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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.

Introduction: Ovarian cancer (OC) 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 efficacy of the Poly (ADP-ribose) polymerase (PARP) inhibitor (olaparib) and the pan-ErbB inhibitor (neratinib) as single agents and in combination in ovarian cancer cell lines and xenografts with variable HER2 expression., Methods: In vitro cell viability with olaparib, neratinib, and their combination was assessed using flow-cytometry based assays against a panel of OC primary cell lines with variable HER2 expression. Immunoblotting experiments were performed to elucidate the mechanism of activity and synergism. The in vivo antitumor activity of the olaparib/neratinib combination versus single agents was tested in HER2 positive xenograft OC models., Results: HER2 + OC cell lines demonstrated higher sensitivity to olaparib and neratinib when compared to HER2 negative tumors (i.e., IC 50 : 2.06 ± 0.33 μM vs. 39.28 ± 30.51 μM, p = 0.0035 for olaparib and 19.42 ± 2.63 nM vs. 235.0 ± 165.0 nM, p = 0.0035 for neratinib). The combination of olaparib with neratinib was more potent when compared to single-agent olaparib or neratinib both in vitro and in vivo, and demonstrated synergy in all primary HER2 + OC models. Western blot experiments showed neratinib decreased pHER2/neu while increased Poly(ADP-ribose) (PAR) enzymatic activity; olaparib increased pHER2/Neu expression and blocked PAR activatio. Olaparib/neratinib in combination decreased both pHER2/Neu as well as PAR activation., Conclusion: The combination of olaparib and neratinib is synergistic and endowed with remarkable preclinical activity against HER2+ ovarian cancers. This combination may represent a novel therapeutic option for ovarian cancer patients with HER2+, homologous recombination-proficient tumors resistant to chemotherapy., Competing Interests: Declaration of Competing Interest Dr. Santin declares grants from PUMA, grants from IMMUNOMEDICS, grants from GILEAD, grants from SYNTHON, grants and personal fees from MERCK, grants from BOEHINGER-INGELHEIM, grants from GENENTECH, grants and personal fees from TESARO and grants and personal fees from EISAI and R-PHARM-US. The other authors declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose of Review: Antibody-drug conjugates (ADCs) represent a new class of drugs that combine a surface receptor-targeting antibody linked to a cytotoxic molecule delivering the potent cytotoxic payload directly to tumor cells. This review summarizes the current literature demonstrating their use in the treatment of gynecologic malignancies., Recent Findings: Tisotumab vedotin is the first U.S. Food and Drug Administration (FDA) approved ADC for the treatment of gynecologic cancers. While in the phase 3 randomized controlled trial in platinum resistant ovarian cancer patients, FORWARD 1, mirvetuximab did not meet its primary endpoint of progression-free survival. But we await more recent data from the two ongoing phase 3 trials of mirvetuximab in recurrent ovarian cancer patients. HER2/neu, Napi2b, mesothelin, and human trophoblast cell-surface marker (Trop-2) overexpression have also been exploited as excellent targets by novel ADCs in multiple tumors including ovarian, endometrial, and cervical cancers., Summary: Current evidence strongly supports the use of ADCs and ongoing clinical trials will provide further information into the potential of making these drugs part of current standard practice allowing patients to be treated with a higher level of personalized cancer care., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Carcinosarcoma of the ovary (OCS) and uterus (UCS) are rare highly aggressive malignancies. Ataxia-telangiectasia-and-Rad3-related (ATR) kinase and homologous recombination play a pivotal role in DNA damage repair. Homologous recombination deficiency (HRD) has been demonstrated in >30% of OCS/UCS. We investigated the preclinical activity of elimusertib, a selective ATR kinase inhibitor, against carcinosarcoma (CS) cell lines and xenografts., Methods: Sensitivity to elimusertib was evaluated in vitro against nine whole exome-sequenced (WES) primary CS cell lines and in vivo against HRD CS xenografts. Western blots were performed to determine baseline ATR and p-ATR protein expression in CS, and ATR pathway downstream effectors and apoptosis markers in CS HRD cell lines after Elimusertib treatment., Results: Out of the 9 CS cell lines, 3 harbored HRD and 6 homologous recombination proficient (HRP) features. Most of CS (i.e., 7/9 = 85%) were found to be sensitive to Elimusertib in vitro. Among the 5 primary CS cell lines with a high-grade pure serous epithelial component, HRD cell lines were more sensitive to elimusertib than HRP tumors (mean IC 50 ± SEM HRD CS = 61.3 nM ±15.2 vs HRP = 361.6 nM ±24.4 (p = 0.01)). Baseline ATR and p-ATR protein expression was higher in HRD CS cell lines. Elimusertib showed tumor growth inhibition in HRD CS xenografts (p < 0.0001) and increased overall animal survival (p < 0.0001). Western blot demonstrated dose-dependent inhibition of ATR, p-ATR and its downstream effector p-CHK1, and a dose-dependent increase in caspase-3 expression., Conclusions: Elimusertib is preclinically active in vitro and in vivo against primary CS cell lines and xenografts, respectively. CS models harboring HRD or with pure/mixed endometrioid histology demonstrated higher sensitivity to ATR inhibition. Clinical trials with elimusertib in CS patients are warranted., Competing Interests: Declaration of Competing Interest A.D.S. reports grants from PUMA, grants from IMMUNOMEDICS, grants from GILEAD, grants from SYNTHON, grants and personal fees from MERCK, grants from BOEHINGER-INGELHEIM, grants from GENENTECH, grants and personal fees from TESARO and grants and personal fees from EISAI and R-Pharm US. L.B.A. is a compensated consultant and has equity interest in io9, LLC. His spouse is an employee of Biotheranostics, Inc. L.B.A. is also an inventor of a US Patent 10,776,718 for source identification by non-negative matrix factorization. L.B.A. declares U.S. provisional applications with serial numbers: 63/289,601; 63/269,033; 63/366,392; 63/367,846; 63/412,835. The other authors declare no conflict of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Opinion Statement: Despite the dismal prognosis of uterine serous carcinoma (USC), recent advances in molecular classification and targeted treatments have demonstrated improvements in survival outcomes for patients both in the upfront and recurrent treatment settings. After appropriate surgical staging and surgical cytoreduction as indicated, correct pathologic and molecular classification of USC is important to provide the most appropriate systemic adjuvant treatment. HER2-targeted agents are one of the most important advances in the treatment of USC in decades. Thus, for HER2-positive tumors, the addition of trastuzumab to conventional chemotherapy is indicated in those with advanced stage and/or recurrent disease. Treatment with pembrolizumab and lenvatinib suggests a 50% response rate in women with recurrent disease which serves as a promising targeted treatment strategy. Overall, emerging targeted therapeutic options with antibody-drug conjugates (i.e. targeting HER2, folic acid receptor alpha, or Trop-2), combinations of immunotherapies and tyrosine kinase inhibitors, PARP inhibitors, WEE1 inhibitors, and AKT inhibitors shed further promise in advancements of effective disease-modifying treatments for this unmet medical need for patients with USC. Several trials evaluating these targeted agents are ongoing, and those results are eagerly awaited. As such, enrollment of patients in clinical trials is highly recommended as it will provide patients with a higher level of personalized cancer care., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Endometrial cancer is the most common gynecologic malignancy in developed countries. The antibody-drug conjugate (ADC) sacituzumab govitecan (SG) targets trophoblast cell-surface antigen-2 (Trop-2) - a cell-surface glycoprotein highly expressed in many epithelial tumors - and delivers the active metabolite of irinotecan SN-38 to Trop-2-positive tumor cells. We evaluated Trop-2 expression in endometrial endometrioid carcinoma (EC) tissues and the activity of SG against primary poorly differentiated EC cell lines and xenografts. Trop-2 expression was assessed in 143 formalin-fixed-paraffin-embedded tumors and seven primary tumor cell lines by immunohistochemistry and flow cytometry, respectively. Cell viability of primary tumor cell lines was assessed following exposure to SG, or control antibodies. Antibody-dependent cell cytotoxicity (ADCC) against Trop-2-positive and Trop-2-negative EC cell lines was measured in vitro using 4-h chromium release assays. A Trop-2-positive EC xenograft model was used to determine the in vivo activity of SG. Moderate-to-strong staining was detected in 84% (120/143) of EC samples, whereas 43% (3/7) of the primary EC cell lines tested overexpressed Trop-2. EC cell lines overexpressing Trop-2 were significantly more sensitive to SG compared to control ADC (P = 0.014 and P = 0.005). Both SG and the unconjugated parental antibody hRS7 mediated high ADCC against Trop-2-positive cell lines. Moreover, SG induced significant bystander killing of Trop-2-negative tumors cocultured with Trop-2-positive tumors. In the xenograft model, intravenous administration of SG twice weekly for three weeks was well tolerated and demonstrated impressive tumor growth inhibition against poorly differentiated, chemotherapy-resistant EC xenografts (P = 0.011). In summary, SG is a novel ADC with remarkable preclinical activity against poorly differentiated EC cell lines overexpressing Trop-2. These findings warrant future clinical trials., (© 2020 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Human trophoblast cell-surface marker (Trop-2) is a surface glycoprotein originally identified in human placental tissue and subsequently found to be highly expressed by various types of human epithelial solid tumors. We investigated the efficacy of sacituzumab govitecan, an antibody-drug conjugate (ADC) comprised of a humanized anti- Trop-2 antibody, conjugated with active metabolite of irinotecan (SN-38), on Trop-2 positive cervical cancer cell lines and a xenograft model. Trop-2 expression was evaluated in 147 primary cervical tumors by immunohistochemistry, real-time polymerase chain reaction, and flow cytometry. For in vitro experiments, two Trop-2 positive (CVX-8, ADX-3), and one Trop-2 negative (ADX-2) cell lines were used. A cell line with a strong Trop-2 expression (CVX-8) was used to test in vivo antitumor activity in xenografts models. Out of 147 primary cervical cancers, 113 were squamous cell carcinomas (SCCs), and 34 were adenocarcinoma/adenosquamous carcinomas. Moderate to strong diffuse staining was seen in 95% (108/113) of SCCs, and 81% (29/34) of adenocarcinoma/adenosquamous cancers on immunohistochemistry. Trop-2 positive cell lines were highly sensitive to sacituzumab govitecan in vitro, with IC 50 values in the range of 0.18 to 0.26 nM (p = 0.02, and p = 0.04 for CVX-8, and ADX-3, respectively). In xenografts, a significant tumor growth inhibition was seen after twice-weekly intravenous administration of the drug for three weeks (p < 0.0001, and p = 0.001 for sacituzumab govitecan vs naked antibody, and sacituzumab govitecan vs control-ADC, respectively). Overall survival at 90 days was significantly improved in the sacituzumab govitecan group (p = 0.014). In conclusion, sacituzumab govitecan may represent a novel targeted therapy option in cervical cancer patients overexpressing Trop-2.

