The efficacy and safety of the addition of poly ADP-ribose polymerase (PARP) inhibitors to therapy for ovarian cancer: a systematic review and meta-analysis

Olaparib plus bevacizumab as a first-line maintenance treatment for patients with advanced ovarian cancer by molecular status: an updated PAOLA-1 based cost-effectiveness analysis

OBJECTIVE

The PAOLA-1 trial (NCT02477644) reported final survival benefit associated with olaparib plus bevacizumab maintenance treatment of patients with advanced ovarian cancer (AOC) based on molecular status. Our aimed to compare the cost-effectiveness of olaparib plus bevacizumab for overall patients, patients with a breast cancer susceptibility genes (BRCA) mutation, homologous recombination deficiency (HRD), or HRD without BRCA mutations AOC from the context of the American healthcare system.

METHODS

Analysis of health outcomes in life-years (LYs), quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER) in various molecular status-based AOC patient at a $150,000/QALY of willingness-to-pay was performed using a state-transitioned Markov model with a 20-year time horizon. Meanwhile, sensitivity analyses assessments were also used to gauge the model's stability.

RESULTS

The ICERs of olaparib plus bevacizumab versus bevacizumab alone were $487,428 ($374,758), $249,579 ($191,649), $258,859 ($198,739), and $270,736 ($206,640) per QALY (LY) in the overall patients, patients with BRCA mutations, patients with HRD, and patients with HRD without BRCA mutations AOC, respectively, which indicated that The ICERs was higher than $150,000/QALY in the US. Progression-free survival (PFS) value and olaparib cost emerged as the primary influencing factors of these findings in the sensitivity analysis.

CONCLUSION

At current cost levels, olaparib plus bevacizumab treatment is not a cost-effective treatment for patients with AOC regardless of their molecular status in the US. However, this maintenance treatment may be more favorable health advantages for patients with BRAC mutations AOC.

Ovarian high-grade serous carcinoma with transitional-like (SET) morphology: a homologous recombination-deficient tumor

Thirteen years ago, we pointed out that ovarian transitional cell carcinomas (TCCs) and conventional high-grade serous carcinomas (HGSCs) had similar genetic alterations and clinical behavior. Consequently, ovarian TCC is now classified as a morphologic variant of HGSC. Defective homologous recombination, resulting from genetic or epigenetic inactivation of DNA damage repair genes, such as BRCA1/2, occurs in approximately 50% of the HGSCs. Although BRCA mutations have been associated with HGSCs with solid, pseudoendometrioid or transitional (SET) features, little is known about the role of non-BRCA homologous recombinationrepair (HRR) genes and the HRR status in these tumors. Using two commercially available assays (Myriad Genetics MyChoice CDx Plus test and SOPHiA Dx Homologous Recombination Deficiency Solution), we study mutations of BRCA1/2 and non-BRCA HRR genes (ATM, BARD1, BRIP1, CDK12, CHEK1/2, FANCL, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D, and RAD54L), and the HRR status in 19 HGSCs with SET features and 20 HGSCs with classic morphology. We also studied, as control cases, 5 endometrioid carcinomas, 1 clear cell carcinoma, 2 low-grade serous carcinomas, and 1 malignant Brenner tumor. Seven HGSCs with SET features (7/19; 37%) showed BRCA mutations (4 BRCA1, 2 BRCA2, and 1 BRCA1/2). Mutations in non-BRCA HRR genes were found in ATM (1/15; 7%), BARD1 (1/15; 7%), and BRIP1 (1/19; 5%). Most HGSCs with SET features (17/19; 90%) were considered to be homologous recombination-deficient tumors. Three HGSCs with classic morphology (3/20; 15%) showed BRCA2 mutations. Mutations in non-BRCA HRR genes were found in CDK12 (2/14; 14%), FANCL (1/14; 7%), RAD51B (1/14; 7%), and RAD54L (1/14; 7%). Eleven HGSCs with classical morphology (11/20; 55%) were considered to be homologous recombination deficient. In contrast, all ovarian carcinoma control cases (5 endometrioid carcinomas, 1 clear cell carcinoma, 2 low-grade serous carcinomas, and 1 malignant Brenner tumor) were homologous recombination proficient and did not have BRCA mutations. Our results show that the majority of HGSCs with SET features are homologous recombination-deficient tumors independently of the BRCA status and highlight the importance of the HRR tumor testing, especially in BRCA wild-type tumors. Recognition of transitional cell variant of HGSCs may help to identify patients most likely to benefit from PARP inhibitors.

