Is Targeting the Folate Receptor in Ovarian Cancer Coming of Age?

Folate Receptor Immunohistochemical Staining and Gynecologic Tumors: Initial Experience With 216 Cases

Folate receptor alpha has been shown to have possible mechanisms of tumorigenesis in malignancies, becoming a potential target for therapy. Mirvetuximab soravtansine is an antifolate receptor alpha monoclonal antibody, with an approved FOLR1-2.1 immunohistochemical biomarker. After IRB approval, a retrospective review of gynecologic pathology cases was performed to identify cases in which FOLR1 immunohistochemistry (IHC) was performed at our institution over a period of 9 months as part of clinical care for therapy eligibility. Clinical data collected included patients' age, tumor histotype, tumor grade, primary tumor site, FIGO stage, dates of recurrence/progression, and use of mirvetuximab therapy. FOLR1 IHC data were recorded, including the date specimen obtained, date IHC was performed, site tested, case type, percentage tumor staining, and intensity. Cases were deemed positive or negative according to current recommendations (75%, 2-3+intensity). Two hundred sixteen cases were identified. Patient ages ranged from 25 to 83 years old (median: 59 yr). Staining intensity was reported as 0 in 15 (6.9%) cases, weak (1+) in 8 (3.7%), moderate (2+) in 27 (12.5%), strong (3+) in 27 (12.5%), weak-to-moderate (1-2+) in 15 (6.9%), and moderate-to-strong (2-3+) in 99 (45.8%); intensity was not provided in 25 (11.6%). Percentage of tumor staining ranged from 0 to 100, with a median of 60. The IHC was overall deemed positive in 98 (45.4%) cases and negative in 118 (54.6%). By histotype, 5 of 17 (29.4%) low-grade serous carcinomas, 88 of 162 (54.3%) high-grade serous carcinomas, 3 of 5 (60%) of carcinosarcomas, and 2 of 6 (33.3%) of mixed carcinomas were positive. No case of clear cell CA, endometrioid CA, Mullerian CA NOS, serous borderline, mucinous CA, or granulosa cell tumor was positive. The primary site of disease was tubo-ovarian in 192 (88.9%) cases, peritoneal in 8 (3.7%) cases, uterine in 3 (1.4%) cases, and unknown in 13 (6%) cases. By site on which immunohistochemical stain was performed: primary site positive in 53 of 96 (55.2%) cases, metastatic site at time of diagnosis/debulking positive in 23 of 41 (52.1%) cases, and metastatic/recurrent cases positive in 22 of 79 (27.8%) cases. There was a statistically significant correlation when comparing the positivity rates between these sites (P = 0.0004). Survival data were examined with high-grade serous carcinoma, with no statistically significant difference between positive and negative cases in overall survival (P = 0.622) or progression-free survival (P = 0.711). Biopsy specimens were positive in 17 (25%) cases, while negative in 51 (75%), whereas resection specimens were positive in 81 (54.7%) and negative in 67 (45.3%), a statistically significant difference (P < 0.0001). Cases that were <19 months old had 38 (36.2%) positive and 67 (63.8%) negative, compared with cases ≥19 months old that had 60 (54.1%) positive and 51 (45.9%) negative, a statistically significant difference (P = 0.0084). Significant differences in FOLR1 staining were noted between histotypes, age of the specimen, type of case tested, and site of disease tested. Further testing is needed to help determine the best tissue to be utilized for this new biomarker.

Effects of solid lipid nanocarrier containing methyl urolithin A by coating folate-bound chitosan and evaluation of its anti-cancer activity

BACKGROUND

Nanotechnology-based drug delivery systems have received much attention over the past decade. In the present study, we synthesized Methyl Urolithin A-loaded solid lipid nanoparticles decorated with the folic acid-linked chitosan layer called MuSCF-NPs and investigated their effects on cancer cells.

METHODS

MuSCF-NPs were prepared using a high-pressure homogenization method and characterized using FTIR, FESEM, DLS, and zeta potential methods. Drug encapsulation was assessed by spectrophotometry and its cytotoxic effect on various cancer cells (MDA-MB231, MCF-7, PANC, AGS, and HepG2) by the MTT method. Antioxidant activity was assessed by the ABTS and DPPH methods, followed by expression of genes involved in oxidative stress and apoptosis by qPCR and flow cytometry.

