Mirvetuximab Soravtansine: First Approval

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.

Polyvalent folate receptor-targeting chimeras for degradation of membrane proteins

Lysosome-targeting chimeras (LYTACs) represent a revolutionary targeted protein degradation technology. However, the advancement of LYTACs faces substantial challenges due to the limited diversity of lysosome-trafficking receptors. In this study, we identified folate receptor α (FRα) as a new class of lysosome-trafficking receptors capable of facilitating the degradation of membrane proteins. Leveraging a polyvalent crosslinking strategy, we developed FRα-targeting chimeras (FRTACs), including enhanced green fluorescent protein-targeting FR-Ctx and PD-L1-targeting FR-Atz. The optimized FRTACs demonstrated subnanomolar potency in eliminating cell-surface targets, with efficacy dependent on both FRα expression and lysosomal activity. Specifically, FR-Ctx inhibited cancer cell proliferation, while FR-Atz enhanced T cell-mediated cytotoxicity against tumor cells. FR-Atz exhibited robust PD-L1 degradation efficiency in vivo and elicited tumor-specific immune responses by reprogramming the tumor microenvironment from an immunosuppressive to an immunostimulatory state in both RM-1 and humanized B16F10 mouse models. These findings establish FRTACs as a promising platform for the design of tumor-targeting LYTACs.

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.

Intraepithelial corneal deposits associated with Mirvetuximab soravtansine use for platinum-resistant ovarian cancer

Purpose

Present a case of Mirvetuximab soravtansine (MIRV)-induced intraepithelial corneal deposits, review a proposed mechanism to explain the blurred vision our patient experienced, and explain clinical exams that may be used to support the diagnosis.

Observations

A 63-year-old female with metastatic ovarian cancer diagnosed with intraepithelial corneal deposits two weeks after her first MIRV infusion. Treatment with topical prednisolone acetate 1 % ophthalmic suspension and lubricating eye drops without interruption of her MIRV infusions resulted in complete resolution of blurry vision and corneal deposits.

Conclusions and importance

The natural reversibility of MIRV-induced keratopathies underscores the need for prompt and regular ophthalmic assessments throughout drug administration. Understanding the mechanism behind these corneal changes, how to recognize them in a clinical setting, and expedite their reversal are essential to improve quality-of-life metrics in patients receiving MIRV transfusions.

Preclinical Activity of Datopotamab Deruxtecan, an Antibody-Drug Conjugate Targeting Trophoblast Cell-Surface Antigen 2, in Uterine Serous Carcinoma

Uterine serous carcinoma (USC) is a rare subset of endometrial cancer with a poor prognosis and high recurrence rate. Datopotamab deruxtecan (Dato-DXd) is a novel antibody-drug conjugate (ADC). The objective of this study was to evaluate the preclinical activity of Dato-DXd in USC in vitro against primary USC cell lines with various trophoblast cell-surface antigen 2 (TROP2) expression and in vivo in TROP2-overexpressing cell line-derived mice xenografts. USC primary tumor cell lines were treated with Dato-DXd and a control ADC (CTL ADC) to evaluate cell viability following exposure. Antibody-dependent cell-mediated cytotoxicity against TROP2-overexpressing and -nonexpressing cell lines was evaluated using a 4-hour chromium release assay. USC xenografts in mice were treated with Dato-DXd, CTL ADC, datopotamab, and vehicle to assess the in vivo effects via retro-orbital Dato-DXd administration. We found USC cell lines with TROP2 overexpression to be significantly more sensitive to killing induced by Dato-DXd compared with CTL ADC in vitro (e.g., IC50: 0.11 µmol/L vs. 30.07 µmol/L, P = 0.0074 and 0.11 µmol/L vs. 48.95 µmol/L, P = 0.0127, respectively). Dato-DXd induced antibody-dependent cell-mediated cytotoxicity in the presence of peripheral blood lymphocytes from healthy donors. TROP2-nonexpressing cell lines demonstrated minimal killing by Dato-DXd; however, when admixed with TROP2-overexpressing cells, a significant bystander effect was appreciated. In vivo, mice xenografts overexpressing TROP2 treated with Dato-DXd demonstrated tumor growth suppression and longer overall survival compared with CTL ADC-treated xenografts. These data demonstrate Dato-DXd to be highly active against TROP2-overexpressing USC in vitro and in vivo. Our preclinical activity results warrant future clinical trials for patients with advanced or recurrent USC.

SIGNIFICANCE

Targeted treatment of USC using the biomarker TROP2 represents a significant opportunity for further treatment options for patients already resistant to other lines of treatment. In this study, we present data showing preclinical evidence of effectiveness of this biomarker-targeted therapy in USC.

Synergistic approach to combating triple-negative breast cancer: DDR1-targeted antibody-drug conjugate combined with pembrolizumab

Discoidin domain receptor 1 (DDR1) is overexpressed in various tumors, such as triple-negative breast cancer (TNBC), and is rarely expressed in normal tissues. These characteristics make DDR1 a preferable target candidate for the construction of an antibody-drug conjugate (ADC) for targeted therapy. Here, we investigated the preparation and preclinical efficacy of DDR1-DX8951, an ADC that includes an anti-DDR1 monoclonal antibody conjugated to DX8951 by a cleavable Gly-Gly-Phe-Gly (GGFG) linker. The anti-DDR1 monoclonal antibody was coupled to DX8951 (i.e., DDR1-DX8951), producing the targeted therapy ADC. The antitumor activities of DDR1-DX8951 monotherapy or DDR1-DX8951 plus pembrolizumab were assessed in TNBC mouse models. DDR1-DX8951 can specifically target DDR1, be quickly internalized by TNBC cells, and reduce the viability of TNBC cells in vitro. The potent antitumor activity of DDR1-DX8951 was revealed in TNBC xenograft models. Importantly, our investigation demonstrated that DDR1-DX8951 plus pembrolizumab not only revealed the inhibitory efficacy on tumor growth and metastasis but also played an important role in improving the immunosuppressive tumor microenvironment (TME) of TNBC. Taken together, this investigation provides justification for large-sample studies to further assess the safety and efficacy of DDR1-DX8951 plus pembrolizumab for TNBC clinical trials.

Antibody-Drug Conjugates (ADCs): current and future biopharmaceuticals

Antibody-drug conjugates (ADCs) represent a novel class of biopharmaceuticals comprising monoclonal antibodies covalently conjugated to cytotoxic agents via engineered chemical linkers. This combination enables targeted delivery of cytotoxic agents to tumor site through recognizing target antigens by antibody while minimizing off-target effects on healthy tissues. Clinically, ADCs overcome the limitations of traditional chemotherapy, which lacks target specificity, and enhance the therapeutic efficacy of monoclonal antibodies, providing higher efficacy and fewer toxicity anti-tumor biopharmaceuticals. ADCs have ushered in a new era of targeted cancer therapy, with 15 drugs currently approved for clinical use. Additionally, ADCs are being investigated as potential therapeutic candidates for autoimmune diseases, persistent bacterial infections, and other challenging indications. Despite their therapeutic benefits, the development and application of ADCs face significant challenges, including antibody immunogenicity, linker instability, and inadequate control over the release of cytotoxic agent. How can ADCs be designed to be safer and more efficient? What is the future development direction of ADCs? This review provides a comprehensive overview of ADCs, summarizing the structural and functional characteristics of the three core components, antibody, linker, and payload. Furthermore, we systematically assess the advancements and challenges associated with the 15 approved ADCs in cancer therapy, while also exploring the future directions and ongoing challenges. We hope that this work will provide valuable insights into the design and optimization of next-generation ADCs for wider clinical applications.

