, highly aggressive form of skin cancer with neuroendocrine features. The origin of this cancer is still unclear, but research in the last 15 years has demonstrated that MCC arises via two distinct etiologic pathways, i.e. virus and UV-induced. Considering the high mortality rate and the limited therapeutic options available, this review aims to highlight the significance of MCC research and the need for advancement in MCC treatment.

AREAS COVERED

With the advent of the immune checkpoint inhibitor therapies, we now have treatment options providing a survival benefit for patients with advanced MCC. However, the issue of primary and acquired resistance to these therapies remains a significant concern. Therefore, ongoing efforts seeking additional therapeutic targets and approaches for MCC therapy are a necessity. Through a comprehensive literature search, we provide an overview on recent preclinical and clinical studies with respect to MCC therapy.

EXPERT OPINION

Currently, the only evidence-based therapy for MCC is immune checkpoint blockade with anti-PD-1/PD-L1 for advanced patients. Neoadjuvant, adjuvant and combined immune checkpoint blockade are promising treatment options.

CD56-positive diffuse large B-cell lymphoma: comprehensive analysis of clinical, pathological, and molecular characteristics with literature review

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. The expression of CD56 in DLBCL is highly unusual. Little is known about its incidence and clinical importance. So far, no genetic profiling was performed in CD56 positive DLBCL.

PATIENTS AND METHODS

Tissue microarrays have been constructed, sectioned, and stained by H&E and immunohistochemistry for 229 patients with DLBCL diagnosed 2008-2017. For CD56 positive cases, clinical data was collected including age at diagnosis, stage of the disease, International Prognostic Index (IPI) score, treatment scheme and number of chemotherapy cycles, radiation therapy, treatment outcome, and possible relapse of the disease. Overall survival (OS) and progression-free survival (PFS) were calculated. For four patients, RNA was extracted and targeted RNA (cDNA) sequencing of 125 genes was performed with the Archer FusionPlex Lymphoma kit.

RESULTS

CD56 expression was found in 7 cases (3%). The intensity of expression varied from weak to moderate focal, to very intensive and diffuse. All patients had de novo DLBCL. The median age at the time of diagnosis was 54.5 years. Five of them were women and 2 males. According to the Hans algorithm, 6 patients had the germinal centre B cells (GBC) type and one non-GBC (activated B-cell [ABC]) type, double expressor. Genetic profiling of four patients according to Schmitz's classification showed that 1 case was of the BN2 subtype, 1 of EZB subtype, 2 were unclassified. The six treated patients reached a complete response and did not experience progression of the disease during the median follow-up period of 80.5 months.

CONCLUSIONS

We report on one of the largest series of CD56+DLBCL with detailed clinicopathological data and for the first time described genetical findings in a limited number of patients. Our results show that CD56 expression is rare, but seems to be present in prognostic favourable subtypes of DLBCL not otherwise specified (NOS) as tested by immunohistochemical or genetic profiling.

CAR T-Cell Therapy in Children with Solid Tumors

The limited efficacy of traditional cancer treatments, including chemotherapy, radiotherapy, and surgery, emphasize the significance of employing innovative methods. CAR (Chimeric Antigen Receptor) T-cell therapy remains the most revolutionizing treatment of pediatric hematological malignancies and solid tumors. Patient’s own lymphocytes are modified ex-vivo using gene transfer techniques and programmed to recognize and destroy specific tumor cells regardless of MHC receptor, which probably makes CAR-T the most personalized therapy for the patient. With continued refinement and optimization, CAR-T cell therapy has the potential to significantly improve outcomes and quality of life for children with limited treatment options. It has shown remarkable success in treating hematological malignancies, such as acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). However, its effectiveness in treating solid tumors is still being investigated and remains an area of active research. In this review we focus on solid tumors and explain the concept of CAR modified T cells, and discuss some novel CAR designs that are being considered to enhance the safety of CAR T-cell therapy in under-mentioned cancers. Furthermore, we summarize the most crucial recent reports concerning the solid tumors treatment in children. In the end we provide a short summary of many challenges that limit the therapeutic efficacy of CAR-T in solid tumors, such as antigen escape, immunosuppressive microenvironment, poor trafficking, and tumor infiltration, on-target off-tumor effects and general toxicity.

Lung cancer immunotherapy: progress, pitfalls, and promises

Lung cancer is the primary cause of mortality in the United States and around the globe. Therapeutic options for lung cancer treatment include surgery, radiation therapy, chemotherapy, and targeted drug therapy. Medical management is often associated with the development of treatment resistance leading to relapse. Immunotherapy is profoundly altering the approach to cancer treatment owing to its tolerable safety profile, sustained therapeutic response due to immunological memory generation, and effectiveness across a broad patient population. Different tumor-specific vaccination strategies are gaining ground in the treatment of lung cancer. Recent advances in adoptive cell therapy (CAR T, TCR, TIL), the associated clinical trials on lung cancer, and associated hurdles are discussed in this review. Recent trials on lung cancer patients (without a targetable oncogenic driver alteration) reveal significant and sustained responses when treated with programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint blockade immunotherapies. Accumulating evidence indicates that a loss of effective anti-tumor immunity is associated with lung tumor evolution. Therapeutic cancer vaccines combined with immune checkpoint inhibitors (ICI) can achieve better therapeutic effects. To this end, the present article encompasses a detailed overview of the recent developments in the immunotherapeutic landscape in targeting small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Additionally, the review also explores the implication of nanomedicine in lung cancer immunotherapy as well as the combinatorial application of traditional therapy along with immunotherapy regimens. Finally, ongoing clinical trials, significant obstacles, and the future outlook of this treatment strategy are also highlighted to boost further research in the field.