Pharmacological depletion of RNA splicing factor RBM39 by indisulam synergizes with PARP inhibitors in high-grade serous ovarian carcinoma

Ovarian high-grade serous carcinoma (HGSC) is the most common subtype of ovarian cancer with limited therapeutic options and a poor prognosis. In recent years, poly-ADP ribose polymerase (PARP) inhibitors have demonstrated significant clinical benefits, especially in patients with BRCA1/2 mutations. However, acquired drug resistance and relapse is a major challenge. Indisulam (E7070) has been identified as a molecular glue that brings together splicing factor RBM39 and DCAF15 E3 ubiquitin ligase resulting in polyubiquitination, degradation, and subsequent RNA splicing defects. In this work, we demonstrate that the loss of RBM39 induces splicing defects in key DNA damage repair genes in ovarian cancer, leading to increased sensitivity to cisplatin and various PARP inhibitors. The addition of indisulam also improved olaparib response in mice bearing PARP inhibitor-resistant tumors. These findings demonstrate that combining RBM39 degraders and PARP inhibitors is a promising therapeutic approach to improve PARP inhibitor response in ovarian HGSC.

The cost-effectiveness analysis of maintenance olaparib plus Bevacizumab in patients with advanced ovarian cancer: based on the final survival results from PAOLA-1 trial

INTRODUCTION

In 2023, the final PAOLA-1 trial (NCT02477644) survival data were published documenting the benefits of therapy consisting of olaparib plus bevacizumab for patients with advanced ovarian cancer (AOC) as a function of molecular status. In light of these new data, the present study was conducted with the goal of evaluating the cost-effectiveness of olaparib plus bevacizumab for the treatment of the overall AOC patient population and for homologous recombination deficiency (HRD)-positive patients, patients with a breast cancer susceptibility gene (BRCA) mutations, homologous recombination proficiency (HRD)-positive, or patients not harboring BRCA mutations AOC from a US payers perspective.

METHODS

A Markov state-transition model with a 15-year time horizon was used to evaluate outcomes of patients administered Olaparib plus bevacizumab versus bevacizumab. Life-years (LYs), quality-adjusted LYs (QALYs), and the incremental cost-effectiveness ratio (ICER) values were evaluated in this study in light of a $150,000/QALY of willingness-to-pay (WTP) threshold. The stability of the established model was evaluated through sensitivity analyses.

RESULTS

Relative to bevacizumab alone, Olaparib plus bevacizumab was associated with mean incremental costs and QALYs (LYs) of olaparib plus bevacizumab versus bevacizumab were $293,656 and 1.85 (2.16), $265,668 and 3.34 (4.02), $242,746 and 1.71 (2.06), and $193,792 and 0.97 (1.14) for overall, BRCA mutation-positive, HRD-positive, and HRD-positive BRCA mutation-negative AOC patients, respectively. The corresponding ICER values for these patient subgroups were $158,729 ($136,218), $79,434 ($66,120), $141,636 ($117,747), and $200,595 ($169,733) per QALY (LY) gained Utility value and the price of olaparib were identified in sensitivity analyses as the primary factors influencing these results.

CONCLUSION

At current pricing levels, maintenance treatment with olaparib plus bevacizumab treatment may represent a cost-effective therapeutic option for BRCA mutations and HRD-positive AOC patients in the USA.