Background: Standard chemotherapy is associated with low response rates and short progression-free survival among patients with pretreated metastatic triple-negative breast cancer. Sacituzumab govitecan-hziy is an antibody-drug conjugate that combines a humanized monoclonal antibody, which targets the human trophoblast cell-surface antigen 2 (Trop-2), with SN-38, which is conjugated to the antibody by a cleavable linker. Sacituzumab govitecan-hziy enables delivery of high concentrations of SN-38 to tumors., Methods: We conducted a phase 1/2 single-group, multicenter trial involving patients with advanced epithelial cancers who received sacituzumab govitecan-hziy intravenously on days 1 and 8 of each 21-day cycle until disease progression or unacceptable toxic effects. A total of 108 patients received sacituzumab govitecan-hziy at a dose of 10 mg per kilogram of body weight after receiving at least two previous anticancer therapies for metastatic triple-negative breast cancer. The end points included safety; the objective response rate (according to Response Evaluation Criteria in Solid Tumors, version 1.1), which was assessed locally; the duration of response; the clinical benefit rate (defined as a complete or partial response or stable disease for at least 6 months); progression-free survival; and overall survival. Post hoc analyses determined the response rate and duration, which were assessed by blinded independent central review., Results: The 108 patients with triple-negative breast cancer had received a median of 3 previous therapies (range, 2 to 10). Four deaths occurred during treatment; 3 patients (2.8%) discontinued treatment because of adverse events. Grade 3 or 4 adverse events (in ≥10% of the patients) included anemia and neutropenia; 10 patients (9.3%) had febrile neutropenia. The response rate (3 complete and 33 partial responses) was 33.3% (95% confidence interval [CI], 24.6 to 43.1), and the median duration of response was 7.7 months (95% CI, 4.9 to 10.8); as assessed by independent central review, these values were 34.3% and 9.1 months, respectively. The clinical benefit rate was 45.4%. Median progression-free survival was 5.5 months (95% CI, 4.1 to 6.3), and overall survival was 13.0 months (95% CI, 11.2 to 13.7)., Conclusions: Sacituzumab govitecan-hziy was associated with durable objective responses in patients with heavily pretreated metastatic triple-negative breast cancer. Myelotoxic effects were the main adverse reactions. (Funded by Immunomedics; IMMU-132-01 ClinicalTrials.gov number, NCT01631552.)., (Copyright © 2019 Massachusetts Medical Society.)

Ovarian cancer remains the most lethal gynecologic malignancy. We analyzed the mutational landscape of 64 primary, 41 metastatic, and 17 recurrent fresh-frozen tumors from 77 patients along with matched normal DNA, by whole-exome sequencing (WES). We also sequenced 13 pairs of synchronous bilateral ovarian cancer (SBOC) to evaluate the evolutionary history. Lastly, to search for therapeutic targets, we evaluated the activity of the Bromodomain and Extra-Terminal motif (BET) inhibitor GS-626510 on primary tumors and xenografts harboring c-MYC amplifications. In line with previous studies, the large majority of germline and somatic mutations were found in BRCA1/2 (21%) and TP53 (86%) genes, respectively. Among mutations in known cancer driver genes, 77% were transmitted from primary tumors to metastatic tumors, and 80% from primary to recurrent tumors, indicating that driver mutations are commonly retained during ovarian cancer evolution. Importantly, the number, mutation spectra, and signatures in matched primary-metastatic tumors were extremely similar, suggesting transcoelomic metastases as an early dissemination process using preexisting metastatic ability rather than an evolution model. Similarly, comparison of SBOC showed extensive sharing of somatic mutations, unequivocally indicating a common ancestry in all cases. Among the 17 patients with matched tumors, four patients gained PIK3CA amplifications and two patients gained c-MYC amplifications in the recurrent tumors, with no loss of amplification or gain of deletions. Primary cell lines and xenografts derived from chemotherapy-resistant tumors demonstrated sensitivity to JQ1 and GS-626510 ( P = 0.01), suggesting that oral BET inhibitors represent a class of personalized therapeutics in patients harboring recurrent/chemotherapy-resistant disease., Competing Interests: The authors declare no conflict of interest.