Design and Synthesis of FR-β Targeting Chimeric Molecules for Reprogramming Tumor-Associated Macrophages Using 6-Substituted Pyrrolo[2,3-d]pyrimidines as Targeting Ligands

Tumor-associated macrophages (TAMs) are highly plastic tumor-infiltrating immune cells. Their reprogramming has emerged as a pivotal strategy in antitumor immunotherapy. The TLR7/8 agonist, IMDQ, has significant potential for reprogramming macrophages but lacks target specificity. To address this challenge, we developed novel folate receptor beta (FR-β) targeting chimeric molecules using 6-substituted pyrrolo[2,3-d]pyrimidines as high-affinity ligands, which demonstrate superior FR-β targeting capability compared with classical folic acid. These molecules integrate the FR-β targeting moiety with IMDQ, marking the first application of this immunomodulator in targeted chimeric constructs. In vitro and in vivo studies demonstrated that our chimeric molecules selectively reprogrammed TAMs toward an immunostimulatory phenotype, reshaped the tumor microenvironment, and inhibited tumor progression without systemic toxicity. Given that TAM accumulation is prevalent across all solid tumors, our strategy of precisely targeting and reprogramming of TAMs is universally applicable to treating various types of cancers, a potent and effective strategy for antitumor immunotherapy.

Fc Multisite Conjugation and Prolonged Delivery of the Folate-Targeted Drug Conjugate EC140

Small molecule-drug conjugate (SMDC) is a targeted drug delivery technology that develops in parallel with the antibody-drug conjugate. However, the clinical translation of SMDC faces challenges due to its limited circulating half-life in vivo. The drawback in pharmacokinetics is that it restricts the exposure time of SMDC to tumor tissues and ultimately reduces the therapeutic efficacy. In this study, we chemically conjugated a folate-targeted SMDC EC140 to the long-circulating Fc protein at multiple sites, yielding a stable and high-DAR Fc-SMDC conjugate (Fc-EC140). Fc-EC140 can bear approximately 4 molecules of EC140 per Fc protein (drug-antibody ratio = 4.1) and display enhanced potency in folate receptor (FR)-positive tumor cells compared to the SMDC comparator. In addition, Fc-EC140 retains the FcRn-mediated recycling function and displays an extended half-life of 28 h in the mice. In vivo, antitumor experiments demonstrate that intravenous administration of Fc-EC140 (Q7D × 3 at a dose of 15 mg/kg) nearly cures the KB tumors, which is far more effective than the comparator EC140 administrated at equivalent doses. This study presents a new strategy for the targeted delivery of SMDC.

Biological, dietetic and pharmacological properties of vitamin B9

Humans must obtain vitamin B9 (folate) from plant-based diet. The sources as well as the effect of food processing are discussed in detail. Industrial production, fortification and biofortification, kinetics, and physiological role in humans are described. As folate deficiency leads to several pathological states, current opinions toward prevention through fortification are discussed. Claimed risks of increased folate intake are mentioned as well as analytical ways for measurement of folate.

Precision Medicine in High-Grade Serous Ovarian Cancer: Targeted Therapies and the Challenge of Chemoresistance

The poor prognosis for high-grade serous ovarian cancer (HGSOC), the dominant subtype of ovarian cancer, reflects its aggressive nature, late diagnosis, and the highest mortality rate among all gynaecologic cancers. Apart from late diagnosis, the main reason for the poor prognosis and its unsuccessful treatment is primarily the emergence of chemoresistance to carboplatin. Although there is a good response to primary treatment, the disease recurs in 80% of cases, at which point it is largely resistant to carboplatin. The introduction of novel targeted therapies in the second decade of the 21st century has begun to transform the treatment of HGSOC, although their impact on overall survival remains unsatisfactory. Targeting the specific pathways known to be abnormally activated in HGSOC is especially difficult due to the molecular diversity of its subtypes. Moreover, a range of molecular changes are associated with acquired chemoresistance, e.g., reversion of BRCA1 and BRCA2 germline alleles. In this review, we examine the advantages and disadvantages of approved targeted therapies, including bevacizumab, PARP inhibitors (PARPis), and treatments targeting cells with neurotrophic tyrosine receptor kinase (NTRK), B-rapidly accelerated fibrosarcoma (BRAF), and rearranged during transfection (RET) gene alterations, as well as antibody-drug conjugates. Additionally, we explore promising new targets under investigation in ongoing clinical trials, such as immune checkpoint inhibitors, anti-angiogenic agents, phosphatidylinositol-3-kinase (PI3K) inhibitors, Wee1 kinase inhibitors, and ataxia telangiectasia and Rad3-related protein (ATR) inhibitors for platinum-resistant disease. Despite the development of new targeted therapies, carboplatin remains the fundamental medicine in HGSOC therapy. The correct choice of treatment strategy for better survival of patients with advanced HGSOC should therefore include a prediction of patients' risks of developing chemoresistance to platinum-based chemotherapy. Moreover, effective targeted therapy requires the selection of patients who are likely to derive clinical benefit while minimizing potential adverse effects, underscoring the essence of precision medicine.

Unlocking the potential of organopalladium complexes for high-grade serous ovarian cancer therapy

High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal subtype of ovarian cancer, known for its high aggressiveness and extensive genomic alterations. Typically diagnosed at an advanced stage, HGSOC presents formidable challenges in drug therapy. The limited efficacy of standard treatments, development of chemoresistance, scarcity of targeted therapies, and significant tumor heterogeneity render this disease incurable with current treatment options, highlighting the urgent need for novel therapeutic approaches to improve patient outcomes. In this study we report a straightforward and stereoselective synthetic route to novel Pd(II)-vinyl and -butadienyl complexes bearing a wide range of monodentate and bidentate ligands. Most of the synthesized complexes exhibited good to excellent in vitro anticancer activity against ovarian cancer cells. Particularly promising is the water-soluble complex bearing two PTA (1,3,5-triaza-7-phosphaadamantane) ligands and the Pd(II)-butadienyl fragment. This compound combines excellent cytotoxicity towards cancer cells with substantial inactivity towards non-cancerous ones. This derivative was selected for further studies on ex vivo tumor organoids and in vivo mouse models, which demonstrate its remarkable efficacy with surprisingly low collateral toxicity even at high dosages. Moreover, this class of compounds appears to operate through a ferroptotic mechanism, thus representing the first such example for an organopalladium compound.