BRCA1 and BRCA2 germline mutation analysis from a cohort of 1267 patients at high risk for breast cancer in Brazil

We determined the frequency and mutational spectrum of BRCA1 and BRCA2 in a series of patients at high risk for developing breast cancer from Brazil. A total of 1267 patients were referred for BRCA genetic testing, and no obligation of fulfilling criteria of mutation probability methods for molecular screening was applied. Germline deleterious mutations in BRCA1/2 (i.e., pathogenic/likely pathogenic variants) were identified in 156 out of 1267 patients (12%). We confirm recurrent mutations in BRCA1/2, but we also report three novel mutations in BRCA2, not previously reported in any public databases or other studies. Variants of unknown significance (VUS) represent only 2% in this dataset and most of them were detected in BRCA2. The overall mutation prevalence in BRCA1/2 was higher in patients diagnosed with cancer at age > 35 years old, and with family history of cancer. The present data expand our knowledge of BRCA1/2 germline mutational spectrum, and it is a valuable clinical resource for genetic counseling and cancer management programs in the country.

Recent Progress of the research on the benzimidazole PARP-1 inhibitors

Poly (ADP-ribose) polymerase-1 (PARP-1) is a multifunctional protein that plays an important role in DNA repair and genome integrity. PARP-1 inhibitors can be used as effective drugs not only to treat BRCA-1/2 deficient cancers because of the effect of synthetically lethal, but also to treat non-BRCA1/2 deficient tumours because of the effect of PARP capture. Therefore, the PARP inhibitors have become a focus of compelling research. Among these inhibitors, substituted benzimidazole derivatives were mainly concerned lead compounds. However, the commercial available benzimidazole PARP-1 inhibitors have some shortcomings such as serious toxicity in combination with chemotherapy drugs, in vivo cardiovascular side effects such as anemia. Therefore it's crucial for scientists to explore more structure-activity relationships of the benzimidazole PARP-1 inhibitors and access safer and more effective PARP inhibitors. As the binding region of PARP-1 and the substrates is usually characterized as NI site and AD site, the modification of benzimidazoles mainly occurs on the benzimidazole skeleton (NI site), and the side chain of benzimidazole on 2-C position (AD site). Herein, the recent progresses of the researches of benzamides PARP inhibitors were introduced. We noticed that even though many efforts were taken to the modification of NI sites, there were still lacks of optimistic and impressive results. However, the structure-activity relationships of the modification of AD sites have not thoroughly discovered yet. We hope that enlightened by the previous researches, more researches of AD site should be occurred and more effective benzimidazole PARP-1 inhibitors could be designed, synthesized, and applied to clinics.

European experts consensus: BRCA/homologous recombination deficiency testing in first-line ovarian cancer

BACKGROUND

Homologous recombination repair (HRR) enables fault-free repair of double-stranded DNA breaks. HRR deficiency is predicted to occur in around half of high-grade serous ovarian carcinomas. Ovarian cancers harbouring HRR deficiency typically exhibit sensitivity to poly-ADP ribose polymerase inhibitors (PARPi). Current guidelines recommend a range of approaches for genetic testing to identify predictors of sensitivity to PARPi in ovarian cancer and to identify genetic predisposition.

DESIGN

To establish a European-wide consensus for genetic testing (including the genetic care pathway), decision making and clinical management of patients with recently diagnosed advanced ovarian cancer, and the validity of biomarkers to predict the effectiveness of PARPi in the first-line setting. The collaborative European experts' consensus group consisted of a steering committee (n = 14) and contributors (n = 84). A (modified) Delphi process was used to establish consensus statements based on a systematic literature search, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

A consensus was reached on 34 statements amongst 98 caregivers (including oncologists, pathologists, clinical geneticists, genetic researchers, and patient advocates). The statements concentrated on (i) the value of testing for BRCA1/2 mutations and HRR deficiency testing, including when and whom to test; (ii) the importance of developing new and better HRR deficiency tests; (iii) the importance of germline non-BRCA HRR and mismatch repair gene mutations for predicting familial risk, but not for predicting sensitivity to PARPi, in the first-line setting; (iv) who should be able to inform patients about genetic testing, and what training and education should these caregivers receive.

CONCLUSION

These consensus recommendations, from a multidisciplinary panel of experts from across Europe, provide clear guidance on the use of BRCA and HRR deficiency testing for recently diagnosed patients with advanced ovarian cancer.

