Luca Palmieri

Preclinical Activity of Datopotamab Deruxtecan (Dato-DXd), an Antibody–Drug Conjugate Targeting TROP2, in Poorly Differentiated Endometrial Carcinomas

Abstract Datopotamab deruxtecan (Dato-DXd) is a novel antibody–drug conjugate (ADC) targeting trophoblast antigen-2 (TROP2), a cell surface glycoprotein highly expressed in many epithelial tumors, to deliver DXd, a potent topoisomerase I inhibitor. We evaluated TROP2 expression in primary endometrial cancer cell lines and the activity of Dato-DXd against endometrial cancer cell lines with different TROP2 expression in vitro and in vivo. TROP2 expression was assessed in nine primary tumor cell lines by flow cytometry. Cell viability after exposure to Dato-DXd was evaluated using flow cytometry–based assays to calculate the IC50. Bystander effect assay assessed the viability of TROP2-negative cells when cocultured with high TROP2-expressing cells. Fluorescent anti–phosphorylated histone H2AX antibody was used to demonstrate double-strand DNA breaks. Antibody-dependent cell cytotoxicity was tested in vitro using 4-hour chromium release assays. In vivo activity of Dato-DXd was evaluated against TROP2-positive endometrial cancer xenografts. A total of 78% (seven of nine) of the primary endometrial cancer cell lines expressed TROP2. Endometrial cancer cell lines expressing TROP2 were significantly more sensitive to Dato-DXd compared with control ADC. Dato-DXd–exposed, TROP2-positive endometrial cancer demonstrated increased double-strand DNA breaks compared with non-binding conjugate exposure. Dato-DXd mediated antibody-dependent cell cytotoxicity against TROP2-positive cell lines and induced significant bystander killing of TROP2-negative tumors when admixed with TROP2-positive tumors. In vivo, injection of Dato-DXd was well tolerated and demonstrated impressive tumor growth inhibition against chemotherapy-resistant poorly differentiated endometrial cancer xenografts (P < 0.0001). In conclusion, Dato-DXd is a novel ADC with remarkable preclinical activity against poorly differentiated endometrial cancer cell lines overexpressing TROP2. Clinical trials with Dato-DXd in patients with recurrent endometrial cancer are warranted. Significance: Targeted treatment of aggressive forms of endometrial cancer using the biomarker TROP2 is a significant opportunity for the development of treatments when patients are resistant to other lines of treatment. Here, we present data showing preclinical evidence of effectiveness of this biomarker-targeted therapy in endometrial cancer.

Preclinical activity of sacituzumab govitecan in TROP2-positive low-grade serous ovarian cancer patient-derived xenograft models

Low-grade serous ovarian cancer is a rare epithelial ovarian cancer subtype characterized by high resistance to chemotherapy and an indolent disease course. The development of novel, effective, targeted treatments for recurrent, chemotherapy-resistant low-grade serous ovarian cancer remains an unmet medical need. We evaluated trophoblast cell-surface antigen 2 (TROP2) expression in a cohort of patients with low-grade serous ovarian cancer and assessed the preclinical activity of sacituzumab govitecan, an antibody-drug conjugate targeting TROP2, in vivo using a patient-derived xenograft (PDX) model. TROP2 expression was evaluated in 26 patients with low-grade serous ovarian cancer using immunohistochemistry. The efficacy of sacituzumab govitecan was assessed in vivo in severe combined immunodeficiency mice using a TROP2-positive low-grade serous ovarian cancer PDX model established from a patient with disease resistant to chemotherapy, aromatase inhibitors, and MEK inhibitors. TROP2 expression was observed in all low-grade serous ovarian cancer cases, with 21 of 26 (81%) samples demonstrating moderate to strong expression. In vivo studies in mice demonstrated that sacituzumab govitecan significantly inhibited tumor growth in a chemotherapy-, aromatase inhibitor-, and MEK inhibitor-resistant low-grade serous ovarian cancer PDX model compared to control animals treated with vehicle/saline (p < .0001). Median survival for control mice was 25 days, while it was not reached by the end of the experiment (day 50) in animals treated with sacituzumab govitecan. TROP2 is a novel biomarker highly expressed in low-grade serous ovarian cancer. Sacituzumab govitecan may represent a potentially effective new treatment option for patients with low-grade serous ovarian cancer progressing after standard treatment modalities. Further clinical trials in low-grade serous ovarian cancer treated with sacituzumab govitecan are warranted.

