Evolving treatment paradigms for platinum-resistant ovarian cancer: An update narrative review.

Platinum-resistant ovarian cancer (PROC) refers to disease progression within 6 months after the completion of platinum-based chemotherapy. Historically, treatment options for PROC were limited with a poor prognosis and non-platinum single agent plus bevacizumab has been the mainstay of treatment. Fortunately, there have been notable advancements in recent years, leading to an advance in treatment paradigms for this challenging disease. Various combinations of chemotherapy, targeted agents such as poly (ADP-ribose) polymerase (PARP) inhibitors, and immunotherapy are being explored for an improved treatment outcome. Antibody-drug conjugates targeting folate receptor alpha, which deliver a cytotoxic payload directly to cancer cells, have emerged as a promising therapeutic approach for PROC. WEE1 inhibitors, such as adavosertib, function by inhibiting the WEE1 kinase activity, leading to premature entry of a cell into mitosis phase and thus increased DNA damage. It has been observed that cancer cells with TP53 mutations may be more sensitive to WEE1 inhibitors. Biomarker testing such as analysis of the expression level of folate receptor alpha or mutation in TP53 may be applicable for identifying patients who are more likely to respond to the specific therapy, enabling a more personalized treatment approach. This overview summarizes key clinical findings on the efficacy and safety of theses novel biomarker-driven therapeutic approaches.

Mirvetuximab after anaphylaxis to Paclitaxel: A case report.

Introduction: Patients with platinum resistant epithelial ovarian cancer have limited treatment options which are further limited by hypersensitivity reactions to first line medications such as paclitaxel. Paclitaxel is a taxane that inhibits microtubules and has a high incidence of hypersensitivity reactions. Mirvetuximab soravtansine-gynx (MIRV) is a folate receptor alpha (FRα) directed antibody and microtubule inhibitor that is approved for patients with FRα positive platinum resistant recurrent epithelial ovarian cancer. Both medications are microtubule-targeting agents with similar binding sites, therefore a theoretical risk of cross reactivity between paclitaxel and MIRV may exist. Additionally, phase II clinical trial, SORAYA, did not include data on patients with prior hypersensitivity to paclitaxel. Case: This is the case of a 33-year-old female with recurrent stage IIIC epithelial ovarian cancer with a history of severe anaphylaxis to paclitaxel. She was deemed eligible for MIRV after progression on multiple regimens, but MIRV was given with caution given her severe reaction history. With proper pre-treatment and monitoring, she was treated with MIRV without a reaction. Discussion: It is suspected that most paclitaxel reactions are due to the cremophor solvent rather than paclitaxel itself; however, cross reactivity with docetaxel which is suspended in a polysorbate solution can also occur. Therefore, there is no clear way to determine the risk of cross reactivity between paclitaxel and similar medications. MIRV is also suspended in polysorbate and has a similar mechanism to taxanes, therefore it was unknown if a patient with a prior grade 5 reaction to paclitaxel would also have a reaction to MIRV. Though this is one case, patients with a history of severe hypersensitivity to paclitaxel and meet the criteria for MIRV could be treated with MIRV with careful monitoring.

The efficacy, safety, and beneficiary population of angiogenesis inhibitor apatinib plus chemotherapy in recurrent platinum-resistant ovarian cancer patients: A comparative cohort study.

AIM: Angiogenesis inhibitor apatinib targets vascular endothelial growth factor receptors and improves the outcomes of patients with gynecologic malignancy. This study aimed to evaluate the efficacy and safety of angiogenesis inhibitor apatinib plus chemotherapy in recurrent platinum-resistant ovarian cancer (RPR-OC) patients. METHODS: This study retrieved 67 RPR-OC patients who received apatinib plus chemotherapy or chemotherapy alone and divided them into apatinib + chemo (N = 30) and chemo alone (N = 37) groups according to the actual medication. RESULTS: Objective response rate (36.7% vs. 16.2%, p = 0.056) and disease control rate (80.0% vs. 59.5%, p = 0.072) showed an increased trend in apatinib + chemo group versus chemo alone group. The progression-free survival (PFS) (p = 0.010) and overall survival (OS) (p = 0.042) were prolonged in apatinib + chemo group versus chemo alone group. The median (95%confidence interval [CI]) PFS was 5.9 (5.5-6.3) months in apatinib + chemo group and 3.8 (2.0-5.6) months in chemo alone group. The median (95%CI) OS was 20.5 (16.5-24.5) months in apatinib + chemo group and 13.6 (8.6-18.6) months in chemo alone group. Apatinib plus chemotherapy was independently related with better PFS (hazard ratio [HR]: 0.354, p < 0.001) and OS (HR: 0.116, p < 0.001). Subgroup analyses indicated that patients with a more serious disease condition might benefit more from apatinib plus chemotherapy. No difference was found in adverse events of all grade or grade ≥3 between the two groups (all p > 0.05). CONCLUSION: Angiogenesis inhibitor apatinib plus chemotherapy shows better treatment efficacy than chemotherapy alone with controllable safety profile in RPR-OC patients.