Antibody-Drug Conjugates for Melanoma and Other Skin Malignancies

OPINION STATEMENT

While most skin malignancies are successfully treated with surgical excision, advanced and metastatic skin malignancies still often have poor long-term outcomes despite therapeutic advances. Antibody-drug conjugates (ADCs) serve as a potentially promising novel therapeutic approach to treat advanced skin cancers as they combine antibody-associated antigen specificity with cytotoxic anti-tumor effects, thereby maximizing efficacy and minimizing systemic toxicity. While no ADCs have gained regulatory approval for advanced skin cancers, several promising agents are undergoing preclinical and clinical investigation. In addition to identifying and validating skin cancer antigen targets, the key to maximizing therapeutic success is the careful development of each component of the ADC complex: antibodies, cytotoxic drugs, and linkers. It is the optimization of each of these components that will be integral in overcoming resistance, maximizing safety, and improving long-term clinical outcomes.

Immunotherapy of Neuroendocrine Neoplasms: Any Role for the Chimeric Antigen Receptor T Cells?

Simple Summary

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of tumors arising in different organs whose clinical course is variable according to histological differentiation and metastatic spread. Therapeutic options have recently expanded, but there is a need for new effective therapies, especially in less differentiated forms. Chimeric antigen receptor T cells (CAR-T) have shown efficacy in several cancers, mainly hematological, but data on NENs are scattered. We aimed to analyze the available preclinical and clinical data about CAR-T in NENs, to highlight their potential role in clinical practice. A significant therapeutic effect of CAR-T cells in NENs emerges from preclinical studies. Results from clinical trials are expected in order to define their effective role in these cancers.

Abstract

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with variable clinical presentation and prognosis. Surgery, when feasible, is the most effective and often curative treatment. However, NENs are frequently locally advanced or already metastatic at diagnosis. Consequently, additional local or systemic therapeutic approaches are required. Immunotherapy, based on chimeric antigen receptor T cells (CAR-T), is showing impressive results in several cancer treatments. The aim of this narrative review is to analyze the available data about the use of CAR-T in NENs, including studies in both preclinical and clinical settings. We performed an extensive search for relevant data sources, comprising full-published articles, abstracts from international meetings, and worldwide registered clinical trials. Preclinical studies performed on both cell lines and animal models indicate a significant therapeutic effect of CAR-T cells in NENs. Ongoing and future clinical trials will clarify the possible role of these drugs in patients with highly aggressive NENs.

Antibody-Drug Conjugate Targets, Drugs and Linkers

Antibody-drug conjugates offer the possibility of directing powerful cytotoxic agents to a malignant tumor while sparing normal tissue. The challenge is to select an antibody target expressed exclusively or at highly elevated levels on the surface of tumor cells and either not all or at low levels on normal cells. The current review explores 78 targets that have been explored as antibody-drug conjugate targets. Some of these targets have been abandoned, 9 or more are the targets of FDA-approved drugs, and most remain active clinical interest. Antibody-drug conjugates require potent cytotoxic drug payloads, several of these small molecules are discussed, as are the linkers between the protein component and small molecule components of the conjugates. Finally, conclusions regarding the elements for the successful antibody-drug conjugate are discussed.

Antibody–Drug Conjugates as an Emerging Therapy in Oncodermatology

Simple Summary

Currently, the therapeutic arsenal to fight cancers is extensive. Among these, antibody–drug conjugates (ADCs) consist in an antibody linked to a cytotoxic agent, allowing a specific delivery to tumor cells. ADCs are an emerging class of therapeutics, with twelve FDA- and EMA-approved drugs for hematological and solid cancers. In recent years, tremendous progress has been observed in therapeutic approaches for advanced skin cancer patients. ADCs appear as an emerging therapeutic option in oncodermatology. After providing an overview of ADC design and development, the goal of this article is to review the potential ADC indications in the field of oncodermatology.

Abstract

Antibody–drug conjugates (ADCs) are an emerging class of therapeutics, with twelve FDA- and EMA-approved drugs for hematological and solid cancers. Such drugs consist in a monoclonal antibody linked to a cytotoxic agent, allowing a specific cytotoxicity to tumor cells. In recent years, tremendous progress has been observed in therapeutic approaches for advanced skin cancer patients. In this regard, targeted therapies (e.g., kinase inhibitors) or immune checkpoint-blocking antibodies outperformed conventional chemotherapy, with proven benefit to survival. Nevertheless, primary and acquired resistances as well as adverse events remain limitations of these therapies. Therefore, ADCs appear as an emerging therapeutic option in oncodermatology. After providing an overview of ADC design and development, the goal of this article is to review the potential ADC indications in the field of oncodermatology.

Antibody-drug conjugates: Resurgent anticancer agents with multi-targeted therapeutic potential

Antibody-drug conjugates (ADCs) constitute a relatively new group of anticancer agents, whose first appearance took place about two decades ago, but a renewed interest occurred in recent years, following the success of anti-cancer immunotherapy with monoclonal antibodies. Indeed, an ADC combines the selectivity of a monoclonal antibody with the cell killing properties of a chemotherapeutic agent (payload), joined together through an appropriate linker. The antibody moiety targets a specific cell surface antigen expressed by tumor cells and/or cells of the tumor microenvironment and acts as a carrier that delivers the cytotoxic payload within the tumor mass. Despite advantages in terms of selectivity and potency, the development of ADCs is not devoid of challenges, due to: i) low tumor selectivity when the target antigens are not exclusively expressed by cancer cells; ii) premature release of the cytotoxic drug into the bloodstream as a consequence of linker instability; iii) development of tumor resistance mechanisms to the payload. All these factors may result in lack of efficacy and/or in no safety improvement compared to unconjugated cytotoxic agents. Nevertheless, the development of antibodies engineered to remain inert until activated in the tumor (e.g., antibodies activated proteolytically after internalization or by the acidic conditions of the tumor microenvironment) together with the discovery of innovative targets and cytotoxic or immunomodulatory payloads, have allowed the design of next-generation ADCs that are expected to possess improved therapeutic properties. This review provides an overview of approved ADCs, with related advantages and limitations, and of novel targets exploited by ADCs that are presently under clinical investigation.