Optimally designed PEGylatied arabinoxylan paclitaxel nano-micelles as alternative delivery for Abraxane®: A potential targeted therapy against breast and lung cancers

Paclitaxel (PTX) binds to spindle microtubules and inhibits mitotic division leading to cell death. However, its wide distribution, high absorption, and less selectively, minimize its application in cancer clinics. In this study, isolated arabinoxylans were used to encapsulate PTX, and then both were covered by polyethylene glycol conjugated to folic acid (FA), to strengthen its specificity to cancerous cells. Beclin-1 and P21 were significantly overexpressed by (79.6 ± 0.97 %, p ≤ 0.00001, &62.2 ± 1.15 % p ≤ 0.0001 in MCF-7 cells) and (74.8 ± 8.04 %, p ≤ 0.0001 &75.3 ± 2.3 %, p ≤ 0.0001, in NSCLCs) respectively after their incubation for 48 h with nano-targeted PTX NPs. Similarly, P53 and GSK3 beta-pSer9 were significantly increased by (63.5 ± 1 % p ≤ 0.0001, & 87 ± 1 % p ≤ 0.0001, in MCF) respectively and (81.5 ± 6 % p ≤ 0.01, & 84.8 ± 3.8 % p ≤ 0.001, in A549) respectively. The findings confirmed the activation of acidic/neutral autophagosomes in acridine orange/ethidium bromide (AO/EB) and nuclear fragmentation was clearly shown by 4', 6-diamidino-2 phenylindole (DAPI) nuclear stains. The findings provide the basis for the potential application of arabinoxylans as a great vehicle for the encapsulation of chemotherapeutic agents such as PTX for target delivery, and also as an immune mediator.

Development of ASGR-Mediated Hepatocyte-Targeting Cytotoxic Drug Conjugates with CTSB-Cleavable Linkers Incorporating Succinimide and Succinic Acid Monoamide

The ASGR-mediated endocytosis has been successfully applied to the hepatocyte-targeted delivery of therapeutic oligonucleotides via glycoconjugates. However, few studies have explored the conjugated small molecules due to the challenge of cleaving suitable linkers for the release of active small molecules, which is especially different from GalNAc-ONs cleaved by the deoxyribonuclease II in the lysosome. In this study, GalNAc-MMAE conjugates linked by CTSB-cleavable linkers were designed and synthesized. A comprehensive approach revealed that the conjugates were endocytosed by ASGR and subsequently hydrolyzed by CTSB, releasing MMAE. The optimized conjugate with a succinic acid monoamide as the fragment of the linker demonstrated favorable plasma stability, excellent biodistribution, and significant antitumor activities in vivo with weight gain at the effective dose in an orthotopic hepatocellular carcinoma mouse model. This research provides a strategy for developing anti-HCC therapeutic agents using GalNAc drug conjugates with CTSB-cleavable linkers to release active small molecules.

Resistance to antibody-drug conjugates: A review

Antibody-drug conjugates (ADCs) are antitumor drugs composed of monoclonal antibodies and cytotoxic payload covalently coupled by a linker. Currently, 15 ADCs have been clinically approved worldwide. More than 100 clinical trials at different phases are underway to investigate the newly developed ADCs. ADCs represent one of the fastest growing classes of targeted antitumor drugs in oncology drug development. It takes advantage of the specific targeting of tumor-specific antigen by antibodies to deliver cytotoxic chemotherapeutic drugs precisely to tumor cells, thereby producing promising antitumor efficacy and favorable adverse effect profiles. However, emergence of drug resistance has severely hindered the clinical efficacy of ADCs. In this review, we introduce the structure and mechanism of ADCs, describe the development of ADCs, summarized the latest research about the mechanisms of ADC resistance, discussed the strategies to overcome ADCs resistance, and predicted biomarkers for treatment response to ADC, aiming to contribute to the development of ADCs in the future.

Maytansinoids in cancer therapy: advancements in antibody-drug conjugates and nanotechnology-enhanced drug delivery systems

Cancer remains the second leading cause of death globally, driving the need for innovative therapies. Among natural compounds, maytansinoids have shown significant promise, contributing to nearly 25% of recently approved anticancer drugs. Despite their potential, early clinical trials faced challenges due to severe side effects, prompting advancements in delivery systems such as antibody-maytansinoid conjugates (AMCs). This review highlights the anticancer activity of maytansinoids, with a focus on AMCs designed to target cancer cells specifically. Preclinical and clinical studies show that AMCs, including FDA-approved drugs like Kadcyla and Elahere, effectively inhibit tumor growth while reducing systemic toxicity. Key developments include improved synthesis methods, linker chemistry and payload design. Ongoing research aims to enhance the safety and efficacy of AMCs, integrate nanotechnology for drug delivery, and identify novel therapeutic targets. These advancements hold potential to transform maytansinoid-based cancer treatments in the future.

Lapatinib: A Potential Therapeutic Agent for Colon Cancer Targeting Ferroptosis

BACKGROUND

Colon cancer poses a significant threat to the lives of several patients, impacting their quality of life, thus necessitating its urgent treatment. Lapatinib, a new generation of targeted anti-tumor drugs for clinical application, has yet to be studied for its molecular mechanisms in treating colon cancer.

OBJECTIVES

This study aimed to uncover the underlying molecular mechanisms through which lapatinib exerts its therapeutic effects in colon cancer treatment.

METHODS

We accessed pertinent data on patients with colon cancer from the Cancer Genome Atlas (TCGA) database and performed bioinformatics analysis to derive valuable insights. The cell counting kit-8 (CCK8) assay was employed to assess whether lapatinib has a potential inhibitory effect on the growth and proliferation of HT- 29 cells. Additionally, we employed western blot and real-time quantitative polymerase chain reaction methods to investigate whether lapatinib regulates the expression of the ferroptosis-associated protein GPX4 in HT-29 cells. Furthermore, we utilized specific assay kits to measure the levels of reactive oxygen species (ROS) and malondialdehyde in HT-29 cells treated with lapatinib, aiming to elucidate the precise pattern of cell damage induced by this compound.

RESULTS

GPX4 exhibited high expression levels in tissues from patients with colon cancer and was significantly associated with patient prognosis and diagnosis. Lapatinib inhibited the growth and proliferation of the colon cancer cell line HT-29. Additionally, lapatinib suppressed the expression of GPX4 in HT-29 cells, while the ferroptosis inhibitor ferrostatin-1 (Fer-1) partially restored its expression. Lapatinib induced an increase in intracellular ROS levels and malondialdehyde content in HT-29 cells, with Fer-1 partially restoring these levels.

CONCLUSION

Our findings demonstrated that lapatinib could effectively suppress the mRNA and protein expression of GPX4 in colon cancer cells, which elevates intracellular levels of ROS and malondialdehyde, ultimately inducing ferroptosis in these cells. This mechanism underscores the potential of lapatinib as a therapeutic strategy for targeting tumors.