RESULTS

The results showed the formation of monodisperse and stable round nanoparticles with a size of 84.8 nm. The drug loading efficiency in MuSCF-NPs was reported to be 88.6%. MuSCF-NPs exhibited selective cytotoxicity against MDA-MB231 cells (IC50 = 40 μg/mL). Molecular analysis showed a significant increase in the expression of Caspases 3, 8, and 9, indicating that apoptosis was occurring in the treated cells. Moreover, flow cytometry results showed that the treated cells were arrested in his SubG1 phase, confirming the pro-apoptotic effect of the nanoparticles. The results indicate a high antioxidant effect of the nanoparticles with IC50 values ​​of 45 μg/mL and 1500 μg/mL against ABTS and DPPH, respectively. The reduction of catalase gene expression confirmed the pro-oxidant effect of nanoparticles in cancer cells treated at concentrations of 20 and 40 μg/mL.

CONCLUSIONS

Therefore, our findings suggest that the MuSCF-NPs are suitable candidates, especially for breast cancer preclinical studies.

Recent advances of novel targeted drug delivery systems based on natural medicine monomers against hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most prevalent type of liver cancer, is often diagnosed at an advanced stage. Surgical interventions are often ineffective, leading HCC patients to rely on systemic chemotherapy. Unfortunately, commonly used chemotherapeutic drugs have limited efficacy and can adversely affect vital organs, causing significant physical and psychological distress for patients. Natural medicine monomers (NMMs) have shown promising efficacy and safety profiles in HCC treatment, garnering attention from researchers. In recent years, the development of novel targeted drug delivery systems (TDDS) combining NMMs with nanocarriers has emerged. These TDDS aim to concentrate drugs effectively in HCC cells by manipulating the characteristics of nanomedicines, leveraging receptor and ligand interactions, and utilizing endogenous stimulatory responses to promote specific nanomedicines distribution. This comprehensive review presents recent research on TDDS for HCC treatment using NMMs from three perspectives: passive TDDS, active TDDS, and stimuli-responsive drug delivery systems (SDDS). It consolidates the current state of research on TDDS for HCC treatment with NMMs and highlights the potential of these innovative approaches in improving treatment outcomes. Moreover, the review also identifies research gaps in the related fields to provide references for future targeted therapy research in HCC.

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.

The effect of paclitaxel- and fisetin-loaded PBM nanoparticles on apoptosis and reversal of drug resistance gene ABCG2 in ovarian cancer

BACKGROUND

High-grade serous ovarian cancer (OvCa) is the most common type of epithelial OvCa. It is usually diagnosed in advanced stages, leaving a woman's chance of survival below 50%. Despite traditional chemotherapeutic therapies, there is often a high recurrence rate following initial treatments. Hence, a targeted drug delivery system is needed to attack the cancer cells and induce apoptosis, overcome acquired drug resistance, and protect normal cells from cytotoxicity. The present study shows that targeting folate receptor alpha (FRα) through planetary ball milling (PBM) nanoparticles (NPs) induces apoptosis in OvCa cells.

RESULTS

Human tissue microarrays (TMAs) show overexpression of FRα in Stage IV OvCa tissues compared to matched normal tissues. They provide a focus for a targeted delivery system. We formulated PBM nanoparticles encapsulated with paclitaxel (PTX) or fisetin (Fis) and conjugated with folic acid (FA). The cytotoxic effect of these PBM NPs reduced the concentration of the toxic chemotherapy drug PTX by five-fold. The combined treatment of PTX-FA NPs and Fis-FA NPs inhibited cell proliferation and induced apoptosis more extensively than the individual drugs alone. Apoptosis of OvCa cells, determined by flow cytometry, showed an increase from 14.4 to 80.4% (OVCAR3 cells) and from 2.69 to 90.0% (CAOV3 cells) in the number of apoptotic cells. Also, expressions of the pro-apoptotic markers, BAK and active caspase-3, were increased after PTX-FA + Fis-FA PBM NP treatment. In addition to looking at targeted treatment effects on apoptosis, drug resistance was investigated. Drug resistance in OvCa cells was reversed by ABCG2, an ABC-transporter marker.