Adcitmer® , a new CD56-targeting monomethyl auristatin E-conjugated antibody, is a potential therapeutic approach in Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive skin cancer, whose tumour cells often express CD56. While immune checkpoint inhibitors constitute a major advance for treating patients with MCC with advanced disease, new therapeutic options are still urgently required.

OBJECTIVES

To produce and evaluate the therapeutic performance of a new antibody-drug conjugate (Adcitmer^® ) targeting CD56 in preclinical models of MCC.

METHODS

CD56 expression was evaluated in a MCC cohort (immunohistochemistry on a tissue microarray of 90 tumour samples) and MCC cell lines. Interaction of an unconjugated CD56-targeting antibody with CD56⁺ MCC cell lines was investigated by immunohistochemistry and imaging flow cytometry. Adcitmer^® product was generated by the bioconjugation of CD56-targeting antibody to a cytotoxic drug (monomethyl auristatin E) using the McSAF Inside^® bioconjugation process. The chemical properties and homogeneity of Adcitmer^® were characterized by hydrophobic interaction chromatography. Adcitmer^® cytotoxicity was evaluated in vitro and in an MCC xenograft mice model.

RESULTS

Similar to previous reports, CD56 was expressed by 66% of MCC tumours in our cohort, confirming its relevance as a therapeutic target. Specific binding and internalization of the unconjugated CD56-targeting antibody was validated in MCC cell lines. The high homogeneity of the newly generated Adcitmer^® was confirmed by hydrophobic interaction chromatography. The CD56-mediated cytotoxicity of Adcitmer^® was demonstrated in vitro in MCC cell lines. Moreover, Adcitmer^® significantly reduced tumour growth in a MCC mouse model.

CONCLUSIONS

Our study suggests that Adcitmer^® should be further assessed as a therapeutic option in patients with MCC, as an alternative therapy or combined with immune checkpoint inhibitors.

Emerging therapies for rare cutaneous cancers: A systematic review

BACKGROUND

Rare cutaneous cancers require early management given their aggressive nature; however, few therapeutic options exist for managing these rare cancers.

OBJECTIVE

To identify emerging therapies for extramammary Paget's disease, Merkel cell carcinoma, sebaceous gland carcinoma, microcystic adnexal carcinoma, Kaposi sarcoma and cutaneous angiosarcoma.

METHODS

A systematic review was conducted using PubMed database from October 2010 to October 2020. Published clinical trials and case reports/series were included if they involved primarily a targeted agent rather than classic cytotoxic chemotherapy or photosensitizing medication. Active clinical trials were evaluated using ClinicalTrials.gov, the Japanese University Hospitals Clinical Information Network, and the ISRCTN registry. Quality of evidence for each study was rated using the Oxford Centre for Evidence-Based Medicine Level of Evidence Rating Scale.

RESULTS

There are several emerging therapies for rare cutaneous cancers with many clinical trials actively recruiting. PD-1 receptor inhibitors were the most investigated treatment, targeting several cancers. Merkel cell carcinoma and Kaposi sarcoma had the most clinical trials while microcystic adnexal carcinoma and sebaceous gland carcinoma had the least. The main limitation was a lack of key findings from clinical trials still in progress.

CONCLUSIONS

Emerging therapies exist for rare cutaneous cancers; results of ongoing studies will provide more robust evidence in the future.

Clinical development of CAR T cell therapy in China: 2020 update

Chimeric antigen receptor (CAR) T-cell therapy has achieved significant success in the treatment of hematological malignancies. In recent years, fast-growing CAR T clinical trials have actively explored their potential application scenarios. According to the data from the clinicaltrials.gov website, China became the country with the most registered CAR T trials in September 2017. As of June 30, 2020, the number of registered CAR T trials in China has reached 357. In addition, as many as 150 other CAR T trials have been registered on ChiCTR. Although CAR T therapy is flourishing in China, there are still some problems that cannot be ignored. In this review, we aim to systematically summarize the clinical practice of CAR T-cell therapy in China. This review will provide an informative reference for colleagues in the field, and a better understanding of the history and current situation will help us more reasonably conduct research and promote cooperation.

Cardiophrenic Lymph Node Metastasis of Ovarian High-grade Serous Carcinoma Showing Wild-type p53 Immunostaining Pattern and Aberrant CD56 Expression

Patterns of p53 immunostaining are used as a surrogate marker for tumor protein 53 (TP53) mutations in the diagnosis of ovarian high-grade serous carcinoma (HGSC). We present a rare case of ovarian HGSC that metastasized to the diaphragm and cardiophrenic lymph nodes and showed the immunostaining pattern of wild-type p53 and aberrant neural cell adhesion molecule (CD56) expression. A 63-year-old woman developed multifocal metastases in the diaphragmatic pleura and cardiophrenic lymph nodes. Because she had a history of ovarian HGSC and pulmonary adenocarcinoma, we considered the possibility that the metastatic carcinoma was of either ovarian or pulmonary origin. Immunostaining revealed that the tumor cells were negative for thyroid transcription factor 1 but positive for Wilms tumor 1. The tumor additionally exhibited strong membranous CD56 expression and patchy p53 expression, both of which were inconsistent with the characteristics of ovarian HGSC. However, targeted sequencing analysis revealed that the tumor harbored a pathogenic mutation at the splice acceptor site of TP53 intron 9 (c.994-1G>C).

Isolation and preliminary characterization of a human 'phage display'-derived antibody against neural adhesion molecule-1 antigen interfering with fibroblast growth factor receptor-1 binding

BACKGROUND

The NCAM or CD56 antigen is a cell surface glycoprotein belonging to the immunoglobulin super-family involved in cell-cell and cell-matrix adhesion. NCAM is also over-expressed in many tumour types and is considered a tumour associated antigen, even if its role and biological mechanisms implicated in tumour progression and metastasis have not yet to be elucidated. In particular, it is quite well documented the role of the interaction between the NCAM protein and the fibroblast growth factor receptor-1 in metastasis and invasion, especially in the ovarian cancer progression.