Mirvetuximab Soravtansine in solid tumors: A systematic review and meta-analysis

BACKGROUND

Mirvetuximab Soravtansine (MIRV) is a promising antibody‒drug conjugate (ADC) that targets folate receptor alpha (FRα), which is overexpressed in several types of solid tumors. In November 2022, MIRV 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 received 1-3 prior systemic treatment regimens. Therefore, high-quality evidence for its efficacy and safety in different cancers is urgently needed.

METHODS

A systematic search (e.g., PubMed, Embase, Web Of Science, Cochrane Library) was conducted to identify all relevant clinical trials of MIRV alone or in combination with chemo- and/or target-therapies in solid tumors. The primary end-point was median progression-free survival (mPFS). The secondary endpoints were the Objective response rate (ORR) and adverse effects (AEs). A random-effects model was applied.

RESULTS

The study included nine research studies with a total of 682 patients. The pooled mPFS and pooled ORR were 6.70 months (95% CI 4.54-8.86, I2 = 96.21%) and 36% (95% CI: 28% to 44%, I2 = 76.79%), respectively. Significant differences were observed among intervention regimens and response to platinum. The pooled mPFS of MIRV monotherapy and MIRV+ Bevacizumab (BEV) combined therapy was 4.28 (95% CI 3.90-4.65, I2 = 0.00%) and 7.78 (95% CI 6.62-8.95, I2 = 0.00%), respectively. The pooled ORRs of MIRV monotherapy and MIRV+BEV combined therapy were 25% (95% CI 21%-29%, I2 = 25.20%) and 43% (95% CI 36%-50%, I2 = 0.01%), respectively. The pooled ORRs of the platinum-sensitive, platinum-resistant groups were 59% (95% CI 36%-81%, I2 = 61.88%), 33% (95% CI 25%-40%, I2 = 69.73%), respectively. In addition, we conducted supplementary subgroup analyses to explore the influence of FRα receptor expression levels and the number of prior treatments on treatment outcomes. The most common adverse effects were blurred vision (45.20%), nausea (40.13%), diarrhea (39.52%), fatigue (33.84%) and keratopathy (31.20%).

CONCLUSIONS

MIRV has significant therapeutic effects in solid tumors, especially when combined with BEV. In platinum-tolerant tumors, the efficacy of MIRV is also considerable. Overall, MIRV is relatively safe in solid tumors, and adverse reactions are relatively rare and mild.

Review of dose justifications for antibody-drug conjugate approvals from clinical pharmacology perspective: A focus on exposure-response analyses

Antibody-drug conjugates (ADCs) are revolutionizing cancer treatment by specific targeting of the cancer cells thereby improving the therapeutic window of the drugs. Nevertheless, they are not free from unwanted toxicities mainly resulting from non-specific targeting and release of the payload. Therefore, the dosing regimen must be optimized through integrated analysis of the risk-benefit profile, to maximize the therapeutic potential. Exposure-response (E-R) analysis is one of the most widely used tools for risk-benefit assessment and it plays a pivotal role in dose optimization of ADCs. However, compared to conventional E-R analysis, ADCs pose unique challenges since they feature properties of both small molecules and antibodies. In this article, we review the E-R analyses that have formed the key basis of dose justification for each of the 12 ADCs approved in the USA. We discuss the multiple analytes and exposure metrics that can be utilized for such analysis and their relevance for safety and efficacy of the treatment. For the endpoints used for the E-R analysis, we were able to uncover commonalities across different ADCs for both safety and efficacy. Additionally, we discuss dose optimization strategies for ADCs which are now a critical component in clinical development of oncology drugs.

Folate Receptor Alpha-A Secret Weapon in Ovarian Cancer Treatment?

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy worldwide. Due to its nonspecific symptoms and unreliable screening tools, EOC is not diagnosed at an early stage in most cases. Unfortunately, despite achieving initial remission after debulking surgery and platinum-based chemotherapy, most patients experience the recurrence of the disease. The limited therapy approaches have encouraged scientists to search for new detection and therapeutic strategies. In this review, we discuss the role of folate receptor alpha (FRα) in EOC development and its potential application as a biomarker and molecular target in designing new EOC screening and treatment methods. We summarize the mechanisms of the action of various therapeutic strategies based on FRα, including MABs (monoclonal antibodies), ADCs (antibody-drug conjugates), FDCs (folate-drug conjugates), SMDCs (small molecule-drug conjugates), vaccines, and CAR-T (chimeric antigen receptor T) cells, and present the most significant clinical trials of some FRα-based drugs. Furthermore, we discuss the pros and cons of different FR-based therapies, highlighting mirvetuximab soravtansine (MIRV) as the currently most promising EOC-targeting drug.

Mirvetuximab soravtansine in platinum-resistant recurrent ovarian cancer with high folate receptor-alpha expression: a cost-effectiveness analysis

OBJECTIVE

Mirvetuximab soravtansine (MIRV), a new antibody-drug conjugate, versus the investigator's choice of chemotherapy (IC) was the first treatment to demonstrate benefits for progression-free and overall survival in platinum-resistant recurrent ovarian cancer (PROC) with high folate receptor-alpha (high-FRα) expression. Efficacy, safety, and economic effectiveness make MIRV the new standard of care for these patients.

METHODS

Based on patients and clinical parameters from MIRASOL (GOG 3045/ENGOT-ov55) phase III randomized controlled trials, the Markov model with a 20-year time horizon was established to evaluate the cost and efficacy of MIRV and IC for PROC with high-FRα expression, considering the bevacizumab-pretreated situation from the American healthcare system. Total cost, life-years (LYs), quality-adjusted life-years (QALYs), incremental cost-effectiveness ratio (ICER), and incremental net health benefits were the main outcome indicators and compared with willingness-to-pay threshold of $100,000/QALY. Sensitivity and scenario analyses were conducted.

RESULTS

Compared with the IC, MIRV was associated with incremental costs of $538,251, $575,674, and $188,248 with the corresponding QALYs (LYs) increased by 0.90 (1.55), 1.09 (1.88), and 0.53 (0.79), leading to ICERs of $596,189/QALY ($347,995/LY), $530,061/QALY ($306,894/LY), and $1,011,310/QALY ($680,025/LY) in the overall, bevacizumab-naïve, and bevacizumab-pretreated patients, respectively. When MIRV is reduced by more than 75%, it may be a cost-effective treatment.

CONCLUSION

At the current price, MIRV for PROC with high-FRα expression is not the cost-effective strategy in the US. However, its treatment has higher health benefits in bevacizumab-naïve patients, which is likely to be an alternative.

