Investigator
Yale University
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.
Reproducibility of scoring criteria for HER2 immunohistochemistry in endometrial serous carcinoma: a multi-institutional interobserver agreement study
Targeted anti-human epidermal growth factor receptor 2 (HER2) therapy has recently been proven to improve progression-free and overall survival of patients with advanced stage or recurrent endometrial serous carcinoma. To date, no specific pathology HER2 testing or scoring guidelines exist for endometrial cancer. However, based on evidence from the recent successful clinical trial and comprehensive pre-trial pathologic studies, a new set of HER2 scoring criteria have been proposed for endometrial serous carcinoma-distinct from the existing breast and gastric cancer-specific criteria. We present the first study assessing interobserver agreement of HER2 scores using the proposed serous endometrial cancer-specific scoring system. A digitally scanned set of 40 HER2-immunostained slides of endometrial serous carcinoma were sent to seven gynecologic pathologists, who independently assigned HER2 scores for each slide following a brief tutorial. Follow-up fluorescent in situ hybridization (FISH) for HER2 gene amplification was performed on cases with interobserver disagreement when a 2+ HER2 score was assigned by at least one observer. Complete agreement of HER2 scores among all 7 observers was achieved on 15 cases, and all but one case had an agreement by at least 4 observers. The overall agreement was 72.3% (kappa 0.60), 77.5% (kappa 0.65), and 83.3% (kappa 0.65), using four (0 to 3+ ), three (0/1+ , 2+ , 3+ ), or two (0/1+ , 2/3+ ) HER2 scoring categories, respectively. Based on the combination of HER2 immunostaining scores and FISH, the interobserver disagreement may have potentially resulted in a clinically significant difference in HER2 status only in three tumors. We conclude, that the proposed serous endometrial cancer-specific HER2 scoring criteria are reproducible among gynecologic pathologists with moderate to substantial interobserver agreement rates comparable to those of previously reported in breast and gastric carcinomas. Our findings significantly strengthen the foundation for establishing endometrial cancer-specific HER2 scoring guidelines in the future.
Integrated mutational landscape analysis of endometrial stromal sarcoma
Endometrial stromal sarcoma (ESS) is a rare uterine malignancy with limited treatment options. We performed integrated whole-genome, whole-exome, and transcriptome sequencing on 80 ESS tumors, comprising 32 low-grade (LG) and 48 high-grade (HG) tumors, to characterize their genetic landscape. The overall mutation burden was modest, with no significant difference between grades; however, we identified six hypermutated cases (7.5%) harboring POLE or mismatch repair mutations, genomic features predictive of immunotherapy response. We identified focal RAD54B amplifications in 15 tumors (18.8%), leading to elevated RAD54B expression and significantly shorter survival. This establishes RAD54B as an oncogenic driver in ESS. Known tumor suppressors (PTEN, TP53) were frequently mutated in HG-ESS but rare in LG-ESS, highlighting distinct grade-specific drivers of malignancy. HG-ESS exhibited widespread chromosomal gains, frequent loss of cell-cycle regulators (RB1, CDKN2A), and numerous private gene fusions arising from complex DNA rearrangements. In contrast, LG-ESS were defined by canonical fusions (e.g., JAZF1–SUZ12 ) and co-occurring deletions in metabolic regulator genes (TSC2, STK11). Finally, in an activating NRAS-mutant (p.Q61R) HG-ESS xenograft, the combination of MEK and FAK inhibition dramatically suppressed tumor growth and prolonged survival, highlighting a promising targeted treatment strategy. Overall, our comprehensive analysis defines the molecular basis of ESS and provides a strong preclinical rationale for precision therapies in this aggressive cancer.
Randomised phase II trial of weekly ixabepilone ± biweekly bevacizumab for platinum-resistant or refractory ovarian/fallopian tube/primary peritoneal cancer
Abstract Background This multi-center RP2 study assessed activity/safety of ixabepilone + bevacizumab compared to ixabepilone in platinum-resistant/refractory ovarian/fallopian tube/primary peritoneal cancer. Additional objectives were to examine the role of prior bevacizumab and taxanes, and explore class III-ß-tubulin (TUBB3) as a predictive biomarker. Methods Participants were randomised to receive ixabepilone 20 mg/m 2 days 1, 8, 15 with (IXA + BEV) or without (IXA) bevacizumab 10 mg/kg days 1, 15 every 28 days. Patients were stratified by prior BEV. The primary endpoint was PFS. OS, safety, and ORR served as secondary endpoints. Results Among 76 evaluable patients who received IXA + BEV ( n = 39) compared to IXA ( n = 37), the ORR was 33% ( n = 13) versus 8% ( n = 3)( P = 0.004), durable at 6 months in 37% ( n = 14) and 3% ( n = 1) ( P < 0.001). BEV significantly improved PFS (median:5.5 vs 2.2 months, HR = 0.33, 95%CI 0.19–0.55, P < 0.001) and OS (median:10.0 vs 6.0 months, HR = 0.52, 95%CI 0.31–0.87, P = 0.006). Both regimens were well-tolerated. TUBB3 expression did not predict response. Subgroup analyses revealed minimal effect of prior BEV or taxane resistant/refractory status on response to IXA + BEV. Conclusions IXA + BEV is a well-tolerated, effective combination for platinum/taxane-resistant ovarian cancer that extends PFS and likely OS relative to IXA monotherapy. Prior receipt of BEV should not preclude the use of IXA + BEV. TUBB3 is not a predictive biomarker. Clinical trial registration NCT3093155.