OBJECTIVE

Here we describe the isolation and preliminary characterization of a novel human anti-NCAM single chain Fragment variable antibody able to specifically bind NCAM-expressing cells, including epithelial ovarian cancer cells.

METHODS

The antibody was isolate by phage display selection and was characterized by ELISA, FACS analysis and SPR experiments. Interference in EOC migration was analyzed by scratch test.

RESULTS

It binds a partially linear epitope lying in the membrane proximal region of two fibronectin-like domains with a dissociation constant of 3.43 × 10-8 M. Interestingly, it was shown to interfere with the NCAM-FGFR1 binding and to partially decrease migration of EOC cells.

CONCLUSIONS

According to our knowledge, this is the first completely human antibody able to interfere with this newly individuated cancer mechanism.

Cell Adhesion Molecules in Plasticity and Metastasis

Prior to metastasis, modern therapeutics and surgical intervention can provide a favorable long-term survival for patients diagnosed with many types of cancers. However, prognosis is poor for patients with metastasized disease. Melanoma is the deadliest form of skin cancer, yet in situ and localized, thin melanomas can be biopsied with little to no postsurgical follow-up. However, patients with metastatic melanoma require significant clinical involvement and have a 5-year survival of only 34% to 52%, largely dependent on the site of colonization. Melanoma metastasis is a multi-step process requiring dynamic changes in cell surface proteins regulating adhesiveness to the extracellular matrix (ECM), stroma, and other cancer cells in varied tumor microenvironments. Here we will highlight recent literature to underscore how cell adhesion molecules (CAM) contribute to melanoma disease progression and metastasis.

A narrative review of progress in diagnosis and treatment of small cell lung cancer patients with hyponatremia

Small cell lung cancer (SCLC) is one of the malignant cancers of lung tumors, and hyponatremia, defined as serum sodium concentration (Na⁺) lower than 135 mmol/L, is the most common complication of solid tumors, with an incidence of up to 18.9% and a negative impact on quality of life in SCLC. As a prognostic index of SCLC, timely monitoring and correcting of hyponatremia is of great clinical significance for prolonging the survival period of patients. In the explore of new drugs for small cell lung cancer, it is necessary to include hyponatremia as an evaluation index in clinical studies. As the occurrence of hyponatremia is sometimes unavoidable owing to SCLC specific neurological characteristics, early monitoring to detect the presence of hyponatremia and timely correction are helpful to improve the prognosis of patients. There are many predisposing factors for hyponatremia, including heterotopia of antidiuretic hormone (ADH), use of platinum-based chemotherapy drugs, and intracranial metastasis, among others. Patients with small cell lung cancer are usually asymptomatic in the early stage, while it is of great significance to find a suitable clinical index to judge whether it is a malignant inducement or not. In the clinical setting, due to different electrolyte levels and therapeutic scheduling for the primary disease, an individualized plan is often made, mainly comprising water restriction, infusion, and medications. This review includes related clinical studies and describes the common symptoms and predisposing factors of hyponatremia in patients with SCLC, and their impact on quality of life and prognosis.

ADVL1522: A phase 2 study of lorvotuzumab mertansine (IMGN901) in children with relapsed or refractory wilms tumor, rhabdomyosarcoma, neuroblastoma, pleuropulmonary blastoma, malignant peripheral nerve sheath tumor, or synovial sarcoma-A Children's Oncology Group study

BACKGROUND

Lorvotuzumab mertansine (IMGN901) is an antibody-drug conjugate linking an antimitotic agent (DM1) to an anti-CD56 antibody (lorvotuzumab). Preclinical efficacy has been noted in Wilms tumor, rhabdomyosarcoma, and neuroblastoma. Synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST), and pleuropulmonary blastoma also express CD56. A phase 2 trial of lorvotuzumab mertansine was conducted to assess its efficacy, recommended phase 2 dose, and toxicities.

METHODS

Eligible patients had relapsed after or progressed on standard therapy for their tumor type. Lorvotuzumab mertansine (110 mg/m² per dose) was administered at the adult recommended phase 2 dose intravenously on days 1 and 8 of 21-day cycles. Dexamethasone premedication was used. Pharmacokinetic samples, peripheral blood CD56-positive cell counts, and tumor CD56 expression were assessed.

RESULTS

Sixty-two patients enrolled. The median age was 14.3 years (range, 2.8-29.9 years); 35 were male. Diagnoses included Wilms tumor (n = 17), rhabdomyosarcoma (n = 17), neuroblastoma (n = 12), synovial sarcoma (n = 10), MPNST (n = 5), and pleuropulmonary blastoma (n = 1). Five patients experienced 9 dose-limiting toxicities: hyperglycemia (n = 1), colonic fistula (n = 1) with perforation (n = 1), nausea (n = 1) with vomiting (n = 1), increased alanine aminotransferase in cycle 1 (n = 2), and increased alanine aminotransferase in cycle 2 (n = 1) with increased aspartate aminotransferase (n = 1). Non-dose-limiting toxicities (grade 3 or higher) attributed to lorvotuzumab mertansine were rare. The median values of the maximum concentration, half-life, and area under the curve from zero to infinity for DM1 were 0.87 µg/mL, 35 hours, and 27.9 µg/mL h, respectively. Peripheral blood CD56+ leukocytes decreased by 71.9% on day 8. One patient with rhabdomyosarcoma had a partial response, and 1 patient with synovial sarcoma achieved a delayed complete response.

CONCLUSIONS

Lorvotuzumab mertansine (110 mg/m² ) is tolerated in children at the adult recommended phase 2 dose; clinical activity is limited.

Immunohistochemistry and Radiomic Features for Survival Prediction in Small Cell Lung Cancer

Background: The aim of the study was to evaluate the role of different immunohistochemical and radiomics features in patients with small cell lung cancer (SCLC).

