Homologous repair deficiency score for identifying breast cancers with defective DNA damage response

Breast cancer (BC) in patients with germline mutations of BRCA1/BRCA2 are associated with benefit from drugs targeting DNA damage response (DDR), but they account for only 5-7% of overall breast cancer. To define the characteristics of these tumors and also to identify tumors without BRCA mutation but with homologous recombination deficiency (HRD) is clinically relevant. To define characteristic features of HRD tumors and analyze the correlations between BRCA1/BRCA2 and BC subtypes, we analyzed 981 breast tumors from the TCGA database using the signature analyzer. The BRCA signature was strongly associated with the HRD score top 10% (score ≥ 57) population. This population showed a high level of mutations in DDR genes, including BRCA1/BRCA2. HRD tumors were associated with high expression levels of BARD1 and BRIP1. Besides, BRCA1/2 mutations were dominantly observed in basal and luminal subtypes, respectively. A comparison of HRD features in BC revealed that BRCA1 exerts a stronger influence inducing HRD features than BRCA2 does. It reveals genetic differences between BRCA1 and BRCA2 and provides a basis for the identification of HRD and other BRCA-associated tumors.

Real world outcomes in platinum sensitive relapsed ovarian, fallopian tube, or peritoneal cancer treated in routine clinical practice in the United Kingdom prior to poly-ADP ribose polymerase inhibitors

Introduction

The introduction of poly-ADP ribose polymerase inhibitors in ovarian cancer has demonstrated significantly improved progression free survival in four randomized controlled clinical trials in patients with platinum sensitive relapsed ovarian cancer. While overall survival data remain immature, this real world evidence study sets a baseline for future evaluation of poly-ADP ribose polymerase inhibitors.

Methods

A retrospective chart review was undertaken to investigate real world survival outcomes across 13 National Health Service Trusts in England, Wales, and Scotland. Patients were included if they had platinum sensitive relapsed high grade serous ovarian cancer and had responded to secondline platinum based chemotherapy. Clinical data were collected retrospectively from electronic prescribing records and chart notes. The index date for overall survival analysis was defined as the later of (1) day 1 of the final secondline platinum based treatment or (2) date of response to secondline treatment. The primary objective was overall survival from the index date. Secondary objectives included progression free survival and overall survival by subsequent line of treatment. BRCA mutation status was collected where available. Quality of life questionnaires were not assessed within this study.

Results

233 patients were identified who met the study inclusion criteria. Patient characteristics were consistent with other published data, with a median age of 61 years (range 35–85). Sensitivity analysis of the primary objective demonstrated that the earliest point poly-ADP ribose polymerase inhibitors may be initiated (following completion of secondline chemotherapy) is associated with a median overall survival of 19.8 months. Secondline median overall survival and progression free survival from the index date were 19.3±2.4 months and 7.3±1.2 months, respectively. 144 patients were treated with thirdline chemotherapy with median overall survival and progression free survival from the index date (either date of last cycle of thirdline treatment or date of response to thirdline treatment) of 8.3±2.6 and 4.4±1.8 months, respectively.

Conclusion

Overall survival was shown to be shorter in this real world study compared with randomized clinical trials, and underlines the differences in clinical outcomes of patients in a real life setting. This baseline real world study has demonstrated poor survival outcomes in this patient group prior to availability of poly-ADP ribose polymerase inhibitors.

Niraparib for the Treatment of Recurrent Epithelial Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

OBJECTIVE

To review the efficacy and safety of niraparib for the treatment of recurrent epithelial ovarian, fallopian tube, and primary peritoneal cancer (OC, FTC, and PPC).

DATA SOURCES

A literature search via MEDLINE through PubMed from August 2013 to January 2020 was performed using the key terms niraparib, PARP inhibitors, ovarian cancer, fallopian tube cancer, and primary peritoneal cancer.

STUDY SELECTION AND DATA EXTRACTION

Completed and ongoing trials were identified through a review of the website trial registry https://www.clinicaltrials.gov.

