Ovarian Cancer Maintenance Research Articles

Consensus on drivers of maintenance treatment choice and patterns of care in advanced ovarian cancer

ObjectivesMaintenance therapies, including poly (ADP-ribose) polymerase (PARP) inhibitors and/or bevacizumab, have substantially improved the prognosis of patients with advanced ovarian cancer. Owing to the variability in treatment strategies across Europe,...

Olaparib and niraparib as maintenance therapy in patients with newly diagnosed and platinum-sensitive recurrent ovarian cancer: A single-center study in China.

Poly adenosine-diphosphate-ribose polymerase (PARP) inhibitors (PARPi) have been approved to act as first-line maintenance (FL-M) therapy and as platinum-sensitive recurrent maintenance (PSR-M) therapy for ovarian cancer in China for >5 years. Herein, we have analyzed the clinical-application characteristics of olaparib and niraparib in ovarian cancer-maintenance therapy in a real-world setting to strengthen our understanding and promote their rational usage. A retrospective chart review identified patients with newly diagnosed or platinum-sensitive recurrent ovarian cancer, who received olaparib or niraparib as maintenance therapy at Sichuan Cancer Hospital between August 1, 2018, and December 31, 2021. Patient medical records were reviewed. We grouped and analyzed patients based on the type of PARPi they used (the olaparib group and the niraparib group) and the line of PARPi maintenance therapy (the FL-M setting and the PSR-M setting). The primary endpoint was the 24-month progression-free survival (PFS) rate. In total, 131 patients (olaparib: n=67, 51.1%; niraparib: n=64, 48.9%) were enrolled. Breast cancer susceptibility genes (BRCA) mutations (BRCAm) were significantly less common in the niraparib group than in the olaparib group [9.4% (6/64) vs. 62.7% (42/67), P<0.001], especially in the FL-M setting [10.4% (5/48) vs. 91.4% (32/35), P<0.001]. The 24-month PFS rates in the FL-M and PSR-M settings were 60.4% and 45.7%, respectively. In patients with BRCAm, the 24-month PFS rates in the FL-M and PSR-M settings were 62.2% and 72.7%, respectively. Olaparib and niraparib were effective in patients with ovarian cancer without any new safety signals except for skin pigmentation. In patients with BRCAm, the 24-month PFS of the PARPi used in the PSR-M setting was even higher than that used in the FL-M setting.

Aggresome formation promotes ASK1/JNK signaling activation and stemness maintenance in ovarian cancer

Aggresomes are the product of misfolded protein aggregation, and the presence of aggresomes has been correlated with poor prognosis in cancer patients. However, the exact role of aggresomes in tumorigenesis and cancer progression remains largely unknown. Herein, the multiomics screening reveal that OTUD1 protein plays an important role in retaining ovarian cancer stem cell (OCSC) properties. Mechanistically, the elevated OTUD1 protein levels lead to the formation of OTUD1-based cytoplasmic aggresomes, which is mediated by a short peptide located in the intrinsically disordered OTUD1 N-terminal region. Furthermore, OTUD1-based aggresomes recruit ASK1 via protein-protein interactions, which in turn stabilize ASK1 in a deubiquitinase-independent manner and activate the downstream JNK signaling pathway for OCSC maintenance. Notably, the disruption of OTUD1-based aggresomes or treatment with ASK1/JNK inhibitors, including ibrutinib, an FDA-approved drug that was recently identified as an MKK7 inhibitor, effectively reduced OCSC stemness (OSCS) of OTUD1high ovarian cancer cells. In summary, our work suggests that aggresome formation in tumor cells could function as a signaling hub and that aggresome-based therapy has translational potential for patients with OTUD1high ovarian cancer.

PARP inhibitors in newly diagnosed or recurrent ovarian cancer maintenance therapy: evidence of efficacy and safety from randomized controlled trials

PARP inhibitors in newly diagnosed or recurrent ovarian cancer maintenance therapy: evidence of efficacy and safety from randomized controlled trials

Targeting Metastases in Optimizing Ovarian Cancer Maintenance Therapy

Targeting Metastases in Optimizing Ovarian Cancer Maintenance Therapy

To Bev or Not to Bev during Ovarian Cancer Maintenance Therapy?