Methods: Consecutive patients with histologically proven SCLC with limited (n = 47, 48%) or extensive disease (n = 51, 52%) treated with radiotherapy and chemotherapy at our department were included in the analysis. The expression of different immunohistochemical markers from the initial tissue biopsy, such as CD56, CD44, chromogranin A, synaptophysin, TTF-1, GLUT-1, Hif-1 a, PD-1, and PD-L1, and MIB-1/KI-67 as well as LDH und NSE from the initial blood sample were evaluated. H-scores were additionally generated for CD44, Hif-1a, and GLUT-1. A total of 72 computer tomography (CT) radiomics texture features from a homogenous subgroup (n = 31) of patients were correlated with the immunohistochemistry, the survival (OS), and the progression-free survival (PFS).

Results: The median OS, calculated from diagnosis, was 21 months for patients with limited disease and 13 months for patients with extensive disease. The expression of synaptophysin correlated with a better OS (HR 0.546 95% CI 0.308–0.966, p = 0.03). The expression of TTF-1 (HR 0.286, 95% CI: 0.117–0.698, p = 0.006) and a lower GLUT-1 H-score (median = 50, HR: 0.511, 95% CI: 0.260–1.003, p = 0.05) correlated with a better PFS. Patients without chromogranin A expression had a higher risk for developing cerebral metastases (p = 0.02) and patients with PD 1 expression were at risk for developing metastases (p = 0.02). Our radiomics analysis did not reveal a single texture feature that correlated highly with OS or PFS. Correlation coefficients ranged between −0.48 and 0.39 for OS and between −0.46 and 0.38 for PFS.

Conclusions: The role of synaptophysin should be further evaluated as synaptophysin-negative patients might profit from treatment intensification. We report an, at most, moderate correlation of radiomics features with overall and progression free survival and no correlation with the expression of different immunohistochemical markers.

Identification of a peptide targeting CD56

Neural cell adhesion molecule 1 (NCAM1/CD56) is expressed on immune cells, myoblasts, and malignant cells, and there is a growing demand for the genetic detection of CD56 and CD56-targeted therapy. In the present study, we developed a novel peptide ligand (designated Natein) that binds to human CD56 by using T7 phage display technology. Natein recognized the extracellular region of CD56 and could bind to natural killer (NK) cells and CD56-positive (CD56⁺) cancer cells. CD56⁺ cells enriched from human peripheral blood mononuclear cells (PBMCs) using biotinylated Natein-conjugated microbeads, similarly to CD56 antibody-isolated cells, demonstrated functional cytotoxicity against K562 cells. In addition, Natein could be used to stain CD56⁺ lymphoma cells in nasal-type extranodal NK/T-cell lymphoma tissues similarly to a CD56 antibody. These findings suggest that Natein has the potential to be alternative to CD56 antibody that could be used for peptide-based cell isolation and diagnosis.

Antibody-Drug Conjugates in Thoracic Malignancies: Clinical Trials Reveal Both Promise and Challenges

Thoracic malignancies are the main cause of cancer-related deaths worldwide. The need to develop new therapies is therefore urgent. The recognition of new potential therapeutic targets in thoracic malignancies has prompted the development of a number of antibody-drug conjugates. This new class of potent anticancer agents is supposed to more specifically and directly target the tumor while limiting toxicity for healthy tissues by delivering a toxic payload to tumor cells that are recognized by the presence of specific cell surface antigens. Progress in the development of antibody-drug conjugates over the last decade has been significant, with several promising advances. Unfortunately, many failures have also been encountered, often because of unexpectedly severe toxicities that contradicted the assumed mechanism of action, and major challenges remain. Various techniques to reduce the toxicities associated with antibody-drug conjugates are being studied, and the panorama of antibody-drug conjugates in clinical stages continues to increase and evolve. Current efforts in the conjugation and linker chemistries could result in the successful construction of clinically effective compounds. The future clinical development of antibody-drug conjugates could benefit from the identification of such payloads that can provide more safe and effective derivatives. Highly potent compounds with reasonable aqueous solubility, non-immunogenic profile, and stability in storage and the bloodstream should be important aspects of research into cytotoxic payloads.

CD56-chimeric antigen receptor T-cell therapy for refractory/recurrent rhabdomyosarcoma: A 3.5-year follow-up case report

RATIONALE

Rhabdomyosarcoma (RMS) is a common soft tissue sarcoma in children with high malignancy. The prognosis of refractory recurrent RMS is extremely poor, and the 5-year survival rate is less than 20%.

PATIENT CONCERNS

We reported a 2-year-old male patient with RMS who underwent 3 operations and 2 recurrences while being treated with regular multidisciplinary therapy.

DIAGNOSES

A diagnosis of embryonal rhabdomyosarcoma with primary bladder (IIIa, TNM stage 2, and medium risk group) was made.

INTERVENTIONS

After repeated recurrence, the patient was treated with chimeric antigen receptor T (CAR-T) cells, which had a safety mechanism and specifically bound the CD56 antigen in the fourth generation.

OUTCOMES

The process of CAR-T cell transfusion was smooth, and there were no significant cytokine release syndrome manifestations after reinfusion. The patient was in complete remission at last follow-up visit after 3.5 years.

CONCLUSION

CD56-CAR-T cell therapy is a safe and effective approach and may be an option for children with solid tumors who are nonresponsive to conventional radiotherapy and chemotherapy, or are unsuitable for hematopoietic stem cell transplantation.

The tumor immune microenvironment in gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a group of rare tumors that are increasing in prevalence. The complex tumor immune microenvironment (TIME) plays an important role in tumor development and the response to immunotherapy but is poorly understood. In this review, the components of the TIME are described in detail, including discussion about infiltrating immune cells, the immune checkpoint system, the cytokine and chemokine milieu, and immunomodulatory factors. Moreover, a comparison between TIMEs among different types of GEP-NENs and the interplay among the TIME, tumor cells, and the stromal microenvironment is described. Novel treatment options for GEP-NENs and potential biomarkers for the immune response are also characterized. We provide a comprehensive generalized review of the TIME that can inform GEP-NEN treatment strategies.