FT-Raman and FTIR spectroscopy as a tools showing marker of platinum-resistant phenomena in women suffering from ovarian cancer.

Platinum-resistant phenomena in ovarian cancer is very dangerous for women suffering from this disease, because reduces the chances of complete recovery. Unfortunately, until now there are no methods to verify whether a woman with ovarian cancer is platinum-resistant. Importantly, histopathology images also were not shown differences in the ovarian cancer between platinum-resistant and platinum-sensitive tissues. Therefore, in this study, Fourier Transform InfraRed (FTIR) and FT-Raman spectroscopy techniques were used to find chemical differences between platinum-resistant and platinum-sensitive ovarian cancer tissues. Furthermore, Principal Component Analysis (PCA) and machine learning methods were performed to show if it possible to differentiate these two kind of tissues as well as to propose spectroscopy marker of platinum-resistant. Indeed, obtained results showed, that in platinum-resistant ovarian cancer tissues higher amount of phospholipids, proteins and lipids were visible, however when the ratio between intensities of peaks at 1637 cm-1 (FTIR) and at 2944 cm-1 (Raman) and every peaks in spectra was calculated, difference between groups of samples were not noticed. Moreover, structural changes visible as a shift of peaks were noticed for C-O-C, C-H bending and amide II bonds. PCA clearly showed, that PC1 can be used to differentiate platinum-resistant and platinum-sensitive ovarian cancer tissues, while two-trace two-dimensional correlation spectra (2T2D-COS) showed, that only in amide II, amide I and asymmetric CH lipids vibrations correlation between two analyzed types of tissues were noticed. Finally, machine learning algorithms showed, that values of accuracy, sensitivity and specificity were near to 100% for FTIR and around 95% for FT-Raman spectroscopy. Using decision tree peaks at 1777 cm-1, 2974 cm-1 (FTIR) and 1714 cm-1, 2817 cm-1 (FT-Raman) were proposed as spectroscopy marker of platinum-resistant.

Case report: Response to everolimus in a patient with platinum resistant, high grade serous ovarian carcinoma with biallelic TSC2 inactivation.

Background: Patients with platinum-resistant recurrent high grade serous ovarian carcinoma have poor outcomes and limited treatment options. Case presentation: We present a case of a 48-year-old woman with platinum-resistant high grade serous ovarian carcinoma harboring the pathogenic TSC2 R611Q variant with concomitant single copy loss of TSC2 (suggesting biallelic TSC2 inactivation) identified in targeted tumor sequencing. The patient was treated with the mTOR inhibitor everolimus, with an excellent response by imaging and a marked decrease in CA125; she remained on everolimus for 19 months until she developed progressive disease. Conclusions: While mTOR inhibition is frequently used in tumors associated with tuberous sclerosis complex (TSC), such as lymphangioleiomyomatosis and malignant perivascular epithelioid cell tumors, this is the first case of a patient with ovarian cancer harboring TSC1/2 mutations who responded to mTOR inhibition. This case highlights the utility of targeted DNA sequencing in the management of ovarian carcinoma and demonstrates the value of tumor-agnostic targeted therapies.

Durvalumab with or without tremelimumab plus chemotherapy in HRR non-mutated, platinum-resistant ovarian cancer (KGOG 3045): A phase II umbrella trial.