Purpose: Hypersensitivity reactions (HSRs) to chemotherapy is an ongoing issue in cancer treatments. Strategies to induce tolerance and maximize chemotherapy efficacy include desensitization protocols. The precise impact of these protocols, however, in the long-term treatments remains unclear. We aim to compare overall survival (OS) in hypersensitive patients treated with carboplatin desensitization to patients without hypersensitivity reactions. We also sought to identify new risk factors for HSRs and reconfirm that the DNA repair enzyme, germline BRCA1/2 (gBRCA1/2), is a risk factor for hypersensitivity., Experimental Design: Retrospective study in patients with ovarian cancer tested for gBRCA1/2 mutations who received more than six infusions of carboplatin from August 2005 to November 2016. Two-sided Fisher exact, Student's t test and Gehan-Breslow-Wilcoxon test were used for statistical analysis. Univariate and multivariate analyses were completed to identify independent predictors of survival. Statistical significance was set with a two-sided p value of 0.05., Results: Ninety-one patients with gBRCA1/2 testing met inclusion. Forty patients (44%) were gBRCA1/2-deficient and 51 (56%) were gBRCA1/2-proficient. Patients with gBRCA1/2 deficiencies had a higher likelihood of developing carboplatin hypersensitivity, HR 6.433 (95% CI: 1.868-22.149). None of the patients with carboplatin hypersensitivity were given PARP inhibitors prior to the development of HSRs. The patients with recurrent advanced stage (III-IV) ovarian cancer had a higher likelihood of developing carboplatin hypersensitivity, HR 4.783 (1.008-22.689). Moreover, we found that hypersensitive patients who underwent carboplatin desensitization had a 48-month longer OS than patients without hypersensitivity to carboplatin not undergoing carboplatin desensitization (p = 0.0094). A subgroup analysis indicated that gBRCA1/2-proficient hypersensitive patients undergoing carboplatin desensitization had a 43-month longer OS than gBRCA1/2-proficient patients without HSRs (p = 0.034)., Conclusions: We confirmed that gBRCA1/2 deficiency and advanced stage are independent risk factors for development of carboplatin hypersensitivity in ovarian cancer patients. Our study also shows improved OS in hypersensitive patients receiving CD compared to non-hypersensitive patients, independent of gBRCA1/2.

Purpose: Uterine serous carcinoma (USC) is a rare and aggressive variant of endometrial cancer. Whole-exome sequencing (WES) studies have recently reported c-Myc gene amplification in a large number of USCs, suggesting c-Myc as a potential therapeutic target. We investigated the activity of novel BET bromodomain inhibitors (GS-5829 and GS-626510, Gilead Sciences Inc.) and JQ1 against primary USC cultures and USC xenografts. Experimental Design: We evaluated c-Myc expression by qRT-PCR in a total of 45 USCs including fresh-frozen tumor tissues and primary USC cell lines. We also performed IHC and Western blot experiments in 8 USC tumors. USC cultures were evaluated for sensitivity to GS-5829, GS-626510, and JQ1 in vitro using proliferation, viability, and apoptosis assays. Finally, the in vivo activity of GS-5829, GS-626510, and JQ1 was studied in USC-ARK1 and USC-ARK2 mouse xenografts. Results: Fresh-frozen USC and primary USC cell lines overexpressed c-Myc when compared with normal tissues ( P = 0.0009 and 0.0083, respectively). High c-Myc expression was found in 7 of 8 of primary USC cell lines tested by qRT-PCR and 5 of 8 tested by IHC. In vitro experiments demonstrated high sensitivity of USC cell lines to the exposure to GS-5829, GS-626510, and JQ1 with BET inhibitors causing a dose-dependent decrease in the phosphorylated levels of c-Myc and a dose-dependent increase in caspase activation (apoptosis). In comparative in vivo experiments, GS-5829 and/or GS-626510 were found more effective than JQ1 at the concentrations/doses used in decreasing tumor growth in both USC-ARK1 and USC-ARK2 mouse xenograft models. Conclusions: GS-5829 and GS-626510 may represent novel, highly effective therapeutics agents against recurrent/chemotherapy-resistant USC-overexpressing c-Myc. Clinical studies with GS-5829 in patients with USC harboring chemotherapy-resistant disease are warranted. Clin Cancer Res; 24(19); 4845-53. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Ovarian cancer is the most lethal gynecologic cancer. Claudin-3 and -4, the receptors for Clostridium perfringens enterotoxin (CPE), are overexpressed in more than 70% of these tumors. Here, we synthesized and characterized poly(lactic-co-glycolic-acid) (PLGA) nanoparticles (NPs) modified with the carboxy-terminal-binding domain of CPE (c-CPE-NP) for the delivery of suicide gene therapy to chemotherapy-resistant ovarian cancer cells. As a therapeutic payload, we generated a plasmid encoding for the diphtheria toxin subunit-A (DT-A) under the transcriptional control of the p16 promoter, a gene highly differentially expressed in ovarian cancer cells. Flow cytometry and immunofluorescence demonstrated that c-CPE-NPs encapsulating the cytomegalovirus (CMV) GFP plasmid (CMV GFP c-CPE-NP) were significantly more efficient than control NPs modified with a scrambled peptide (CMV GFP scr-NP) in transfecting primary chemotherapy-resistant ovarian tumor cell lines in vitro (P = 0.03). Importantly, c-CPE-NPs encapsulating the p16 DT-A vector (p16 DT-A c-CPE-NP) were significantly more effective than control p16 DT-A scr-NP in inducing ovarian cancer cell death in vitro (% cytotoxicity: mean ± SD = 32.9 ± 0.15 and 7.45 ± 7.93, respectively, P = 0.03). In vivo biodistribution studies demonstrated efficient transfection of tumor cells within 12 hours after intraperitoneal injection of CMV GFP c-CPE-NP in mice harboring chemotherapy-resistant ovarian cancer xenografts. Finally, multiple intraperitoneal injections of p16 DT-A c-CPE-NP resulted in a significant inhibition of tumor growth compared with control NP in chemotherapy-resistant tumor-bearing mice (P = 0.041). p16 DT-A c-CPE-NP may represent a novel dual-targeting therapeutic approach for the selective delivery of gene therapy to chemotherapy-resistant ovarian cancer cells. Mol Cancer Ther; 16(2); 323-33. ©2016 AACR., Competing Interests: The authors declare no potential conflicts of interest., (©2016 American Association for Cancer Research.)