Molecular and immune targets for Merkel cell carcinoma therapy and prevention

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin, for which the exact mechanisms of carcinogenesis remain unknown. Therapeutic options for this highly aggressive malignancy have historically been limited in both their initial response and response durability. Recent improvements in our understanding of MCC tumor biology have expanded therapeutic options for these patients, namely through the use of immunotherapies such as immune checkpoint inhibitors. Further elucidation of the tumor mutational landscape has identified molecular targets for therapies, which have demonstrated success in other cancer types. In this review, we discuss both current and investigational immune and molecular targets of therapy for MCC.

Antibody-Drug Conjugates (ADC) Against Cancer Stem-Like Cells (CSC)-Is There Still Room for Optimism?

Cancer stem-like cells (CSC) represent a subpopulation of tumor cells with peculiar functionalities that distinguish them from the bulk of tumor cells, most notably their tumor-initiating potential and drug resistance. Given these properties, it appears logical that CSCs have become an important target for many pharma companies. Antibody-drug conjugates (ADC) have emerged over the last decade as one of the most promising new tools for the selective ablation of tumor cells. Three ADCs have already received regulatory approval and many others are in different phases of clinical development. Not surprisingly, also a considerable number of anti-CSC ADCs have been described in the literature and some of these have entered clinical development. Several of these ADCs, however, have yielded disappointing results in clinical studies. This is similar to the results obtained with other anti-CSC drug candidates, including native antibodies, that have been investigated in the clinic. In this article we review the anti-CSC ADCs that have been described in the literature and, in the following, we discuss reasons that may underlie the failures in clinical trials that have been observed. Possible reasons relate to the biology of CSCs themselves, including their heterogeneity, the lack of strictly CSC-specific markers, and the capacity to interconvert between CSCs and non-CSCs; second, inherent limitations of some classes of cytotoxins that have been used for the construction of ADCs; third, the inadequacy of animal models in predicting efficacy in humans. We conclude suggesting some possibilities to address these limitations.

CAR T Cell Therapy for Neuroblastoma

Patients with high risk neuroblastoma have a poor prognosis and survivors are often left with debilitating long term sequelae from treatment. Even after integration of anti-GD2 monoclonal antibody therapy into standard, upftont protocols, 5-year overall survival rates are only about 50%. The success of anti-GD2 therapy has proven that immunotherapy can be effective in neuroblastoma. Adoptive transfer of chimeric antigen receptor (CAR) T cells has the potential to build on this success. In early phase clinical trials, CAR T cell therapy for neuroblastoma has proven safe and feasible, but significant barriers to efficacy remain. These include lack of T cell persistence and potency, difficulty in target identification, and an immunosuppressive tumor microenvironment. With recent advances in CAR T cell engineering, many of these issues are being addressed in the laboratory. In this review, we summarize the clinical trials that have been completed or are underway for CAR T cell therapy in neuroblastoma, discuss the conclusions and open questions derived from these trials, and consider potential strategies to improve CAR T cell therapy for patients with neuroblastoma.

Production and characterization of monoclonal antibody against a triple negative breast cancer cell line

Breast cancer is the most prevalent malignancy among women around the world such that more than 1,400,000 new cases are being diagnosed each year. Despite immense studies over many years on diagnosis and treatment of breast cancer, about 30% of treated patients will relapse and require subsequent therapy. By development of hybridoma technology, murine monoclonal antibodies (MAbs) against several human tumor-associated antigens have been produced and characterized in many laboratories. The purpose of these studies is to generate effective monoclonal antibodies that could be useful in tumor diagnosis and therapy. In this study, splenic lymphocytes of immunized BALB/c mouse with a new established breast cancer cell line (Pari-ICR cell line, established in Shiraz Institute for Cancer Research) were fused with the mouse myeloma cell line SP2/0 in the presence of polyethylene glycol. We generated a panel of monoclonal antibodies against the newly established cell line. The hybrid cultures were screened by flow cytometry. Hybridomas that produced antibody to surface antigens of immunizing cell line but not to Human Gingival Fibroblasts, adipose stem cells, and leucocytes isolated from peripheral blood were selected and cloned by limiting dilution method. The 1E3 clone (IgG2a type) that displayed clonal stability was further analyzed for specificity by flow cytometry. MAb 1E3 showed weak to strong reactivity to other cell lines compared with Pari-ICR cell line. Antigen identification was performed by a workflow consisting of immunoaffinity purification, SDS-PAGE, Western blotting, and mass spectrometry analysis. The target of 1E3 mAb was identified as NCAM1. In conclusion, using the antibody-based strategy we identified NCAM1 as a potential therapeutic target and biomarker for breast cancer.

Antibody drug conjugates in thoracic malignancies

Antibody drug conjugates (ADCs) have the potential to alter the efficacy: toxicity ratio of cytotoxic therapy utilizing surface markers on cancer cells as antibody targets to preferentially deliver toxic payloads to tumor cells while limiting systemic toxicity. Multiple ADCs, differing in their antibody targets, cytotoxic payloads and linker molecules are currently being evaluated in non-small-cell lung cancer, small-cell lung cancer and malignant pleural mesothelioma. Here we review the available data in thoracic malignancies and the potential issues influencing the efficacy and toxicity of these approaches.