DATA SYNTHESIS

In a phase III, double-blind clinical trial, progression-free survival improved in patients treated with niraparib compared with placebo as maintenance treatment for patients with platinum-sensitive, recurrent OC: 21 versus 5.5 months in the germline breast cancer susceptibility gene (gBRCA) cohort (hazard ratio [HR] = 0.27; 95% CI = 0.17 to 0.41; P < 0.001) and 9.3 versus 3.9 months in the overall nongermline breast cancer susceptibility gene (non-gBRCA) cohort (HR = 0.45; 95% CI = 0.34 to 0.61; P < 0.001). Adverse events included thrombocytopenia and anemia.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Poly (ADP-ribose) polymerase (PARP) inhibitors have gained a place in the therapeutic management of OC, FTC, and PPC because of their ability to suppress growth of homologous recombination deficiency-positive tumors, including those with BRCA1/2 mutations. Niraparib inhibits the DNA repair mechanism vital to the survival of cancer cells, poly-ADP ribose polymerase.

CONCLUSIONS

PARP inhibitors can be used as a single agent for maintenance therapy for platinum-sensitive recurrent disease in patients with partial or complete response following 2 or more rounds of platinum-based therapy.

Sharing real-world experiences to optimize the management of olaparib toxicities: a practical guidance from an Italian expert panel

Olaparib is the first poly(ADP-ribose) polymerase inhibitor approved as maintenance therapy of recurrent ovarian cancer (OC) patients with a BRCA mutation. To achieve the maximum clinical benefit, adherence to olaparib must be persistent. However, in clinical practice, this is challenged by the frequent suboptimal management of toxicities. In view of the expanding use of olaparib also in Italy, physicians must learn how to adequately and promptly manage drug toxicities not to unnecessarily interrupt or reduce the dose. The experts agreed that nausea,vomiting, anemia, and fatigue are the most frequent events experienced by OC patients on olaparib, and that these toxicities usually develop early during treatment, are mainly of grade 1-2 and transient and can be managed with simple non-pharmacological interventions. By sharing their real-world experiences, the panel prepared, for each toxicity, an algorithm organized by grade and besides the procedures indicated in the local label, included supportive care interventions based also on nutritional and lifestyle modifications and psycho-oncology consultation. Moreover, in view of the tablet entry into the Italian market, the full and reduced dosages of capsules and tablets were compared. This practical guidance is intended to be a tool to support especially less-experienced physicians in the management of these complex patients, with the aim to help preventing the worsening of patients' conditions and the unnecessary interruption/reduction of olaparib dosage, which may jeopardize treatment efficacy.

Niraparib Maintenance Treatment Improves Time Without Symptoms or Toxicity (TWiST) Versus Routine Surveillance in Recurrent Ovarian Cancer: A TWiST Analysis of the ENGOT-OV16/NOVA Trial

PURPOSE

This study estimated time without symptoms or toxicity (TWiST) with niraparib compared with routine surveillance (RS) in the maintenance treatment of patients with recurrent ovarian cancer.

PATIENTS AND METHODS

Mean progression-free survival (PFS) was estimated for niraparib and RS by fitting parametric survival distributions to Kaplan-Meier data for 553 patients with recurrent ovarian cancer who were enrolled in the phase III ENGOT-OV16/NOVA trial. Patients were categorized according to the presence or absence of a germline BRCA mutation—gBRCAmut and non-gBRCAmut cohorts. Mean time with toxicity was estimated based on the area under the Kaplan-Meier curve for symptomatic grade 2 or greater fatigue, nausea, and vomiting adverse events (AEs). Time with toxicity was the number of days a patient experienced an AE post–random assignment and before disease progression. TWiST was estimated as the difference between mean PFS and time with toxicity. Uncertainty was explored using alternative PFS estimates and considering all symptomatic grade 2 or greater AEs.

RESULTS

In the gBRCAmut and non-gBRCAmut cohorts, niraparib treatment resulted in a mean PFS benefit of 3.23 years and 1.44 years, respectively, and a mean time with toxicity of 0.28 years and 0.10 years, respectively, compared with RS. Hence, niraparib treatment resulted in a mean TWiST benefit of 2.95 years and 1.34 years, respectively, compared with RS, which is equivalent to more than four-fold and two-fold increases in mean TWiST between niraparib and RS in the gBRCAmut and non-gBRCAmut cohorts, respectively. This TWiST benefit was consistent across all sensitivity analyses, including modeling PFS over 5-, 10-, and 15-year time horizons.

CONCLUSION

Patients who were treated with niraparib compared with RS experienced increased mean TWiST. Thus, patients who were treated with niraparib in the ENGOT-OV16/NOVA trial experienced more time without symptoms or symptomatic toxicities compared with control.