Purpose: The management of endometrial carcinoma no longer amenable to treatment with surgery or radiotherapy has not improved significantly with modern chemotherapy. Alternative therapeutic options are desperately needed., Experimental Design: We describe 2 heavily pretreated patients with recurrent disease refractory to surgery, radiotherapy, and chemotherapy who were treated with the anti-PD-1 immune checkpoint inhibitor nivolumab., Results: Patient #1 harbored an ultra-mutated tumor (mutation load/MB = 117.3, total mutations = 4,660) driven by mutation in the exonuclease domain of the DNA polymerase ε gene. Patient #2 harbored a hyper-mutated tumor (mutation load/MB = 33.5, total mutations = 1,037) due to a germinal MSH6 gene mutation. Both patients demonstrated a remarkable clinical response to the anti-PD-1 immune checkpoint inhibitor nivolumab. Patients' clinical responses remain unchanged at the time of the writing of this report, with no grade 3 or higher side effects reported to date., Conclusions: Anti-PD-1 inhibitors represent a novel treatment option for recurrent/metastatic, ultra/hyper-mutated human tumors refractory to salvage treatment. Clin Cancer Res; 22(23); 5682-7. ©2016 AACRSee related commentary by Piulats and Matias-Guiu, p. 5623., (©2016 American Association for Cancer Research.)

Uterine serous carcinoma (USC) is an aggressive form of endometrial cancer. Up to 35% of USC may overexpress the HER2/neu oncogene at strong (i.e., 3+) levels by IHC while an additional 40% to 50% express HER2/neu at moderate (2+) or low (1+) levels. We investigated the efficacy of SYD985, (Synthon Biopharmaceuticals), a novel HER2-targeting antibody-drug conjugate (ADC) composed of the mAb trastuzumab linked to a highly potent DNA-alkylating agent (i.e., duocarmycin) in USC. We also compared the antitumor activity of SYD985 in head-to-head experiments to trastuzumab emtansine (T-DM1), a FDA-approved ADC, against multiple primary USC cell lines expressing different levels of HER2/neu in in vitro and in vivo experiments. Using antibody-dependent cellular cytotoxicity (ADCC), proliferation, viability, and bystander killing assays as well as propidium iodide-based flow cytometry assays and multiple in vivo USC mouse xenograft models, we demonstrate for the first time that SYD985 is a novel ADC with activity against USC with strong (3+) as well as low to moderate (i.e., 1+/2+) HER2/neu expression. SYD985 is 10- to 70-fold more potent than T-DM1 in comparative experiments and, unlike T-DM1, it is active against USC demonstrating moderate/low or heterogeneous HER2/neu expression. Clinical studies with SYD985 in patients harboring chemotherapy-resistant USC with low, moderate, and high HER2 expression are warranted. Mol Cancer Ther; 15(8); 1900-9. ©2016 AACR., (©2016 American Association for Cancer Research.)

Uterine serous carcinoma (USC) is a rare but aggressive subtype of endometrial cancer. Although it represents only 10% of all endometrial cancer cases, USC accounts for up to 40% of all endometrial cancer-related recurrences and subsequent deaths. With such a dismal prognosis, there is an expanding role for novel targeted approaches in the treatment of USC. Recent whole-exome sequencing studies have demonstrated gain of function of the HER2/NEU gene, as well as driver mutations in the PIK3CA/AKT/mTOR and cyclin E/FBXW7 oncogenic pathways in a large number of USCs. The results emphasize the relevance of these novel therapeutic targets for biologic therapy of USC, which will be reviewed in this article.

Introduction: Endometrial cancer (EC) is the most common gynecologic malignancy in the developed world and is increasing in incidence. While the mainstay of treatment for EC is surgery followed by chemotherapy and/or radiation therapy, the available pharmacotherapies are rapidly and constantly evolving. Understanding these new therapies is an important part of the research and clinical care of women with EC. A review of available literature from MEDLINE (1879-2015) was conducted for the historic treatments and current therapies available for endometrial tumors., Areas Covered: This article reviews the current conventional therapies and discusses novel therapeutic agents, some of which are available to clinicians while others are currently being investigated in the preclinical setting., Expert Opinion: Genomic and immunohistochemical characterization of endometrial cancer may soon be the best approach for the identification of aggressive forms of tumor. Targeted therapies will soon be standard in the management of endometrial cancer.

Background: Uterine serous carcinoma is an aggressive form of endometrial cancer that carries an extremely poor prognosis. Solitomab is a novel bispecific single-chain antibody construct that targets epithelial cell adhesion molecule on tumor cells and also contains a CD3 binding region. We evaluated the expression levels of epithelial cell adhesion molecule and the in vitro activity of solitomab against primary uterine serous carcinoma cell lines in vitro and ex-vivo in the ascites of patients with uterine serous carcinoma., Objective: The purpose of this study was to determine the frequency of expression of epithelial cell adhesion molecule on uterine serous carcinoma cell lines and the ability of solitomab to modulate immune responses (T-cell proliferation, activation, cytokine production, and tumor killing) to tumor cells when it is combined with lymphocytes and epithelial cell adhesion molecule-positive cell lines or epithelial cell adhesion molecule-positive ascitic fluid in vitro., Study Design: Epithelial cell adhesion molecule expression was evaluated by flow cytometry in a total of 14 primary uterine serous carcinoma cell lines. Sensitivity to solitomab-dependent cellular-cytotoxicity was tested against a panel of primary uterine serous carcinoma cell lines that express different levels of epithelial cell adhesion molecule in standard 4-hour chromium release assays. The proliferative activity, activation, cytokine secretion (ie, type I vs type II), and cytotoxicity of solitomab in autologous tumor-associated T cells in the ascitic fluid of patients with uterine serous carcinoma was also evaluated by carboxyfluorescein succinimidyl ester and flow-cytometry assays. Differences in epithelial cell adhesion molecule expression, solitomab-dependent cellular-cytotoxicity levels were analyzed with the use of an unpaired t test. T-cell activation marker increase and cytokine release were analyzed by a paired t test., Results: Surface expression of epithelial cell adhesion molecule was found in 85.7% (12 of 14) of the uterine serous carcinoma cell lines that were tested by flow cytometry. Epithelial cell adhesion molecule-positive cell lines were found resistant to natural killer cells or T-cell-mediated killing after exposure to peripheral blood lymphocytes in 4-hour chromium-release assays (mean killing ± standard of the mean, 2.7% ± 3.1% after incubation of epithelial cell adhesion molecule-positive cell lines with control bispecific antibody construct). In contrast, after incubation with solitomab, epithelial cell adhesion molecule-positive uterine serous carcinoma cells became highly sensitive to T-cell cytotoxicity (mean killing, 25.7% ± 4.5%; P < .0001) by peripheral blood lymphocytes. Ex vivo incubation of autologous tumor-associated lymphocytes with epithelial cell adhesion molecule that expressed malignant cells in ascites with solitomab resulted in a significant increase in T-cell proliferation in both CD4+ and CD8+ T cells, increase in T-cell activation markers (ie, CD25 and HLA-DR), and a reduction in number of viable uterine serous carcinoma cells in ascites (P < .001)., Conclusion: Solitomab induces robust immunologic responses in vitro that result in increased T-cell activation, proliferation, production of cytokines, and direct killing of tumor cells. These findings suggest that solitomab may represent a novel, potentially effective agent for the treatment of recurrent/metastatic and/or chemo-resistant uterine serous carcinoma-overexpressing epithelial cell adhesion molecule., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Uterine and ovarian carcinosarcomas (CS) are rare but highly aggressive gynecologic tumors which carry an extremely poor prognosis. We evaluated the expression levels of EpCAM and the in vitro activity of solitomab, a bispecific single-chain antibody construct which targets epithelial-cell-adhesion-molecule (EpCAM) on tumor cells and also contains a CD3 binding region, against primary uterine and ovarian CS cell lines., Methods: EpCAM expression was evaluated by flow cytometry in a total of 5 primary CS cell lines. Sensitivity to solitomab-dependent-cellular-cytotoxicity (ADCC) was tested against the panel of primary CS cell lines expressing different levels of EpCAM in standard 4 h (51)Cr release-assays. The proliferative activity, activation, cytokine secretion (i.e., Type I vs Type II) and cytotoxicity of solitomab in autologous tumor-associated-T cells (TAL) in the pleural fluid of a CS patient were also evaluated by CFSE and flow-cytometry assays., Results: Surface expression of EpCAM was found in 80.0 % (4 out of 5) of the CS cell lines tested by flow cytometry. EpCAM positive cell lines were found resistant to NK or T-cell-mediated killing after exposure to peripheral blood lymphocytes (PBL) in 4-h chromium-release assays (mean killing ± SEM = 1.1 ± 1.6 %, range 0-5.3 % after incubation of EpCAM positive cell lines with control BiTE®). In contrast, after incubation with solitomab, EpCAM positive CS cells became highly sensitive to T-cell-cytotoxicity (mean killing ± SEM of 19.7 ± 6.3 %; range 10.0-32.0 %; P < 0.0001). Ex vivo incubation of autologous TAL with EpCAM expressing malignant cells in pleural effusion with solitomab, resulted in a significant increase in T-cell proliferation in both CD4+ and CD8+ T cells, increase in T-cell activation markers (i.e., CD25 and HLA-DR), and a reduction in number of viable CS cells in the exudate (P < 0.001)., Conclusions: Solitomab may represent an effective treatment for patients with recurrent/metastatic and/or chemo-resistant CS overexpressing EpCAM.