AIM: We investigated the efficacy and safety of durvalumab (D) with or without tremelimumab (T) in addition to single-agent chemotherapy (CT) in patients with platinum-resistant recurrent ovarian cancer (PROC) lacking homologous recombination repair (HRR) gene mutations. PATIENTS AND METHODS: KGOG 3045 was an open-label, investigator-initiated phase II umbrella trial. Patients with PROC without HRR gene mutations who had received ≥2 prior lines of therapy were enrolled. Patients with high PD-L1 expression (TPS ≥25%) were assigned to arm A (D + CT), whereas those with low PD-L1 expression were assigned to arm B (D + T75 + CT). After completing arm B recruitment, patients were sequentially assigned to arms C (D + T300 + CT) and D (D + CT). RESULTS: Overall, 58 patients were enrolled (5, 18, 17, and 18 patients in arms A, B, C, and D, respectively). The objective response rates were 20.0, 33.3, 29.4, and 22.2%, respectively. Grade 3-4 treatment-related adverse events were observed in 20.0, 66.7, 47.1, and 66.7 of patients, respectively, but were effectively managed. Multivariable analysis demonstrated that adding T to D + CT improved progression-free survival (adjusted HR, 0.435; 95% CI, 0.229-0.824; P = 0.011). Favorable response to chemoimmunotherapy was associated with MUC16 mutation (P = 0.0214), high EPCAM expression (P = 0.020), high matrix remodeling gene signature score (P = 0.017), and low FOXP3 expression (P = 0.047). Patients showing favorable responses to D + T + CT exhibited significantly higher EPCAM expression levels (P = 0.008) and matrix remodeling gene signature scores (P = 0.031) than those receiving D + CT. CONCLUSIONS: Dual immunotherapy with chemotherapy showed acceptable response rates and tolerable safety in HRR non-mutated PROC, warranting continued clinical investigation.

Nanoparticle Targeting in Chemo-Resistant Ovarian Cancer Reveals Dual Axis of Therapeutic Vulnerability Involving Cholesterol Uptake and Cell Redox Balance.

Platinum (Pt)-based chemotherapy is the main treatment for ovarian cancer (OC); however, most patients develop Pt resistance (Pt-R). This work shows that Pt-R OC cells increase intracellular cholesterol through uptake via the HDL receptor, scavenger receptor type B-1 (SR-B1). SR-B1 blockade using synthetic cholesterol-poor HDL-like nanoparticles (HDL NPs) diminished cholesterol uptake leading to cell death and inhibition of tumor growth. Reduced cholesterol accumulation in cancer cells induces lipid oxidative stress through the reduction of glutathione peroxidase 4 (GPx4) leading to ferroptosis. In turn, GPx4 depletion induces decreased cholesterol uptake through SR-B1 and re-sensitizes OC cells to Pt. Mechanistically, GPx4 knockdown causes lower expression of the histone acetyltransferase EP300, leading to reduced deposition of histone H3 lysine 27 acetylation (H3K27Ac) on the sterol regulatory element binding transcription factor 2 (SREBF2) promoter and suppressing expression of this key transcription factor involved in the regulation of cholesterol metabolism. SREBF2 downregulation leads to decreased SR-B1 expression and diminished cholesterol uptake. Thus, chemoresistance and cancer cell survival under high ROS burden obligates high GPx4 and SR-B1 expression through SREBF2. Targeting SR-B1 to modulate cholesterol uptake inhibits this axis and causes ferroptosis in vitro and in vivo in Pt-R OC.

Cytoreductive surgery is feasible in patients with limited regional platinum-resistant recurrent ovarian cancer.

INTRODUCTION: To evaluate the efficacy of cytoreductive surgery versus chemotherapy for the treatment of limited regional, platinum-resistant ovarian cancer (PROC). MATERIALS AND METHODS: The clinical records of all patients with PROC treated in our center between March 2015 and March 2022 were retrospectively reviewed. We compared the oncology outcomes of patients who received cytoreduction or chemotherapy alone at relapse and presented information about postoperative adjuvant chemotherapy. RESULTS: Among 52 patients with limited regional recurrence, 40.4% (21/52) underwent cytoreduction because of platinum resistance, and 59.6% (31/52) received chemotherapy alone. No residual disease (R0) was achieved in 20 patients (95.2%). The severe morbidity rate within 30 days after the surgery was 15%. The median follow-up was 70.6 months. Compared with the chemotherapy alone group, the surgery group with R0 had better progression-free survival (PFS) (10.6 vs. 5.1 months; hazard ratio (HR) = 0.421; P = 0.0035) and post-relapse survival (PRS) (32.6 vs. 16.3 months; HR = 0.478; P = 0.047), but there was no difference in overall survival (OS) between the two groups. Laparoscopy is associated with lesser intraoperative blood loss with no differences in survival and postoperative complications compared to the open approach (P = 0.0042). Subgroup survival analysis showed that compared with chemotherapy alone, surgery prolonged PFS in patients regardless of tumor size (greater than or equal to 4 cm or less). Surgery group patients who achieved R0 had an objective response rate (ORR) of 36.8% (7/19), among whom 40% (4/10) received platinum rechallenge chemotherapy and 33.3% (3/9) were administered non-platinum chemotherapy. CONCLUSION: When well-selected PROC patients with limited regional recurrence achieved R0, their outcomes were superior to those of patients who received only chemotherapy with an acceptable morbidity rate. Laparoscope technology could be a reliable alternative surgical approach. The reintroduction of platinum agents may be considered following surgery. Further analyses in a larger population are warranted to elucidate the risks and benefits of this surgery and adjuvant chemotherapy strategy.