Folate receptor alpha as a successful biomarker in the treatment of low-grade serous ovarian cancer patients using preclinical and clinical models

Low-grade serous ovarian cancer is a rare epithelial ovarian cancer subtype characterized by high resistance to chemotherapy. Development of novel, effective, targeted treatments for recurrent low-grade serous ovarian cancer remains an unmet medical need. We evaluated FOLR1 expression in a cohort of low-grade serous ovarian cancer patients and the preclinical and clinical activity of mirvetuximab soravtansine, an antibody-drug conjugate targeting FOLR1, in vivo in a patient-derived xenograft model and in a heavily pretreated low-grade serous ovarian cancer patient progressing after chemotherapy, aromatase inhibitor, and MEK inhibitor treatment. FOLR1 expression was evaluated in 27 low-grade serous ovarian cancer patients using immunohistochemistry. The efficacy of mirvetuximab soravtansine was assessed in vivo in a low-grade serous ovarian cancer patient-derived xenograft model in severe combined immunodeficient mice, as well as in a patient harboring a recurrent low-grade serous ovarian cancer resistant to standard treatment modalities. FOLR1 expression was detected in all 27 (100%) low-grade serous ovarian cancer cases, with 21 of 27 (78%) of the samples demonstrating 2+/3+ in ≥75% of tumor cells. In vivo studies in mice demonstrated that mirvetuximab soravtansine inhibited tumor growth and prolonged survival in a low-grade serous ovarian cancer patient-derived xenograft model derived from a patient progressing after chemotherapy/aromatase inhibitor/MEK inhibitor. Clinical evidence further supported the therapeutic activity of mirvetuximab soravtansine in a FOLR1-positive low-grade serous ovarian cancer patient, as indicated by a prolonged partial response after 8 months of treatment. FOLR1 is overexpressed in a large percentage of low-grade serous ovarian cancers. Mirvetuximab soravtansine may represent a novel treatment option for low-grade serous ovarian cancer patients progressing after standard treatment modalities. Clinical trials with mirvetuximab soravtansine in FOLR1-positive low-grade serous ovarian cancers are warranted.

Back to the future: The impact of oestrogen receptor profile in the era of molecular endometrial cancer classification

The aim of this study is to evaluate the impact of the oestrogen receptor (ER) profile on oncologic outcomes in the new endometrial cancer (EC) risk classification. Immunohistochemistry (IHC) analyses were performed in a retrospectively reviewed large series of ECs to assess the presence/absence of oestrogen receptors (ER0\1+ or ER2+\3+) and other molecular factors (i.e. p53 mutation, p53mut; and mismatch repair mutational status, MMRd (mismatch repair deficient) versus MMRp (mismatch repair proficient)), histopathologic and clinical outcomes. ER status was correlated with molecular, histologic, clinical and prognostic data. 891 EC patients were included in the study (211 ER0\1+ and 680 ER2+\3+). The ER0\1+ phenotype was associated with an unfavourable clinicopathological profile (i.e. grading, histotype, lymphovascular space invasion (LVSI), stages, etc.). Simple regression showed that risk class, p53mut, and ER0/1+ impacted on both disease-free survival (DFS) and overall survival (OS) (p  0.05). In multiple regression, age, high and advanced/metastatic risk classes influenced survival outcomes (p  0.05). ER-positivity retained a remarkable prognostic impact even after stratification of the population according to the European Society of Gynaecological Oncology, the European Society for Radiotherapy and Oncology, and the European Society of Pathology (ESGO/ESTRO/ESP) 2021 risk classes and molecular classification. ER0/1+ intermediate, high-intermediate, high and advanced risk versus ER2+/3+ intermediate, high-intermediate, high and advanced risk classes showed statistically different OS and DFS (p< 0.001). ER0/1+ status was associated with a worse prognosis when associated with MMRp, MMRd and p53mut compared to the same molecular classes associated with ER2+/3 (p < 0.001). We demonstrated that ER status has a significant impact on oncologic outcomes, regardless of risk class and p53/MMR status. Based on our results, we recommend the inclusion of ER assessment in featured EC risk classification system.