CONCLUSIONS

Our study shows that PTX-FA and Fis-FA PBM NPs directly target platinum-resistant OvCa cells, induce cytotoxic/apoptotic effects, and reverse multi-drug resistance (MDR). These findings allow us to create new clinical applications using PTX-FA and Fis-FA combination nanoparticles to treat drug-resistant cancers.

FDA Approval Summary: Mirvetuximab Soravtansine-Gynx for FRα-Positive, Platinum-Resistant Ovarian Cancer

On November 14, 2022, the FDA granted accelerated approval to mirvetuximab soravtansine-gynx for treatment of adult patients with folate receptor-α (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received one to three prior systemic therapies. The VENTANA FOLR1 (FOLR-2.1) RxDx Assay was approved as a companion diagnostic device to select patients for this indication. Approval was based on Study 0417 (SORAYA, NCT04296890), a single-arm, multicenter trial. In 104 patients with measurable disease who received mirvetuximab soravtansine-gynx, the overall response rate was 31.7% [95% confidence interval (CI), 22.9-41.6] with a median duration of response of 6.9 months (95% CI, 5.6-9.7). Ocular toxicity was included as a Boxed Warning in the U.S. Prescribing Information (USPI) to alert providers of the risks of developing severe ocular toxicity including vision impairment and corneal disorders. Pneumonitis and peripheral neuropathy were additional important safety risks included as Warnings and Precautions in the USPI. This is the first approval of a targeted therapy for FRα-positive, platinum-resistant ovarian cancer and the first antibody-drug conjugate approved for ovarian cancer. This article summarizes the favorable benefit-risk assessment leading to FDA's approval of mirvetuximab soravtansine-gynx.

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.

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.

Strategies for Prevention and Management of Ocular Events Occurring With Mirvetuximab Soravtansine

Mirvetuximab soravtansine (MIRV) is a first-in-class antibody-drug conjugate (ADC) targeting folate receptor alpha (FRα) and is indicated for the treatment of adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1 to 3 prior systemic treatment regimens. MIRV has demonstrated single-agent anticancer activity in clinical trials, with a differentiated safety profile comprising primarily low-grade, resolvable gastrointestinal and ocular adverse events (AEs). Pooled safety analysis of 464 MIRV-treated patients across 3 trials, including the phase 2 SORAYA study, found that 50% of patients had ≥1 ocular AEs of interest (AEIs) of blurred vision or keratopathy, the majority being grade ≤2. Grade 3 ocular AEIs occurred in 5% of patients, and 1 patient (0.2%) had a grade 4 event of keratopathy. All grade ≥2 AEIs of blurred vision and keratopathy resolved to grade 1 or 0 in patients with complete follow-up data. MIRV-associated ocular AEs were primarily characterized by resolvable changes to the corneal epithelium, with no cases of corneal ulcers or perforations. This reflects the distinctive, milder ocular safety profile for MIRV compared with that of other ADCs with ocular toxicities in clinical use. To maintain a generally low incidence of severe ocular AEs, patients should follow recommendations for maintaining ocular surface health, including daily use of lubricating eye drops and periodic use of corticosteroid eye drops, and should undergo an eye examination at baseline, at every other cycle for the first 8 cycles of treatment, and as clinically indicated. Dose modification guidelines should be followed to maximize patients' ability to remain on therapy. Close collaboration between all care team members, including oncologists and eye care professionals, will help patients benefit from this novel and promising anticancer agent. This review focuses on the etiology, rates, prevention, and management of MIRV-associated ocular events.

Efficacy and Safety of Mirvetuximab Soravtansine in Patients With Platinum-Resistant Ovarian Cancer With High Folate Receptor Alpha Expression: Results From the SORAYA Study

PURPOSE

Single-agent chemotherapies have limited activity and considerable toxicity in patients with platinum-resistant epithelial ovarian cancer (PROC). Mirvetuximab soravtansine (MIRV) is an antibody-drug conjugate targeting folate receptor α (FRα). SORAYA is a single-arm, phase II study evaluating efficacy and safety of MIRV in patients with PROC.