Correlation of Poly (adenosine diphosphate[ADP]-ribose) Polymerase Expression and Prognosis in Ovarian Cancer: A Systematic Review and Meta-analysis

PURPOSE

This meta-analysis evaluated the correlation between poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) expression and prognosis in patients with ovarian cancer.

METHODS

Eligible studies were extracted from the electronic databases of PubMed, Web of Science, and EMBASE until 1 August 2019. The included studies investigated the correlation between PARP expression and clinical outcomes in patients with ovarian cancer. Clinical outcomes are overall survival (OS) and progression free survival (PFS). The clinical data of patients, such as clinicopathologic characteristics and survival, were analyzed. The language was limited to English, and studies conducted at the cellular level, animal studies, and non-original research were excluded. The odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were used for this meta-analysis.

RESULTS

A total of 9 eligible studies involving 1230 patients were included in our meta-analysis. Based on the analysis, higher PARP expression was correlated with worse overall survival [OS] (HR,1.64; 95% CI, 1.08-2.49; P = 0.020) in the univariate analysis, whereas results from multivariate analysis indicated that PARP overexpression wasn't statistically associated with worse OS (HR, 1.36; 95% CI, 0.98-1.90; P = 0.069). Moreover, the pooled results revealed that patients with PARP overexpression were not associated with worse histologic grade (OR,2.22; 95% CI, 0.98-5.02; P = 0.06).

CONCLUSION

PARP overexpression maybe associated with poor prognosis and survival in patients with ovarian cancer. The patients with PARP over expression were not tended to have a worse histologic grade. Findings require further validation.

Poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of ovarian cancer

BACKGROUND

Ovarian cancer is the sixth most common cancer in women world-wide. Epithelial ovarian cancer (EOC) is the most common; three-quarters of women present when disease has spread outside the pelvis (stage III or IV). Treatment consists of a combination of  surgery and platinum-based chemotherapy. Although initial responses to chemotherapy are good, most women with advanced disease will relapse. PARP (poly (ADP-ribose) polymerase) inhibitors (PARPi), are a type of anticancer treatment that works by preventing cancer cells from repairing DNA damage, especially in those with breast cancer susceptibility gene (BRCA) variants. PARPi offer a different mechanism of anticancer treatment from conventional chemotherapy.

OBJECTIVES

To determine the benefits and risks of poly (ADP-ribose) polymerase) inhibitors (PARPi) for the treatment of epithelial ovarian cancer (EOC).

SEARCH METHODS

We identified randomised controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (Central 2020, Issue 10), Cochrane Gynaecological Cancer Group Trial Register, MEDLINE (1990 to October 2020), Embase (1990 to October 2020), ongoing trials on www.controlled-trials.com/rct, www.clinicaltrials.gov, www.cancer.gov/clinicaltrials, the National Research Register (NRR), FDA database and pharmaceutical industry biomedical literature.

SELECTION CRITERIA

We included trials that randomised women with EOC to PARPi with no treatment, or PARPi versus conventional chemotherapy, or PARPi together with conventional chemotherapy versus conventional chemotherapy alone.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Two review authors independently assessed whether studies met the inclusion criteria. We contacted investigators for additional data. Outcomes included overall survival (OS), objective response rate (ORR), quality of life (QoL) and rate of adverse events.