Antitumor activity of CD56-chimeric antigen receptor T cells in neuroblastoma and SCLC models

The CD56 antigen (NCAM-1) is highly expressed on several malignancies with neuronal or neuroendocrine differentiation, including small-cell lung cancer and neuroblastoma, tumor types for which new therapeutic options are needed. We hypothesized that CD56-specific chimeric antigen receptor (CAR) T cells could target and eliminate CD56-positive malignancies. Sleeping Beauty transposon-generated CD56R-CAR T cells exhibited αβT-cell receptors, released antitumor cytokines upon co-culture with CD56⁺ tumor targets, demonstrated a lack of fratricide, and expression of cytolytic function in the presence of CD56⁺ stimulation. The CD56R-CAR⁺ T cells are capable of killing CD56⁺ neuroblastoma, glioma, and SCLC tumor cells in in vitro co-cultures and when tested against CD56⁺ human xenograft neuroblastoma models and SCLC models, CD56R-CAR⁺ T cells were able to inhibit tumor growth in vivo. These results indicate that CD56-CARs merit further investigation as a potential treatment for CD56⁺ malignancies.

CD56 (Neural Cell Adhesion Molecule) Expression in Ovarian Carcinomas: Association With High-Grade and Advanced Stage But Not With Neuroendocrine Differentiation

OBJECTIVE

Neural cell adhesion molecule (CD56) has been proposed as a potential marker for neuroendocrine differentiation in carcinomas, together with synaptophysin and chromogranin A. However, CD56 immunoreactivity by itself can be found in a broad variety of tumors, including ovarian neoplasms. CD56 has recently been suggested as a potential target for antibody-based therapy. However, for ovarian carcinoma, there is only limited data available regarding the pattern of CD56 immunoreactivity, coexpression of neuroendocrine markers, and correlation with histological types and clinical parameters.

METHODS

In our study, we therefore evaluated CD56 staining by immunohistochemistry on a tissue micrroarray with 206 ovarian carcinomas, including 151 high-grade serous, 7 low-grade serous, 32 endometrioid, 11 clear cell, 5 mucinous, as well as 33 atypically proliferating serous tumors/serous borderline tumors.

RESULTS

At least focal CD56 immunoreactivity was observed in 65% of carcinomas of all histological types. Moderate staining with at least 10% positive cells was found in 44 (28%) high-grade serous carcinomas (HGSOCs), 2 (29%) low-grade serous and 3(9%) endometrioid carcinomas. Strong immunoreactivity was limited to 10 (7%) HGSOCs. There was no correlation with the expression of chromogranin or synaptophysin. Serous borderline tumors showed only weak and focal staining in 11 (33%). Expression of CD56 overall was significantly associated with high-grade and advanced stage. In the subgroup of HGSOCs, CD56 expression was associated with reduced overall survival (median 30 vs. 47 months, P = 0.039, log rank, univariate analysis).

CONCLUSIONS

CD56 (neural cell adhesion molecule) is frequently expressed in ovarian carcinomas and is significantly associated with HGSOC and advanced tumor stage. Due to its lack of correlation with neuroendocrine differentiation, CD56 expression is of limited diagnostic value, but may rather serve as a marker for tumor progression or as a potential therapeutic target.

αvβ3 integrin-targeted micellar mertansine prodrug effectively inhibits triple-negative breast cancer in vivo

Antibody-mertansine (DM1) conjugates (AMCs) are among the very few active targeting therapeutics that are approved or clinically investigated for treating various cancers including metastatic breast cancer. However, none of the AMCs are effective for the treatment of triple-negative breast cancers (TNBCs). Here, we show that cRGD-decorated, redox-activatable micellar mertansine prodrug (cRGD-MMP) can effectively target and deliver DM1 to α_vβ₃ integrin overexpressing MDA-MB-231 TNBC xenografts in nude mice, resulting in potent tumor growth inhibition. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays showed that cRGD-MMP had obvious targetability to MDA-MB-231 cells with a low half-maximal inhibitory concentration (IC₅₀) of 0.18 μM, which was close to that of free DM1 and 2.2-fold lower than that of micellar mertansine prodrug (MMP; nontargeting control). The confocal microscopy studies demonstrated that cRGD-MMP mediated a clearly more efficient cellular uptake and intracellular release of doxorubicin (used as a fluorescent anticancer drug model) in MDA-MB-231 cells. Notably, cRGD-MMP loaded with 1,1′-dioctadecyltetramethyl indotricarbocyanine iodide (DiR; a hydrophobic near-infrared dye) was shown to quickly accumulate in the MDA-MB-231 tumor with strong DiR fluorescence from 2 to 24 h post injection. MMP loaded with DiR could also accumulate in the tumor, although significantly less than cRGD-MMP. The biodistribution studies revealed a high DM1 accumulation of 8.1%ID/g in the tumor for cRGD-MMP at 12 h post injection. The therapeutic results demonstrated that cRGD-MMP effectively suppressed MDA-MB-231 tumor growth at 1.6 mg DM1 equiv./kg without causing noticeable side effects, as shown by little body weight loss and histological analysis. This MMP has appeared as a promising platform for potent treatment of TNBCs.

Recent Insights and Advances in the Management of Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroendocrine malignancy with a propensity for recurrence and a poor prognosis. Incidence of MCC is on the rise and is known to increase with advanced age, immunosuppression, and UV exposure. Merkel cell polyomavirus is implicated in the pathogenesis of virus-positive MCC and accounts for 80% of MCCs in the northern hemisphere and 25% in southern latitudes. In contrast, tumorigenesis of virus-negative MCC is linked to UV-induced DNA damage. Interplay between ubiquitous Merkel cell polyomavirus skin infections that commonly occur in healthy skin and other established risk factors, such as immunosuppression and UV exposure, remains poorly understood. Surgery and radiotherapy achieves excellent locoregional control; however, invariably, a significant proportion of patients develop disseminated disease that is incurable. Chemotherapy offers a high response rate for metastatic disease, but responses are short-lived and the impact on survival is not established. Recent advances in our understanding of the genetic landscape and immunobiology of MCC has led to investigation of novel treatments, including immune checkpoint inhibitors, which are likely to rapidly transform the way we manage these patients. We review epidemiologic, clinical, and histopathologic features of MCC; describe recent insights in MCC biology; and discuss novel therapeutic approaches.