METHODS

SORAYA enrolled FRα-high patients with PROC who had received one to three prior therapies, including required bevacizumab. The primary end point was confirmed objective response rate (ORR) by investigator; duration of response was the key secondary end point.

RESULTS

One hundred six patients were enrolled; 105 were evaluable for efficacy. All patients had received prior bevacizumab, 51% had three prior lines of therapy, and 48% received a prior poly ADP-ribose polymerase inhibitor. Median follow-up was 13.4 months. ORR was 32.4% (95% CI, 23.6 to 42.2), including five complete and 29 partial responses. The median duration of response was 6.9 months (95% CI, 5.6 to 9.7). In patients with one to two priors, the ORR by investigator was 35.3% (95% CI, 22.4 to 49.9) and in patients with three priors was 30.2% (95% CI, 18.3 to 44.3). The ORR by investigator was 38.0% (95% CI, 24.7 to 52.8) in patients with prior poly ADP-ribose polymerase inhibitor exposure and 27.5% (95% CI, 15.9 to 41.7) in those without. The most common treatment-related adverse events (all grade and grade 3-4) were blurred vision (41% and 6%), keratopathy (29% and 9%), and nausea (29% and 0%). Treatment-related adverse events led to dose delays, reductions, and discontinuations in 33%, 20%, and 9% of patients, respectively.

CONCLUSION

MIRV demonstrated consistent clinically meaningful antitumor activity and favorable tolerability and safety in patients with FRα-high PROC who had received up to three prior therapies, including bevacizumab, representing an important advance for this biomarker-selected population.

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

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

Antibody therapeutics for epithelial ovarian cancer

INTRODUCTION

High-grade serous ovarian carcinoma (HGSC) is an aggressive subtype of epithelial ovarian carcinoma (EOC) and remains the most lethal gynecologic cancer. A lack of effective and tolerable therapeutic options and nonspecific symptoms at presentation with advanced stage of disease are among the challenges in the management of the disease.

AREAS COVERED

An overview of ovarian cancer, followed by a discussion of the current therapeutic regimes and challenges that arise during and after the treatment of EOC. We discuss different formats of antibody therapeutics and their usage in targeting validated targets implicated in ovarian cancer, as well as three emerging novel proteins as examples recently implicated in their contribution to adaptive resistance in ovarian cancer.

EXPERT OPINION

Antibody therapeutics allow for a unique and effective way to target proteins implicated in cancer and other diseases, and have the potential to radically change the outcomes of patients suffering from ovarian cancer. The vast array of targets that have been implicated in ovarian cancer and yet the lack of effective therapeutic options for patients further stresses the importance of discovering novel proteins that can be targeted, as well as predictive biomarkers that can inform the stratification of patients into treatment-specific populations.

Anti-cancer activity of sustained release capsaicin formulations

Capsaicin (trans-8-methyl-N-vanillyl-6-noneamide) is a hydrophobic, lipophilic vanilloid phytochemical abundantly found in chili peppers and pepper extracts. Several convergent studies show that capsaicin displays robust cancer activity, suppressing the growth, angiogenesis and metastasis of several human cancers. Despite its potent cancer-suppressing activity, the clinical applications of capsaicin as a viable anti-cancer drug have remained problematic due to its poor bioavailability and aqueous solubility properties. In addition, the administration of capsaicin is associated with adverse side effects like gastrointestinal cramps, stomach pain, nausea and diarrhea and vomiting. All these hurdles may be circumvented by encapsulation of capsaicin in sustained release drug delivery systems. Most of the capsaicin-based the sustained release drugs have been tested for their pain-relieving activity. Only a few of these formulations have been investigated as anti-cancer agents. The present review describes the physicochemical properties, bioavailability, and anti-cancer activity of capsaicin-sustained release agents. The asset of such continuous release capsaicin formulations is that they display better solubility, stability, bioavailability, and growth-suppressive activity than the free drug. The encapsulation of capsaicin in sustained release carriers minimizes the adverse side effects of capsaicin. In summary, these capsaicin-based sustained release drug delivery systems have the potential to function as novel chemotherapies, unique diagnostic imaging probes and innovative chemosensitization agents in human cancers.