Overcoming the challenges of drug development in platinum-resistant ovarian cancer.

The definition of "platinum-resistant ovarian cancer" has evolved; it now also reflects cancers for which platinum treatment is no longer an option. Standard of care for platinum-resistant ovarian cancer is single-agent, non-platinum chemotherapy with or without bevacizumab, which produces modest response rates, with the greatest benefits achieved using weekly paclitaxel. Several recent phase 3 trials of pretreated patients with prior bevacizumab exposure failed to meet their primary efficacy endpoints, highlighting the challenge in improving clinical outcomes among these patients. Combination treatment with antiangiogenics has improved outcomes, whereas combination strategies with immune checkpoint inhibitors have yielded modest results. Despite extensive translational research, there has been a lack of reliable and established biomarkers that predict treatment response in platinum-resistant ovarian cancer. Additionally, in the platinum-resistant setting, implications for the time between the penultimate dose of platinum therapy and platinum retreatment remain an area of debate. Addressing the unmet need for an effective treatment in the platinum-resistant setting requires thoughtful clinical trial design based on a growing understanding of the disease. Recent cancer drug approvals highlight the value of incorporating molecular phenotypes to better define patients who are more likely to respond to novel therapies. Clinical trials designed per the Gynecologic Cancer InterGroup recommendations-which advocate against relying solely upon the platinum-free interval-will help advance our understanding of recurrent ovarian cancer response where platinum rechallenge in the platinum-resistant setting may be considered. The inclusion of biomarkers in clinical trials will improve patient stratification and potentially demonstrate correlations with biomarker expression and duration of response. With the efficacy of antibody-drug conjugates shown for the treatment of some solid and hematologic cancers, current trials are evaluating the use of various novel conjugates in the setting of platinum-resistant ovarian cancer. Emerging novel treatments coupled with combination trials and biomarker explorations offer encouraging results for potential strategies to improve response rates and prolong progression-free survival in this population with high unmet need. This review outlines existing data from contemporary clinical trials of patients with platinum-resistant ovarian cancer and suggests historical synthetic benchmarks for non-randomized trials.

Niraparib and dostarlimab for the treatment of recurrent platinum-resistant ovarian cancer: results of a Phase II study (MOONSTONE/GOG-3032).

OBJECTIVE: This study assessed the efficacy, safety, and health-related quality of life (HRQoL) of the treatment regimen of dostarlimab, a programmed death-1 inhibitor, combined with niraparib, a poly (ADP-ribose) polymerase inhibitor, in patients with BRCA wild type (BRCAwt) recurrent platinum-resistant ovarian cancer (PROC) who had previously received bevacizumab treatment. METHODS: This Phase II, open-label, single-arm, multicenter study, conducted in the USA, enrolled patients with recurrent PROC to receive niraparib and dostarlimab until disease progression or unacceptable toxicity (up to 3 years). A preplanned interim futility analysis was performed after the first 41 patients had undergone ≥1 radiographic evaluation (approximately 9 weeks from the first treatment). RESULTS: The prespecified interim futility criterion was met and the study was therefore terminated. For the 41 patients assessed, the objective response rate (ORR) was 7.3% (95% confidence interval: 1.5-19.9); no patients achieved a complete response, 3 patients (7.3%) achieved a partial response (duration of response; 3.0, 3.8, and 9.2 months, respectively), and 9 patients (22.0%) had stable disease. In total, 39 patients (95.1%) experienced a treatment-related adverse event, but no new safety issues were observed. HRQoL, assessed using FOSI, or Functional Assessment of Cancer Therapy - Ovarian Symptom Index scores, worsened over time compared with baseline scores. CONCLUSIONS: The study was terminated due to the observed ORR at the interim futility analysis. This highlights a need for effective therapies in treating patients with recurrent BRCAwt PROC.

