Mirvetuximab Soravtansine (IMGN853), a Folate Receptor Alpha-Targeting Antibody-Drug Conjugate, Potentiates the Activity of Standard of Care Therapeutics in Ovarian Cancer Models

Folate receptor alpha for cancer therapy: an antibody and antibody-drug conjugate target coming of age

Folate receptor alpha (FRα) has long been the focus of therapeutics development in oncology across several solid tumors, notably ovarian, lung, and subsets of breast cancers. Its multiple roles in cellular metabolism and carcinogenesis and tumor-specific overexpression relative to normal tissues render FRα an attractive target for biological therapies. Here we review the biological significance, expression distribution, and characteristics of FRα as a highly promising and now established therapy target. We discuss the ongoing development of FRα-targeting antibodies and antibody-drug conjugates (ADCs), the first of which has been approved for the treatment of ovarian cancer, providing the impetus for heightened research and therapy development. Novel insights into the tumor microenvironment, advances in antibody engineering to enhance immune-mediated effects, the emergence of ADCs, and several studies of anti-FRα agents combined with chemotherapy, targeted and immune therapy are offering new perspectives and treatment possibilities. Hence, we highlight key translational research and discuss several preclinical studies and clinical trials of interest, with an emphasis on agents and therapy combinations with potential to change future clinical practice.

Monotherapy and combination therapy using antibody‑drug conjugates for platinum‑resistant ovarian cancer

Platinum‑resistant ovarian cancer (PROC) is a significant clinical challenge due to the limited number of treatment options and poor outcomes. Moreover, cytotoxic drugs have an unsatisfactory therapeutic efficacy, high toxicity and side effects. An antibody‑drug conjugate (ADC) is a novel cancer therapeutic strategy that combines an antibody, a linker and a payload. ADCs precisely target the tumor cells by binding to the antigen on the surface of tumor cells, thus accurately delivering the cytotoxic drugs and minimizing systemic toxicity. The approval of mirvetuximab soravtansine by the US Food and Drug Administration for treating folate receptor alpha‑positive, platinum‑resistant epithelial ovarian cancer has promoted studies on the use of ADCs in ovarian cancer. A phase III clinical trial showed that mirvetuximab soravtansine achieved an objective remission rate of 42.3% in platinum‑resistant, FRα‑positive ovarian cancer, compared with 15.9% using chemotherapy, demonstrating its immense potential for ADC development. The present review summarizes the research progress on the use of ADCs in PROC as a monotherapy and combination therapy and considers the future development direction of ADCs in PROC.

Nutritional Strategies in Oncology: A Narrative Review of Advances in Folate-Targeted Therapeutic Approaches for Cancer Treatment

Folate, a water-soluble B vitamin crucial for DNA synthesis and repair, is internalized by cells through specific folate receptors (FRs), which are frequently overexpressed in various types of cancers. In this comprehensive study, we conducted a review of the literature from Google Scholar, PubMed, and Science Direct, focusing on research published between 1980 and 2024 to evaluate folate-targeted therapeutic strategies in oncology. Our study design involved a rigorous review of both preclinical and clinical research, emphasizing strategies such as folate-drug conjugates, antibody-drug conjugates, and folate-targeted nanoparticles. Key findings indicate that targeting FRs in cancers such as ovarian, breast, cervical, renal, and colorectal enhances drug delivery specificity to tumors, increases therapeutic efficacy, and decreases systemic toxicity compared to traditional chemotherapy. Several clinical trials reported improved progression-free survival and overall response rates among patients receiving folate-targeted therapies. In conclusion, our review highlights the significant potential of folate-targeted strategies in advancing precision oncology while these approaches provide substantial benefits in terms of efficacy and safety, further research is essential to refine drug design and expand clinical applications. Such initiatives will facilitate the development of more personalized cancer treatment protocols that maximize therapeutic outcomes while minimizing adverse effects.

The antibody-drug conjugate targeting ROR1, NBE-002, is active in high-grade serous ovarian cancer preclinical models

Background

Novel therapeutics are urgently needed for high-grade serous ovarian cancer (HGSOC). We identified the receptor tyrosine kinase-like orphan receptor 1 (ROR1) as a therapeutic target. NBE-002, an antibody-drug conjugate (ADC) consisting of a humanised anti-ROR1 antibody, huXBR1-402, linked to a highly potent anthracycline-derivative (PNU), has activity in ROR1-positive haematologic malignancies.

Objectives

This study explored the anti-cancer effects of NBE-002 alone and in combination with standard HGSOC therapies, carboplatin, paclitaxel and olaparib.

Design

A ROR1-ADC was tested in cell lines and in vivo models of HGSOC.

Methods

Different ROR1-targeting antibodies and payload compositions were constructed and tested in vitro. The dose effect of NBE-002 alone and in combination with carboplatin, paclitaxel or olaparib was analysed in ROR1+ HGSOC cell lines. Growth inhibition and apoptosis were monitored by live cell imaging and combination effects determined. Ten HGSOC PDX models were treated with NBE-002 alone, or in combination with carboplatin or olaparib, over 4 weeks and tumour volume and overall survival evaluated.

Results

Synergistic interaction was observed in two out of five HGSOC cell lines treated with NBE-002 and carboplatin (PEO4 and OC023, chemo-resistant), in one out of five treated with NBE-002 and olaparib (PEO1, BRCA2 mutated, HR deficient) and none of five treated with NBE-002 and paclitaxel. In vivo, NBE-002 exhibited activity in PA-1 xenografts and three HGSOC PDX models with high ROR1 expression, platinum sensitivity and homologous recombination DNA repair deficient (HRD). When NBE-002 was combined with carboplatin, activity was observed in 7 of 10 ROR1-expressing PDX models, regardless of platinum or HRD status. The activity was demonstrated in combination with olaparib in both PDX tested, one HRD and one HRD reverted.

Conclusion

The ROR1-targeting ADC, NBE-002, has therapeutic potential in HGSOC, with single agent activity observed both in vitro and in vivo. Broader clinical applications were evident when NBE-002 was combined with carboplatin or olaparib.

Advances in the Release of Amide-Containing Molecules

The ability to release a molecule from a larger construct in a controlled manner is of great importance to produce effective prodrugs, antibody-drug conjugates, and chemical probes. Amides are ubiquitous functional groups and yet methods to utilise them as molecular release handles are seldom reported. This concept article highlights the advances made in amide release strategies and how these approaches have been utilised.

Recent Advances in Smart Linkage Strategies for Developing Drug Conjugates for Targeted Delivery

Targeted drug delivery systems effectively solve the problem of off-target toxicity of chemotherapeutic drugs by combining chemotherapeutic drugs with antibodies or peptides, thereby promoting drug targeting to the tumor site and bringing further hope for cancer treatment. The development of stimulus-responsive smart linkage technologies has led to the emergence of drug conjugates. Linkage technologies play a crucial role in the design, synthesis, and in vivo circulation of drug conjugates, as they determine the release of cytotoxic drugs from the conjugates and their subsequent therapeutic efficacy. This article reviews some of the smart linkage strategies used in designing drug conjugates, with a focus on the tumor microenvironment and exogenous stimuli as conditions influencing controlled drug release. This review introduces linker classifications and cleavage mechanisms, discusses modular linkers that promote the efficient synthesis of conjugates, and discusses the differences between linkage strategies. Furthermore, this article focuses on the implementation of self-assembly in drug conjugates, which is currently of great interest. Related concepts are introduced and relevant examples of their applications are provided. Furthermore, a comprehensive discourse is presented on the challenges that may arise in the research and clinical implementation of diverse linkage strategies, along with the associated enhancement measures. Finally, the factors that should be considered when designing linkage strategies for drug conjugates are summarized, offering strategies and ideas for scientists involved in drug conjugate research. It is particularly noteworthy that appropriate linkage strategies allow for the intracellular release of drugs after internalization of the conjugates, thereby maximizing their tumor cell-killing effect.