Nanotechnology for boosting ovarian cancer immunotherapy

Ovarian cancer, often referred to as the "silent killer," is notoriously difficult to detect in its early stages, leading to a poor prognosis for many patients. Diagnosis is often delayed until the cancer has advanced, primarily due to its ambiguous and frequently occurring clinical symptoms. Ovarian cancer leads to more deaths than any other cancer of the female reproductive system. The main reasons for the high mortality rates include delayed diagnosis and resistance to treatment. As a result, there is an urgent need for improved diagnostic and treatment options for ovarian cancer. The standard treatments typically involve debulking surgery along with platinum-based chemotherapies. Among patients with advanced-stage cancer who initially respond to current therapies, 50-75% experience a recurrence. Recently, immunotherapy-based approaches to enhance the body's immune response to combat tumor growth have shown promise. Immune checkpoint inhibitors have shown promising results in treating other types of tumors. However, in ovarian cancer, only a few of these inhibitors have been effective because the tumor's environment suppresses the immune system and creates barriers for treatment. This hampers the effectiveness of existing immunotherapies. Nonetheless, advanced immunotherapy techniques and delivery systems based on nanotechnology hold promise for overcoming these challenges.

Preclinical activity of datopotamab deruxtecan, a novel TROP2 directed antibody-drug conjugate targeting trophoblast cell-surface antigen 2 (TROP2) in ovarian carcinoma

INTRODUCTION

Epithelial ovarian cancer (EOC) is associated with the highest gynecologic cancer mortality. The development of novel, effective combinations of targeted therapeutics remains an unmet medical need. We evaluated the preclinical activity of datopotamab deruxtecan (Dato-Dxd), a novel TROP2 targeting antibody drug conjugate (ADC) in ovarian cancer cell lines and xenografts with variable TROP2 expression.

METHODS

In vitro cell viability with Dato-DXd was assessed using flow-cytometry based assays against a panel of EOC primary cell lines with variable TROP2 expression. Fluorescent anti-phospho-histone H2A.X antibody was used to detect dsDNA breaks by flow-cytometry. The in vivo antitumor activity of Dato-DXd was tested in TROP2 overexpressing xenografts.

RESULTS

TROP2 overexpressing (3+) and moderate (2+) expressing EOC cell lines demonstrated higher sensitivity to Dato-DXd when compared to TROP2 negative tumors. Dato-DXd exposed TROP2+ EOC demonstrated increased dsDNA breaks and Annexin-V positivity (a marker of apoptosis) when compared to tumor cells exposed to the non-binding conjugate (p = 0.001 and p = 0.016, respectively). Dato-DXd induced significant antibody-dependent cellular cytotoxicity (ADCC) in the presence of peripheral-blood-lymphocytes. While negligible activity was detected against EOC cell lines with low TROP2 expression, Dato-DXd demonstrated significant bystander killing against tumor cells with low/negligible TROP2 when such cells were admixed with TROP2 3+ tumor cells in vitro. Dato-DXd showed tumor growth suppression against EOC cell line derived xenograft models that overexpress TROP2 at 3+ levels, prolonging survival when compared to controls, with minimal toxicity.

CONCLUSION

Dato-DXd shows promising preclinical activity against TROP2 overexpressing ovarian cancers. Future clinical trials in ovarian cancer patients are warranted.

Ovarian cancer: Diagnosis and treatment strategies (Review)

Ovarian cancer is a malignant tumor that seriously endangers health. Early ovarian cancer symptoms are frequently challenging to detect, resulting in a large proportion of patients reaching an advanced stage when diagnosed. Conventional diagnosis relies heavily on serum biomarkers and pathological examination, but their sensitivity and specificity require improvement. Targeted therapy inhibits tumor growth by targeting certain characteristics of tumor cells, such as signaling pathways and gene mutations. However, the effectiveness of targeted therapy varies among individuals due to differences in their unique biological characteristics and requires individualized strategies. Immunotherapy is a promising treatment for ovarian cancer due to its long-lasting antitumor effect. Nevertheless, issues such as variable efficacy, immune-associated adverse effects and drug resistance remain to be resolved. The present review discusses the diagnostic strategies, rationale, treatment strategies and prospects of targeted therapy and immunotherapy for ovarian cancer.

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.

Unveiling the Therapeutic Potential of Folate-Dependent One-Carbon Metabolism in Cancer and Neurodegeneration

Cellular metabolism is crucial for various physiological processes, with folate-dependent one-carbon (1C) metabolism playing a pivotal role. Folate, a B vitamin, is a key cofactor in this pathway, supporting DNA synthesis, methylation processes, and antioxidant defenses. In dividing cells, folate facilitates nucleotide biosynthesis, ensuring genomic stability and preventing carcinogenesis. Additionally, in neurodevelopment, folate is essential for neural tube closure and central nervous system formation. Thus, dysregulation of folate metabolism can contribute to pathologies such as cancer, severe birth defects, and neurodegenerative diseases. Epidemiological evidence highlights folate's impact on disease risk and its potential as a therapeutic target. In cancer, antifolate drugs that inhibit key enzymes of folate-dependent 1C metabolism and strategies targeting folate receptors are current therapeutic options. However, folate's impact on cancer risk is complex, varying among cancer types and dietary contexts. In neurodegenerative conditions, including Alzheimer's and Parkinson's diseases, folate deficiency exacerbates cognitive decline through elevated homocysteine levels, contributing to neuronal damage. Clinical trials of folic acid supplementation show mixed outcomes, underscoring the complexities of its neuroprotective effects. This review integrates current knowledge on folate metabolism in cancer and neurodegeneration, exploring molecular mechanisms, clinical implications, and therapeutic strategies, which can provide crucial information for advancing treatments.

Unlocking the potential of bispecific ADCs for targeted cancer therapy

Antibody-drug conjugates (ADCs) are biologically targeted drugs composed of antibodies and cytotoxic drugs connected by linkers. These innovative compounds enable precise drug delivery to tumor cells, minimizing harm to normal tissues and offering excellent prospects for cancer treatment. However, monoclonal antibody-based ADCs still present challenges, especially in terms of balancing efficacy and safety. Bispecific antibodies are alternatives to monoclonal antibodies and exhibit superior internalization and selectivity, producing ADCs with increased safety and therapeutic efficacy. In this review, we present available evidence and future prospects regarding the use of bispecific ADCs for cancer treatment, including a comprehensive overview of bispecific ADCs that are currently in clinical trials. We offer insights into the future development of bispecific ADCs to provide novel strategies for cancer treatment.

Antibody-drug conjugates in cancer therapy: mechanisms and clinical studies

Antibody-drug conjugates (ADCs) consist of monoclonal antibodies that target tumor cells and cytotoxic drugs linked through linkers. By leveraging antibodies' targeting properties, ADCs deliver cytotoxic drugs into tumor cells via endocytosis after identifying the tumor antigen. This precise method aims to kill tumor cells selectively while minimizing harm to normal cells, offering safe and effective therapeutic benefits. Recent years have seen significant progress in antitumor treatment with ADC development, providing patients with new and potent treatment options. With over 300 ADCs explored for various tumor indications and some already approved for clinical use, challenges such as resistance due to factors like antigen expression, ADC processing, and payload have emerged. This review aims to outline the history of ADC development, their structure, mechanism of action, recent composition advancements, target selection, completed and ongoing clinical trials, resistance mechanisms, and intervention strategies. Additionally, it will delve into the potential of ADCs with novel markers, linkers, payloads, and innovative action mechanisms to enhance cancer treatment options. The evolution of ADCs has also led to the emergence of combination therapy as a new therapeutic approach to improve drug efficacy.