Diandric triploid partial mole versus digynic nonmolar triploidy: is morphological assessment sufficient for the diagnostic distinction?
AimsDiagnostic separation of diandric triploid gestation, i.e. partial mole from digynic triploid gestation, is clinically relevant, as the former may progress to postmolar gestational trophoblastic neoplasia. The aim of the study was to investigate if the combination of abnormal histology combined with ploidy analysis‐based triploidy is sufficient to accurately diagnose partial mole.Methods and ResultsA genotype–phenotype correlation study was undertaken to reappraise histological parameters among 20 diandric triploid gestations and 22 digynic triploid gestations of comparable patient age, gestational weeks, and clinical presentations. Two villous populations, irregular villous contours, pseudoinclusions, and syncytiotrophoblast knuckles, were common in both groups. Villous size ≥2.5 mm, cistern formation, trophoblastic hyperplasia, and syncytiotrophoblast lacunae were significantly more common in the partial hydatidiform mole. Cistern formation had the highest positive predictive value (PPV) (93%) and highest specificity (96%) for diandric triploid gestation, although the sensitivity was 70%. Cistern formation combined with villous size ≥2.5 mm or trophoblast hyperplasia or syncytiotrophoblast lacunae had 100% specificity and PPV, but a marginal sensitivity of 60%–65%. A moderate interobserver agreement (Kappa = 0.57, Gwet's AC1 = 0.59) was achieved among four observers who assigned diagnosis of diandric triploid gestation or digynic triploidy solely based on histology.ConclusionsNone of histological parameters are unique to either diandric triploid gestation or digynic triploid gestation. Cistern formation is the most powerful discriminator, with 93% PPV and 70% sensitivity for diandric triploid gestation. While cistern formation combined with either trophoblastic hyperplasia or villous size ≥2.5 mm or syncytiotrophoblast lacunae has 100% PPV and specificity for diandric triploid gestation, the sensitivity is only 60% to 65%. Therefore, in the presence of triploidy, histological assessment is unable to precisely classify 35% to 40% of diandric triploid gestations or partial moles.
Integrated mutational landscape analysis of poorly differentiated high-grade neuroendocrine carcinoma of the uterine cervix
High-grade neuroendocrine cervical cancers (NETc) are exceedingly rare, highly aggressive tumors. We analyzed 64 NETc tumor samples by whole-exome sequencing (WES). Human papillomavirus DNA was detected in 65.6% (42/64) of the tumors. Recurrent mutations were identified in PIK3CA, KMT2D/MLL2, K-RAS, ARID1A, NOTCH2, and RPL10. The top mutated genes included RB1, ARID1A, PTEN, KMT2D / MLL2, and WDFY3, a gene not yet implicated in NETc. Somatic CNV analysis identified two copy number gains (3q27.1 and 19q13.12) and five copy number losses (1p36.21/5q31.3/6p22.2/9q21.11/11p15.5). Also, gene fusions affecting the ACLY-CRHR1 and PVT1-MYC genes were identified in one of the eight samples subjected to RNA sequencing. To resolve evolutionary history, multiregion WES in NETc admixed with adenocarcinoma cells was performed (i.e., mixed-NETc). Phylogenetic analysis of mixed-NETc demonstrated that adenocarcinoma and neuroendocrine elements derive from a common precursor with mutations typical of adenocarcinomas. Over one-third (22/64) of NETc demonstrated a mutator phenotype of C > T at CpG consistent with deficiencies in MBD4 , a member of the base excision repair (BER) pathway. Mutations in the PI3K/AMPK pathways were identified in 49/64 samples. We used two patient-derived-xenografts (PDX) (i.e., NET19 and NET21) to evaluate the activity of pan-HER (afatinib), PIK3CA (copanlisib), and ATR (elimusertib) inhibitors, alone and in combination. PDXs harboring alterations in the ERBB2/PI3K/AKT/mTOR/ATR pathway were sensitive to afatinib, copanlisib, and elimusertib ( P < 0.001 vs. controls). However, combinations of copanlisib/afatinib and copanlisib/elimusertib were significantly more effective in controlling NETc tumor growth. These findings define the genetic landscape of NETc and suggest that a large subset of these highly lethal malignancies might benefit from existing targeted therapies.