IMGN853 Induces Autophagic Cell Death in Combination Therapy for Ovarian Cancer

SIGNIFICANCE

FOLR1 is heterogeneously overexpressed in epithelial ovarian cancer. We examined the combined effects of the anti-FOLR1 antibody-drug conjugate (IMGN853) with other drugs, including topotecan, anti-VEGF-A antibody, and olaparib. These findings could contribute to the continued development of IMGN853 in the treatment of ovarian cancer.

Opportunities for predictive proteogenomic biomarkers of drug treatment sensitivity in epithelial ovarian cancer

Genomic analysis has played a significant role in the identification of driver mutations that are linked to disease progression and response to drug treatment in ovarian cancer. A prominent example is the stratification of epithelial ovarian cancer (EOC) patients with homologous recombination deficiency (HRD) characterized by mutations in DNA damage repair genes such as BRCA1/2 for treatment with PARP inhibitors. However, recent studies have shown that some epithelial ovarian tumors respond to PARP inhibitors irrespective of their HRD or BRCA mutation status. An exclusive focus on the genome overlooks the significant insight that can be gained from other biological analytes, including proteins, which carry out cellular functions. Proteogenomics is the integration of genomics, transcriptomics, epigenomics and proteomics data. This review paper provides novel insight into the role of proteogenomics as an analytical approach to identify predictive biomarkers of drug treatment response in epithelial ovarian cancer. Proteogenomic analysis can facilitate the identification of predictive biomarkers of drug treatment response, consequently greatly improving the stratification of patients with EOC for treatment towards a goal of personalized medicine.

Efficacy and safety of RC48-ADC in HER2-positive and HER2-low metastatic breast cancer: a multicenter, real-world study

Background

A standard treatment recommendation for third-line and subsequent treatments for advanced HER2-positive breast cancer is still missing, especially for low HER2 expression. Nevertheless, there is evidence that these patients might benefits from antibody-drug conjugates (ADCs) treatment. Therefore, this study aimed to evaluate the clinical efficacy, safety, and factors affecting efficacy of Disitamab Vedotin (RC48) for treating HER2-positive and HER2-low metastatic breast cancer (MBC) in the real-world setting.

Methods

A retrospective study at five clinical sites was conducted in China, enrolling MBC patients treated with RC48 from July 01, 2021 and May 31, 2023. Patient demographics, treatment patterns, and adverse events (AEs) were recorded and analyzed.

Results

A total of 154 patients were included: 104 (67.53%) patients with HER2-positive and 50 (32.47%) patients with HER2-low MBC. The median progression-free survival (mPFS) was 5.06 months. The objective response rate (ORR) and disease control rate (DCR) were 36.36% and 68.83%, respectively. HER2-positive patients exhibited a mPFS of 5.93 and an ORR of 41.35%. In contrast, patients with low-HER2 had a mPFS of 4.28 months and an ORR of 26.00%. The most common AEs included neutropenia (54.55%), increased AST (53.25%), leukopenia (51.95%), and fatigue (43.51%), mostly graded mild to moderate (grade 1-2).

Conclusions

This extensive study in China demonstrated that RC48 has excellent therapeutic potential for both HER2-positive and HER2-low MBC with a favorable safety profile. The study also suggests that combination therapy significantly boosts efficacy beyond monotherapy, indicating a promising avenue for future ADC development.

Efficacy of disitamab vedotin in non-small cell lung cancer with HER2 alterations: a multicenter, retrospective real-world study

Background

Non-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations poses a substantial treatment challenge. Current HER2-targeted therapies offer limited efficacy. Antibody-drug conjugates (ADCs) targeting HER2 have emerged as a promising therapeutic strategy. This study aimed to evaluate the clinical response to a novel ADC drug Disitamab vedotin (RC48) in advanced NSCLC with HER2 alterations.

Methods

This study conducted a retrospective review of patients harboring HER2 alterations treated with RC48 in the real world. Clinical outcomes were evaluated in terms of objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS).

Results

Out of 22 patients, 21 (95.5%) received RC48 combination therapy, while one received RC48 monotherapy. The ORR of all patients reached 45.5%, and the DCR stood at 90.9%. The median PFS (mPFS) was 7.5 months. Among patients receiving RC48 combination therapy, the ORR was 47.7%, and the mPFS of 8.1 months. The combination of RC48 with platinum+/- bevacizumab resulted in the highest ORR of 71.4% (5 out of 7 patients), with HER2 TKI following at a 50.0% ORR (4 out of 8 patients). First-line (1L) treatment with RC48 showed an ORR of 62.5% (5 out of 8 patients), second-line (2L) treatments had a 57.1% ORR (4 out of 7 patients), and beyond second-line (>2L) treatments exhibited a 14.3% ORR (1 out of 7 patients). Patients with 1L, 2L, or >2L treatment had a mPFS of 8.1 months, 7.2 months, and 7.4 months, respectively. Patients with HER2 mutations or amplifications, and those with concurrent mutations and amplifications at baseline, showed mPFS of 8.1 months, 9.4 months, and 7.4 months, respectively. The mPFS was significantly longer in patients with HER2 amplification. The most common adverse events included hand-foot syndrome (54.5%), asthenia (50.0%), decreased white blood cell count (45.5%), and liver impairment (45.5%). Grade 3 adverse events occurred in one (4.5%) patient.

Conclusion

RC48, particularly in combination regimens, demonstrates promising efficacy in advanced NSCLC with HER2 alterations. These findings underscore the need for further research to validate RC48's application in clinical practice.

Advances in Trop-2 targeted antibody-drug conjugates for breast cancer: mechanisms, clinical applications, and future directions

Breast cancer remains a leading cause of cancer-related deaths among women worldwide, highlighting the need for novel therapeutic strategies. Trophoblast cell surface antigen 2 (Trop-2), a type I transmembrane glycoprotein highly expressed in various solid tumors including all subtypes of breast cancer, has emerged as a promising target for cancer therapy. This review focuses on recent advancements in Trop-2-targeted antibody-drug conjugates (ADCs) for breast cancer treatment. We comprehensively analyzed the structure and mechanism of action of ADCs, as well as the role of Trop-2 in breast cancer progression and prognosis. Several Trop-2-targeted ADCs, such as Sacituzumab Govitecan (SG) and Datopotamab Deruxtecan (Dato-DXd), have demonstrated significant antitumor activity in clinical trials for both triple-negative breast cancer (TNBC) and hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer. We systematically reviewed the ongoing clinical studies of these ADCs, highlighting their efficacy and safety profiles. Furthermore, we explored the potential of combining Trop-2-targeted ADCs with other therapeutic modalities, including immunotherapy, targeted therapies, and small molecule inhibitors. Notably, Trop-2-targeted ADCs have shown promise in reprogramming the tumor microenvironment through multiple signaling pathways, potentially enhancing antitumor immunity. This review aims to provide new insights and research directions for the development of innovative breast cancer therapies, offering potential solutions to improve treatment outcomes and quality of life for breast cancer patients.

Development of an FRα Companion Diagnostic Immunohistochemical Assay for Mirvetuximab Soravtansine

CONTEXT.—

Folate receptor-α (FRα, encoded by the FOLR1 gene) is overexpressed in several solid tumor types, including epithelial ovarian cancer (EOC), making it an attractive biomarker and target for FRα-based therapy in ovarian cancer.

OBJECTIVE.—

To describe the development, analytic verification, and clinical performance of the VENTANA FOLR1 Assay (Ventana Medical Systems Inc) in EOC.