Biopolymeric Prodrug Systems as Potential Antineoplastic Therapy

Nowadays, cancer represents a major public health issue, a substantial economic issue, and a burden for society. Limited by numerous disadvantages, conventional chemotherapy is being replaced by new strategies targeting tumor cells. In this context, therapies based on biopolymer prodrug systems represent a promising alternative for improving the pharmacokinetic and pharmacologic properties of drugs and reducing their toxicity. The polymer-directed enzyme prodrug therapy is based on tumor cell targeting and release of the drug using polymer–drug and polymer–enzyme conjugates. In addition, current trends are oriented towards natural sources. They are biocompatible, biodegradable, and represent a valuable and renewable source. Therefore, numerous antitumor molecules have been conjugated with natural polymers. The present manuscript highlights the latest research focused on polymer–drug conjugates containing natural polymers such as chitosan, hyaluronic acid, dextran, pullulan, silk fibroin, heparin, and polysaccharides from Auricularia auricula.

Folic Acid Enables Targeting Delivery of Lipodiscs by Circumventing IgM-Mediated Opsonization

Folic acid (FA) is one of the most widely utilized small-molecule ligands for cancer targeted drug delivery. Natural IgM was recently found to avidly absorb on the surface of FA-functionalized liposomes (FA-sLip), negatively regulating the in vivo performance by efficiently activating complement. Herein, FA-functionalized lipodiscs (FA-Disc) were constructed to successfully circumvent IgM-mediated opsonization and retained binding activity with folate receptors in vivo. The FA moiety along with the bound IgM was restricted to the highly curved rim of lipodiscs, leading to IgM incapability of presenting the membrane-bound conformation to trigger complement activation. The C1q docking, C3 binding, and C5a release were blocked and accelerated blood clearance phenomenon was mitigated of FA-Disc. FA-Disc retained folate binding activity and could effectively target folate receptor positive tumors in vivo. The present study provides a useful solution to avoid the negative regulation by IgM and achieve FA-enabled targeting by exploring disc-shaped nanocarriers.

Protein Expression of Folate Receptor Alpha in Adenoid Cystic Carcinoma of the Head and Neck

Purpose

Folate receptor alpha (FRα) is overexpressed in various cancer entities while expression in normal tissue is limited. Thus, FRα is an attractive target in cancer therapy. Currently, various therapeutic and diagnostic approaches are under investigation in clinical trials. The aim of this study was to assess the expression and clinical relevance of FRα in adenoid cystic carcinoma of the head and neck.

Patients and Methods

In this retrospective cohort study, 43 patients with adenoid cystic carcinoma (ACC) of the head and neck were included. FRα expression was analyzed in tumor tissue and tumor-free margin in a tissue microarray using immunohistochemical staining. Protein levels were correlated with clinical parameters.

Results

FRα staining was positive in 47% of ACC patients. The tumor-free margin was positive in 22%. Patients with positive tumor tissue showed positive margin staining in 55%. FRα expression was not associated with the clinical parameters (sex, age, staging, grading, perineural invasion, lymphovascular invasion).

Conclusion

FRα expression is common in ACC of the head and neck. Therefore, FRα should be further evaluated as a therapeutic target in ACC.

Advancing antibody-drug conjugates in gynecological malignancies: myth or reality?

Antibody-drug conjugates (ADCs) represent a new class of therapeutic agents designed to target specific antigens on tumor cells, combining the specificity of monoclonal antibodies to the cytotoxicity of classic chemotherapy agents. These drugs have been extensively studied both in solid and hematologic malignancies, leading to substantial improvement in the therapeutic landscape for several tumors. Despite no ADC have been yet approved for the treatment of gynecological malignancies, some agents have shown promising results and might have the potential to become part of the standard of care. Among them, mirvetuximab soravtansine has shown activity in platinum-resistant ovarian cancer with high folate-α receptor expression, as a single agent and in combination. Tisotumab vedotin is active in patients with pre-treated cervical cancer, and further investigation is ongoing. The purpose of this review is to summarize the structural and functional characteristics of ADCs and analyze the most recent and promising data regarding the clinical development of ADCs in gynecological malignancies. The available data on the efficacy of the more studied ADCs in ovarian, endometrial, and cervical cancers will be discussed along with toxicities of special interest, the mechanisms of resistance, and future possible drugs combination.

