Ingrid Boere

Epigenetic and Genomic Hallmarks of PARP-Inhibitor Resistance in Ovarian Cancer Patients

Background: Patients with advanced-stage epithelial ovarian cancer (EOC) receive treatment with a poly-ADP ribose-polymerase (PARP) inhibitor (PARPi) as maintenance therapy after surgery and chemotherapy. Unfortunately, many patients experience disease progression because of acquired therapy resistance. This study aims to characterize epigenetic and genomic changes in cell-free DNA (cfDNA) associated with PARPi resistance. Materials and Methods: Blood was taken from 31 EOC patients receiving PARPi therapy before treatment and at disease progression during/after treatment. Resistance was defined as disease progression within 6 months after starting PARPi and was seen in fifteen patients, while sixteen patients responded for 6 to 42 months. Blood cfDNA was evaluated via Modified Fast Aneuploidy Screening Test-Sequencing System (mFast-SeqS to detect aneuploidy, via Methylated DNA Sequencing (MeD-seq) to find differentially methylated regions (DMRs), and via shallow whole-genome and -exome sequencing (shWGS, exome-seq) to define tumor fractions and mutational signatures. Results: Aneuploid cfDNA was undetectable pre-treatment but observed in six patients post-treatment, in five resistant and one responding patient. Post-treatment ichorCNA analyses demonstrated in shWGS and exome-seq higher median tumor fractions in resistant (7% and 9%) than in sensitive patients (7% and 5%). SigMiner analyses detected predominantly mutational signatures linked to mismatch repair and chemotherapy. DeSeq2 analyses of MeD-seq data revealed three methylation signatures and more tumor-specific DMRs in resistant than in responding patients in both pre- and post-treatment samples (274 vs. 30 DMRs, 190 vs. 57 DMRs, Χ2-test p < 0.001). Conclusion: Our genome-wide Next-Generation Sequencing (NGS) analyses in PARPi-resistant patients identified epigenetic differences in blood before treatment, whereas genomic alterations were more frequently observed after progression. The epigenetic differences at baseline are especially interesting for further exploration as putative predictive biomarkers for PARPi resistance.

Genome-wide cell-free DNA methylation profiling in advanced stage ovarian cancer. Are we looking at the tumor or the patient's immune response to the tumor?

The aim of this study was to identify differentially methylated regions in cell-free DNA (cfDNA) between healthy persons and patients with advanced stage ovarian cancer (ASOC) and to identify differences in cfDNA methylation before and after cytoreductive surgery. Plasma-derived cfDNA was analyzed by a high-throughput genome wide DNA methylation sequencing technique: MeD-seq. A training set of therapy naïve cfDNA samples of patients with ASOC (≥FIGO stage IIIB, n=10) was compared with cfDNA of healthy controls (n=10) to define a ASOC specific cfDNA methylation signature. A cumulative hypermethylation score was constructed and a validation set of pre- and postoperative samples of 39 patients were compared using this score. MeD-seq results of tumor tissue samples were correlated with cfDNA results. Patients with ASOC showed a clear distinct cfDNA methylation signature from healthy controls (p<0.0001). This cfDNA-methylation signature resulted in preoperative hypermethylation scores (135; interquartile range 110-163) that were significantly higher than postoperative hypermethylation scores (91; interquartile range 76-101) (p<0.001). The cfDNA methylation signature at baseline differed from tumor tissue and was more closely related to DNA methylation of immune-related cells (T-lymphocytes, neutrophil granulocytes, monocytes, and B-lymphocytes) than to ASOC tissue. MeD-seq provides a promising method for genome wide methylation profiling of cfDNA. Patients with ASOC could clearly be distinguished from healthy controls and differed pre- and postoperatively.

RECIST 1.1 versus clinico-radiological response assessment for locally advanced cervical cancer: implications on interpreting survival outcomes of future trials

To investigate differences in standard clinico-radiological evaluation versus Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for reporting survival outcomes in patients with locally advanced cervical cancer treated with chemoradiation and brachytherapy. Between November 2017 and March 2020, patients recruited in cervical cancer trials were identified. MRI at diagnosis and at least one follow-up imaging was mandatory. Disease-free survival and progression-free survival were determined using standard evaluation (clinical examination and symptom-directed imaging) and RECIST 1.1. Agreement between criteria was estimated using κ value. Sensitivity analysis was done to test the sensitivity, specificity, and accuracy of RECIST 1.1 in detecting response to treatment. Sixty-nine eligible patients had at least one target lesion. Thirty-three patients (47.8%) had pathological lymph nodes. Of these 33 patients, RECIST 1.1 classified only 18% (6/33) as 'target nodal lesions' and the remaining nodes as 'non-target'. There were 6 (8.7%) and 8 (11.6%) patients with disease events using RECIST 1.1 and standard evaluation, respectively. The disease-free survival at 12, 18, and 24 months using RECIST 1.1 was 94.2%, 91.2%, 91.2%, and with standard evaluation was 94.2%, 89.7%, and 88.2%, respectively (p=0.58). Whereas, progression-free survival at 12, 18, and 24 months using RECIST 1.1 and standard evaluation were same (94.2%, 91.2%, and 91.2%, respectively). The κ value was 0.84, showing strong agreement in assessing disease-free survival, although an absolute difference of 3% between endpoint assessment methodologies. RECIST 1.1 had a sensitivity of 75% (95% CI 34.91% to 96.81%), specificity of 100% (95% CI 94.13% to 100%), and accuracy of 97.1% (95% CI 89.92% to 99.65%). The study showed 1.5% and 3% difference in disease-free survival at 18 and 24 months and no difference in progression-free survival between RECIST 1.1 and standard evaluation in a patient cohort with low event rate.