DESIGN.—

We used industry standard studies to establish the analytic verification of the VENTANA FOLR1 Assay. Furthermore, the VENTANA FOLR1 Assay was used in the ImmunoGen Inc-sponsored SORAYA study to select patients for treatment with mirvetuximab soravtansine (MIRV) in platinum-resistant EOC.

RESULTS.—

The VENTANA FOLR1 Assay is highly reproducible, demonstrated by a greater than 98% overall percent agreement (OPA) for repeatability and intermediate precision studies, greater than 93% OPA for interreader and greater than 96% for intrareader studies, and greater than 90% OPA across all observations in the interlaboratory reproducibility study. The performance of the VENTANA FOLR1 Assay in the SORAYA study was evaluated by the overall staining acceptability rate, which was calculated using the number of patient specimens that were tested with the VENTANA FOLR1 Assay that had an evaluable result. In the SORAYA trial, data in patients who received MIRV demonstrated clinically meaningful efficacy, and the overall staining acceptability rate of the assay was 98.4%, demonstrating that the VENTANA FOLR1 Assay is safe and effective for selecting patients who may benefit from MIRV. Together, these data showed that the assay is highly reliable, consistently producing evaluable results in the clinical setting.

CONCLUSIONS.—

The VENTANA FOLR1 Assay is a robust and reproducible assay for detecting FRα expression and identifying a patient population that derived clinically meaningful benefit from MIRV in the SORAYA study.

Ecological and evolutionary dynamics to design and improve ovarian cancer treatment

Ovarian cancer ecosystems are exceedingly complex, consisting of a high heterogeneity of cancer cells. Development of drugs such as poly ADP-ribose polymerase (PARP) inhibitors, targeted therapies and immunotherapies offer more options for sequential or combined treatments. Nevertheless, mortality in metastatic ovarian cancer patients remains high because cancer cells consistently develop resistance to single and combination therapies, urging a need for treatment designs that target the evolvability of cancer cells. The evolutionary dynamics that lead to resistance emerge from the complex tumour microenvironment, the heterogeneous populations, and the individual cancer cell's plasticity. We propose that successful management of ovarian cancer requires consideration of the ecological and evolutionary dynamics of the disease. Here, we review current options and challenges in ovarian cancer treatment and discuss principles of tumour evolution. We conclude by proposing evolutionarily designed strategies for ovarian cancer, with the goal of integrating such principles with longitudinal, quantitative data to improve the treatment design and management of drug resistance. KEY POINTS/HIGHLIGHTS: Tumours are ecosystems in which cancer and non-cancer cells interact and evolve in complex and dynamic ways. Conventional therapies for ovarian cancer inevitably lead to the development of resistance because they fail to consider tumours' heterogeneity and cellular plasticity. Eco-evolutionarily designed therapies should consider cancer cell plasticity and patient-specific characteristics to improve clinical outcome and prevent relapse.

Pharmaceutical innovation and advanced biotechnology in the biotech-pharmaceutical industry for antibody-drug conjugate development

Antibody-drug conjugates (ADCs), from prototypes in the 1980s to first- and second-generation products in the 2000s, and now in their multiformats, have progressed tremendously to meet oncological challenges. Currently, 13 ADCs have been approved for medical practice, with over 200 candidates in clinical trials. Moreover, ADCs have evolved into different formats, including bispecific ADCs, probody-drug conjugates, pH-responsive ADCs, target-degrading ADCs, and immunostimulating ADCs. Technologies from biopharmaceutical industries have a crucial role in the clinical transition of these novel biotherapeutics. In this review, we highlight several features contributing to the prosperity of bioindustrial ADC development. Various proprietary technologies from biopharmaceutical companies are discussed. Such advances in biopharmaceutical industries are the backbone for the success of ADCs in development and clinical application.

Antibody-drug conjugates as a novel therapeutic modality to treat recurrent refractory germ cell tumors

This review provides a rationale for using the Food and Drug Administration (FDA)-approved antibody-drug conjugates (ADCs) for implementing as therapy in recurrent refractory germ cell tumors similar to their position in the treatment of other types of chemoresistant solid tumors. Germ cell tumors (GCTs) originate from germ cells; they most frequently develop in ovaries or in the testes, while being the most common type of malignancy in young men. GCTs are very sensitive to cisplatin-based chemotherapy, but therapeutic resistance occurs in a considerable number of cases, which is associated with disease recurrence and poor patient prognosis. ADCs are a novel type of targeted antitumor agents that combine tumor antigen-specific monoclonal antibodies with chemically linked chemotherapeutic drugs (payload) exerting a cytotoxic effect. Several FDA-approved ADCs use as targeting moieties the antigens that are also detected in the GCTs, offering a benefit of this type of targeted therapy even for patients with relapsed/refractory testicular GCTs (rrTGCT) unresponsive to standard chemotherapy.

Maintenance with mirvetuximab soravtansine plus bevacizumab vs bevacizumab in FRα-high platinum-sensitive ovarian cancer

At first recurrence, platinum-sensitive ovarian cancer (PSOC) is frequently treated with platinum-based chemotherapy doublets plus bevacizumab, then single-agent bevacizumab. Most patients' disease progresses within a year after chemotherapy, emphasizing the need for novel strategies. Mirvetuximab soravtansine-gynx (MIRV), an antibody-drug conjugate, comprises a folate receptor alpha (FRα)-binding antibody and tubulin-targeting payload (maytansinoid DM4). In FRα-high PSOC, MIRV plus bevacizumab previously showed promising efficacy (objective response rate, 69% [95% CI: 41-89]; median progression-free survival, 13.3 months [95% CI: 8.3-18.3]; median duration of response, 12.9 months [95% CI: 6.5-15.7]) and safety. The Phase III randomized GLORIOSA trial will evaluate MIRV plus bevacizumab vs. bevacizumab alone as maintenance therapy in patients with FRα-high PSOC who did not have disease progression following second-line platinum-based doublet chemotherapy plus bevacizumab.Clinical Trial Registration: ClinicalTrials.gov ID: NCT05445778; GOG.org ID: GOG-3078; ENGOT.ESGO.org ID: ENGOT-ov76.

Spotlight on ideal target antigens and resistance in antibody-drug conjugates: Strategies for competitive advancement

Antibody-drug conjugates (ADCs) represent a novel and promising approach in targeted therapy, uniting the specificity of antibodies that recognize specific antigens with payloads, all connected by the stable linker. These conjugates combine the best targeted and cytotoxic therapies, offering the killing effect of precisely targeting specific antigens and the potent cell-killing power of small molecule drugs. The targeted approach minimizes the off-target toxicities associated with the payloads and broadens the therapeutic window, enhancing the efficacy and safety profile of cancer treatments. Within precision oncology, ADCs have garnered significant attention as a cutting-edge research area and have been approved to treat a range of malignant tumors. Correspondingly, the issue of resistance to ADCs has gradually come to the fore. Any dysfunction in the steps leading to the ADCs' action within tumor cells can lead to the development of resistance. A deeper understanding of resistance mechanisms may be crucial for developing novel ADCs and exploring combination therapy strategies, which could further enhance the clinical efficacy of ADCs in cancer treatment. This review outlines the brief historical development and mechanism of ADCs and discusses the impact of their key components on the activity of ADCs. Furthermore, it provides a detailed account of the application of ADCs with various target antigens in cancer therapy, the categorization of potential resistance mechanisms, and the current state of combination therapies. Looking forward, breakthroughs in overcoming technical barriers, selecting differentiated target antigens, and enhancing resistance management and combination therapy strategies will broaden the therapeutic indications for ADCs. These progresses are anticipated to advance cancer treatment and yield benefits for patients.