Objectives: We evaluated the role of PIK3CA-mutations as mechanism of resistance to trastuzumab in primary HER2/neu-amplified uterine-serous-carcinoma (USC) cell lines., Methods: Fifteen whole-exome-sequenced USC cell lines were tested for HER2/neu-amplification and PIK3CA-mutations. Four HER2/neu-amplified USC (2-harbouring wild-type-PIK3CA-genes and 2-harbouring oncogenic-PIK3CA-mutations) were evaluated in in vitro dose-titration-proliferation-assays, cell-viability and HER2 and S6-protein-phosphorylation after exposure to trastuzumab. USC harbouring wild-type-PIK3CA were transfected with plasmids encoding oncogenic PIK3CA-mutations (i.e., H1047R/R93Q) and exposed to trastuzumab. Finally, trastuzumab efficacy was tested by using two USC xenograft mouse models., Results: Seven out of fifteen (46%) of the USC cell lines were HER2/neu-amplified by fluorescence in situ hybridisation. Within these tumours four out of seven (57%) were found to harbour oncogenic PIK3CA-mutations vs two out of eight (25%) of the HER2/neu not amplified cell lines (P=0.01). HER2/neu-amplified/PIK3CA-mutated USC were highly resistant to trastuzumab when compared with HER2/neu-amplified/wild-type-PIK3CA cell lines (P=0.02). HER2/neu-amplified/PIK3CA wild-type cell lines transfected with oncogenic PIK3CA-mutations increased their resistance to trastuzumab (P<0.0001). Trastuzumab was effective in reducing tumour growth (P=0.001) and improved survival (P=0.0001) in mouse xenografts harbouring HER2-amplified/PIK3CA wild-type USC but not in HER2-amplified/PIK3CA-mutated tumours., Conclusions: Oncogenic PIK3CA mutations are common in HER2/neu-amplified USC and may constitute a major mechanism of resistance to trastuzumab treatment.

Ovarian and uterine carcinosarcoma (CS) are characterized by their aggressive clinical behavior and poor prognosis. We evaluated the efficacy of trastuzumab-emtansine (T-DM1), against primary HER2 positive and HER2 negative CS cell lines in vitro and in vivo. Eight primary CS cell lines were evaluated for HER2 amplification and protein expression by fluorescence in situ hybridization, immunohistochemistry, flow cytometry and qRT-PCR. Sensitivity to T-DM1-induced antibody-dependent-cell-mediated-cytotoxicity (ADCC) was evaluated in 4-h-chromium-release-assays. T-DM1 cytostatic and apoptotic activities were evaluated using flow cytometry based proliferation assays. In vivo activity of T-DM1 was also evaluated. HER2 protein overexpression and gene amplification were detected in 25 % (2/8) of the primary CS cell lines. T-DM1 and T were similarly effective in inducing strong ADCC against CS overexpressing HER2 at 3+ levels. In contrast, T-DM1 was dramatically more effective than T in inhibiting cell proliferation (P < 0.0001) and in inducing G2/M phase cell cycle arrest in the HER2 expressing cell lines (shift of G2/M: mean ± SEM from 14.87 ± 1.23 to 66.57 ± 4.56 %, P < 0.0001). Importantly, T-DM1 was highly active at reducing tumor formation in vivo in CS xenografts overexpressing HER2 (P = 0.0001 and P < 0.0001 compared to T and vehicle respectively) with a significantly longer survival when compared to T and vehicle mice (P = 0.008 and P = 0.0001 respectively). T-DM1 may represent a novel treatment option for the subset of HER2 positive CS patients with disease refractory to chemotherapy.

Objective: To evaluate the efficacy of taselisib, a selective inhibitor of PIK3CA, against primary uterine serous carcinomas (USC) harboring PIK3CA mutations and HER2/neu gene amplification., Methods: Sensitivity to taselisib was evaluated by flow-cytometry viability assays in vitro against nine primary USC cell lines. Cell cycle distribution and downstream signaling were assessed by measuring the DNA content of cells and by phosphorylation of the S6 protein by flow-cytometry. Preclinical efficacy of taselisib was also evaluated in vivo in a mouse model., Results: Four USC cell lines harbored HER2/neu gene amplification by FISH and two of them harbored oncogenic PIK3CA mutations. Taselisib caused a strong differential growth inhibition in both HER2/neu FISH positive and HER2/neu FISH positive/PIK3CA mutated USC cell lines when compared to lines that were FISH negative and PIK3CA wild type (taselisib IC50 mean±SEM=0.042±0.006μM in FISH+ versus 0.38±0.06μM in FISH-tumors, P<0.0001). Taselisib growth-inhibition was associated with a significant and dose-dependent increase in the percentage of cells in the G0/G1 phase of the cell cycle and dose-dependent decline in the phosphorylation of S6. Taselisib was highly active at reducing tumor growth in vivo in USC mouse xenografts harboring PIK3CA mutation and overexpressing HER2/neu (P=0.007). Mice treated with taselisib had significantly longer survival when compared to control mice (P<0.0001)., Conclusions: Taselisib represents a novel therapeutic option in patients harboring PIK3CA mutations and/or HER2/neu gene amplification., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Amplification of c-erbB2 has been reported in over 30% of uterine serous carcinoma (USC) and found to confer poor survival because of high proliferation and increased resistance to therapy. In this study, we evaluated for the first time Trastuzumab emtansine (T-DM1), a novel antibody-drug conjugate, against multiple epidermal growth factor receptor-2 (HER2)-positive USC cells in vitro followed by developing a supportive in vivo model. Fifteen primary USC cell lines were assessed by immunohistochemistry (IHC) and flow cytometry for HER2 protein expression. C-erbB2 gene amplification was evaluated using fluorescent in situ hybridization. Sensitivity to T-DM1 and trastuzumab (T)-induced antibody-dependent cell-mediated cytotoxicity was evaluated in 5-h chromium release assays. T-DM1 and T cytostatic and apoptotic activities were evaluated using flow-cytometry-based proliferation assays. In vivo activity of T-DM1 versus T in USC xenografts in SCID mice was also evaluated. High levels of HER2 protein overexpression and HER2 gene amplification were detected in 33% of USC cell lines. T-DM1 was considerably more effective than trastuzumab in inhibiting cell proliferation and in causing apoptosis (P = 0.004) of USC showing HER2 overexpression. Importantly, T-DM1 was highly active at reducing tumor formation in vivo in USC xenografts overexpressing HER2 (P = 0.04) and mice treated with TDM-1 had significantly longer survival when compared to T-treated mice and control mice (P ≤ 0.0001). T-DM1 shows promising antitumor effect in HER2-positive USC cell lines and USC xenografts and its activity is significantly higher when compared to T. T-DM1 may represent a novel treatment option for HER2-positive USC patients with disease refractory to trastuzumab and traditional chemotherapy., (© 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Uterine serous carcinoma (USC) is a highly aggressive variant of endometrial cancer. Although it only represents less than 10% of all cases, it accounts for a disproportionate number of deaths from endometrial cancer. Comprehensive surgical staging followed by carboplatin and paclitaxel chemotherapy represents the mainstay of USC therapy. Vaginal cuff brachytherapy is also of potential benefit in USC. Recent whole-exome sequencing studies have demonstrated gain of function of the HER2/NEU gene, as well as driver mutations in the PIK3CA/AKT/mTOR and cyclin E/FBXW7 oncogenic pathways in a large number of USCs. These results emphasize the relevance of these novel therapeutic targets for biologic therapy of chemotherapy-resistant recurrent USC.