CINOVA: a phase II study of CPC634 (nanoparticulate docetaxel) in patients with platinum resistant recurrent ovarian cancer

Recurrent platinum-resistant ovarian cancer has a poor prognosis with limited therapeutic options. Sub-therapeutic intra-tumoral drug concentrations may add to therapy resistance. CPC634 (docetaxel entrapped in CriPec nanoparticles) was designed to enhance tumor accumulation of drug with localized drug release at the target site to increase therapeutic efficacy. This study investigated the therapeutic effect of CPC634 in patients with platinum-resistant ovarian cancer. According to a Simon 2-stage design trial, the first stage included 13 patients, and 12 patients were enrolled in the second stage. Eligible patients had measurable disease and had progressed ≤6 months after the last platinum-based therapy. Platinum-refractory disease was excluded. In stage 1, the number of previous treatment lines was unlimited; in the second stage, a maximum of two prior lines altogether were allowed. The primary endpoint was the objective response rate by Response Evaluation Criteria in Solid Tumor (RECIST) V1.1. Secondary endpoints included safety, progression-free survival at 6 months, cancer antigen 125 (CA125) response, and disease control rate. The patients' median age was 66 years (range 22-77) and most were International Federation of Gynecology and Obstetrics (FIGO) stage III (56%). The median number of previous treatment lines was 3 (range 3-5) in stage I and 2 (range 1-4) in stage II of the study. None of the patients had an objective response, one patient had a CA125 response (5%), and seven patients had stable disease at first evaluation (35%). Median progression-free survival was 1.4 months in stage 1 and 3.0 months in stage 2. Adverse events (all grades) were mainly gastrointestinal in 24 patients (96%), fatigue in 11 (44%), dyspnea in 10 (40%), and infections in 10 (40%) of patients. Grade 3 or higher adverse events occurred in 14 patients (36%), including gastrointestinal in 4 (16%), anemia in 3 (12%), and febrile neutropenia, fatigue, chronic kidney disease, dehydration, and hypertension each in 1 (4%) patient. The trial was stopped prematurely due to futility. Treatment with CPC634 was feasible, but without apparent clinical activity in patients with recurrent platinum-resistant ovarian cancer. Side effects were mainly gastrointestinal in 24 (96%) patients, including nausea, vomiting, and decreased appetite, fatigue, anemia, and dyspnea.

TP53 Mutations in Serum Circulating Cell-Free Tumor DNA As Longitudinal Biomarker for High-Grade Serous Ovarian Cancer

The aim of this study was to determine an optimal workflow to detect TP53 mutations in baseline and longitudinal serum cell free DNA (cfDNA) from high-grade serous ovarian carcinomas (HGSOC) patients and to define whether TP53 mutations are suitable as biomarker for disease. TP53 was investigated in tissue and archived serum from 20 HGSOC patients by a next-generation sequencing (NGS) workflow alone or combined with digital PCR (dPCR). AmpliSeq™-focused NGS panels and customized dPCR assays were used for tissue DNA and longitudinal cfDNAs, and Oncomine NGS panel with molecular barcoding was used for baseline cfDNAs. TP53 missense mutations were observed in 17 tissue specimens and in baseline cfDNA for 4/8 patients by AmpliSeq, 6/9 patients by Oncomine, and 4/6 patients by dPCR. Mutations in cfDNA were detected in 4/6 patients with residual disease and 3/4 patients with disease progression within six months, compared to 5/11 patients with no residual disease and 6/13 patients with progression after six months. Finally, mutations were detected at progression in 5/6 patients, but not during chemotherapy. NGS with molecular barcoding and dPCR were most optimal workflows to detect TP53 mutations in baseline and longitudinal serum cfDNA, respectively. TP53 mutations were undetectable in cfDNA during treatment but re-appeared at disease progression, illustrating its promise as a biomarker for disease monitoring.