Maintenance therapy with PARP inhibitors and bevacizumab is approved for ovarian cancer treatment in the first and second line settings, but selecting the optimal sequence is challenging due to restrictions on using the same medication twice. This review aims to establish guidelines for ovarian cancer maintenance therapy based on the strength of scientific evidence, the most effective treatment strategy, and the impact on the healthcare system. Six questions were formulated to evaluate the scientific evidence supporting different maintenance therapy options using the AGREE II guideline evaluation tool. The questions address the acceptability of reusing the same medication, the efficacy of bevacizumab and PARP inhibitors in the first and second line settings, the comparative efficacy of these medications, the potential benefit of combination maintenance therapy, and the economic impact of maintenance therapy. Based on the available evidence, bevacizumab should be preserved for second line maintenance therapy, and maintenance therapy with PARP inhibitors should be offered to all advanced ovarian cancer patients who have responded to first line platinum-based chemotherapy. Additional molecular predictors for bevacizumab efficacy are needed. The presented guidelines offer an evidence-based framework for selecting the most effective maintenance therapy for ovarian cancer patients. Further research is necessary to refine these recommendations and improve outcomes for patients with this disease.

Olaparib plus bevacizumab first-line maintenance in ovarian cancer: final overall survival results from the PAOLA-1/ENGOT-ov25 trial

In the PAOLA-1/ENGOT-ov25 primary analysis, maintenance olaparib plus bevacizumab demonstrated a significant progression-free survival (PFS) benefit in newly diagnosed advanced ovarian cancer patients in clinical response after first-line platinum-based chemotherapy plus bevacizumab, irrespective of surgical status. Prespecified, exploratory analyses by molecular biomarker status showed substantial benefit in patients with a BRCA1/BRCA2 mutation (BRCAm) or homologous recombination deficiency (HRD; BRCAm and/or genomic instability). We report the prespecified final overall survival (OS) analysis, including analyses by HRD status. Patients were randomized 2:1 to olaparib (300 mg bid; up to 24 months) plus bevacizumab (15 mg/kg q3w; 15 months total) or placebo plus bevacizumab. Analysis of OS, a key secondary endpoint in hierarchical testing, was planned for ∼60% maturity or 3 years after the primary analysis. After median follow-up of 61.7 and 61.9 months in the olaparib and placebo arms, respectively, median OS was 56.5 versus 51.6 months in the ITT (hazard ratio [HR]=0.92, 95% CI 0.76-1.12; P=0.4118). Subsequent poly(ADP-ribose) polymerase (PARP) inhibitor therapy was received by 105 (19.6%) olaparib patients versus 123 (45.7%) placebo patients. In the HRD-positive population, OS was longer with olaparib plus bevacizumab (HR=0.62, 95% CI 0.45-0.85; 5-year OS rate, 65.5% versus 48.4%); at 5 years, updated PFS also showed a higher proportion of olaparib plus bevacizumab patients without relapse (HR=0.41, 95% CI 0.32-0.54; 5-year PFS rate, 46.1% versus 19.2%). Myelodysplastic syndrome, acute myeloid leukemia, aplastic anemia, and new primary malignancy incidence remained low and balanced between arms. Olaparib plus bevacizumab provided clinically meaningful OS improvement for first-line patients with HRD-positive ovarian cancer. These prespecified exploratory analyses demonstrated improvement despite a high proportion of patients in the placebo arm receiving PARP inhibitors post-progression, confirming the combination as one of the standards of care in this setting with the potential to enhance cure.

Oligoprogression on PARP maintenance in ovarian cancer, what's the story and where do we go?

Oligometastasis is an increasingly recognized clinical disease state, but the concept of oligoprogression is not as well studied. For patients on targeted therapies, disease progression limited to 1–3 sites may be considered amenable to treatment with local therapy allowing continuation of the targeted agent. To evaluate this concept in ovarian cancer, we investigated the proportion of patients on poly (ADP-ribose) polymerase (PARP) maintenance who developed oligoprogression and their clinical outcomes.

Evaluation of patterns of progression on poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance in ovarian cancer: a cross-sectional study

IntroductionDespite improvement in progression-free survival with poly (ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy for ovarian cancer, many patients will eventually progress on therapy. Oligoprogression is uniquely suited to considerations...