Targeting RAS-ERK pathway alterations with MEK inhibitors to improve chemosensitivity in high grade serous ovarian cancers.

OBJECTIVE: Assess if MEK inhibitor blockade of RAS-ERK pathway adaptive response in high grade serous ovarian cancers (HGSOC) improves platinum sensitivity. METHODS: Three HGSOC cell lines and three patient derived organoid (PDOs) samples from ascites of platinum resistant HGSOC patients were collected. Cell lines and PDOs were exposed to carboplatin and MEK inhibitors cobimetinib or trametinib. Cytotoxic effects of MEK inhibitors alone or combined with carboplatin were established. Western blots demonstrated RAS-ERK pathway blockage after MEK inhibitor treatment. RNA sequencing assessed gene expression after MEK inhibitor treatment. Cell line NF1 gene knockdown was performed with corresponding chemosensitivity levels. RESULTS: High carboplatin IC50 levels indicated platinum resistance in cell lines and PDOs. Cobimetinib induced cytotoxicity in cell lines and PDOs, while trametinib was less effective. Western blot confirmed MEK-ERK pathway blockage at minimal concentrations of MEK inhibitors in cell lines and PDOs. Phosphorylated-ERK levels of untreated cells indicated higher levels of RAS-ERK pathway activation in OVSAHO and OVCAR7 compared to OVCAR3. OVSAHO harbors a NF1 mutation and had highest levels of RAS-ERK activation. Cotreatment with carboplatin and MEK inhibitors showed varying synergistic cytotoxic effects at different combinations. Synergistic effect was most prominent in the OVSAHO carboplatin and cobimetinib combination. RNA sequencing identified downregulation of c-MYC and FOXM1 gene expression after MEK inhibitor treatment. NF1 gene knockdown showed an acquired increased IC50 compared to parental cells. CONCLUSION: MEK inhibitors block RAS-ERK pathways in platinum resistant HGSOC cells and PDOs. MEK inhibitors with carboplatin have select synergistic effects which may indicate a strategy to improve platinum sensitivity.

Heterogeneous effects of cytotoxic chemotherapies for platinum-resistant ovarian cancer.

BACKGROUND: Single-agent chemotherapy with or without bevacizumab (Bev) is a standard therapy for platinum-resistant ovarian cancer (PR-OC). However, there is a lack of literature on chemotherapy agent selection in heterogenous PR-OC. Therefore, we aimed to clarify the heterogeneous treatment effects of each chemotherapy agent. METHODS: Patients who underwent single-drug chemotherapy agents or Bev combination therapy for PR-OC between January 2009 and June 2022 were included in this study. We assessed the impact of each chemotherapy agent on the time to treatment failure (TTF) according to histological type, platinum-free interval (PFI), and Bev usage. RESULTS: A total of 158 patients received 343 different chemotherapy regimens. In patients with clear cell carcinoma/mucinous carcinoma (CC/MC), gemcitabine (GEM) had the strongest effect with a median TTF of 5.3 months, whilst nedaplatin (NDP) had the lowest effect with a median TTF of 1.4 months. In contrast, in the non-CC/MC group, irinotecan (CPT-11) and NDP had a better TTF than GEM and pegylated liposomal doxorubicin (PLD). There were notable differences in the treatment efficacy of NDP according to PFI. Specifically, NDP prolonged the TTF in patients with a PFI ≥ 3 months. Compared with GEM alone, GEM + Bev tended to prolong the TTF more effectively; however, an additive effect was not observed with PLD + Bev. CONCLUSIONS: This study demonstrated that the effect of chemotherapy agents differed according to the tumor and background characteristics of the patient. Our findings will improve selection of effective therapies for patients with PR-OC by considering their background characteristics.

Efficacy and safety of apatinib combined with liposomal doxorubicin or paclitaxel versus liposomal doxorubicin or paclitaxel monotherapy in patients with recurrent platinum-resistant ovarian cancer.