Antibody-drug conjugates combinations in cancer treatment

Antibody-drug conjugates (ADCs) have emerged as a promising class of anticancer agents. Currently, the Food and Drug Administration has granted approval to 12 compounds, with 2 later undergoing withdrawal. Moreover, several other compounds are currently under clinical development at different stages. Despite substantial antitumoral activity observed among different tumor types, adverse events and the development of resistance represent significant challenges in their use. Over the last years, an increasing number of clinical trials have been testing these drugs in different combinations with other anticancer agents, such as traditional chemotherapy, immune checkpoint inhibitors, monoclonal antibodies, and small targeted agents, reporting promising results based on possible synergistic effects and a potential for improved treatment outcomes among different tumor types. Here we will review combinations of ADCs with other antitumor agents aiming at describing the current state of the art and future directions.

Mirvetuximab soravtansine: A breakthrough in targeted therapy for platinum-resistant ovarian cancer

Ovarian cancer, ranked as the second leading cause of gynecologic malignancy-related deaths globally, poses a formidable challenge despite advances in early detection and treatment modalities. This paper explores the efficacy and safety of mirvetuximab soravtansine, the first folate receptor alpha (FRα)-targeting antibody-drug conjugate, in platinum-resistant ovarian cancer expressing FRα. A review of 4 key studies involving 453 participants consistently demonstrates mirvetuximab soravtansine's clinically meaningful antitumor activity and favorable safety profile. Clinical implications emphasize mirvetuximab soravtansine's pivotal role in targeted therapy, especially for high FRα-expressing tumors, potentially reshaping platinum-resistant ovarian cancer management. The combination therapy approach introduces a novel dimension, suggesting enhanced therapeutic outcomes. Even in heavily pretreated patients, mirvetuximab soravtansine's favorable tolerability positions it as a viable option. The reliability of archival tissue for FRα assessment simplifies patient selection, streamlining accessibility to targeted therapies. However, identified gaps, including limited diversity in patient populations, sparse quality of life data, and the need for long-term safety information, indicate areas for future research. Exploration of additional biomarkers predicting mirvetuximab soravtansine responsiveness is essential for personalized treatment.

Unlocking Amides: A General Method for the Self-Immolative Release of Amide-Containing Molecules

The controlled liberation of molecules from a constructed framework is a subject of profound interest across various chemical fields. It allows for the masking of a molecule's properties and precise deployment upon a single controllable release event. While numerous methodologies have been developed for amines, alcohols, and thiols, approaches for utilising amides as payload-release handles are still in their early stages of development, despite the prevalence of amides in therapeutic compounds and materials. Herein, is presented a comprehensive strategy for the controlled and selective release of a diverse range of amides with stable linkers. The versatility of this approach is demonstrated by its successful application in the targeted release of various amide-containing drugs in their natural form via the use of commonly used trigger motifs, such as dipeptides or glycosides. As a proof of concept, the FDA-approved antibiotic linezolid has been successfully converted into a prodrug form and released selectively only in the presence of the trigger event. Significantly, in its prodrug state, no activity against Mycobacterium tuberculosis was exhibited. Linezolid's full potential was achieved only upon controlled release, where an equipotent efficacy to the free linezolid control was demonstrated, thus emphasising the immense potential of this method.

Folate receptor alpha protein expression in ovarian serous cystadenocarcinoma tumors of The Cancer Genome Atlas: exploration beyond single-agent therapy

Epithelial ovarian cancer (EOC) can be highly lethal, with limited therapeutic options for patients with non-homologous recombination deficient (HRD) disease. Folate receptor alpha (FOLR1/FRα)-targeting agents have shown promise both alone and in combination with available therapies, but the relationship of FRα to other treatment-driving biomarkers is unknown. The Cancer Genome Atlas (TCGA) was queried to assess protein and mRNA expression and mutational burden in patients with differential FRα protein-expressing ovarian tumors, and the results referenced against the standard 324 mutations currently tested through FoundationOne Companion Diagnostics to identify targets of interest. Of 585 samples within TCGA, 121 patients with serous ovarian tumors for whom FRα protein expression was quantified were identified. FRα protein expression significantly correlated with FOLR1 mRNA expression (p=7.19×1014). Progression free survival (PFS) for the FRα-high group (Q1) was 20.7 months, compared to 16.6 months for the FRα-low group (Q4, Logrank, p=0.886). Overall survival (OS) was 54.1 months versus 36.3 months, respectively; however, this result was not significant (Q1 vs. Q4, Logrank, p=0.200). Mutations more commonly encountered in patients with high FRα-expressing tumors included PIK3CA and FGF family proteins. Combinations of FRα-targeting agents with PI3K, mTOR, FGF(R) and VEGF inhibitors warrant investigation to evaluate their therapeutic potential.

Prospects and challenges of CAR-T cell therapy combined with ICIs

Immune checkpoint molecules are a group of molecules expressed on the surface of immune cells that primarily regulate their immune homeostasis. Chimeric antigen receptor (CAR) T cell therapy is an immunotherapeutic technology that realizes tumor-targeted killing by constructing synthetic T cells expressing specific antigens through biotechnology. Currently, CAR-T cell therapy has achieved good efficacy in non-solid tumors, but its treatment of solid tumors has not yielded the desired results. Immune checkpoint inhibitors (ICIs) combined with CAR-T cell therapy is a novel combination therapy with high expectations to defeat solid tumors. This review addresses the challenges and expectations of this combination therapy in the treatment of solid tumors.

Drug conjugates for the treatment of lung cancer: from drug discovery to clinical practice

A drug conjugate consists of a cytotoxic drug bound via a linker to a targeted ligand, allowing the targeted delivery of the drug to one or more tumor sites. This approach simultaneously reduces drug toxicity and increases efficacy, with a powerful combination of efficient killing and precise targeting. Antibody‒drug conjugates (ADCs) are the best-known type of drug conjugate, combining the specificity of antibodies with the cytotoxicity of chemotherapeutic drugs to reduce adverse reactions by preferentially targeting the payload to the tumor. The structure of ADCs has also provided inspiration for the development of additional drug conjugates. In recent years, drug conjugates such as ADCs, peptide‒drug conjugates (PDCs) and radionuclide drug conjugates (RDCs) have been approved by the Food and Drug Administration (FDA). The scope and application of drug conjugates have been expanding, including combination therapy and precise drug delivery, and a variety of new conjugation technology concepts have emerged. Additionally, new conjugation technology-based drugs have been developed in industry. In addition to chemotherapy, targeted therapy and immunotherapy, drug conjugate therapy has undergone continuous development and made significant progress in treating lung cancer in recent years, offering a promising strategy for the treatment of this disease. In this review, we discuss recent advances in the use of drug conjugates for lung cancer treatment, including structure-based drug design, mechanisms of action, clinical trials, and side effects. Furthermore, challenges, potential approaches and future prospects are presented.

Recent Therapeutic Advances in Gynecologic Oncology: A Review

Gynecologic malignancies have high incidence rates both nationally and internationally, and cervical, endometrial, and ovarian cancers account for high mortality rates worldwide. Significant research is ongoing to develop targeted therapies to address unmet needs in the field and improve patient outcomes. As tumors mutate and progress through traditional lines of treatment, new therapies must be developed to overcome resistance and target cancer-specific receptors and mutations. Recent advances in the development of immunotherapy and antibody-drug conjugates have resulted in compelling and clinically meaningful results in cervical, endometrial, and ovarian cancers. In the last decade, several immunotherapy agents have received FDA approval or NCCN guideline recommendation for the treatment of gynecologic malignancies, including dostarlimab for advanced or recurrent endometrial cancer and pembrolizumab for advanced or recurrent cervical and endometrial cancers. Several other immunotherapeutic agents are under active investigation. Development of antibody-drug conjugates including tisotumab vedotin in cervical cancer, mirvetuximab soravtansine in ovarian cancer, and trastuzumab deruxtecan in multiple gynecologic cancers has translated into exciting efficacy signals, prompting full drug approvals and additional investigation. This article aims to review recent novel advances in targeted treatments for gynecologic malignancies, highlighting the trials and data underlying these novel interventions.