Olaparib in germline-mutated metastatic breast cancer: implications of the OlympiAD trial

Breast cancer remains a leading cause of death worldwide. Our increased understanding of cellular mechanisms inherent to cancer has led to the development of new therapeutic targets. One such therapy is that of poly(ADP-ribose) polymerase (PARP) inhibitors, with PARP playing a key role in the repair of single stranded DNA breaks. The development of drugs able to inhibit PARP led to their investigation in tumors that have defective DNA repair, including that of BRCA1/2-associated cancers. The PARP inhibitor Olaparib, has recently been evaluated in the Phase III OlympiAD trial, and demonstrated a significant progression-free survival advantage in patients with HER2-negative metastatic breast cancer and a germline BRCA-mutation. This article will review the findings and potential implications of the trial.

Olaparib as maintenance treatment for patients with platinum-sensitive relapsed ovarian cancer

Poly (ADP-ribose) polymerase (PARP) inhibitors were developed with the intention of treating patients with homologous recombination repair deficiency (HRD), specifically for patients with tumours that harbour a BRCA mutation (BRCAm). Evidence from clinical trials to date has demonstrated that patients with a BRCAm derive the greatest benefit from PARP inhibitors. However, clinical studies have also shown that PARP inhibitors provide benefit to women with ovarian cancer who do not have a BRCAm. The recent updated approvals of olaparib, niraparib and rucaparib by the US Food and Drug Administration and the European Medicines Agency for the treatment of all platinum-sensitive relapsed (PSR) ovarian-cancer populations, regardless of their BRCAm status, support this. Long-term tolerability and efficacy of olaparib have been demonstrated in patients both with and without a BRCAm, with 13% of patients receiving maintenance olaparib for at least 5 years in one study, which is unprecedented in the relapsed ovarian-cancer setting (versus 1% on placebo). Further studies should be performed to elucidate which non-BRCAm patients are deriving benefit and what molecular processes are enabling this, so that patients continue to receive optimal treatment for their disease. Here, we review clinical and molecular markers of HRD, the long-term clinical safety and efficacy of PARP inhibitors in ovarian cancer, with a focus on olaparib and the current approved indications for PARP inhibitors, as well as guidance on treatment decisions for patients with PSR ovarian cancer.

Cost-Effectiveness of Niraparib Versus Routine Surveillance, Olaparib and Rucaparib for the Maintenance Treatment of Patients with Ovarian Cancer in the United States

OBJECTIVES

The aim was to evaluate the cost-effectiveness of niraparib compared with routine surveillance (RS), olaparib and rucaparib for the maintenance treatment of patients with recurrent ovarian cancer (OC).

METHODS

A decision-analytic model estimated the cost per quality-adjusted life-year (QALY) gained for niraparib versus RS, olaparib, and rucaparib from a US payer perspective. The model considered recurrent OC patients with or without germline BRCA mutations (gBRCAmut and non-gBRCAmut), who were responsive to their last platinum-based chemotherapy regimen. Model health states were: progression-free disease, progressed disease and dead. Mean progression-free survival (PFS) was estimated using parametric survival distributions based on ENGOT-OV16/NOVA (niraparib phase III trial), ARIEL3 (rucaparib phase III trial) and Study 19 (olaparib phase II trial). Mean overall survival (OS) benefit was estimated as double the mean PFS benefit based on the relationship between PFS and OS observed in Study 19. Costs included: drug, chemotherapy, monitoring, adverse events, and terminal care. EQ-5D utilities were estimated from trial data.

RESULTS

Compared to RS, niraparib was associated with an incremental cost-effectiveness ratio (ICER) of US$68,287/QALY and US$108,287/QALY for gBRCAmut and non-gBRCAmut, respectively. Compared to olaparib and rucaparib, niraparib decreased costs and increased QALYs, with a cost saving of US$8799 and US$22,236 versus olaparib and US$198,708 and US$73,561 versus rucaparib for gBRCAmut and non-gBRCAmut, respectively.

CONCLUSIONS

Niraparib was estimated to be less costly and more effective compared to olaparib and rucaparib, and the ICER fell within an acceptable range compared to RS. Therefore, niraparib may be considered a cost-effective maintenance treatment for patients with recurrent OC.