MAIN RESULTS

We included 15 studies (6109 participants); four (3070 participants) with newly-diagnosed, advanced EOC and 11 (3039 participants) with recurrent EOC. The studies varied in types of comparisons and evaluated PARPi. Eight studies were judged as at low risk of bias in most of the domains. Quality of life data were generally poorly reported. Below we present six key comparisons.  The majority of participants had BRCA mutations, either in their tumour (sBRCAmut) and/or germline (gBRCAmut), or homologous recombination deficiencies (HRD) in their tumours. Newly diagnosed EOC Overall, four studies evaluated the effect of PARPi in newly-diagnosed, advanced EOC. Two compared PARPi with chemotherapy and chemotherapy alone. OS data were not reported. The combination of PARPi with chemotherapy may have little to no difference in progression-free survival (PFS) (two studies, 1564 participants; hazard ratio (HR) 0.82, 95% confidence interval (CI 0).49 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months' 63% with PARPi versus 69% for placebo).  PARPi with chemotherapy likely increases any severe adverse event (SevAE) (grade 3 or higher) slightly (45%) compared with chemotherapy alone (51%) (two studies, 1549 participants, risk ratio (RR) 1.13, 95% CI 1.07 to 1.20; high-certainty evidence). PARPi combined with chemotherapy compared with chemotherapy alone likely results in little to no difference in the QoL (one study; 744 participants, MD 1.56 95% CI -0.42 to 3.54; moderate-certainty evidence).  Two studies compared PARPi monotherapy with placebo as maintenance after first-line chemotherapy in newly diagnosed EOC. PARPi probably results in little to no difference in OS (two studies, 1124 participants; HR 0.81, 95%CI 0.59 to 1.13; moderate-certainty evidence) (alive at 12 months 68% with PARPi versus 62% for placebo). However, PARPi may increase PFS (two studies, 1124 participants; HR 0.42, 95% CI 0.19 to 0.92; low-certainty evidence) (no evidence of disease progression at 12 months' 55% with PARPi versus 24% for placebo). There may be an increase in the risk of experiencing any SevAE (grade 3 or higher) with PARPi (54%) compared with placebo (19%)(two studies, 1118 participants, RR 2.87, 95% CI 1.65 to 4.99; very low-certainty evidence), but the evidence is very uncertain. There is probably a slight reduction in QoL with PARPi, although this may not be clinically significant (one study, 362 participants; MD -3.00, 95%CI -4.48 to -1.52; moderate-certainty evidence).  Recurrent, platinum-sensitive EOC Overall, 10 studies evaluated the effect of PARPi in recurrent platinum-sensitive EOC. Three studies compared PARPi monotherapy with chemotherapy alone. PARPi may result in little to no difference in OS (two studies, 331 participants; HR 0.95, 95%CI 0.62 to 1.47; low-certainty evidence) (percentage alive at 36 months 18% with PARPi versus 17% for placebo). Evidence is very uncertain about the effect of PARPi on PFS (three studies, 739 participants; HR 0.88, 95%CI 0.56 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months 26% with PARPi versus 22% for placebo). There may be little to no difference in rates of any SevAE (grade 3 or higher) with PARPi (50%) than chemotherapy alone (47%) (one study, 254 participants; RR 1.06, 95%CI 0.80 to 1.39; low-certainty evidence). Four studies compared PARPi monotherapy as maintenance with placebo. PARPi may result in little to no difference in OS (two studies, 560 participants; HR 0.88, 95%CI 0.65 to 1.20; moderate-certainty evidence)(percentage alive at 36 months 21% with PARPi versus 17% for placebo). However, evidence suggests that PARPi as maintenance therapy results in a large PFS (four studies, 1677 participants; HR 0.34, 95% CI 0.28 to 0.42; high-certainty evidence)(no evidence of disease progression at 12 months 37% with PARPi versus 5.5% for placebo). PARPi maintenance therapy may result in a large increase in any SevAE (51%) (grade 3 or higher) than placebo (19%)(four studies, 1665 participants, RR 2.62, 95%CI 1.85 to 3.72; low-certainty evidence). PARPi compared with chemotherapy may result in little or no change in QoL (one study, 229 participants, MD 1.20, 95%CI -1.75 to 4.16; low-certainty evidence). Recurrent, platinum-resistant EOC Two studies compared PARPi with chemotherapy. The certainty of evidence in both studies was graded as very low. Overall, there was minimal information on the QoL and adverse events.

AUTHORS' CONCLUSIONS

PARPi maintenance treatment after chemotherapy may improve PFS in women with newly-diagnosed and recurrent platinum-sensitive EOC; there may be little to no effect on OS, although OS data are immature. Overall, this is likely at the expense of an increase in SevAE. It is  disappointing that data on quality of life outcomes  are relatively sparse. More research is needed to determine whether PARPi have a role to play in platinum-resistant disease.