Ocoxin Oral Solution Triggers DNA Damage and Cell Death in Ovarian Cancer

Ovarian cancer is the most fatal of all the reproductive cancers within the female population, mainly due to its late diagnosis that limits surgery and medical treatment. Classically, ovarian cancer therapy has included conventional chemotherapy, and other therapeutic approaches are now being used to treat these patients, but the outcomes of the disease are still poor. Therefore, new strategies are needed to improve life expectancy and life quality of ovarian cancer patients. Considering that, we investigated the effect of the nutritional supplement Ocoxin Oral Solution (OOS) in ovarian cancer models. OOS contains several nutritional supplements, some of them with demonstrated antitumoral action. In vitro studies showed that OOS inhibited the proliferation of several ovarian cancer cell lines, especially of those representative of the endometrioid subtype, in a time- and dose-dependent manner. A fast cell death induction after OOS treatment was observed, and when the molecular mechanisms leading to this effect were investigated, an activation of the DNA damage checkpoint was detected, as shown by activation (phosphorylation) of CHK1 and CHK2 kinases that was followed by the phosphorylation of the target protein histone H2AX. When tested in animal models of ovarian cancer, OOS reduced tumor growth without any observed secondary effects. Moreover, such reduction in tumor proliferation was caused by the induction of DNA damage as corroborated by the in vivo phosphorylation of CHK2 and Histone H2AX. Finally, OOS potentiated the action of carboplatin or olaparib, the standard of care treatments used in ovarian clinics, opening the possibility of including OOS in combination with those standard of care agents in patients with ovarian cancer.

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.

New hopes and promises in the treatment of ovarian cancer focusing on targeted treatment-a narrative review

Unfortunately, ovarian cancer is still diagnosed most often only in an advanced stage and is also the most lethal gynecological cancer. Another problem is the fact that treated patients have a high risk of disease recurrence. Moreover, ovarian cancer is very diverse in terms of molecular, histological features and mutations. Many patients may also develop platinum resistance, resulting in poor response to subsequent lines of treatment. To improve the prognosis of patients with ovarian cancer, it is expected to make better existing and implement new, promising treatment methods. Targeted therapies seem very promising. Currently, bevacizumab - a VEGF inhibitor and therapy with olaparib - a polyADP-ribose polymerase inhibitor are approved. Other methods worth considering in the future include: folate receptor α, immune checkpoints or other immunotherapy methods. To improve the treatment of ovarian cancer, it is also important to ameliorate the determination of molecular features to describe and understand which group of patients will benefit most from a given treatment method. This is important because a larger group of patients treated for ovarian cancer can have a greater chance of surviving longer without recurrence.

Bispecific antibody drug conjugates: Making 1+1>2

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

In Situ Nanofiber Formation Blocks AXL and GAS6 Binding to Suppress Ovarian Cancer Development

Anexelekto (AXL) is an attractive molecular target for ovarian cancer therapy because of its important role in ovarian cancer initiation and progression. To date, several AXL inhibitors have entered clinical trials for the treatment of ovarian cancer. However, the disadvantages of low AXL affinity and severe off-target toxicity of these inhibitors limit their further clinical applications. Herein, by rational design of a nonapeptide derivative Nap-Phe-Phe-Glu-Ile-Arg-Leu-Arg-Phe-Lys (Nap-IR), a strategy of in situ nanofiber formation is proposed to suppress ovarian cancer growth. After administration, Nap-IR specifically targets overexpressed AXL on ovarian cancer cell membranes and undergoes a receptor-instructed nanoparticle-to-nanofiber transition. In vivo and in vitro experiments demonstrate that in situ formed Nap-IR nanofibers efficiently induce apoptosis of ovarian cancer cells by blocking AXL activation and disrupting subsequent downstream signaling events. Remarkably, Nap-IR can synergistically enhance the anticancer effect of cisplatin against HO8910 ovarian tumors. It is anticipated that the Nap-IR can be applied in clinical ovarian cancer therapy in the near future.

A review of the clinical efficacy of FDA-approved antibody‒drug conjugates in human cancers

While strategies such as chemotherapy and immunotherapy have become the first-line standard therapies for patients with advanced or metastatic cancer, acquired resistance is still inevitable in most cases. The introduction of antibody‒drug conjugates (ADCs) provides a novel alternative. ADCs are a new class of anticancer drugs comprising the coupling of antitumor mAbs with cytotoxic drugs. Compared with chemotherapeutic drugs, ADCs have the advantages of good tolerance, accurate target recognition, and small effects on noncancerous cells. ADCs occupy an increasingly important position in the therapeutic field. Currently, there are 13 Food and Drug Administration (FDA)‒approved ADCs and more than 100 ADC drugs at different stages of clinical trials. This review briefly describes the efficacy and safety of FDA-approved ADCs, and discusses the related problems and challenges to provide a reference for clinical work.

Combinatorial Biosynthesis of 3-O-Carbamoylmaytansinol by Rational Engineering of the Tailoring Steps of Ansamitocins

Currently, most maytansine-containing antibody-drug conjugates (ADCs) in clinical trials are prepared with DM1 or DM4, which in turn is synthesized mainly from ansamitocin P-3 (AP-3), a bacterial maytansinoid, isolated from Actinosynnema pretiosum. However, due to the high self-toxicity of AP-3 to A. pretiosum, the yield of AP-3 has been difficult to improve. Herein, a new maytansinoid with much lower self-toxicity to A. pretiosum, 3-O-carbamoylmaytansinol (CAM, 3), was designed and generated by introducing the 3-O-carbamoyltransferase gene asc21b together with the N-methyltransferase genes from exogenous maytansinoid gene clusters into the 3-O-acyltransferase gene (asm19) deleted mutant HGF052. Meanwhile, two new shunt products, 20-O-demethyl-19-dechloro-N-demethyl-4,5-desepoxy-CAM (4) and 20-O-demethyl-N-demethyl-4,5-desepoxy-CAM (5) were identified from the recombinant strain. Furthermore, by screening of liquid fermentation media, overexpression of bottleneck tailoring enzymes and the pathway-specific activator, the titer of CAM reached 498 mg/L in the engineered strain. Since the 3-O-carbamoyl group of CAM can be removed by chemical cleavage as AP-3 to produce maytansinol, our work suggests that CAM may be a promising alternative to AP-3 in the future development of ADCs.

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.