Preclinical Efficacy of the Estrogen Receptor Degrader Fulvestrant in Combination with RAF/MEK Clamp Avutometinib and FAK Inhibitor in a Low-Grade Serous Ovarian Cancer Animal Model with Acquired Resistance to Chemotherapy and Aromatase Inhibitor

Low-grade-serous ovarian carcinomas (LGSOC) are rare tumors characterized by a high recurrence rate and limited treatment options. Most LGSOC are estrogen receptor (ER)-positive and demonstrate alterations in the RAS/MAPK pathway. Avutometinib is a dual RAF/MEK clamp, whereas defactinib and VS-4718 are focal adhesion kinase (FAK) inhibitors. Fulvestrant is an ER antagonist/degrader. We assessed the preclinical efficacy of fulvestrant, avutometinib + VS-4718 (FAKi), and the triple combination in a chemotherapy/aromatase inhibitor-resistant LGSOC patient-derived tumor xenograft (PDX) model. Tissue obtained from a LGSOC patient wild-type for KRAS/NRAS/BRAF mutations in progression after chemotherapy/anastrozole was transplanted into female CB17/lcrHsd-Prkdc/SCID mice (PDX-OVA(K)250). The animals were treated with either saline/control, fulvestrant, avutometinib/FAKi, or the triple combination of avutometinib/FAKi/fulvestrant. Avutometinib and FAKi were given five-days on and two-days off through oral gavage. Fulvestrant was administered subcutaneously weekly. Mechanistic studies were performed ex vivo using Western blot assays. Animals treated with the triple combination demonstrated stronger tumor growth inhibition compared to all the other experimental groups including control/saline (p &lt; 0.001), single-agent fulvestrant (p = 0.04 from day eight and onwards), and avutometinib/FAKi (p = 0.02 from day 18). Median survival for mice treated with saline/control was 29 days while mice in all other experimental groups were alive at day 60 (p &lt; 0.0001). Treatment was well tolerated across all experimental treatments. By Western blot, exposure of OVA(K)250 to the triple combination demonstrated a decrease in phosphorylated MEK (p-MEK) and p-ERK levels. The addition of fulvestrant to avutometinib/FAKi is well tolerated in vivo and enhances the antitumor activity of avutometinib/FAKi in a LGSOC-PDX model with acquired resistance to chemotherapy/aromatase inhibitors. These results support the clinical evaluation of avutometinib/defactinib in combination with fulvestrant or an aromatase inhibitor in patients with recurrent LGSOC.

HER2/neu as a Signaling and Therapeutic Marker in Uterine Serous Carcinoma

Research into aggressive gynecologic cancers such as uterine serous carcinoma (USC) has recently evolved from chemotherapy to the development of drugs targeting specific biomarkers differentially expressed/active in tumor cells. One such target is HER2/neu, which plays an important role in the coordination of cell growth and differentiation. Importantly, when overexpressed and/or amplified in tumor cells, the downstream tyrosine kinase of HER2/neu becomes constitutively activated, causing dysregulated gene transcription. In breast cancer patients, HER2/neu has been successfully utilized for many years as a target for multiple monoclonal antibodies and more recently antibody–drug conjugates (ADCs). Use in gynecologic malignancies has been slower, however, due to recently identified unique characteristics of HER2/neu protein expression and gene amplification in biologically aggressive tumors such as USC including its major heterogeneity and lack of apical staining when compared to breast cancer. Accordingly, the use of optimal testing algorithms for HER2/neu status in patients with USC may have important implications for the development of novel, effective, and targeted treatment modalities against this lethal variant of endometrial cancer. In this review, we discuss HER2/neu gene expression in USC, evaluate the efficacy of HER2/neu-directed therapies in both preclinical and clinical settings, and discuss possible mechanisms of resistance to HER2/neu targeting agents.

Robotic approach for the treatment of gynecological cancers recurrences: A ten-year single-institution experience.

Although the management of gynecological cancers recurrences may be challenging, due to the heterogeneity of recurrent disease, the aim of this work is to present a descriptive analysis of gynecological malignancies recurrences in our institution treated by robotic approach. We performed a retrospective review and analysis of data of patients who underwent robotic surgery for recurrent gynecological malignancies at Catholic University of the Sacred Hearth, Rome, from January 2013 to January 2024. A total of 54 patients underwent successful robotic cytoreductive surgery. The median age was 63 years; the median BMI was 33 kg/m Robotic approach in the treatment of recurrent gynecological cancers should be considered in selected patients with oligometastatic disease, in high-volume centers with expert surgeons, particularly in obese patients.