Predictive value of DNA repair gene expression for response to neoadjuvant chemotherapy in breast cancer

Genome-wide analysis using microarrays has revolutionized breast cancer (BC) research. A substantial body of evidence supports the clinical utility of the 21-gene assay (Oncotype DX) and 70-gene assay (MammaPrint) to predict BC recurrence and the magnitude of benefit from chemotherapy. However, there is currently no genetic tool able to predict chemosensitivity and chemoresistance to neoadjuvant chemotherapy (NACT) during BC treatment. In this study, we explored the predictive value of DNA repair gene expression in the neoadjuvant setting. We selected 98 patients with BC treated with NACT. We assessed DNA repair expression in 98 formalin-fixed, paraffin-embedded core biopsy fragments used at diagnosis and in 32 formalin-fixed, paraffin-embedded post-NACT residual tumors using quantitative reverse transcription-polymerase chain reaction. The following genes were selected: BRCA1, PALB2, RAD51C, BRCA2, ATM, FANCA, MSH2, XPA, ERCC1, PARP1, and SNM1. Of 98 patients, 33 (33.7%) achieved pathologic complete response (pCR). The DNA expression of 2 genes assessed in pre-NACT biopsies (PALB2 and ERCC1) was lower in pCR than in non-pCR patients (P=0.005 and P=0.009, respectively). There was no correlation between molecular subtype and expression of DNA repair genes. The genes BRCA2 (P=0.009), ATM (P=0.004), FANCA (P=0.001), and PARP1 (P=0.011) showed a lower expression in post-NACT residual tumor samples (n=32) than in pre-NACT biopsy samples (n=98). The expression of 2 genes (PALB2 and ERCC1) was lower in pCR patients. These alterations in DNA repair could be considered suitable targets for cancer therapy.

Research progress on the association between environmental pollutants and the resistance mechanism of PARP inhibitors in ovarian cancer

The occurrence and progression of ovarian cancer are closely related to genetics and environmental pollutants. Poly(ADP-ribose) polymerase (PARP) inhibitors have been a major breakthrough in the history of ovarian cancer treatment. PARP is an enzyme responsible for post-translational modification of proteins and repair of single-stranded DNA damage. PARP inhibitors can selectively inhibit PARP function, resulting in a synthetic lethal effect on tumor cells defective in homologous recombination repair. However, with large-scale application, drug resistance also inevitably appears. For PARP inhibitors, the diversity and complexity of drug resistance mechanisms have always been difficult problems in clinical treatment. Herein, we mainly summarized the research progress of DNA damage repair and drug resistance mechanisms related to PARP inhibitors and the impact of environmental pollutants on DNA damage repair to aid the development prospects and highlight urgent problems to be solved.

Long non-coding RNA SDCBP2-AS1 delays the progression of ovarian cancer via microRNA-100-5p-targeted EPDR1

Background

Dysregulation of long non-coding RNAs has been implied to connect with cancer progression. This research was to decipher the mechanism of long non-coding RNA SDCBP2-AS1 in ovarian cancer (OC) through regulation of microRNA (miR)-100-5p and ependymin-related protein 1 (EPDR1).

Methods

LncRNA SDCBP2-AS1 and EPDR1 levels in OC were assessed by Gene Expression Profiling Interactive Analysis. lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1 levels in OC tissues and cells were determined. SKOV3 and A2780 cells were transfected with lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1-related plasmids or sequences, and then their functions in cell viability, apoptosis, migration, and invasion were evaluated. The interplay of lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1 was clarified.

Results

LncRNA SDCBP2-AS1 and EPDR1 levels were suppressed whilst miR-100-5p level was elevated in OC. After upregulating lncRNA SDCBP2-AS1 or EPDR1, viability, migration, and invasion of OC cells were impaired, and apoptosis rate was increased. Downregulating EPDR1 or upregulating miR-100-5p partially mitigated upregulated lncRNA SDCBP2-AS1-induced impacts on the biological functions of OC cells. LncRNA SDCBP2-AS1 sponged miR-100-5p, and EPDR1 was targeted by miR-100-5p.

Conclusion

It is illustrated that lncRNA SDCBP2-AS1 regulates EPDR1 by sponge adsorption of miR-100-5p to inhibit the progression of OC.