Paradigm Shift: A Comprehensive Review of Ovarian Cancer Management in an Era of Advancements

Ovarian cancer (OC) is the female genital malignancy with the highest lethality. Patients present a poor prognosis mainly due to the late clinical presentation allied with the common acquisition of chemoresistance and a high rate of tumour recurrence. Effective screening, accurate diagnosis, and personalised multidisciplinary treatments are crucial for improving patients' survival and quality of life. This comprehensive narrative review aims to describe the current knowledge on the aetiology, prevention, diagnosis, and treatment of OC, highlighting the latest significant advancements and future directions. Traditionally, OC treatment involves the combination of cytoreductive surgery and platinum-based chemotherapy. Although more therapeutical approaches have been developed, the lack of established predictive biomarkers to guide disease management has led to only marginal improvements in progression-free survival (PFS) while patients face an increasing level of toxicity. Fortunately, because of a better overall understanding of ovarian tumourigenesis and advancements in the disease's (epi)genetic and molecular profiling, a paradigm shift has emerged with the identification of new disease biomarkers and the proposal of targeted therapeutic approaches to postpone disease recurrence and decrease side effects, while increasing patients' survival. Despite this progress, several challenges in disease management, including disease heterogeneity and drug resistance, still need to be overcome.

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.

Preclinical Evaluation of Novel Folate Receptor 1-Directed CAR T Cells for Ovarian Cancer

Treatment options for ovarian cancer patients are limited, and a high unmet clinical need remains for targeted and long-lasting, efficient drugs. Genetically modified T cells expressing chimeric antigen receptors (CAR), are promising new drugs that can be directed towards a defined target and have shown efficient, as well as persisting, anti-tumor responses in many patients. We sought to develop novel CAR T cells targeting ovarian cancer and to assess these candidates preclinically. First, we identified potential CAR targets on ovarian cancer samples. We confirmed high and consistent expressions of the tumor-associated antigen FOLR1 on primary ovarian cancer samples. Subsequently, we designed a series of CAR T cell candidates against the identified target and demonstrated their functionality against ovarian cancer cell lines in vitro and in an in vivo xenograft model. Finally, we performed additional in vitro assays recapitulating immune suppressive mechanisms present in solid tumors and developed a process for the automated manufacturing of our CAR T cell candidate. These findings demonstrate the feasibility of anti-FOLR1 CAR T cells for ovarian cancer and potentially other FOLR1-expressing tumors.

Pharmacological Profile of Novel Anti-cancer Drugs Approved by USFDA in 2022: A Review

BACKGROUND

For any drug molecule, it is mandatory to pass the drug approval process of the concerned regulatory authority, before being marketed. The Food and Drug Administration (FDA), throughout the year, approves several new drugs for safety and efficacy. In addition to new drug approvals, FDA also works on improving access to generic drugs, aimed to lower the cost of drugs for patients and improve access to treatments. In the year 2022 twelve new drug therapies were approved for managing varying cancers.

METHODS

This manuscript is focused to describe the pharmacological aspects including therapeutic uses, mechanisms of actions, pharmacokinetics, adverse effects, doses, indication for special cases, contraindications, etc., of novel FDA-approved anticancer drug therapies in the year 2022.

RESULT

FDA has approved about 29% (11 out of 37) novel drug therapies for varying types of cancers such as lung cancer, breast cancer, prostate cancer, melanoma, leukemia, etc. The Center for Drug Evaluation and Research CDER has reported that 90% of these anticancer drugs (e.g. Adagrasib, Futibatinib, Mirvetuximabsoravtansinegynx, Mosunetuzumab-axb, Nivolumab and relatlimab-rmbw, Olutasidenib, Pacritinib, Tebentafusp-tebn, Teclistamab-cqyv, and Tremelimumab-actl) as orphan drugs and recommended to treat rare or uncommon cancers such as non-small cell lung cancer, metastatic intrahepatic cholangio-carcinoma, epithelial ovarian cancer, follicular lymphoma, metastatic melanoma, metastatic uveal melanoma, etc. CDER has identified six anticancer drugs (e.g. Lutetium (177Lu)vipivotidetetraxetan, Mirvetuximabsoravtansine- gynx, Mosunetuzumab-axb, Nivolumab and relatlimab-rmbw, Tebentafusp-tebn, Teclistamab-cqyv) as first-in-class drugs i.e. drugs having different mechanisms of action from the already existing ones. The newly approved anticancer drugs shall provide more efficient treatment options for cancer patients. Three FDA-approved anticancer drugs in the year 2023 are also briefly described in the manuscript.

CONCLUSION

This manuscript, describing the pharmacological aspects of eleven anticancer novel drug therapies approved by the FDA, shall serve as a helpful document for cancer patients, concerned academicians, researchers, and clinicians, especially oncologists.

Front-line chemoimmunotherapy for treating epithelial ovarian cancer: Part II promising results of phase 2 study of paclitaxel-carboplatin-oregovomab regimen

In the Part I, we have discussed the background of CA125 and the development of anti-CA125 monoclonal antibody (MAb) to highlight the potential role of CA125 and anti-CA125 MAb in the management of women with advanced stage epithelial ovarian cancer (EOC). Glycosylation change either by N-link or by O-link of CA125 is supposed to play a role in the modification of immunity. Anti-CA125 MAb, which can be classified as OC 125-like Abs, M11-like Abs, and OV197-like Abs, is often used for diagnosing, screening, monitoring and detecting the mesothelin-related diseases of the abdominal cavity, particular for those women with EOC. Additionally, anti-CA125 MAb also plays a therapeutic role, named as OvaRex MAb-B43.13 (oregovomab), which has also been extensively reviewed in the Part I review article. The main mechanisms include (a) forming CA125 immune complexes to activate the antigen-presenting cells; (b) triggering induction of CA125-specific immune responses, including anti-CA125 Abs against various epitopes and CA125-specific B and T cell responses; and (c) triggering CD4 and CD8 T-cell responses specific for B43.13 to produce specific and non-specific immune response. With success in vitro, in vivo and in primitive studies, phase II study was conducted to test the effectiveness of chemoimmunotherapy (CIT) for the management of EOC patients. In the 97 EOC patients after optimal debulking surgery (residual tumor <1 cm or no gross residual tumor), patients treated with CIT had a dramatical and statistically significant improvement of both progression-free survival (PFS) and overall survival (OS) compared to those treated with chemotherapy alone with a median PFS of 41.8 months versus 12.2 months (hazard ratio [HR] 0.46, 95 % confidence interval [CI] 0.28-0.7) and OS not yet been reached (NE) versus 42.3 months (HR 0.35, 95 % CI 0.16-0.74), respectively. The current review as Part II will explore the possibility of using CIT as front-line therapy in the management of advanced-stage EOC patients after maximal cytoreductive surgery based on the evidence by many phase 2 studies.