Objective: To evaluate PIK3CA mutational status and c-erbB2 gene amplification in a series of primary uterine serous carcinomas (USC) cell lines. To assess the efficacy of GDC-0980, a potent inhibitor of Class I PI3 kinase and mTOR kinase (TORC1/2), against primary USC harboring HER2/neu gene amplification and/or PIK3CA mutations., Study Design: Twenty-two primary USC cell lines were evaluated for c-erbB2 oncogene amplification by fluorescence in situ hybridization (FISH) assays and for PIK3CA gene mutations by direct DNA sequencing of exons 9 and 20. In vitro sensitivity to GDC-0980 was evaluated by flow-cytometry-based viability and proliferation assays. Downstream cellular responses to GDC-0980 were assessed by measuring phosphorylation of the 4-EBP1 protein by flow-cytometry., Results: Five of 22 (22.7%) USC cell lines contained oncogenic PIK3CA mutations although 9 (40.9%) harbored c-erbB2 gene amplification by FISH. GDC-0980 caused a strong differential growth inhibition in FISH+ USC when compared with FISH- (GDC-0980 IC50 mean ± SEM = 0.29 ± 0.05 μM in FISH+ vs 1.09 ± 0.20 μM in FISH- tumors, P = .02). FISH+ USC harboring PIK3CA mutations were significantly more sensitive to GDC-0980 exposure when compared with USC cell lines harboring wild-type PIK3CA (P = .03). GDC-0980 growth-inhibition was associated with a significant and dose-dependent decline in phosphorylated 4-EBP1 levels., Conclusion: Oncogenic PIK3CA mutations and c-erbB2 gene amplification may represent biomarkers to identify patients harboring USC who may benefit most from the use of GDC-0980., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Objective: Clear cell carcinoma of the ovary is a distinct subtype of epithelial cancer associated with chemoresistance and poor outcome compared with serous papillary carcinomas. Resistance to paclitaxel has been linked to serous papillary overexpression of class III β-tubulin in several human cancers but inadequately characterized among clear cell carcinoma of the ovary. Chemoresistance has also been variably linked to the drug efflux pump p-glycoprotein. Epothilones are microtubule-stabilizing agents with putative activity in paclitaxel-resistant malignancies. In this study, we clarify the relationship between class III β-tubulin and p-glycoprotein expression in clear cell carcinoma of the ovary, clinical outcome, and in vitro responsiveness to patupilone and paclitaxel., Study Design: Class III β-tubulin and p-glycoprotein were quantified by real time polymerase chain reaction in 61 fresh-frozen tissue samples and 11 cell lines. Expression by polymerase chain reaction was correlated with immunohistochemistry and overall survival. IC50 was determined using viability/metabolic assays. Impact of class III β-tubulin down-regulation on IC50 was assessed with small interfering RNAs., Results: Clear cell carcinoma of the ovary overexpressed class III β-tubulin and p-glycoprotein relative to serous papillary carcinomas carcinomas in fresh-frozen tissues and cell lines. Class III β-tubulin immunohistochemistry reflected real time polymerase chain reaction results and overexpression stratified patients by overall survival. P-glycoprotein correlated with in vitro paclitaxel resistance, but not clinical outcome. Clear cell carcinoma of the ovary were exquisitely sensitive to patupilone in a manner that correlated with class III β-tubulin expression., Conclusion: Class III β-tubulin overexpression in clear cell carcinoma of the ovary discriminates poor prognosis, serves as a marker for sensitivity to patupilone, and may contribute to paclitaxel resistance. Immunohistochemistry reliably identifies tumors with overexpression of class III β-tubulin, and accordingly a subset of individuals likely to respond to patupilone., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Objective: To compare the in vitro sensitivity/resistance to patupilone versus paclitaxel in uterine and ovarian carcinosarcomas (CS)., Methods: Five primary carcinosarcoma cell lines, two from uterine and three of ovarian origin, were evaluated for growth rate and tested for their in vitro sensitivity/resistance to patupilone versus paclitaxel by MTS assays. To identify potential mechanisms underlying the differential sensitivity/resistance to patupilone, expression levels of β-tubulin III (TUBB3) were determined with quantitative-real-time-polymerase-chain-reaction (q-RT-PCR) in primary uterine and ovarian CS cell lines and in 26 uterine and 9 ovarian CS fresh-frozen-tissues., Results: No appreciable difference in sensitivity to patupilone versus paclitaxel was noted in ovarian CS cell lines, or when uterine and ovarian CS cell lines were compared in their response to paclitaxel. In contrast, uterine CS cell lines were found to be significantly more sensitive to patupilone than to paclitaxel (P<0.002) and demostrated lower IC(50s) to patupilone (range 0.76-0.93nM) when compared to ovarian CS (range 1.9-3.4 nM, p<0.05). Higher levels of TUBB3 were detected in uterine CS cell lines and fresh frozen tissues when compared to ovarian CS (P<0.05)., Conclusions: Uterine CS cell lines are significantly more sensitive than ovarian CS cell lines to patupilone versus paclitaxel. High expression of TUBB3 is associated with sensitivity to patupilone in primary CS cell lines and may act as a genetic marker to predict chemotherapy efficacy. Patupilone may represent a promising drug in the treatment of this subset of rare but highly aggressive gynecological tumors., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: The Gynecologic Oncology Group (GOG) conducted a phase II trial to assess the efficacy and tolerability of the anti-EGFR antibody cetuximab, in persistent or recurrent carcinoma of the cervix., Patients and Methods: Eligible patients had cervical cancer, measurable disease, and GOG performance status ≤2. Treatment consisted of cetuximab 400 mg/m(2) initial dose followed by 250 mg/m(2) weekly until disease progression or prohibitive toxicity. The primary endpoints were progression-free survival (PFS) at 6 months and response. The study used a 2-stage group sequential design., Results: Thirty-eight patients were entered with 3 exclusions, leaving 35 evaluable for analysis. Thirty-one patients (88.6%) received prior radiation as well as either 1 (n=25, 71.4%) or 2 (n=10) prior cytotoxic regimens. Twenty-four patients (68.6%) had a squamous cell carcinoma. Grade 3 adverse events possibly related to cetuximab included dermatologic (n=5), GI (n=4), anemia (n=2), constitutional (n=3), infection (n=2), vascular (n=2), pain (n=2), and pulmonary, neurological, vomiting and metabolic (n=1 each). No clinical responses were detected. Five patients (14.3%; two-sided 90% CI, 5.8% to 30%) survived without progression for at least 6 months. The median PFS and overall survival (OS) times were 1.97 and 6.7 months, respectively. In this study, all patients with PFS at 6 months harbored tumors with squamous cell histology., Conclusion: Cetuximab is well tolerated but has limited activity in this population. Cetuximab activity may be limited to patients with squamous cell histology., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: To compare the in vitro sensitivity/resistance to patupilone versus paclitaxel in uterine serous papillary carcinoma (USPC) with high versus low HER-2/neu expression., Methods: Six primary USPC cell lines, half of which overexpress HER-2/neu at a 3+ level, were evaluated for growth rate and tested for their in vitro sensitivity/resistance to patupilone versus paclitaxel by MTS assays. Quantitative RT-PCR was used to identify potential mechanisms underlying the differential sensitivity/resistance to patupilone versus paclitaxel in primary USPC cell lines., Results: Cell lines overexpressing HER-2/neu showed higher proliferation when compared to low HER-2/neu-expressing cell lines. Compared to low-expressing cell lines, high HER-2/neu expressors were significantly more sensitive to patupilone than to paclitaxel (P<0.0002). In contrast, there was no appreciable difference in sensitivity to patupilone versus paclitaxel in primary USPC cell lines with low HER-2/neu expression. Higher levels of β-tubulin III (TUBB3) and P-glycoprotein (ABCB1) were detected in USPC cell lines with high versus low HER-2/neu expression (P<0.05)., Conclusions: USPC overexpressing HER-2/neu display greater in vitro sensitivity to patupilone and higher levels of the patupilone molecular target TUBB3 when compared to low HER-2/neu expressors. Due to the adverse prognosis associated with HER-2/neu overexpression in USPC patients, patupilone may represent a promising novel drug to combine to platinum compounds in this subset of aggressive endometrial tumors., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Objective: To study the effect of trastuzumab in patients with progressive or recurrent metastatic endometrial carcinoma shown by immunohistochemistry to overexpress the HER2/neu receptor., Methods: Disease progression was examined in 2 patients who met the study criteria, had c-erbB2 gene amplification by fluorescence in situ hybridization, and were treated with trastuzumab following radiation treatment and/or salvage chemotherapy., Results: The clinical responses to trastuzumab as a single agent or in combination with chemotherapy were confirmed in both patients by serial CT scans and serum CA-125 evaluations. These patients with progressive or recurrent metastatic disease experienced relief from their symptoms and prolonged survival with no significant toxicity observed., Conclusion: Trastuzumab may be a viable therapeutic option as single agent or in combination with chemotherapy in patients with advanced, recurrent, and/or metastatic endometrial carcinomas overexpressing HER2/neu.