Real-world data analysis of the utilization of second-line maintenance therapy for patients with advanced ovarian cancer.

e18702 Background: Although ovarian cancer (OC) represents about 1% of all new cancer cases in the US, it is the 5th leading cause of cancer death among women. Several maintenance therapies have been introduced (ie, bevacizumab and poly[ADP-ribose] polymerase inhibitors [PARPi]) to extend the time between chemotherapy and relapse (ie, progression-free survival) in this population. Both bevacizumab and PARPi have been recommended as second-line (2L) maintenance treatment by the National Comprehensive Cancer Network for OC patients (pts) with and without BRCA alterations since 2013 and 2017, respectively. We present recent estimates of 2L maintenance utilization. Methods: From the iKnowMed electronic health record database of the US Oncology Network, which includes 1,200 physicians operating in over 470 sites of care in the US, adult females were included if diagnosed with advanced OC, received a 2L platinum-containing regimen for advanced OC, and had ≥2 visits within the database between 1 Jan 2016 and 31 July 2020. Pts were followed longitudinally until 31 Oct 2020, the last pt record, or date of death, whichever occurred earliest. Rates of 2L maintenance therapy (ie, bevacizumab monotherapy or PARPi following discontinuation of 2L platinum-based chemotherapy) were determined for 1) all pts, 2) pts with a BRCA1 or BRCA2 gene alteration (BRCA+), and 3) pts without a BRCA alteration (BRCA-). Results: 11,494 pts were identified with a diagnosis of advanced OC; of those, 1,051 met the study inclusion criteria. Median age at advanced OC diagnosis was 64.2 years. Median follow-up time from discontinuation of 2L platinum chemotherapy until the end of observation was 24.6 mo. Of 1,051 pts who received 2L platinum-based chemotherapy, 513 (49%) subsequently received maintenance therapy (271 [26%] PARPi, 294 [28%] bevacizumab, 32 [3%] a non-platinum chemotherapy) and 538 (51%) did not receive maintenance (ie, underwent “active surveillance”). The proportion of eligible pts receiving 2L maintenance did not increase over the study period, with 53%, 58%, and 56% of pts receiving 2L maintenance versus 47%, 42%, and 44% of pts undergoing active surveillance in the years 2017, 2018, and 2019, respectively. Among the 1,051 pts who received 2L platinum chemotherapy, 662 pts had a documented BRCA test result (94 [14%] BRCA+, 568 [86%] BRCA-). Among BRCA+ pts, 67% received 2L maintenance, while BRCA- pts received significantly less maintenance treatment (53%, p = 0.0104). Conclusions: Despite having several treatment options available for 2L advanced OC maintenance, fewer than half of eligible pts receive maintenance treatment. Although the utilization rate was higher among pts with BRCA alterations versus those without, our data suggest that there is a significant proportion of eligible pts who are not receiving maintenance therapy despite treatment guideline recommendations.

Current Ovarian Cancer Maintenance Strategies and Promising New Developments.

While ovarian cancer typically responds well to front line treatment, many patients will relapse within 5 years. Treatment options are less effective at each recurrence highlighting the need for novel maintenance therapies. PolyADP-ribose polymerase (PARP) inhibitors have recently gained approval in ovarian cancer maintenance. Niraparib was approved regardless of BRCA mutation status, however impact on overall survival is limited. Oliparib was approved for BRCA mutant and BRCA wildtype/homologous recombination deficient patients. This review will focus on current frontline ovarian cancer treatment as well molecularly based approaches to ovarian cancer management.

Current and future landscape of poly (ADP-ribose) polymerase inhibition resistance.

To highlight relevant strategies to overcome poly(ADP-ribose) polymerase (PARP) inhibitor resistance and present key clinical trials. The use of PARP inhibition (PARPi) for frontline maintenance offers substantial clinical benefit in patients with homologous recombination-deficient tumors. However, expanding PARPi from recurrent therapy to frontline maintenance may potentially result in more PARPi resistant tumors earlier in the treatment continuum and data for the use of PARPi after PARPi remain limited. Clinical evidence demonstrates tumors may develop resistance to PARPi through demethylation of the BRCA promoter or BRCA reversion mutations. Multiple clinical trials investigating therapeutic strategies to overcome resistance, such as combinations of PARPi with antiangiogenic drugs, PI3K/AKT/mTOR, or MEK inhibitors have already been reported and more are ongoing. Furthermore, increasing the amount of DNA damage in the tumor using chemotherapy or cell cycle inhibitors such as ATM, ATR/CHK1/WEE1 is also under exploration. There is increasing clinical interest to identify options to enhance PARPi efficacy and overcome adaptive resistance. PARPi represent a class of drugs that have significantly impacted the treatment and maintenance of ovarian cancer; as the use of PARPi increases, better understanding of resistance mechanisms is essential.