Interaction between Merkel cell carcinoma and the immune system: Pathogenetic and therapeutic implications

Merkel cell carcinoma (MCC) is a rare, aggressive primary cutaneous neuroendocrine carcinoma. It usually appears on the face and neck of elderly Caucasian people as a flesh-colored, erythematous or violaceous dome-shaped, non-tender nodule with a smooth surface. In immunocompromised patients with T-cell dysfunction, such as patients with acquired immunodeficiency syndrome (AIDS) or solid organ transplant recipients, the incidence of this disease is markedly increased. This suggests a link between the development of MCC and the immune system. Merkel cell polyolmavirus (MCPyV) is clonally integrated into the majority of MCCs, suggesting its causative role in the pathogenesis of the majority of these tumors. Despite wide local excision, sentinel lymph node biopsy, and eventually, adjuvant radiation therapy, which remains the first-line treatment for MCC, the identification of MCPyV has opened novel therapeutic insights. Novel therapeutic strategies could be to inhibit MCPyV oncoproteins and to stimulate immune responses against virus-infected tumor cells by immunostimulatory cytokines, including interferons and interleukin-2.

Treatment advances in small cell lung cancer (SCLC)

Small cell lung cancer (SCLC) is an aggressive tumor characterized by rapid doubling time and high propensity for early development of disseminated disease. Although most patients respond to initial therapy with a platinum doublet, the majority of those with limited stage and virtually all patients with metastatic disease eventually develop tumor progression for which there are limited treatment options. There have been no recent changes in the treatment of SCLC, with platinum plus etoposide and topotecan as the standard first-line and second-line respectively, neither showing survival benefit over the combination of cyclophosphamide, doxorubicin and vincristine, which was developed in the 1970s. More recently, a new understanding of the biology of SCLC has led to the development of novel drugs, of which the most promising are the immune checkpoint inhibitors and the antibody drug conjugate rovalpituzumab tesirine.

Harnessing the Immune System Against Leukemia: Monoclonal Antibodies and Checkpoint Strategies for AML

Acute myeloid leukemia (AML) is the most common leukemia among adults and is associated with a poor prognosis, especially in patients with adverse prognostic factors, older age, or relapsed disease. The last decade has seen a surge in successful immune-based therapies in various solid tumors; however, the role of immune therapies in AML remains poorly defined. This chapter describes the rationale, clinical data, and toxicity profiles of immune-based therapeutic modalities in AML including naked and conjugated monoclonal antibodies, bispecific T-cell engager antibodies, chimeric antigen receptor (CAR)-T cells, and checkpoint blockade via blockade of PD1/PDL1 or CTLA4. Monoclonal antibodies commonly used in AML therapy target highly expressed "leukemia" surface antigens and include (1) naked antibodies against common myeloid markers such as anti-CD33 (e.g., lintuzumab), (2) antibody-drug conjugates linked to either, (a) a highly potent toxin such as calicheamicin, pyrrolobenzodiazepine, maytansine, or others in various anti-CD33 (gemtuzumab ozogamicin, SGN 33A), anti-123 (SL-401), and anti-CD56 (lorvotuzumab mertansine) formulations, or (b) radioactive particles, such as 131I, 213Bi, or 225Ac-labeled anti-CD33 or CD45 antibodies. Novel monoclonal antibodies that recruit and promote proximity-induced cytotoxicity of tumor cells by T cells (bispecific T-cell engager [BiTE] such as anti CD33/CD3, e.g., AMG 330) or block immune checkpoint pathways such as CTLA4 (e.g., ipilimumab) or PD1/PD-L1 (e.g., nivolumab) unleashing the patients T cells to fight leukemic cells are being evaluated in clinical trials in patients with AML. The numerous ongoing clinical trials with immunotherapies in AML will improve our understanding of the biology of AML and allow us to determine the best approaches to immunotherapy in AML.

Phase 1/2 Study of the CD56-Targeting Antibody-Drug Conjugate Lorvotuzumab Mertansine (IMGN901) in Combination With Carboplatin/Etoposide in Small-Cell Lung Cancer Patients With Extensive-Stage Disease

INTRODUCTION

This trial assessed the safety and efficacy of LM in combination with carboplatin/etoposide therapy compared to carboplatin/etoposide treatment alone in patients with previously untreated extensive-disease small-cell lung cancer (ED-SCLC).

PATIENTS AND METHODS

A run-in phase 1 stage was used to determine the recommended phase 2 dose and characterize the dose-limiting toxicities of LM in combination with carboplatin/etoposide followed by LM alone in patients with CD56-positive solid tumors. In phase 2, chemotherapy-naive ED-SCLC patients were randomized 2:1 to carboplatin AUC (area under the plasma concentration vs. time curve) of 5 day 1 + etoposide 100 mg/m² days 1 to 3 plus LM (arm 1) or alone (arm 2).

RESULTS

In the phase 1 study (n = 33), a dose of LM at 112 mg/m² with carboplatin/etoposide was identified as the recommended phase 2 dose. However, because of an increased incidence of peripheral neuropathy events during early phase 2, this dose was reduced to 90 mg/m². In phase 2, a total of 94 and 47 evaluable patients were assigned to arms 1 and 2, respectively. No difference in median progression-free survival was observed between arms 1 and 2 (6.2 vs. 6.7 months). The most common treatment-emergent adverse event leading to discontinuation was peripheral neuropathy (29%). A total of 21 patients had a treatment-emergent adverse event leading to death (18 in arm 1 and 3 in arm 2); for 10 individuals, this was an infection (pneumonia or sepsis) deemed to be related to the study drug.

CONCLUSION

The combination of LM plus carboplatin/etoposide did not improve efficacy over standard carboplatin/etoposide doublet therapy in ED-SCLC patients and showed increased toxicity, including a higher incidence of serious infections with fatal outcomes.