Recent insights into the therapeutic strategies targeting the pseudokinase PTK7 in cancer

The generation of drugs counteracting deregulated protein kinases has been a major focus in cancer therapy development. Breakthroughs in this effort have produced many therapeutic agents to the benefit of patients, mostly through the development of chemical or antibody-based drugs targeting active kinases. These strategies are challenged when considering catalytically inactive protein kinases (or pseudokinases), which represent 10% of the human kinome with many of relevance in cancer. Among the so-called pseudotyrosine kinases, the PTK7 receptor tyrosine kinase (RTK) stands as a bona fide target overexpressed in several solid tumors and hematological malignancies and linked to metastasis, poor prognosis, and resistance to treatment. Despite the lack of catalytic activity, PTK7 has signaling capacities through heterodimerization with active RTKs and offers pharmacological targeting opportunities through its inactive kinase domain. Moreover, PTK7-targeting strategies based on antibody-drug conjugates, aptamers, and CAR-T cell-based therapies have demonstrated encouraging results in preclinical and clinical settings. We review the most recent data assigning to PTK7 a prominent role in cancer progression as well as current preclinical and clinical targeting strategies against RTK family pseudokinases including PTK7.

A review of recent advances on single use of antibody-drug conjugates or combination with tumor immunology therapy for gynecologic cancer

Immune checkpoint inhibitors have made significant progress in the treatment of various cancers. However, due to the low ICI responsive rate for the gynecologic cancer, ICI two-drug combination therapy tends to be a predominant way for clinical treatment. Antibody-drug conjugates, a promising therapeutic modality for cancer, have been approved by the FDA for breast cancer, lymphoma, multiple myeloma and gastric cancer. On September 2021, the FDA granted accelerated approval to tisotumab vedotin for patients with recurrent or metastatic cervical cancer. Currently, the role of therapy of ADCs on gynecologic tumors was also included in medication regimens. Now more than 30 ADCs targeting for 20 biomarkers are under clinical trials in the field, including monotherapy or combination with others for multiple lines of therapy. Some ADCs have been proved to enhance the antitumor immunity effect on both pre-clinical models and clinical trials. Therefore, combination of ADCs and ICIs are expected in clinical trials. In this review, we discuss current development of ADCs in gynecologic oncology and the combination effects of ICIs and ADCs.

Actively Targeted Nanomedicines in Breast Cancer: From Pre-Clinal Investigation to Clinic

Simple Summary

Despite all the efforts and advances made in the treatment of breast cancer, this pathology continues to be one of the main causes of cancer death in women, particularly triple-negative breast cancer (TNBC), and, although to a lesser degree, HER-2 receptor-positive tumors. Chemotherapy is one of the main treatments available. However, it shows numerous limitations due to its lack of selectivity. In this sense, the selective delivery of antineoplastics to cancer cells can reduce their adverse effects and increase their efficacy. The use of active targeted nanomedicine is a good strategy to achieve this selective chemotherapy. In fact, in recent decades, several active targeted nanoformulations have been approved or reached clinical investigation with excellent results. Among all nanomedicines, antibody-drug conjugates are the most promising.