AIM: Apatinib is an effective treatment for patients with gynecological cancers. This study aimed to further explore the efficacy and safety of apatinib plus chemotherapy in patients with recurrent platinum-resistant ovarian cancer (PROC). METHODS: Totally, 105 patients with recurrent PROC receiving apatinib plus chemotherapy (N = 51) and chemotherapy alone (N = 54) were retrospectively enrolled in this cohort study. RESULTS: Objective response rate (37.3% vs. 14.8%) (p = 0.009) and disease control rate (80.4% vs. 61.1%) (p = 0.030) were increased in the apatinib plus chemotherapy group versus the chemotherapy group. The median (95% confidence interval [CI]) progression-free survival (PFS) and overall survival (OS) were 5.5 (3.4-7.6) and 21.4 (16.2-26.6) months in the apatinib plus chemotherapy group, and they were 3.8 (3.0-4.6) and 14.8 (11.9-17.7) months in the chemotherapy group. Meanwhile, the Kaplan-Meier curves revealed that PFS (p = 0.008) and OS (p = 0.012) were prolonged in the apatinib plus chemotherapy group versus the chemotherapy group. This finding was confirmed by multivariate Cox's proportional regression analyses: enter method (hazard ratio [HR] = 0.515, p = 0.007 for PFS; HR = 0.222, p < 0.001 for OS) and step-forward method (HR = 0.608, p = 0.019 for PFS; HR = 0.346, p = 0.001 for OS). Additionally, the incidence of hypertension was increased in the apatinib plus chemotherapy group versus the chemotherapy group (p = 0.038), while others were not different between the two groups (all p > 0.05). Grades 3 and 4 adverse events were neutropenia, hypertension, leukopenia, hand-foot syndrome, nausea and vomiting, fatigue, thrombocytopenia, and anemia in the apatinib plus chemotherapy group. CONCLUSION: Apatinib combined with chemotherapy is a superior choice over chemotherapy alone for recurrent PROC management.

Pazopanib with Topotecan weekly for patients with platinum-resistant or intermediate-sensitive recurrent ovarian cancer: results of a multicentre, open label phase I/II study (TOPAZ).

PURPOSE: Pazopanib has promising antiangiogenetic activity in solid cancers. The investigator-initiated phase I/II trial evaluated the combination of Topotecan with Pazopanib in platinum-resistant or intermediate-sensitive recurrent ovarian cancer (ROC). METHODS: Patients (≥ 18 years) with first or second recurrence were enrolled in this multicentre open-label trial. Phase I analysed Topotecan 4 mg/m2 (day 1, 8, 15, ever 28 days) for six cycles to identify the maximum tolerated dose (MTD) of Pazopanib added in a dose-escalating scheme with 400 mg starting dose. The phase II analysed safety and efficacy aspects. For all patients with clinical remission a maintenance with Pazopanib until progression was allowed. This trial is registered with ClinicalTrials.gov, number NCT01600573. RESULTS: Between June 2012 and February 2017, 11 patients were enrolled in the phase I, and 50 patients in the phase II study. The MTD of Pazopanib was determined by 400 mg/daily. Haematological and liver toxicities determined the dose limiting toxicities (DLT) and the most common grade 3-4 adverse events: leucopenia (25%), neutropenia (22%), thrombocytopenia (19%), accumulation of cholestatic (20%) and hepatocellular damage (15%), which often caused dose modifications, but no new life-threatening events. Overall response was 16% and clinical benefit rate 68%. Median progression-free survival (PFS) was 3.5 months (95% CI 2.0-5.0). Due to early progression only 20% of the patients were able to start with maintenance treatment. CONCLUSION: The combination of pazopanib and weekly topotecan is feasible, resulting in a manageable haematological and liver toxicity, but despite its encouraging response rate, was not associated with a significant survival benefit.

Safety and efficacy of mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in combination with bevacizumab in patients with platinum-resistant ovarian cancer.