Tumor cells from five freshly isolated ovarian tumors and four established human ovarian carcinoma cell lines were analyzed for the production of the immunoinhibitory cytokine transforming growth factor-beta (TGF-beta) before and after exposure to gamma irradiation and/or the cytokines TNF-alpha plus IFN-gamma. All fresh tumors secreted high levels of TGF-beta when compared to the levels produced by the established ovarian carcinoma cell lines. TGF-beta produced by fresh tumors was significantly reduced after high doses of gamma irradiation (10,000 cGy). In contrast with the established cell lines, irradiation significantly increased TGF-beta secretion. Exposure of fresh tumor cells to cytokines followed by irradiation caused significant reduction of TGF-beta released when compared to the amount released after exposure to cytokines only. However, in the established cell lines, cytokines followed by irradiation again significantly increased TGF-beta production. These data indicate that high doses of irradiation in fresh ovarian tumors, unlike established ovarian carcinoma cell lines, can significantly reduce the local production of this potent immunoinhibitory cytokine. This effect could work to further amplify weak immunological responses within the tumor. In addition, these findings indicate major differences between fresh tumor samples and established cell lines and warn against the sole use of continuous cell lines as models for tumors growing in vivo.

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. They enable delivery of cytotoxic therapy more directly to tumor cells and minimize delivery to healthy tissues. This review summarizes the existing literature about ADC therapies approved for use in gynecologic malignancies, relevant preclinical studies, as well as ongoing clinical trials. [ABSTRACT FROM AUTHOR]

The prognosis of patients with metastatic cervical cancer is poor with a median survival of 8–13 months. Despite the potency of chemotherapeutic drugs, this treatment is rarely curative and should be considered palliative only. In the last few years, a better understanding of Human papillomavirus tumor-host immune system interactions and the development of new therapeutics targeting immune check points have renewed interest in the use of immunotherapy in cervical cancer patients. Moreover, next generation sequencing has emerged as an attractive option for the identification of actionable driver mutations and other markers. In this review, we provide background information on the molecular biology of cervical cancer and summarize immunotherapy studies, targeted therapies, including those with angiogenesis inhibitors and tyrosine kinase inhibitors recently completed or currently on-going in cervical cancer patients. [ABSTRACT FROM PUBLISHER]

Simple Summary: Microtubule-interfering drugs have been used alone or in combination in the treatment of epithelial ovarian cancer. Over the years and with increasing chemoresistance to taxanes, epothilones (i.e., ixabepilone) have become of interest as alternatives to taxanes. In this review, we discuss the role of microtubule-interfering chemotherapeutic agents in treatment of newly diagnosed and recurrent ovarian cancer, as well as common mechanisms of chemoresistance. We also discuss future directions for the use of microtubule-interfering agents in ovarian cancer. Taxanes and epothilones are chemotherapeutic agents that ultimately lead to cell death through inhibition of normal microtubular function. This review summarizes the literature demonstrating their current use and potential promise as therapeutic agents in the treatment of epithelial ovarian cancer (EOC), as well as putative mechanisms of resistance. Historically, taxanes have become the standard of care in the front-line and recurrent treatment of epithelial ovarian cancer. In the past few years, epothilones (i.e., ixabepilone) have become of interest as they may retain activity in taxane-treated patients since they harbor several features that may overcome mechanisms of taxane resistance. Clinical data now support the use of ixabepilone in the treatment of platinum-resistant or refractory ovarian cancer. Clinical data strongly support the use of microtubule-interfering drugs alone or in combination in the treatment of epithelial ovarian cancer. Ongoing clinical trials will shed further light into the potential of making these drugs part of current standard practice. [ABSTRACT FROM AUTHOR]