Potential and mechanism of mebendazole for treatment and maintenance of ovarian cancer

ObjectiveMebendazole and other anti-parasitic drugs are being used off-prescription based on social media and unofficial accounts of their anti-cancer activity. The purpose of this study was to conduct a controlled evaluation of mebendazole's therapeutic efficacy in cell culture and in vivo models of ovarian cancer. The majority of ovarian cancers harbor p53 null or missense mutations, therefore the effects of p53 mutations and a mutant p53 reactivator, PRIMA-1MET (APR246) on mebendazole activity were evaluated. MethodsMebendazole was evaluated in cisplatin-resistant high grade serous stage 3C ovarian cancer patient derived xenograft (PDX) models: PDX-0003 (p53 null) and PDX-0030 (p53 positive), and on ovarian cancer cell lines: MES-OV (p53 R282W), ES2 (p53 S241F), A2780 (p53 wild type), SKOV3 parental (p53 null) and isogenic sublines, SKOV3 R273H p53 and SKOV3 R248W p53. Drug synergy and mechanisms were evaluated in cell cultures using isobolograms, clonogenic assays and western blots. Prevention of tumor establishment was studied in a MES-OV orthotopic model. ResultsMebendazole inhibited growth of ovarian cancer cell cultures at nanomolar concentrations and PDXs at doses up to 50 mg/kg, and reduced orthotopic tumor establishment at 50 mg/kg. The mechanism of mebendazole was associated with p53-independent induction of p21 and tubule depolymerization. PRIMA-1MET also inhibited tumor establishment and worked synergistically with mebendazole in cell culture to inhibit growth and induce intrinsic apoptosis through a p53- and tubule destabilization-independent mechanism. ConclusionThis work demonstrates the therapeutic potential of repurposing mebendazole and supports clinical development of mebendazole for ovarian cancer therapy and maintenance.

Breast cancer (BRCA) gene testing in ovarian cancer.

The discovery of cancer-causing BRCA1/2 mutations and the emergence of genetic testing have brought precision in patient selection for poly-(ADP)-ribose polymerase inhibitor (PARPi) treatment. Interestingly, patients who are carriers of BRCA1/2 mutations have a higher risk for developing cancer, but respond better to DNA-damaging cytotoxic therapy, such as platinum-based chemotherapy. The distinctive biology of ovarian cancer involves high genomic instability consisting of gene amplification, gene deletion, oncogene hypomethylation, loss of heterozygosity, and tumor suppressor gene promoter hypermethylation in many of the DNA damage response (DDR) genes, including BRCA1/2. Several of these genetic abnormalities can impair high fidelity DNA damage repair increasing the therapeutic audience for PARPi's. This is especially important given the clinical development over the last decade of this group of agents and the dramatic increase in progression free survival among ovarian cancer patients who received PARPi, both in treatment or maintenance setting. In this review, we summarize our current understanding of the role of BRCA1/2 mutations in ovarian cancer and present relevant clinical trials in which BRCA1/2 was investigated as biomarker for therapy. We also outline the role of homologous recombination (HR) deficiency as biomarker by presenting the recent clinical development and recent approvals PARPi for firstline maintenance in ovarian cancer.

Front-line ovarian cancer maintenance therapy: PARP inhibitors for all?

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Efficacy and safety updates of poly ADP-ribose polymerase (PARP) inhibitor maintenance in ovarian cancer from ASCO 2020.

Poly ADP-ribose polymerase (PARP) inhibitors have transformed the treatment landscape of high-grade ovarian cancer.[1][1] The presence of homologous recombination deficiencies and particularly alterations in the BRCA genes are well described biomarkers of response.[2][2] Until the American Society

Latest clinical evidence of maintenance therapy in ovarian cancer.

To summarize the data supporting the use of maintenance therapy in ovarian cancer treatment. Since December 2016, the United States Food and Drug Administration has approved four drugs for six different ovarian cancer maintenance indications based on the results of clinical trials demonstrating efficacy and tolerability. These include antiangiogenesis and poly (adenosine diphosphate-ribose) inhibitors (PARP inhibitors). Four drugs are approved for use in maintenance therapy for recurrent ovarian cancer, including bevacizumab (GOG-0213 and OCEANS), niraparib (NOVA), olaparib (Study 19 and SOLO2) and rucaparib (ARIEL3). Two drugs are approved for use in maintenance therapy in newly diagnosed ovarian cancer, including bevacizumab (GOG-0218) and olaparib (SOLO1). New data were reported at the European Society for Medical Oncology Congress in October 2019 that may lead to the approval of additional strategies in front-line maintenance, including the use of niraparib (PRIMA), veliparib (VELIA) and bevacizumab + olaparib (PAOLA). The landscape of maintenance treatment options for ovarian cancer has been rapidly expanding and continues to evolve as new data emerge. Currently approved strategies include antiangiogenesis and PARP inhibitor treatments.