Emerging targeted drug delivery strategies toward ovarian cancer

Ovarian cancer is a high-mortality malignancy in women. The contemporary clinical chemotherapy with classic cytotoxic drugs, targeted molecular inhibitors would mostly fail when ovarian cancer cells become drug-resistant or metastasize through the body or when patients bare no more toleration because of strong adverse effects. The past decade has spotted varying targeted delivery systems including antibody-drug conjugates (ADCs), peptide/folate/aptamer-drug conjugates, polymer-drug conjugates, ligand-functionalized nanomedicines, and dual-targeted nanomedicines that upgrade ovarian cancer chemo- and molecular therapy effectively in preclinical/clinical settings via endowing therapeutic agents selectivity and bypassing drug resistance as well as lessening systemic toxicity. The targeted delivery approaches further provide means to potentiate emergent treatment modalities such as molecular therapy, gene therapy, protein therapy, photodynamic therapy, dual-targeting therapy and combination therapy for ovarian cancer. This review highlights up-to-date development of targeted drug delivery strategies toward advanced, metastatic, relapsed, and drug resistant ovarian cancers.

Interrogation of Folic Acid-Functionalized Nanomedicines: The Regulatory Roles of Plasma Proteins Reexamined

Folic acid (FA) has been extensively exploited to facilitate targeted delivery of nanomedicines by recognizing the folate receptor-α (FR-α) overexpressed in many human cancers. Unfortunately, none have been approved for clinical use yet. Here we reveal that FA functionalization induces heavy natural IgM absorption on the liposomal surface, depriving FA of receptor recognition and accelerating complement activation in vivo. FA functionalization does not enhance distribution of liposomes in FR-α-overexpressed tumors in comparison to plain liposomes (without FA), but leads to aggravated capture of liposomes by macrophages in the tumor, liver, and spleen. In addition, FA-functionalized polymeric nanoparticles are also vulnerable to natural IgM absorption. This work highlights the pivotal roles of natural IgM in regulating in vivo delivery of FA-functionalized nanomedicines. Due to the prevalent association of immune disorders and varying levels of immunoglobulins with cancer patients, extraordinary cautiousness is urged for clinical translation of FA-enabled targeted delivery systems.

Th17-inducing autologous dendritic cell vaccination promotes antigen-specific cellular and humoral immunity in ovarian cancer patients

In ovarian cancer (OC), IL-17-producing T cells (Th17s) predict improved survival, whereas regulatory T cells predict poorer survival. We previously developed a vaccine whereby patient-derived dendritic cells (DCs) are programmed to induce Th17 responses to the OC antigen folate receptor alpha (FRα). Here we report the results of a single-arm open-label phase I clinical trial designed to determine vaccine safety and tolerability (primary outcomes) and recurrence-free survival (secondary outcome). Immunogenicity is also evaluated. Recruitment is complete with a total of 19 Stage IIIC-IV OC patients in first remission after conventional therapy. DCs are generated using our Th17-inducing protocol and are pulsed with HLA class II epitopes from FRα. Mature antigen-loaded DCs are injected intradermally. All patients have completed study-related interventions. No grade 3 or higher adverse events are seen. Vaccination results in the development of Th1, Th17, and antibody responses to FRα in the majority of patients. Th1 and antibody responses are associated with prolonged recurrence-free survival. Antibody-dependent cell-mediated cytotoxic activity against FRα is also associated with prolonged RFS. Of 18 patients evaluable for efficacy, 39% (7/18) remain recurrence-free at the time of data censoring, with a median follow-up of 49.2 months. Thus, vaccination with Th17-inducing FRα-loaded DCs is safe, induces antigen-specific immunity, and is associated with prolonged remission.