Abstract

Breast cancer is one of the most frequently diagnosed tumors and the second leading cause of cancer death in women worldwide. The use of nanosystems specifically targeted to tumor cells (active targeting) can be an excellent therapeutic tool to improve and optimize current chemotherapy for this type of neoplasm, since they make it possible to reduce the toxicity and, in some cases, increase the efficacy of antineoplastic drugs. Currently, there are 14 nanomedicines that have reached the clinic for the treatment of breast cancer, 4 of which are already approved (Kadcyla^®, Enhertu^®, Trodelvy^®, and Abraxane^®). Most of these nanomedicines are antibody–drug conjugates. In the case of HER-2-positive breast cancer, these conjugates (Kadcyla^®, Enhertu^®, Trastuzumab-duocarmycin, RC48, and HT19-MMAF) target HER-2 receptors, and incorporate maytansinoid, deruxtecan, duocarmicyn, or auristatins as antineoplastics. In TNBC these conjugates (Trodelvy^®, Glembatumumab-Vedotin, Ladiratuzumab-vedotin, Cofetuzumab-pelidotin, and PF-06647263) are directed against various targets, in particular Trop-2 glycoprotein, NMB glycoprotein, Zinc transporter LIV-1, and Ephrin receptor-4, to achieve this selective accumulation, and include campthotecins, calicheamins, or auristatins as drugs. Apart from the antibody–drug conjugates, there are other active targeted nanosystems that have reached the clinic for the treatment of these tumors such as Abraxane^® and Nab-rapamicyn (albumin nanoparticles entrapping placlitaxel and rapamycin respectively) and various liposomes (MM-302, C225-ILS-Dox, and MM-310) loaded with doxorubicin or docetaxel and coated with ligands targeted to Ephrin A2, EPGF, or HER-2 receptors. In this work, all these active targeted nanomedicines are discussed, analyzing their advantages and disadvantages over conventional chemotherapy as well as the challenges involved in their lab to clinical translation. In addition, examples of formulations developed and evaluated at the preclinical level are also discussed.

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.

First-in-Human Study of PF-06647020 (Cofetuzumab Pelidotin), an Antibody-Drug Conjugate Targeting Protein Tyrosine Kinase 7, in Advanced Solid Tumors

PURPOSE

We investigated safety, tolerability, pharmacokinetics, and antitumor activity of the protein tyrosine kinase 7 (PTK7)-targeted, auristatin-based antibody-drug conjugate (ADC) PF-06647020/cofetuzumab pelidotin (NCT02222922).

PATIENTS AND METHODS

Patients received PF-06647020 intravenously every 3 weeks at 0.2-3.7 mg/kg or every 2 weeks at 2.1-3.2 mg/kg, in sequential dose escalation, following a modified toxicity probability interval method. In dose expansion, pretreated patients with advanced, platinum-resistant ovarian cancer, non-small cell lung cancer (NSCLC), or triple-negative breast cancer (TNBC) received PF-06647020 2.8 mg/kg every 3 weeks.

RESULTS

The most common, treatment-related adverse events for PF-06647020 administered every 3 weeks were nausea, alopecia, fatigue, headache, neutropenia, and vomiting (45%-25%); 25% of patients had grade ≥ 3 neutropenia. Two patients experienced dose-limiting toxicities (grade 3 headache and fatigue) at the highest every 3 weeks dose evaluated. The recommended phase II dose was 2.8 mg/kg every 3 weeks. The overall safety profile observed with PF-06647020 administered every 2 weeks was similar to that of the every 3 weeks regimen. Systemic exposure for the ADC and total antibody generally increased in a dose-proportional manner. Antitumor activity was observed in treated patients with overall objective response rates of 27% in ovarian cancer (n = 63), 19% in NSCLC (n = 31), and 21% in TNBC (n = 29). Responders tended to have moderate or high PTK7 tumor expression by IHC.

CONCLUSIONS

This PTK7-targeted ADC demonstrated therapeutic activity in previously treated patients with ovarian cancer, NSCLC, and TNBC at a dose range of 2.1-3.2 mg/kg, supporting further clinical evaluation to refine dose, schedule, and predictive tissue biomarker testing in patients with advanced malignancies.

Targeted therapy in advanced non-small cell lung cancer: current advances and future trends

Lung cancer remains the leading cause of cancer-related mortality in both men and women in the US and worldwide. Non-small cell lung cancer is the most common variety accounting for 84% of the cases. For a subset of patients with actionable mutations, targeted therapy continues to provide durable responses. Advances in molecular and immunohistochemical techniques have made it possible to usher lung cancer into the era of personalized medicine, with the patient getting individualized treatment based on these markers. This review summarizes the recent advances in advanced NSCLC targeted therapy, focusing on first-in-human and early phase I/II clinical trials in patients with advanced disease. We have divided our discussion into different topics based on these agents' mechanisms of action. This article is aimed to be the most current review of available and upcoming targeted NSCLC treatment options. We will also summarize the currently available phase I/II clinical trial for NSCLC patients at the end of each section.