Objective: We sought to identify effective chemotherapy regimens against uterine serous papillary adenocarcinoma (USPC). Study Design: Six USPC, half of which overexpress HER-2/neu at 3+ level, were evaluated for growth rate and in vitro sensitivity to 14 single-agent chemotherapies and 5 combinations by ChemoFx (Precision Therapeutics Inc, Pittsburgh, PA). Results: Cell lines overexpressing HER-2/neu showed higher proliferation when compared to low HER-2/neu-expressing cell lines and a lower half maximum inhibitory concentration (IC50) when exposed to the majority of single-agent chemotherapies. High HER-2/neu expressors were more sensitive to platinum compounds, manifesting a 5.22-fold decrease in carboplatin-IC50 (P = .005) and a 5.37-fold decrease in cisplatin-IC50 (P = .02). When all cell lines were analyzed as a group, chemotherapy agents tested demonstrated lower IC50 when used in combination than as individual agents. Conclusion: USPC overexpressing HER-2/neu display greater in vitro sensitivity to platinum compounds when compared to low HER-2/neu expressors. Higher proliferative capability rather than increased drug resistance may be responsible for the adverse prognosis associated with HER-2/neu overexpression in USPC. [Copyright &y& Elsevier]

Background: Standard therapy for advanced endometrial cancer after failure of platinum-based chemotherapy remains unclear.Methods: In this phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with advanced endometrial cancer who had previously received at least one platinum-based chemotherapy regimen to receive either lenvatinib (20 mg, administered orally once daily) plus pembrolizumab (200 mg, administered intravenously every 3 weeks) or chemotherapy of the treating physician's choice (doxorubicin at 60 mg per square meter of body-surface area, administered intravenously every 3 weeks, or paclitaxel at 80 mg per square meter, administered intravenously weekly [with a cycle of 3 weeks on and 1 week off]). The two primary end points were progression-free survival as assessed on blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1, and overall survival. The end points were evaluated in patients with mismatch repair-proficient (pMMR) disease and in all patients. Safety was also assessed.Results: A total of 827 patients (697 with pMMR disease and 130 with mismatch repair-deficient disease) were randomly assigned to receive lenvatinib plus pembrolizumab (411 patients) or chemotherapy (416 patients). The median progression-free survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 6.6 vs. 3.8 months; hazard ratio for progression or death, 0.60; 95% confidence interval [CI], 0.50 to 0.72; P<0.001; overall: 7.2 vs. 3.8 months; hazard ratio, 0.56; 95% CI, 0.47 to 0.66; P<0.001). The median overall survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 17.4 vs. 12.0 months; hazard ratio for death, 0.68; 95% CI, 0.56 to 0.84; P<0.001; overall: 18.3 vs. 11.4 months; hazard ratio, 0.62; 95% CI, 0.51 to 0.75; P<0.001). Adverse events of grade 3 or higher occurred in 88.9% of the patients who received lenvatinib plus pembrolizumab and in 72.7% of those who received chemotherapy.Conclusions: Lenvatinib plus pembrolizumab led to significantly longer progression-free survival and overall survival than chemotherapy among patients with advanced endometrial cancer. (Funded by Eisai and Merck Sharp and Dohme [a subsidiary of Merck]; Study 309-KEYNOTE-775 ClinicalTrials.gov number, NCT03517449.). [ABSTRACT FROM AUTHOR]

Background Epithelial ovarian cancer (EOC) is an aggressive and heterogeneous disease. < 10% of EOC demonstrate HER2/neu 3 + receptor over-expression. However, moderate to low (i.e., 2 + and 1 +) HER2/neu expression is reported in up to 50% of EOC. The objective of this study was to compare the anti-tumor activity of SYD985, a novel HER2-targeting antibody-drug conjugate (ADC), to trastuzumab emtansine (T-DM1) in EOC models with differential HER2/neu expression. Methods The cytotoxicity of SYD985 and T-DM1 was evaluated using ten primary EOC cell lines with 0/1 +, 2 +, and 3 + HER2/neu expression in antibody-dependent cellular cytotoxicity (ADCC), proliferation, viability and bystander killing experiments. Finally, the in vivo activity of SYD985 and T-DM1 was also studied in ovarian cancer xenografts. Results SYD985 and T-DM1 induced similar ADCC in the presence of peripheral blood lymphocytes (PBL) against EOC cell lines with differential HER2/neu expression. In contrast, SYD985 was 3 to 42 fold more cytotoxic in the absence of PBL when compared to T-DM1 ( p < 0.0001). Unlike T-DM1, SYD985 induced efficient bystander killing of HER2/neu 0/1 + tumor cells when admixed with HER2/neu 3 + EOC cells. In vivo studies confirmed that SYD985 is significantly more active than T-DM1 against HER2/neu 3 + EOC xenografts. Conclusions SYD985 is a novel ADC with remarkable activity against EOC with strong (3 +) as well as moderate to low (i.e., 2 + and 1 +) HER2/neu expression. SYD985 is more potent than T-DM1 in comparative experiments and unlike T-DM1, it is active against EOC demonstrating moderate/low or heterogeneous HER2/neu expression. [ABSTRACT FROM AUTHOR]

Objectives: Carcinosarcomas (CSs) are highly aggressive gynecologic malignancies containing both carcinomatous and sarcomatous elements with heterogeneous HER2/neu expression. We evaluated the preclinical in vitro and in vivo activity of trastuzumab deruxtecan (DS-8201a), a novel HER2/neu-targeting antibody-drug conjugate (ADC) against primary uterine and ovarian CSs overexpressing HER2/neu. Methods: Twelve primary uterine and ovarian CS cell lines were evaluated for HER2/neu surface expression by immunohistochemistry (IHC) and by flow cytometry, and gene amplification by 13cytotoxicity, viability, and bystander killing effect assays. In vivo activity was studied in mouse CS xenograft models. Results: DS-8201a, as compared to MAAA-9199 control ADC, was found to be highly effective against uterine and ovarian CS cell lines demonstrating 3+ HER2/neu expression. Specifically, the mean half-maximal inhibitory concentrations (IC50's) were 0.02931 μg/mL and 9.75 μg/mL (p<0.0001) against 3+ HER2/neu uterine cell line, and 0.0285 μg/mL and 20.9 μg/mL (p<0.0001) against 3+ ovarian HER2/neu cell lines for DS-8201a versus MAAA-9199, respectively. There was no significant difference between DS-8201a and MAAA-9199 against CS cell lines with low/negligible HER2/neu expression. Importantly, DS-8201a induced an efficient bystander killing effect of HER2/neu negative tumor cells when admixed with 3+ HER2/neu cells. In vivo studies confirmed that DS-8201a was significantly more effective than MAAA-9199 in decreasing tumor volume and prolonging life in 3+ HER2/neu-expressing CS xenografts (attached Figure). There was no significant toxicity demonstrated between treatment and control groups. Conclusions: Trastuzumab deruxtecan (DS-8201a) is a novel ADC with remarkable activity against CS with strong (3+) HER2/neu expression. Clinical studies with DS-8201a in patients harboring chemotherapy-resistant CS with high HER2/neu expression are warranted. DS-8201a showing significant tumor growth inhibition in 3+ HER2/neu expression mice. Day 8 mean tumor volumes in treated mice with DS-8201a (0.271 cm3) versus ADC isotope control (0.859 cm3, p = 0.0011) and vehicle control (0.804 cm3, p = 0.0047). Day 11 mean tumor volumes in treated mice with DS-8201a (0.179 cm3) versus ADC isotope control (1.166 cm3, p <0.0001) and vehicle control (1.151 cm3, p <0.0001). [Display omitted] [ABSTRACT FROM AUTHOR]