PURPOSE: Evaluate the antitumor activity and safety profile of the combination of mirvetuximab soravtansine and bevacizumab in patients with platinum-resistant ovarian cancer. METHODS: Patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, whose most recent platinum-free interval was ≤6 months, were administered mirvetuximab soravtansine (6 mg/kg adjusted ideal body weight) and bevacizumab (15 mg/kg), intravenously, once every 3 weeks. Eligibility included FRα expression by immunohistochemistry (IHC; ≥25% of cells with ≥2+ intensity). Prior bevacizumab and/or PARP inhibitor (PARPi) treatment were permitted. The primary endpoint was confirmed objective response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and safety. RESULTS: Ninety-four patients received combination treatment with mirvetuximab soravtansine and bevacizumab. Median age was 62 years (range, 39-81). Fifty-two percent had ≥3 prior therapies; 59% had prior bevacizumab; and 27% had prior PARPi. ORR was 44% (95% CI 33, 54) with 5 complete responses, median DOR 9.7 months (95% CI 6.9, 14.1), and median PFS 8.2 months (95% CI 6.8, 10.0). Treatment-related adverse events were consistent with the profiles of each agent, with the most common being blurred vision (all grades 57%; grade 3, 1%), diarrhea (54%; grade 3, 1%), and nausea (51%; grade 3, 1%). CONCLUSION: The mirvetuximab soravtansine plus bevacizumab doublet is an active and well-tolerated regimen in patients with FRα-expressing platinum-resistant ovarian cancer. Promising activity was observed for patients regardless of level of FRα expression or prior bevacizumab. These data underscore the potential for mirvetuximab soravtansine as the combination partner of choice for bevacizumab in this setting.

Case report: Interstitial implantation radiotherapy combined with immunotherapy and GM-CSF in oligometastatic platinum-resistant ovarian cancer.

Background: Treatment for platinum-resistant ovarian cancer is challenging. Currently, platinum-resistant ovarian cancer is typically treated with non-platinum single-agent chemotherapy ± bevacizumab, but the prognosis is often extremely poor. In the treatment of platinum-resistant ovarian cancer patients, reports of triple therapy with interstitial implantation radiotherapy combined with immunotherapy and granulocyte-macrophage colony-stimulating factor (GM-CSF) (PRaG for short) are relatively rare. Case description: Here, we report a patient with oligometastatic platinum-resistant ovarian cancer. The patient achieved partial response (PR) of the lesion and sustained benefit for more than six months after receiving interstitial implantation radiotherapy combined with immunotherapy along with GM-CSF. Conclusion: This triple therapy may provide additional options for these patients.

ATR Inhibitors in Platinum-Resistant Ovarian Cancer.

Platinum-resistant ovarian cancer (PROC) is one of the deadliest types of epithelial ovarian cancer, and it is associated with a poor prognosis as the median overall survival (OS) is less than 12 months. Targeted therapy is a popular emerging treatment method. Several targeted therapies, including those using bevacizumab and poly (ADP-ribose) polymerase inhibitor (PARPi), have been used to treat PROC. Ataxia telangiectasia and RAD3-Related Protein Kinase inhibitors (ATRi) have attracted attention as a promising class of targeted drugs that can regulate the cell cycle and influence homologous recombination (HR) repair. In recent years, many preclinical and clinical studies have demonstrated the efficacy of ATRis in PROC. This review focuses on the anticancer mechanism of ATRis and the progress of research on ATRis for PROC.

Effects of Wee1 inhibitor adavosertib on patient-derived high-grade serous ovarian cancer cells are multiple and independent of homologous recombination status.

Objective: A major challenge in the treatment of platinum-resistant high-grade serous ovarian cancer (HGSOC) is lack of effective therapies. Much of ongoing research on drug candidates relies on HGSOC cell lines that are poorly documented. The goal of this study was to screen for effective, state-of-the-art drug candidates using primary HGSOC cells. In addition, our aim was to dissect the inhibitory activities of Wee1 inhibitor adavosertib on primary and conventional HGSOC cell lines. Methods: A comprehensive drug sensitivity and resistance testing (DSRT) on 306 drug compounds was performed on three patient-derived genetically unique HGSOC cell lines and two commonly used ovarian cancer cell lines. The effect of adavosertib on the cell lines was tested in several assays, including cell-cycle analysis, apoptosis induction, proliferation, wound healing, DNA damage, and effect on nuclear integrity. Results: Several compounds exerted cytotoxic activity toward all cell lines, when tested in both adherent and spheroid conditions. In further cytotoxicity tests, adavosertib exerted the most consistent cytotoxic activity. Adavosertib affected cell-cycle control in patient-derived and conventional HGSOC cells, inducing G2/M accumulation and reducing cyclin B1 levels. It induced apoptosis and inhibited proliferation and migration in all cell lines. Furthermore, the DNA damage marker γH2AX and the number of abnormal cell nuclei were clearly increased following adavosertib treatment. Based on the homologous recombination (HR) signature and functional HR assays of the cell lines, the effects of adavosertib were independent of the cells' HR status. Conclusion: Our study indicates that Wee1 inhibitor adavosertib affects several critical functions related to proliferation, cell cycle and division, apoptosis, and invasion. Importantly, the effects are consistent in all tested cell lines, including primary HGSOC cells, and independent of the HR status of the cells. Wee1 inhibition may thus provide treatment opportunities especially for patients, whose cancer has acquired resistance to platinum-based chemotherapy or PARP inhibitors.