Emerging drugs for the treatment of adrenocortical carcinoma

Introduction: Adrenocortical cancer (ACC) is a rare and aggressive disease with a median survival of 14-17 months and 5-year survival of around 20% for advanced disease. Emerging evidence of sub-groups of ACC with specific molecular drivers indicate ACC may be amenable to inhibition of receptor tyrosine kinases involved in growth and angiogenic signaling. A significant subset of patients may also be responsive to immune strategies.Areas covered: This review outlines approaches of targeting upregulated growth pathways including Insulin-like Growth Factor, Vascular Endothelial Growth Factor, Fibroblast Growth Factor and Epidermal Growth Factor Receptor in ACC. Data of immune checkpoint blockade with nivolumab, ipilimumab, pembrolizumab and avelumab is explored in detail. Genomic studies indicate that up to 40% of ACC are driven by dysregulated WNT and glucocorticoid signaling, special focus is placed on emerging drugs in these pathways.Expert opinion: Progress in the treatment of ACC has faced challenges stemming from the rarity of the disease. Given recent advances in the understanding of the molecular pathogenesis of ACC, a window of opportunity has now opened to make significant progress in developing therapeutic options that target key pathways such as excessive glucocorticoid signaling, WNT signaling, cell cycle and immune checkpoints.

Ovarian cancer: new strategies and emerging targets for the treatment of patients with advanced disease

Recently approved therapies have contributed to a significant progress in the management of ovarian cancer; yet, more options are needed to further improve outcomes in patients with advanced disease. Here we review the rationale and ongoing clinical trials of novel combination strategies involving chemotherapy, poly ADP ribose polymerase, programmed death 1 (PD-1)/PD-ligand 1 immune checkpoint and/or vascular endothelial growth factor receptor inhibitors. Further, we discuss novel agents aimed at targets associated with ovarian cancer growth or progression that are emerging as potential new treatment approaches. Among them, agents targeted to folate receptor α, tissue factor, and protein kinase-mediated pathways (WEE1 kinase, phosphatidylinositol-3 kinase α, cell cycle checkpoint kinase 1/2, ATR kinase) are currently in clinical development as mono- or combination therapies. If successful, findings from these extensive development efforts may further transform treatment of patients with advanced ovarian cancer.

Antibody-Drug Conjugates for Cancer Therapy

Antibody-drug conjugates (ADCs) are novel drugs that exploit the specificity of a monoclonal antibody (mAb) to reach target antigens expressed on cancer cells for the delivery of a potent cytotoxic payload. ADCs provide a unique opportunity to deliver drugs to tumor cells while minimizing toxicity to normal tissue, achieving wider therapeutic windows and enhanced pharmacokinetic/pharmacodynamic properties. To date, nine ADCs have been approved by the FDA and more than 80 ADCs are under clinical development worldwide. In this paper, we provide an overview of the biology and chemistry of each component of ADC design. We briefly discuss the clinical experience with approved ADCs and the various pathways involved in ADC resistance. We conclude with perspectives about the future development of the next generations of ADCs, including the role of molecular imaging in drug development.

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.

Antibody-drug conjugates for the treatment of ovarian cancer

INTRODUCTION

Ovarian cancer typically presents at an advanced stage and while initial chemotherapy response rates are favorable, a majority of patients experience recurrence with the subsequent development of chemoresistance. Recurrent, platinum-resistant disease is associated with a very poor prognosis as treatment in this setting is often limited by systemic toxicity. Antibody-drug conjugates (ADCs) are novel therapeutic agents designed to target antigens specific to ovarian tumor cells with direct delivery of cytotoxic agents to combat recurrent, platinum-resistant disease while limiting systemic toxicity.