Mirvetuximab soravtansine in ovarian cancer therapy: expert opinion on pharmacological considerations

ImmunoGen developed mirvetuximab soravtansine as an antibody-drug conjugate comprising of a humanized anti-folate receptor-α (FRα) monoclonal antibody of IgG1k subtype, a cleavable linker, and a cytotoxic payload, DM4. Mirvetuximab soravtansine was granted accelerated approval by the US FDA on November 14, 2022, for the treatment of adult patients with FRα positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. The approval of mirvetuximab soravtansine represents a breakthrough for addressing the unmet medical needs of ovarian cancer, especially for up to 80% of patients who relapse and become resistant to platinum-based chemotherapy, resulting in poor prognosis and limited treatment options. However, it is my impression that addressing several pharmacological factors could improve the safety and efficacy of mirvetuximab soravtansine. This article summarizes the current pharmacological profile of mirvetuximab soravtansine and provides an expert opinion on pharmacological strategies for optimizing its safety and efficacy profile for the treatment of platinum-resistant ovarian cancer.

Efficacy and safety of mirvetuximab soravtansine in recurrent ovarian cancer with FRa positive expression: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of mirvetuximab soravtansine in treating recurrent ovarian cancer with folate receptor alpha (FRa) expression.

METHODS

A comprehensive search was conducted on online databases, including PubMed, Cochrane Library, and EMBASE, to identify relevant literature about the efficacy and safety of mirvetuximab soravtansine in recurrent ovarian cancer with FRa-positive expression. The keywords were the following: recurrent ovarian cancer, mirvetuximab soravtansine, FRa, and antibody-drug conjugate. Furthermore, studies that satisfied the necessary qualifications were carefully evaluated for further meta-analysis.

RESULTS

This meta-analysis involved the examination of seven trials with a total of 631 patients. According to the pooled data, the objective response rate (ORR) was 36% (95%CI: 27%-45%). Similarly, the disease control rate (DCR) was 88% (95% CI: 84-91%). Furthermore, the median progression-free survival (PFS) was determined to be 6.1 months (95% CI: 4.27-7.47). The overall response rate and PFS for platinum-resistant ovarian cancer were found to be 29% (95% CI: 25-32%) and 6.26 months (95% CI: 4.67-7.85), respectively. The most often observed adverse events (AEs) in patients with recurrent ovarian cancer (OC) receiving mirvetuximab soravtansine were blurred vision (all grades: 45%, Grade III: 2%), nausea (all grades: 42%, Grade III: 1%), and diarrhea (all grades: 42%, Grade III: 2%). These AEs were specifically associated with the safety profile of mirvetuximab soravtansine in this patient population.

CONCLUSION

The efficacy of mirvetuximab soravtansine in treating recurrent ovarian cancer with FRa-positive expression is satisfactory, and the safety is tolerable.

The promise and challenges of combination therapies with antibody-drug conjugates in solid tumors

Antibody-drug conjugates (ADCs) represent an important class of cancer therapies that have revolutionized the treatment paradigm of solid tumors. To date, many ongoing studies of ADC combinations with a variety of anticancer drugs, encompassing chemotherapy, molecularly targeted agents, and immunotherapy, are being rigorously conducted in both preclinical studies and clinical trial settings. Nevertheless, combination therapy does not always guarantee a synergistic or additive effect and may entail overlapping toxicity risks. Therefore, understanding the current status and underlying mechanisms of ADC combination therapy is urgently required. This comprehensive review analyzes existing evidence concerning the additive or synergistic effect of ADCs with other classes of oncology medicines. Here, we discuss the biological mechanisms of different ADC combination therapy strategies, provide prominent examples, and assess their benefits and challenges. Finally, we discuss future opportunities for ADC combination therapy in clinical practice.

Chemical technology principles for selective bioconjugation of proteins and antibodies

Proteins are multifunctional large organic compounds that constitute an essential component of a living system. Hence, control over their bioconjugation impacts science at the chemistry-biology-medicine interface. A chemical toolbox for their precision engineering can boost healthcare and open a gateway for directed or precision therapeutics. Such a chemical toolbox remained elusive for a long time due to the complexity presented by the large pool of functional groups. The precise single-site modification of a protein requires a method to address a combination of selectivity attributes. This review focuses on guiding principles that can segregate them to simplify the task for a chemical method. Such a disintegration systematically employs a multi-step chemical transformation to deconvolute the selectivity challenges. It constitutes a disintegrate (DIN) theory that offers additional control parameters for tuning precision in protein bioconjugation. This review outlines the selectivity hurdles faced by chemical methods. It elaborates on the developments in the perspective of DIN theory to demonstrate simultaneous regulation of reactivity, chemoselectivity, site-selectivity, modularity, residue specificity, and protein specificity. It discusses the progress of such methods to construct protein and antibody conjugates for biologics, including antibody-fluorophore and antibody-drug conjugates (AFCs and ADCs). It also briefs how this knowledge can assist in developing small molecule-based covalent inhibitors. In the process, it highlights an opportunity for hypothesis-driven routes to accelerate discoveries of selective methods and establish new targetome in the precision engineering of proteins and antibodies.

Drug-Resistant Epithelial Ovarian Cancer: Current and Future Perspectives

Epithelial ovarian cancer (EOC) is a complex disease with diverse histological subtypes, which, based on the aggressiveness and course of disease progression, have recently been broadly grouped into type I (low-grade serous, endometrioid, clear cell, and mucinous) and type II (high-grade serous, high-grade endometrioid, and undifferentiated carcinomas) categories. Despite substantial differences in pathogenesis, genetics, prognosis, and treatment response, clinical diagnosis and management of EOC remain similar across the subtypes. Debulking surgery combined with platinum-taxol-based chemotherapy serves as the initial treatment for High Grade Serous Ovarian Carcinoma (HGSOC), the most prevalent one, and for other subtypes, but most patients exhibit intrinsic or acquired resistance and recur in short duration. Targeted therapies, such as anti-angiogenics (e.g., bevacizumab) and PARP inhibitors (for BRCA-mutated cancers), offer some success, but therapy resistance, through various mechanisms, poses a significant challenge. This comprehensive chapter delves into emerging strategies to address these challenges, highlighting factors like aberrant miRNAs, metabolism, apoptosis evasion, cancer stem cells, and autophagy, which play pivotal roles in mediating resistance and disease relapse in EOC. Beyond standard treatments, the focus of this study extends to alternate targeted agents, including immunotherapies like checkpoint inhibitors, CAR T cells, and vaccines, as well as inhibitors targeting key oncogenic pathways in EOC. Additionally, this chapter covers disease classification, diagnosis, resistance pathways, standard treatments, and clinical data on various emerging approaches, and advocates for a nuanced and personalized approach tailored to individual subtypes and resistance mechanisms, aiming to enhance therapeutic outcomes across the spectrum of EOC subtypes.

Understanding the promising role of antibody drug conjugates in breast and ovarian cancer

A nascent category of anticancer therapeutic drugs called antibody-drug conjugates (ADCs) relate selectivity of aimed therapy using chemotherapeutic medicines with high cytotoxic power. Progressive linker technology led to the advancement of more efficacious and safer treatments. It offers neoteric as well as encouraging therapeutic strategies for treating cancer. ADCs selectively administer a medication by targeting antigens which are abundantly articulated on the membrane surface of tumor cells. Tumor-specific antigens are differently expressed in breast and ovarian cancers and can be utilized to direct ADCs. Compared to conventional chemotherapeutic drugs, this approach enables optimal tumor targeting while minimizing systemic damage. A cleavable linker improves the ADCs because it allows the toxic payload to be distributed to nearby cells that do not express the target protein, operating on assorted tumors with dissimilar cell aggregation. Presently fifteen ADCs are being studied in breast and ovarian carcinoma preclinically, and assortment of few have already undergone promising early-phase clinical trial testing. Furthermore, Phase I and II studies are investigating a wide variety of ADCs, and preliminary findings are encouraging. An expanding sum of ADCs will probably become feasible therapeutic choices as solo agents or in conjunction with chemotherapeutic agents. This review accentuates the most recent preclinical findings, pharmacodynamics, and upcoming applications of ADCs in breast and ovarian carcinoma.