CAR-T cell immunotherapy for ovarian cancer: hushing the silent killer

As the most lethal gynecologic oncological indication, carcinoma of the ovary has been ranked as the 5th cause of cancer-related mortality in women, with a high percentage of the patients being diagnosed at late stages of the disease and a five-year survival of ~ 30%. Ovarian cancer patients conventionally undergo surgery for tumor removal followed by platinum- or taxane-based chemotherapy; however, a high percentage of patients experience tumor relapse. Cancer immunotherapy has been regarded as a silver lining in the treatment of patients with various immunological or oncological indications; however, mirvetuximab soravtansine (a folate receptor α-specific mAb) and bevacizumab (a VEGF-A-specific mAb) are the only immunotherapeutics approved for the treatment of ovarian cancer patients. Chimeric antigen receptor T-cell (CAR-T) therapy has achieved tremendous clinical success in the treatment of patients with certain B-cell lymphomas and leukemias, as well as multiple myeloma. In the context of solid tumors, CAR-T therapies face serious obstacles that limit their therapeutic benefit. Such hindrances include the immunosuppressive nature of solid tumors, impaired tumor infiltration, lack of qualified tumor-associated antigens, and compromised stimulation and persistence of CAR-Ts following administration. Over the past years, researchers have made arduous attempts to apply CAR-T therapy to ovarian cancer. In this review, we outline the principles of CAR-T therapy and then highlight its limitations in the context of solid tumors. Ultimately, we focus on preclinical and clinical findings achieved in CAR-T-mediated targeting of different ovarian cancer-associated target antigens.

Introduction of Carbonyl Groups into Antibodies

Antibodies and their derivatives (scFv, Fabs, etc.) represent a unique class of biomolecules that combine selectivity with the ability to target drug delivery. Currently, one of the most promising endeavors in this field is the development of molecular diagnostic tools and antibody-based therapeutic agents, including antibody-drug conjugates (ADCs). To meet this challenge, it is imperative to advance methods for modifying antibodies. A particularly promising strategy involves the introduction of carbonyl groups into the antibody that are amenable to further modification by biorthogonal reactions, namely aliphatic, aromatic, and α-oxo aldehydes, as well as aliphatic and aryl-alkyl ketones. In this review, we summarize the preparation methods and applications of site-specific antibody conjugates that are synthesized using this approach.

hIMB1636-MMAE, a Novel TROP2-Targeting Antibody-Drug Conjugate Exerting Potent Antitumor Efficacy in Pancreatic Cancer

Herein, we first prepared a novel anti-TROP2 antibody-drug conjugate (ADC) hIMB1636-MMAE using hIMB1636 antibody chemically coupled to monomethyl auristatin E (MMAE) via a Valine-Citrulline linker and then reported its characteristics and antitumor activity. With a DAR of 3.92, it binds specifically to both recombinant antigen (KD ∼ 0.687 nM) and cancer cells and could be internalized by target cells and selectively kill them with IC50 values at nanomolar/subnanomolar levels by inducing apoptosis and G2/M phase arrest. hIMB1636-MMAE also inhibited cell migration, induced ADCC effects, and had bystander effects. It displayed significant tumor-targeting ability and excellent tumor-suppressive effects in vivo, resulting in 5/8 tumor elimination at 12 mg/kg in the T3M4 xenograft model or complete tumor disappearance at 10 mg/kg in BxPc-3 xenografts in nude mice. Its half-life in mice was about 87 h. These data suggested that hIMB1636-MMAE was a promising candidate for the treatment of pancreatic cancer with TROP2 overexpression.

Antibody-Drug Conjugates (ADC) in HER2/neu-Positive Gynecologic Tumors

Antibody-drug conjugates (ADCs) are a new class of targeted anti-cancer therapies that combine a monoclonal tumor-surface-receptor-targeting antibody with a highly cytotoxic molecule payload bonded through specifically designed cleavable or non-cleavable chemical linkers. One such tumor surface receptor is human epidermal growth factor 2 (HER2), which is of interest for the treatment of many gynecologic tumors. ADCs enable the targeted delivery of a variety of cytotoxic therapies to tumor cells while minimizing delivery to healthy tissues. This review summarizes the existing literature about HER2-targeting ADC therapies approved for use in gynecologic malignancies, relevant preclinical studies, strategies to address ADC resistance, and ongoing clinical trials.

Front-line chemo-immunotherapy for treating epithelial ovarian cancer: Part I CA125 and anti-CA125

The current standard therapy of epithelial ovarian cancer (EOC) is the combination of surgery (primary cytoreductive surgery or interval cytoreductive surgery) and platinum-based chemotherapy (mainly using paclitaxel and carboplatin either by neoadjuvant chemotherapy and/or by postoperative adjuvant chemotherapy) with/without adding targeted therapy (mainly using anti-angiogenesis agent- bevacizumab). After front-line chemotherapy, the advanced-stage EOC can be successfully controlled and three-quarters of patients can achieve a complete clinical remission. Unfortunately, nearly all patients will recur and progression-free survival (PFS) of these patients is seldom more than 3 years with a dismal median PFS of 12-18 months. With each recurrence, patients finally develop resistance to standard chemotherapy regimen, contributing to fewer than half of women who survive for more than 5 years after diagnosis with a median overall survival (OS) of 40.7 months. Due to the lower PFS and OS, particularly for those advanced-stage patients, novel therapeutic options during the front-line therapy are desperately needed to decrease the occurrence of recurrence, and the majority of them are still under investigation. It is well-known that overexpression of CA125 has been associated with attenuated cellular apoptosis, platinum chemotherapy resistance, tumor proliferation and disease progression, suggesting that anti-CA125 may play a role in the management of patients with EOC. The current review is a Part I which will focus on development of anti-CA125 monoclonal antibody, hoping that alternation of the front-line therapy by chemo-immunotherapy will be beneficial for prolonged survival of patients with EOC.

Targeting carcinoma-associated mesothelial cells with antibody-drug conjugates in ovarian carcinomatosis

Ovarian carcinomatosis is characterized by the accumulation of carcinoma-associated mesothelial cells (CAMs) in the peritoneal stroma and mainly originates through a mesothelial-to-mesenchymal transition (MMT) process. MMT has been proposed as a therapeutic target for peritoneal metastasis. Most ovarian cancer (OC) patients present at diagnosis with peritoneal seeding, which makes tumor progression control difficult by MMT modulation. An alternative approach is to use antibody-drug conjugates (ADCs) targeted directly to attack CAMs. This strategy could represent the cornerstone of precision-based medicine for peritoneal carcinomatosis. Here, we performed complete transcriptome analyses of ascitic fluid-isolated CAMs in advanced OC patients with primary-, high-, and low-grade, serous subtypes and following neoadjuvant chemotherapy. Our findings suggest that both cancer biological aggressiveness and chemotherapy-induced tumor mass reduction reflect the MMT-associated changes that take place in the tumor surrounding microenvironment. Accordingly, MMT-related genes, including fibroblast activation protein (FAP), mannose receptor C type 2 (MRC2), interleukin-11 receptor alpha (IL11RA), myristoylated alanine-rich C-kinase substrate (MARCKS), and sulfatase-1 (SULF1), were identified as specific actionable targets in CAMs of OC patients, which is a crucial step in the de novo design of ADCs. These cell surface target receptors were also validated in peritoneal CAMs of colorectal cancer peritoneal implants, indicating that ADC-based treatment could extend to other abdominal tumors that show peritoneal colonization. As proof of concept, a FAP-targeted ADC reduced tumor growth in an OC xenograft mouse model with peritoneal metastasis-associated fibroblasts. In summary, we propose MMT as a potential source of ADC-based therapeutic targets for peritoneal carcinomatosis. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.