AREAS COVERED

The basic structure and function of ADCs will be reviewed as well as the current data on ADCs under investigation in ovarian cancer.

EXPERT OPINION

ADCs represent a promising class of targeted therapy in recurrent ovarian cancer with excellent response rates particularly when utilized as combination therapy. While mirvetuximab soravtansine is the only ADC that has been evaluated in a phase 3 trial, many other ADCs and trials are on the horizon. As the field of targeted therapy continues to evolve, continued development of target antigens and ADCs are likely to represent a key development in treatment of recurrent, platinum-resistant disease.

Emerging therapeutic agents for advanced non-small cell lung cancer

Advanced non-small cell lung cancer (NSCLC) is the most common type of lung cancer, with a poor prognosis and no known cure. Survival time is often short because of limited treatment options. Recent advances in targeted therapy and immunotherapy have changed the landscape for the treatment of advanced NSCLC. In the last 10 years, the US Food and Drug Administration (FDA) has approved more than 17 new medications for this devastating disease and more are coming. Molecular and immunogenic testing makes personalized medicine possible for patients with advanced NSCLC. The new medications provide promising efficacy and safety resulting in improved long-term survival for a significant number of patients. In this review, we summarize the recent advances in advanced/metastatic NSCLC therapeutics with a specific focus on first in-human or early-phase I/II clinical trials. These drugs either offer better alternatives to current standard drugs in the same class or are a completely new class of drugs with novel mechanisms of action. Advances are divided into (1) targeted agents, (2) antibody-drug conjugates, and (3) immunotherapies. Finally, we present a brief review of the emerging agents and ongoing clinical studies.

Biologic therapy for advanced breast cancer: recent advances and future directions

INTRODUCTION

Advanced breast cancer (ABC) is a leading cause of mortality, morbidity, and disability in women worldwide. For decades, treatment of ABC has relied on chemotherapy and endocrine treatments (ET), until HER2 was recognized as a 'druggable' target in the 1990s. Thereafter, various anti-HER2 drugs have been approved for the HER2-positive subtype, but only in the last few years, biologic agents targeting different pathways have entered the therapeutic arsenal of luminal and triple-negative cancers.

AREAS COVERED

The purpose of the present review is to recapitulate the most promising novel biologic agents being developed for the treatment of ABC. New drugs for all breast cancer subtypes are discussed, as well as some potential future directions in ABC treatment.

EXPERT OPINION

Several biologic drugs have been recently approved, revolutionizing ABC treatment algorithms: key examples are CDK4/6-inhibitors and the PI3K-inhibitor alpelisib for endocrine-positive ABC; atezolizumab for triple-negative cancers; two PARP-inhibitors for HER2-negative germinal BRCA-mutated cancers. Additionally, multiple drugs are demonstrating activity in late-phase clinical trials for all subtypes. While some of these represent pharmacological evolutions of previously approved drugs, some others might pave the way for new paradigms in ABC, challenging both its classification and current treatment algorithms.

The physiological role of Wnt pathway in normal development and cancer

Over the decades, many studies have illustrated the critical roles of Wnt signaling pathways in both developmental processes as well as tumorigenesis. Due to the complexity of Wnt signaling regulation, there are still questions to be addressed about ways cells are able to manipulate different types of Wnt pathways in order to fulfill the requirements for normal or cancer development. In this review, we will describe different types of Wnt signaling pathways and their roles in both normal developmental processes and their role in cancer development and progression. Additionally, we will briefly introduce new strategies currently in clinical trials targeting Wnt signaling pathway components for cancer therapy.