A comprehensive overview on antibody-drug conjugates: from the conceptualization to cancer therapy

Antibody-Drug Conjugates (ADCs) represent an innovative class of potent anti-cancer compounds that are widely used in the treatment of hematologic malignancies and solid tumors. Unlike conventional chemotherapeutic drug-based therapies, that are mainly associated with modest specificity and therapeutic benefit, the three key components that form an ADC (a monoclonal antibody bound to a cytotoxic drug via a chemical linker moiety) achieve remarkable improvement in terms of targeted killing of cancer cells and, while sparing healthy tissues, a reduction in systemic side effects caused by off-tumor toxicity. Based on their beneficial mechanism of action, 15 ADCs have been approved to date by the market approval by the Food and Drug Administration (FDA), the European Medicines Agency (EMA) and/or other international governmental agencies for use in clinical oncology, and hundreds are undergoing evaluation in the preclinical and clinical phases. Here, our aim is to provide a comprehensive overview of the key features revolving around ADC therapeutic strategy including their structural and targeting properties, mechanism of action, the role of the tumor microenvironment and review the approved ADCs in clinical oncology, providing discussion regarding their toxicity profile, clinical manifestations and use in novel combination therapies. Finally, we briefly review ADCs in other pathological contexts and provide key information regarding ADC manufacturing and analytical characterization.

Application of curcumin nanoformulations to target folic acid receptor in cancer: Recent trends and advances

Curcumin, derived from turmeric, has a strong anticancer potential known for millennia. The development of this phytochemical as a medicine has been hampered by several significant deficiencies, including its poor water solubility and low bioavailability. This review article discusses possibilities to overcome these bottlenecks by focusing on this natural polyphenol's nanoformulation. Moreover, preparation of curcumin conjugates containing folates as ligands for folic acid receptors can add a new important dimension in this field, allowing specific targeting of cancer cells, considering the significantly higher expression of these receptors in malignant tissues compared to normal cells. It is highly expected that simultaneous improvement of different aspects of curcumin in fighting against such a complex and multifaceted disease like cancer. Therefore, we can better comprehend cancer biology by developing a mechanistic understanding of curcumin, which will also inspire the scientific community to develop new pharmacological models, and exploration of emerging directions to revitalize application of natural products in cancer therapy.

Therapeutic strategies targeting folate receptor α for ovarian cancer

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer, and presents a major clinical challenge due to limited treatment options. Folate receptor alpha (FRα), encoded by the FOLR1 gene, is an attractive therapeutically target due to its prevalent and high expression in EOC cells. Recent basic and translational studies have explored several modalities, such as antibody-drug conjugate (ADC), monoclonal antibodies, small molecules, and folate-drug conjugate, to exploit FRα for EOC treatment. In this review, we summarize the function of FRα, and clinical efficacies of various FRα-based therapeutics. We highlight mirvetuximab soravtansine (MIRV), or Elahere (ImmunoGen), the first FRα-targeting ADC approved by the FDA to treat platinum-resistant ovarian cancer. We discuss potential mechanisms and management of ocular adverse events associated with MIRV administration.

Disitamab Vedotin (RC48) combined with bevacizumab for treatment of HR-negative/HER2-positive metastatic breast cancer with liver and brain involvement: A case report

Background

The overexpression of human epidermal growth factor receptor 2 (HER2) is strongly correlated with an elevated risk of developing distant metastases, particularly brain metastases, in breast cancer (BC) cases. RC48 (also known as Disitamab vedotin), represents a promising antibody-drug conjugate (ADC), that comprises three well-defined components: hertuzumab against the prominent tumor target-HER2, monomethyl auristatin E (MMAE) and a cleavable linker. Preclinical studies have demonstrated its robust antitumor activity in BC patient-derived xenograft models with HER2-positive or HER2-low expression. Additionally, antiangiogenic drugs like bevacizumab have shown potential efficacy on advanced BC via inhibiting pathological neovascularizationits.

Case presentation

Here, we will share our experience in treating a 49-year-old woman initially diagnosed with stage IV breast cancer characterized by hormone receptor (HR)-negativity and HER2-positivity. This complex case entailed brain and liver metastases, and the patient exhibited resistance to various HER2-targeted treatment regimens. Finally, the patient received RC48 plus bevacizumab as the advanced forth-line treatment, which was well tolerated with no observed toxicities. Subsequent radiological assessments revealed remarkable regression in the brain metastatic lesions, classified as having partial response based on the RECIST 1.1 system. The period of progression-free survival (PFS) was 7 months.

Conclusion

The present study underscores the efficacy of systemic treatment with RC48 in conjunction, showcasing substantial enhancement in both radiographic indicators and clinical symptomatology among patients with brain metastatic breast cancer (BMBC). More specifically, the sequential application of ADCs in combination with antiangiogenics presents a novel avenue for advancing the treatment landscape of metastatic BC.

Antibody-Drug Conjugates: A Review of Approved Drugs and Their Clinical Level of Evidence

Antibody-drug conjugates (ADCs) are an innovative family of agents assembled through linking cytotoxic drugs (payloads) covalently to monoclonal antibodies (mAbs) to be delivered to tumor tissue that express their particular antigen, with the theoretical advantage of an augmented therapeutic ratio. As of June 2023, eleven ADCs have been approved by the Food and Drug Administration (FDA) and are on the market. These drugs have been added to the therapeutic armamentarium of acute myeloblastic and lymphoblastic leukemias, various types of lymphoma, breast, gastric or gastroesophageal junction, lung, urothelial, cervical, and ovarian cancers. They have proven to deliver more potent and effective anti-tumor activities than standard practice in a wide variety of indications. In addition to targeting antigen-expressing tumor cells, bystander effects have been engineered to extend cytotoxic killing to low-antigen-expressing or negative tumor cells in the heterogenous tumor milieu. Inevitably, myelosuppression is a common side effect with most of the ADCs due to the effects of the cytotoxic payload. Also, other unique side effects are specific to the tissue antigen that is targeted for, such as the cardiac toxicity with Her-2 targeting ADCs, and the hemorrhagic side effects with the tissue factor (TF) targeting Tisotumab vedotin. Further exciting developments are centered in the strategies to improve the tolerability and efficacy of the ADCs to improve the therapeutic window; as well as the development of novel payloads including (1) peptide-drug conjugates (PDCs), with the peptide replacing the monoclonal antibody, rendering greater tumor penetration; (2) immune-stimulating antibody conjugates (ISACs), which upon conjugation of the antigen, cause an influx of pro-inflammatory cytokines to activate dendritic cells and harness an anti-tumor T-cell response; and (3) the use of radioactive isotopes as a payload to enhance cytotoxic activity.