Novel ovarian cancer maintenance therapy targeted at mortalin and mutant p53.

Current ovarian cancer maintenance therapy is limited by toxicity and no proven impact on overall survival. To study a maintenance strategy targeted at missense mutant p53, we hypothesized that the release of mutant p53 from mortalin inhibition by the SHetA2 drug combined with reactivation of mutant p53 with the PRIMA-1MET drug inhibits growth and tumor establishment synergistically in a mutant-p53 dependent manner. The Cancer Genome Atlas (TCGA) data and serous ovarian tumors were evaluated for TP53 and HSPA9/mortalin status. SHetA2 and PRIMA-1MET were tested in ovarian cancer cell lines and fallopian tube secretory epithelial cells using isobolograms, fluorescent cytometry, Western blots and ELISAs. Drugs were administered to mice after peritoneal injection of MESOV mutant p53 ovarian cancer cells and prior to tumor establishment, which was evaluated by logistic regression. Fifty-eight percent of TP53 mutations were missense and there were no mortalin mutations in TCGA high-grade serous ovarian cancers. Mortalin levels were sequentially increased in serous benign, borderline and carcinoma tumors. SHetA2 caused p53 nuclear and mitochondrial accumulation in cancer, but not in healthy, cells. Endogenous or exogenous mutant p53 increased SHetA2 resistance. PRIMA-1MET decreased this resistance and interacted synergistically with SHetA2 in mutant and wild type p53-expressing cell lines in association with elevated reactive oxygen species/ATP ratios. Tumor-free rates in animals were 0% (controls), 25% (PRIMA1MET ), 42% (SHetA2) and 67% (combination). SHetA2 (p = 0.004) and PRIMA1MET (p = 0.048) functioned additively in preventing tumor development with no observed toxicity. These results justify the development of SHetA2 and PRIMA-1MET alone and in combination for ovarian cancer maintenance therapy.

Olaparib and bevacizumab in front-line maintenance of ovarian cancer: an over reliance in unpowered subgroup analysis of the PAOLA-1 trial?

Olaparib and bevacizumab in front-line maintenance of ovarian cancer: an over reliance in unpowered subgroup analysis of the PAOLA-1 trial?

Olaparib plus Bevacizumab as First-Line Maintenance in Ovarian Cancer

BackgroundOlaparib has shown significant clinical benefit as maintenance therapy in women with newly diagnosed advanced ovarian cancer with a BRCA mutation. The effect of combining maintenance olaparib and bevacizumab in patients regardless of BRCA mutation status is unknown.MethodsWe conducted a randomized, double-blind, international phase 3 trial. Eligible patients had newly diagnosed, advanced, high-grade ovarian cancer and were having a response after first-line platinum–taxane chemotherapy plus bevacizumab. Patients were eligible regardless of surgical outcome or BRCA mutation status. Patients were randomly assigned in a 2:1 ratio to receive olaparib tablets (300 mg twice daily) or placebo for up to 24 months; all the patients received bevacizumab at a dose of 15 mg per kilogram of body weight every 3 weeks for up to 15 months in total. The primary end point was the time from randomization until investigator-assessed disease progression or death.ResultsOf the 806 patients who underwent randomization, 537 were assigned to receive olaparib and 269 to receive placebo. After a median follow-up of 22.9 months, the median progression-free survival was 22.1 months with olaparib plus bevacizumab and 16.6 months with placebo plus bevacizumab (hazard ratio for disease progression or death, 0.59; 95% confidence interval [CI], 0.49 to 0.72; P<0.001). The hazard ratio (olaparib group vs. placebo group) for disease progression or death was 0.33 (95% CI, 0.25 to 0.45) in patients with tumors positive for homologous-recombination deficiency (HRD), including tumors that had BRCA mutations (median progression-free survival, 37.2 vs. 17.7 months), and 0.43 (95% CI, 0.28 to 0.66) in patients with HRD-positive tumors that did not have BRCA mutations (median progression-free survival, 28.1 vs. 16.6 months). Adverse events were consistent with the established safety profiles of olaparib and bevacizumab.ConclusionsIn patients with advanced ovarian cancer receiving first-line standard therapy including bevacizumab, the addition of maintenance olaparib provided a significant progression-free survival benefit, which was substantial in patients with HRD-positive tumors, including those without a BRCA mutation. (Funded by ARCAGY Research and others; PAOLA-1 ClinicalTrials.gov number, NCT02477644.)