Antibody-drug conjugates for lung cancer in the era of personalized oncology

With 9.6 million deaths in 2018, cancer represents one of the most common causes of death, both in men and women. Despite recent advances in the understanding of molecular mechanisms involved in cancer development and progression, treatment options are still limited. Limitations of traditional chemotherapy include the lack of selectivity and the unfavorable safety profile. The efficacy of targeted therapies (e.g., tyrosine kinase inhibitors) is also limited by their cytostatic action, which inhibits tumor cell proliferation without inducing tumor cell death, and by the risk of acquired resistance. Antibody-drug conjugates (ADCs), a newly developed class of engineered anticancer drugs, consist of recombinant monoclonal antibodies against tumor-specific antigens that are covalently bound to cytotoxic agents. They have been designed to overcome the limitations of traditional chemotherapy and targeted therapies by combining the target selectivity of monoclonal antibodies with the high potency of cytotoxic drugs. Currently, ADCs that have received regulatory approval include brentuximab vedotin for CD30-positive Hodgkin lymphoma and trastuzumab emtansine for human epidermal growth factor receptor 2-positive breast cancer. However, over 80 novel ADCs are actively being investigated in preclinical studies and early-phase clinical trials. In this review, we will provide a comprehensive overview of the biological rational, efficacy and safety of ADCs as therapeutic agents against non-small cell lung cancer and small cell lung cancer.

Precision medicine for human cancers with Notch signaling dysregulation (Review)

NOTCH1, NOTCH2, NOTCH3 and NOTCH4 are transmembrane receptors that transduce juxtacrine signals of the delta-like canonical Notch ligand (DLL)1, DLL3, DLL4, jagged canonical Notch ligand (JAG)1 and JAG2. Canonical Notch signaling activates the transcription of BMI1 proto-oncogene polycomb ring finger, cyclin D1, CD44, cyclin dependent kinase inhibitor 1A, hes family bHLH transcription factor 1, hes related family bHLH transcription factor with YRPW motif 1, MYC, NOTCH3, RE1 silencing transcription factor and transcription factor 7 in a cellular context-dependent manner, while non-canonical Notch signaling activates NF-κB and Rac family small GTPase 1. Notch signaling is aberrantly activated in breast cancer, non-small-cell lung cancer and hematological malignancies, such as T-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma. However, Notch signaling is inactivated in small-cell lung cancer and squamous cell carcinomas. Loss-of-function NOTCH1 mutations are early events during esophageal tumorigenesis, whereas gain-of-function NOTCH1 mutations are late events during T-cell leukemogenesis and B-cell lymphomagenesis. Notch signaling cascades crosstalk with fibroblast growth factor and WNT signaling cascades in the tumor microenvironment to maintain cancer stem cells and remodel the tumor microenvironment. The Notch signaling network exerts oncogenic and tumor-suppressive effects in a cancer stage- or (sub)type-dependent manner. Small-molecule γ-secretase inhibitors (AL101, MRK-560, nirogacestat and others) and antibody-based biologics targeting Notch ligands or receptors [ABT-165, AMG 119, rovalpituzumab tesirine (Rova-T) and others] have been developed as investigational drugs. The DLL3-targeting antibody-drug conjugate (ADC) Rova-T, and DLL3-targeting chimeric antigen receptor-modified T cells (CAR-Ts), AMG 119, are promising anti-cancer therapeutics, as are other ADCs or CAR-Ts targeting tumor necrosis factor receptor superfamily member 17, CD19, CD22, CD30, CD79B, CD205, Claudin 18.2, fibroblast growth factor receptor (FGFR)2, FGFR3, receptor-type tyrosine-protein kinase FLT3, HER2, hepatocyte growth factor receptor, NECTIN4, inactive tyrosine-protein kinase 7, inactive tyrosine-protein kinase transmembrane receptor ROR1 and tumor-associated calcium signal transducer 2. ADCs and CAR-Ts could alter the therapeutic framework for refractory cancers, especially diffuse-type gastric cancer, ovarian cancer and pancreatic cancer with peritoneal dissemination. Phase III clinical trials of Rova-T for patients with small-cell lung cancer and a phase III clinical trial of nirogacestat for patients with desmoid tumors are ongoing. Integration of human intelligence, cognitive computing and explainable artificial intelligence is necessary to construct a Notch-related knowledge-base and optimize Notch-targeted therapy for patients with 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.