Tisotumab Vedotin in Combination With Carboplatin, Pembrolizumab, or Bevacizumab in Recurrent or Metastatic Cervical Cancer: Results From the innovaTV 205/GOG-3024/ENGOT-cx8 Study

PURPOSE Tissue factor is highly expressed in cervical carcinoma and can be targeted by tisotumab vedotin (TV), an antibody-drug conjugate. This phase Ib/II study evaluated TV in combination with bevacizumab, pembrolizumab, or carboplatin for recurrent or metastatic cervical cancer (r/mCC). METHODS This open-label, multicenter study (ClinicalTrials.gov identifier: NCT03786081 ) included dose-escalation arms that assessed dose-limiting toxicities (DLTs) and identified the recommended phase II dose (RP2D) of TV in combination with bevacizumab (arm A), pembrolizumab (arm B), or carboplatin (arm C). The dose-expansion arms evaluated TV antitumor activity and safety at RP2D in combination with carboplatin as first-line (1L) treatment (arm D) or with pembrolizumab as 1L (arm E) or second-/third-line (2L/3L) treatment (arm F). The primary end point of dose expansion was objective response rate (ORR). RESULTS A total of 142 patients were enrolled. In dose escalation (n = 41), no DLTs were observed; the RP2D was TV 2 mg/kg plus bevacizumab 15 mg/kg on day 1 once every 3 weeks, pembrolizumab 200 mg on day 1 once every 3 weeks, or carboplatin AUC 5 on day 1 once every 3 weeks. In dose expansion (n = 101), the ORR was 54.5% (n/N, 18/33; 95% CI, 36.4 to 71.9) with 1L TV + carboplatin (arm D), 40.6% (n/N, 13/32; 95% CI, 23.7 to 59.4) with 1L TV + pembrolizumab (arm E), and 35.3% (12/34; 19.7 to 53.5) with 2L/3L TV + pembrolizumab (arm F). The median duration of response was 8.6 months, not reached, and 14.1 months, in arms D, E, and F, respectively. Grade ≥3 adverse events (≥15%) were anemia, diarrhea, nausea, and thrombocytopenia in arm D and anemia in arm F (none ≥15%, arm E). CONCLUSION TV in combination with bevacizumab, carboplatin, or pembrolizumab demonstrated manageable safety and encouraging antitumor activity in treatment-naive and previously treated r/mCC.

Emerging Radiopharmaceuticals Beyond FDG for Ovarian Cancer: A Review of Advances in Nuclear Medicine

ABSTRACT Aims This review summarizes the role and future prospects of nuclear medicine in ovarian cancer, focusing on novel radiopharmaceuticals beyond FDG for diagnostic, predictive, and therapeutic applications within a theranostic framework. Materials and Methods A narrative literature review was conducted using major databases. Peer‐reviewed articles addressing non‐FDG radiopharmaceuticals in ovarian cancer were identified and assessed; FDG‐based studies were excluded due to the availability of prior comprehensive reviews. Results Novel radiopharmaceuticals show potential to enhance diagnostic accuracy, allow early evaluation of treatment response, predict chemotherapy resistance, and support stratification for targeted therapies. Several tracers are under investigation for theranostic use, offering combined diagnostic and therapeutic benefits. Discussion Incorporating novel radiopharmaceuticals into ovarian cancer management may help overcome limitations of conventional imaging and systemic therapy. Theranostic strategies, uniting molecular imaging with radionuclide therapy, represent a promising step toward personalized medicine and could significantly influence clinical outcomes. Conclusion Nuclear medicine, through innovative radiopharmaceuticals and theranostic approaches beyond FDG, is expected to expand its role in ovarian cancer care. Further research is needed to validate these applications and facilitate their integration into clinical practice.

Changes in bone marrow fat fraction and immune cell counts in women with cervical cancer treated with primary chemoradiotherapy

Hematologic toxicity (HT) is a common effect of chemoradiotherapy in primary locally advanced cervical cancer (LACC) and related to bone marrow (BM) fat increase. However, longitudinal effects and dose-relationships are unknown. In this study, pre- and post-treatment BM fat fraction and blood immune cell counts were evaluated in women with primary LACC undergoing BM sparing chemoradiotherapy. Water-fat MRI scans and blood samples were obtained at baseline, during, and at 3 and 12 months (post-)treatment. The mean proton density fat fraction (PDFF) [%] was calculated for each vertebra, categorized into a no (5 Gy) dose group, and the pelvic bones. Associations between PDFF and dose, immune cells, and patient characteristics were assessed with linear mixed models. Eighteen women were included. Vertebral PDFF in the no dose group remained unchanged, whereas the low and high dose group showed an increase of 24-35 PDFF% during treatment. PDFF in the low dose group recovered slightly but remained elevated up to 12 months post-treatment. Mean dose to pelvic subregions was ≥ 18.8 Gy and PDFF increase was 12-29 PDFF%. Only the lower pelvic PDFF recovered to baseline. Blood immune cell decline lasted up to 12 months post-treatment and was correlated with higher mean vertebral PDFF. Vertebral fat fraction increased during treatment for dose > 1 Gy, without post-treatment recovery for dose > 5 Gy. Immunosuppression persisted up to 12 months post-treatment and was related to a higher mean vertebral PDFF. 5 Gy might be relevant for BM damage, but this threshold should be validated.

Safety and Efficacy of Tisotumab Vedotin Monotherapy & in Combination With Other Cancer Agents in Subjects With Cervical Cancer

This is an open label, multi-center trial of tisotumab vedotin monotherapy and in combination with bevacizumab, pembrolizumab, or carboplatin in subjects with recurrent or stage IVB cervical cancer. The trial consists of two-parts a dose escalation part and an expansion part. The expansion part of the trial will be initiated once the Recommended Phase 2 Dose (RP2D) of the combinations have been determined in the dose escalation part.