Mirvetuximab Soravtansine in Platinum-Resistant Ovarian Cancer

Ovarian cancer is the second leading cause of death from gynecologic malignancies worldwide. Management of platinum-resistant disease is challenging and clinical outcomes with standard chemotherapy are poor. Over the past decades, significant efforts have been made to understand drug resistance and develop strategies to overcome treatment failure. Antibody drug conjugates (ADCs) are a rapidly growing class of oncologic therapeutics, which combine the ability to target tumor-specific antigens with the cytotoxic effects of chemotherapy. Mirvetuximab soravtansine is an ADC comprising an IgG1 monoclonal antibody against the folate receptor alpha (FRα) conjugated to the cytotoxic maytansinoid effector molecule DM4 that has shown promising clinical activity in patients with FR-α-positive ovarian cancer. This review summarizes current evidence of mirvetuximab soravtansine in platinum-resistant ovarian cancer, focusing on clinical activity, toxicity, and future directions.

Mirvetuximab soravtansine for platinum-resistant epithelial ovarian cancer

INTRODUCTION

Mirvetuximab soravtansine (mirvetuximab) is an antibody drug conjugate (ADC) comprised of a humanized folate receptor alpha (FRα)-binding monoclonal antibody attached via a cleavable linker to the cytotoxic maytansinoid molecule, DM4. FRα is expressed in several epithelial cancers, including high grade serous ovarian cancer (HGSOC). Mirvetuximab received accelerated approval by the United States Food and Drug Administration (FDA) in November 2022 based on the results of the SORAYA trial, which tested mirvetuximab for the treatment of patients with recurrent platinum resistant HGSOC with high FRα expression and showed an overall response rate (ORR) of 32.4% and a median duration of response of 6.9 months. Mirvetuximab toxicities included low grade ocular and gastrointestinal toxicities. The National Comprehensive Cancer Network (NCCN) ovarian cancer 2023 guidelines adopted mirvetuximab as 2A, and mirvetuximab combined with bevacizumab as 2B, recommendations.

AREAS COVERED

This manuscript will review the preclinical and clinical development of mirvetuximab, the toxicities associated with mirvetuximab and mitigation strategies, and future applications of mirvetuximab.

EXPERT OPINION

Mirvetuximab represents the first biomarker-directed therapy with an indication specifically for the treatment of PROC. The efficacy and favorable safety profile support further development of mirvetuximab and mirvetuximab combinations in platinum sensitive and newly diagnosed ovarian cancer.

The efficacy and toxicity of mirvetuximab soravtansine, a novel antibody-drug conjugate, in the treatment of advanced or recurrent ovarian cancer: a meta-analysis

INTRODUCTION

This meta-analysis aims to systematically analyze the efficacy and toxicity of mirvetuximab soravtansine (MIRV) as second-line and above treatment for advanced or recurrent ovarian cancer.

METHODS

Candidate studies were identified in PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases up to 1 May 2023. Objective response rate (ORR), progression-free survival (PFS), the incidence of adverse events (AEs), and incidence of grade ≥ 3 AEs were extracted and calculated by meta-analysis of merging ratios or mean to describe the efficacy and toxicity of MIRV.

RESULTS

Seven eligible prospective studies were included in this meta-analysis, including 605 patients with advanced ovarian cancer who received second-line or higher therapy. ORR of MIRV was 34.2% (95% confidence interval [CI] 25.0-43.5), and PFS was 5.82 months (95%CI 4.47-7.18). The overall incidence of AEs was 87.4% (95%CI 52.9-100.0) and the incidence of grade ≥ 3 AEs was 27.1% (95%CI 18.9-36.1). The most common AEs were vision blurring, nausea, and diarrhea, with incidence of 46.7% (39.6-53.8), 41.8% (34.0-49.9), and 41.3% (30.4-52.5), respectively.

CONCLUSIONS

MIRV has definite efficacy and good safety as a novel choice for second-line and above treatment of advanced or recurrent FRα positive ovarian cancer. This may have promising application in patients with platinum-resistant diseases.

PROSPERO REGISTRATION NUMBER

CRD42023428599.

Targeting Trop-2 in cancer: Recent research progress and clinical application

The development of new antitumor drugs depends mainly upon targeting tumor cells precisely. Trophoblast surface antigen 2 (Trop-2) is a type I transmembrane glycoprotein involved in Ca2+ signaling in tumor cells. It is highly expressed in various tumor tissues than in normal tissues and represents a novel and promising molecular target for caner targeted therapy. Up to now, the mechanisms and functions associated with Trop-2 have been extensively studied in a variety of solid tumors. According to these findings, Trop-2 plays an important role in cell proliferation, apoptosis, cell adhesion, epithelial-mesenchymal transition, as well as tumorigenesis and tumor progression. In addition, Trop-2 related drugs are also being developed widely. There are a number of Trop-2 related ADC drugs that have demonstrated potent antitumor activity and are currently been studied, such as Sacituzumab Govitecan (SG) and Datopotamab Deruxtecan (Dato-Dxd). In this study, we reviewed the progress of Trop-2 research in solid tumors. We also sorted out the composition and rationale of Trop-2 related drugs and summarized the related clinical trials. Finally, we discussed the current status of Trop-2 research and expanded our perspectives on its future research directions. Importantly, we found that Trop-2 targeted ADCs have great potential for combination with other antitumor therapies. Trop-2 targeted ADCs can reprogramme tumor microenvironment through multiple signaling pathways, ultimately activating antitumor immunity.

Recent advances in using folate receptor 1 (FOLR1) for cancer diagnosis and treatment, with an emphasis on cancers that affect women

A glycosylphosphatidylinositol (GPI)-anchored glycoprotein called the folate receptor 1 (FOLR1) facilitates the transportation of folate by mediating receptor-mediated endocytosis in response to ligand binding. While FOLR1 expression is typically restricted to the apical surfaces of the epithelium in the lung, kidney, and choroid plexus in healthy people, it is overexpressed in a number of solid tumours, including high-grade osteosarcoma, breast cancer, ovarian cancer, and non-small cell lung cancer. As a result, FOLR1 has become an attractive target for cancer detection and therapy, particularly for cancers that affect women. A number of methods have been developed to target FOLR1 in cancer therapy, including the development of FOLR1-targeted imaging agents for cancer diagnosis and the use of folate conjugates to deliver cytotoxic agents to cancer cells that overexpress FOLR1. Therefore, we focus on the most recent developments in employing FOLR1 for cancer diagnosis and treatment in this review, particularly with regard to cancers that affect women.

Deregulated Metabolic Pathways in Ovarian Cancer: Cause and Consequence

Ovarian cancers are tumors that originate from the different cells of the ovary and account for almost 4% of all the cancers in women globally. More than 30 types of tumors have been identified based on the cellular origins. Epithelial ovarian cancer (EOC) is the most common and lethal type of ovarian cancer which can be further divided into high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. Ovarian carcinogenesis has been long attributed to endometriosis which is a chronic inflammation of the reproductive tract leading to progressive accumulation of mutations. Due to the advent of multi-omics datasets, the consequences of somatic mutations and their role in altered tumor metabolism has been well elucidated. Several oncogenes and tumor suppressor genes have been implicated in the progression of ovarian cancer. In this review, we highlight the genetic alterations undergone by the key oncogenes and tumor suppressor genes responsible for the development of ovarian cancer. We also summarize the role of these oncogenes and tumor suppressor genes and their association with a deregulated network of fatty acid, glycolysis, tricarboxylic acid and amino acid metabolism in ovarian cancers. Identification of genomic and metabolic circuits will be useful in clinical stratification of patients with complex etiologies and in identifying drug targets for personalized therapies against cancer.

Antibody-drug conjugates: in search of partners of choice

Antibody-drug conjugates (ADCs) have become a credentialled class of anticancer drugs for both solid and hematological malignancies, with regulatory approvals mainly as single agents. Despite extensive preclinical and clinical efforts to develop rational ADC-based combinations, to date only a limited number have demonstrated survival improvements over standard of care. The most appealing partners for ADCs are those that offer additive or synergistic effects on tumor cells or their microenvironment without unacceptable overlapping toxicities. Coadministration with antiangiogenic compounds, HER2-targeting drugs, DNA-damage response agents and immune checkpoint inhibitors (ICIs) represent active forerunners. Through the identification of targets with tumor-specific expression, improved conjugation technologies, and novel linkers and payloads offering superior therapeutic indices, the next generation of ADCs brings optimism to combinatorial approaches.