Patterns of palliative care referral in platinum resistant ovarian cancer demonstrate reactive rather than proactive approach.

Objective: To evaluate patterns of palliative care (PC) integration in patients with platinum resistant ovarian cancer. Methods: Single institution retrospective study of patients with ovarian, tubal, or peritoneal high-grade carcinoma treated 2011-2020. Platinum resistance was identified by chemotherapy regimen or provider definition. Data was extracted evaluating treatment regimens, time to progression, PC and hospice referrals, and survival. Descriptive statistics and survival analyses were performed. Results: We identified 258 patients with platinum resistant ovarian cancer. Median survival from diagnosis of platinum resistance was 15 months (range 0-161). Most (71 %) patients were referred to PC, with 43 % of referrals within 3 months of death. Fourteen percent of patients were referred directly to hospice without PC involvement. Of 46 patients living with platinum resistant disease, 93 % meet criteria for early PC referral, but less than half have seen PC. Median time from platinum resistance to PC referral was 9 months (range 0-157) and from PC referral to death was 3 months (range 0-110). Median time from platinum resistance to hospice referral was 7 months (range 1-57) and from hospice referral to death was < 1 month (range 0-12). Conclusion: While rates of PC referral in our cohort are high compared with other single institution cohorts, timing of PC referral suggests referral patterns that are reactive to clinical decline rather than proactive as per national recommendations. A significant percentage of patients are directly referred to hospice for end-of-life care, reflecting missed opportunity for concurrent PC and oncology care earlier in the disease course. Diagnosis of platinum resistance should serve as a stimulus for PC involvement.

Effectiveness of oral etoposide in recurrent or refractory epithelial ovarian cancer, primary peritoneal cancer and fallopian tube cancer.

The aim of treatment in recurrent or refractory epithelial ovarian cancer is palliation. In a patient with platinum-resistant status, several chemotherapy regimens have been reported with similar response rates. Among these agents, the oral etoposide holds an advantage of the route of administration and management in the out-patient setting. This retrospective study was conducted to evaluate the effectiveness of oral etoposide. Data of patients with recurrent or refractory epithelial ovarian, primary peritoneal and fallopian tube cancer who received oral etoposide treatment in Ramathibodi Hospital, Mahidol University from January 1997 to December 2017 were collected. Progression-free survival (PFS) and overall survival (OS) were primary and secondary outcomes, respectively. The oral etoposide at a dose of 50 mg/m2 was prescribed. Sixty-six records were analysed. Median OS and median PFS were 8.3 months (95% confidence interval (CI): 6.8, 10.4) and 3.1 months (95%CI: 2.3, 3.9), respectively. Other factors including age, body mass index (BMI), histopathology subtype, primary treatment, result of the primary surgery, platinum status, site and size of recurrent cancer, treatment after discontinuation of oral etoposide and the line of chemotherapy regimen were not associated with the prognosis. The initial cancer stage was the only independent poor prognostic factor. The main toxicity was neutropenia. Impact StatementWhat is already known on this subject? After the recurrence of epithelial ovarian cancer, peritoneal cancer or fallopian tube cancer, the aim of treatment in this setting is palliation with accentuating on symptomatic control and enhancing the quality of life. According to previous clinical trials, the chemotherapy regimens which were considered as a second-line or beyond the second-line therapy have been reported with similar response rates. Among these agents, the oral etoposide could be administrated by oral route. There were several articles reported the effectiveness of oral etoposide in different dosage.What do the results of this study add? This study adds that administration of oral etoposide at a dose of 50 mg/m2 showed fairish oncologic outcomes with manageable toxicity.What are the implications of these findings for clinical practice and/or further research? The results will provide evidence that the oral etoposide can be considerate as a choice of palliative chemotherapy because of an advantage of the route of administration and management in the out-patient setting.