Randomized Phase II Trial of Imiquimod with or without 9-Valent HPV Vaccine versus Observation in Patients with High-grade Pre-neoplastic Cervical Lesions (NCT02864147)
Abstract Purpose: We report the results of a randomized phase II trial of imiquimod, a topical immune-response modulator versus imiquimod plus a 9-valent human papillomavirus (HPV) vaccine (9vHPV) versus clinical surveillance in cervical intraepithelial neoplasia (CIN2/3) patients. Patients and Methods: We randomly allocated 133 patients with untreated CIN2/3 in equal proportions to a 4-month treatment with self-applied vaginal suppositories containing imiquimod (Arm B) or imiquimod plus a 9vHPV (Arm C) versus clinical surveillance (Arm A). The main outcome was efficacy, defined as histologic regression to CIN1 or less. Secondary outcomes were HPV clearance and tolerability. Exploratory objectives included the comparison of cervical CD4/CD8 T-cell infiltration at baseline, mid-study, and posttreatment by flow cytometry among study arms. Results: Of the 114 evaluable patients 77% and 23% harbored CIN2 and CIN3, respectively. Regression to CIN1 or less was observed in 95% of patients in the imiquimod group (Arm B) compared with 79% in the control/surveillance (Arm A); P = 0.043 and 84% in the imiquimod+9vHPV group (Arm C; P = 0.384 vs. Arm A). Neither of the treatment-arm differences from Arm A reached the prespecified α = 0.025 significance level. No significant differences were noted in the secondary outcome of rate of HPV clearance. The number of tissue-resident memory CD4/CD8 T cells in cytobrush samples demonstrated a &gt;5-fold increase in Arm B/imiquimod when compared with Arm A/surveillance (P &lt; 0.01). In contrast, there was no significant difference in T-cell responses among participants in Arm C when compared with Arm A. Imiquimod treatment was well tolerated. Conclusions: Although imiquimod induced a higher regression to CIN1 or less and significant increases in CD4/CD8 T cells infiltrating the cervix, it did not meet its prespecified statistical outcome for efficacy. A higher regression rate than expected was observed in the surveillance arm of this prospective trial. Future clinical trials with imiquimod targeting CIN3 patients are warranted.
Extrauterine epithelioid trophoblastic tumour and its somatic carcinoma mimics: short tandem repeat genotyping meets the diagnostic challenges
AimsWhile epithelioid trophoblastic tumour (ETT) primarily arises from the uterus, cases have been increasingly documented at extrauterine sites, originating from an ectopic gestation or presenting as a metastatic tumour, leading to the major differential diagnosis of somatic carcinoma with trophoblastic differentiation. The precise separation of a gestational trophoblastic tumour from its somatic carcinoma mimics is highly relevant and crucial for patient management and prognosis.Methods and resultsWe summarise the clinicopathological and molecular features of four challenging epithelioid malignancies presenting at extrauterine sites, with ETT as the main differential diagnosis. All four tumours demonstrated histological and immunohistochemical features overlapping between a somatic carcinoma and an ETT, combined with inconclusive clinical and imaging findings. Serum beta‐hCG elevation was documented in two cases. Short tandem repeat (STR) genotyping was performed and was informative in all cases. The presence of a unique paternal allelic pattern in the tumour tissue confirmed the diagnosis of ETT in two cases with an initial consideration of either somatic carcinoma or suspicion of a gestational trophoblastic tumour. The presence of matching genetic profile with the patient's paired normal tissue was seen in two other cases (both initially considered as ETT), confirming their somatic origin, including one metastatic triple‐negative breast carcinoma and one primary lung carcinoma.ConclusionsDiagnostic separation of ETT at an extrauterine site from its somatic carcinoma mimics can be difficult at the histological and immunohistochemical levels. STR genotyping offers a robust ancillary tool that precisely separates ETT from somatic carcinomas with trophoblastic differentiation.
Evaluation of Weekly Ixabepilone With or Without Biweekly Bevacizumab
This is a randomized, two-arm, open-label Phase II multicenter study designed to examine the effects of adding bevacizumab to ixabepilone for the treatment of patients who have recurrent or persistent platinum-resistant/refractory epithelial (non-mucinous) ovarian, fallopian tube, or primary peritoneal cancer. Its primary objective is to assess whether adding bevacizumab to ixabepilone improves progression-free survival in its target population. Study participants will be stratified by (a) study site and (b) previous receipt of bevacizumab prior to randomization.