Safety and efficacy of mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in combination with bevacizumab in patients with platinum-resistant ovarian cancer

PURPOSE

Evaluate the antitumor activity and safety profile of the combination of mirvetuximab soravtansine and bevacizumab in patients with platinum-resistant ovarian cancer.

METHODS

Patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, whose most recent platinum-free interval was ≤6 months, were administered mirvetuximab soravtansine (6 mg/kg adjusted ideal body weight) and bevacizumab (15 mg/kg), intravenously, once every 3 weeks. Eligibility included FRα expression by immunohistochemistry (IHC; ≥25% of cells with ≥2+ intensity). Prior bevacizumab and/or PARP inhibitor (PARPi) treatment were permitted. The primary endpoint was confirmed objective response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and safety.

RESULTS

Ninety-four patients received combination treatment with mirvetuximab soravtansine and bevacizumab. Median age was 62 years (range, 39-81). Fifty-two percent had ≥3 prior therapies; 59% had prior bevacizumab; and 27% had prior PARPi. ORR was 44% (95% CI 33, 54) with 5 complete responses, median DOR 9.7 months (95% CI 6.9, 14.1), and median PFS 8.2 months (95% CI 6.8, 10.0). Treatment-related adverse events were consistent with the profiles of each agent, with the most common being blurred vision (all grades 57%; grade 3, 1%), diarrhea (54%; grade 3, 1%), and nausea (51%; grade 3, 1%).

CONCLUSION

The mirvetuximab soravtansine plus bevacizumab doublet is an active and well-tolerated regimen in patients with FRα-expressing platinum-resistant ovarian cancer. Promising activity was observed for patients regardless of level of FRα expression or prior bevacizumab. These data underscore the potential for mirvetuximab soravtansine as the combination partner of choice for bevacizumab in this setting.

Mirvetuximab Soravtansine: First Approval

Mirvetuximab soravtansine (mirvetuximab soravtansine-gynx; Elahere™) is an antibody-drug conjugate (ADC), which is comprised of a folate receptor α (FRα) directed antibody conjugated to a microtubule inhibitor via a cleavable linker. The ADC is being developed by ImmunoGen for the treatment of FRα expressing cancers. In November 2022, mirvetuximab soravtansine was approved in the USA for the treatment of adult patients with FRα positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. This article summarizes the milestones in the development of mirvetuximab soravtansine leading to this first approval.

Targeted therapy and immunotherapy: Diamonds in the rough in the treatment of epithelial ovarian cancer

Currently, for ovarian cancer, which has the highest mortality rate among all gynecological cancers, the standard treatment protocol is initial tumor cytoreductive surgery followed by platinum-based combination chemotherapy. Although the survival rate after standard treatment has improved, the therapeutic effect of traditional chemotherapy is very limited due to problems such as resistance to platinum-based drugs and recurrence. With the advent of the precision medicine era, molecular targeted therapy has gradually entered clinicians' view, and individualized precision therapy has been realized, surpassing the limitations of traditional therapy. The detection of genetic mutations affecting treatment, especially breast cancer susceptibility gene (BRCA) mutations and mutations of other homologous recombination repair defect (HRD) genes, can guide the targeted drug treatment of patients, effectively improve the treatment effect and achieve a better patient prognosis. This article reviews different sites and pathways of targeted therapy, including angiogenesis, cell cycle and DNA repair, and immune and metabolic pathways, and the latest research progress from preclinical and clinical trials related to ovarian cancer therapy.

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.

High Expression of Folate Receptor Alpha (FOLR1) is Associated With Aggressive Tumor Behavior, Poor Response to Chemoradiotherapy, and Worse Survival in Rectal Cancer

Objectives: Recently, molecular medicine targeting Folate Receptor Alpha (FOLR1), which mediates intracellular folate uptake and tumor cell proliferation, has been identified in several malignancies. However, the association between FOLR1 expression and rectal cancer remains unclear. Methods: Immunostaining of FOLR1 was performed on biopsy specimens from 172 rectal cancer patients undergoing preoperative chemoradiotherapy (CRT). FOLR1 expression was measured and divided into low (0+-2+) or high (3+-4+) level. Correlations between FOLR1 status and clinicopathologic features, tumor regression grade, disease-specific survival (DSS), local recurrence-free survival, and metastasis-free survival (MeFS) were analyzed, retrospectively. Results: High FOLR1 expression was significantly associated with advanced post-treatment tumor and nodal status (T3-4; N1-2, P = .001), vascular invasion (P = .042), perineural invasion (P = .012), and poor regression change after CRT (P = .001). In uni- and multi-variable survival analysis, FOLR1 overexpression remained a significant predictor of lower DSS (hazard ratio [HR], 2.328; 95% confidence interval [CI], 1.014-5.344; P = .046) and MeFS (HR, 2.177; 95% CI, 1.000-1.1286; P = .050). Conclusion: These results indicate that high FOLR1 status is associated with aggressive tumor behavior, poor response to CRT, and worse survival. Therefore, FOLR1 expression at initial biopsy may be useful in predicting outcomes and also be a target for the exploration of FOLR1-based therapeutic agents.

Active Targeted Nanoformulations via Folate Receptors: State of the Art and Future Perspectives

In normal tissues, the expression of folate receptors is low and limited to cells that are important for embryonic development or for folate reabsorption. However, in several pathological conditions some cells, such as cancer cells and activated macrophages, overexpress folate receptors (FRs). This overexpression makes them a potential therapeutic target in the treatment of cancer and inflammatory diseases to obtain a selective delivery of drugs at altered cells level, and thus to improve the therapeutic efficacy and decrease the systemic toxicity of the pharmacological treatments. Two strategies have been used to achieve this folate receptor targeting: (i) the use of ligands with high affinity to FRs (e.g., folic acid or anti-FRs monoclonal antibodies) linked to the therapeutic agents or (ii) the use of nanocarriers whose surface is decorated with these ligands and in which the drug is encapsulated. This manuscript analyzes the use of FRs as a target to develop new therapeutic tools in the treatment of cancer and inflammatory diseases with an emphasis on the nanoformulations that have been developed for both therapeutic and imaging purposes.

Revisiting antibody-drug conjugates and their predictive biomarkers in platinum-resistant ovarian cancer

Until to date, platinum derived drugs are still the backbone of treating ovarian cancer (OC). Most patients treated with platinum-based chemotherapy develop resistance during the course of their management. The treatment of platinum-resistant ovarian cancer (PROC) is challenging. Few therapeutic options are available for patients with this aggressive disease. Besides, there are liminal advances regarding new anticancer drugs as well as validated predictive biomarkers of clinical outcomes in this setting. The enrollment of PROC patients in interventional studies is limited as compared to newly launched clinical trials for platinum-sensitive OC. Enthusiastically, the emergence of antibody-drug conjugates (ADCs) has provided promising findings for further clinical development in PROC. ADCs have the advantage to selectively deliver cytotoxic drugs to cancer cells expressing several of antigens using specific monoclonal antibodies based on the concept of immune bioconjugation. This innovative class of therapeutics showed encouraging early signs of clinical efficacy in PROC particularly mirvetuximab soravtansine that has been successfully introduced into three randomized and controlled phase III studies. In this review, the evidence from clinical trials supporting the development of ADCs targeting folate receptor alpha, sodium-dependent phosphate transporter 2B, dipeptidase 3, mesothelin, mucin 16, and tissue factor using various cytotoxic payloads in PROC is reviewed.