Maintenance Olaparib in Patients with Newly Diagnosed Advanced Ovarian Cancer

BACKGROUND

Most women with newly diagnosed advanced ovarian cancer have a relapse within 3 years after standard treatment with surgery and platinum-based chemotherapy. The benefit of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor olaparib in relapsed disease has been well established, but the benefit of olaparib as maintenance therapy in newly diagnosed disease is uncertain.

METHODS

We conducted an international, randomized, double-blind, phase 3 trial to evaluate the efficacy of olaparib as maintenance therapy in patients with newly diagnosed advanced (International Federation of Gynecology and Obstetrics stage III or IV) high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian-tube cancer (or a combination thereof) with a mutation in BRCA1, BRCA2, or both ( BRCA1/2) who had a complete or partial clinical response after platinum-based chemotherapy. The patients were randomly assigned, in a 2:1 ratio, to receive olaparib tablets (300 mg twice daily) or placebo. The primary end point was progression-free survival.

RESULTS

Of the 391 patients who underwent randomization, 260 were assigned to receive olaparib and 131 to receive placebo. A total of 388 patients had a centrally confirmed germline BRCA1/2 mutation, and 2 patients had a centrally confirmed somatic BRCA1/2 mutation. After a median follow-up of 41 months, the risk of disease progression or death was 70% lower with olaparib than with placebo (Kaplan-Meier estimate of the rate of freedom from disease progression and from death at 3 years, 60% vs. 27%; hazard ratio for disease progression or death, 0.30; 95% confidence interval, 0.23 to 0.41; P<0.001). Adverse events were consistent with the known toxic effects of olaparib.

CONCLUSIONS

The use of maintenance therapy with olaparib provided a substantial benefit with regard to progression-free survival among women with newly diagnosed advanced ovarian cancer and a BRCA1/2 mutation, with a 70% lower risk of disease progression or death with olaparib than with placebo. (Funded by AstraZeneca and Merck; SOLO1 ClinicalTrials.gov number, NCT01844986 .).

Long-term efficacy, tolerability and overall survival in patients with platinum-sensitive, recurrent high-grade serous ovarian cancer treated with maintenance olaparib capsules following response to chemotherapy

Background

In Study 19, maintenance monotherapy with olaparib significantly prolonged progression-free survival vs placebo in patients with platinum-sensitive, recurrent high-grade serous ovarian cancer.

Methods

Study 19 was a randomised, placebo-controlled, Phase II trial enrolling 265 patients who had received at least two platinum-based chemotherapy regimens and were in complete or partial response to their most recent regimen. Patients were randomised to olaparib (capsules; 400 mg bid) or placebo. We present long-term safety and final mature overall survival (OS; 79% maturity) data, from the last data cut-off (9 May 2016).

Results

Thirty-two patients (24%) received maintenance olaparib for over 2 years; 15 (11%) did so for over 6 years. No new tolerability signals were identified with long-term treatment and adverse events were generally low grade. The incidence of discontinuations due to adverse events was low (6%). An apparent OS advantage was observed with olaparib vs placebo (hazard ratio 0.73, 95% confidence interval 0.55‒0.95, P = 0.02138) irrespective of BRCA1/2 mutation status, although the predefined threshold for statistical significance was not met.

Conclusions

Study 19 showed a favourable final OS result irrespective of BRCA1/2 mutation status and unprecedented long-term benefit with maintenance olaparib for a subset of platinum-sensitive, recurrent ovarian cancer patients.

The Chemoprevention of Ovarian Cancer: the Need and the Options

PURPOSE OF REVIEW

Ovarian cancer (OvCa) is the most lethal of all gynecological cancers, with a 5-year survival around 46%, mainly due to limitations in early diagnosis and treatment. Consequently, the chemoprevention of OvCa emerges as an important option to control this dismal disease. Here, we discuss the role of risk assessment in the design of chemoprevention strategies for OvCa, describe candidate agents, and assess future directions in this field.

RECENT FINDINGS

OvCa chemoprevention represents an opportunity for all women, especially those at high risk such as carriers of BRCA1 or BRCA2 mutations. The use of oral contraceptives confers substantial protection against OvCa including women at high risk, which increases with longer use. Despite strong evidence for their efficacy, safety concerns and the magnitude of the requisite interventional clinical trials seem to have precluded definitive studies of oral contraceptives for this application. Several other classes of drugs, including non-steroidal anti-inflammatory drugs, retinoids, angiopreventive agents, poly(ADP-ribose) polymerase inhibitors, and tyrosine kinase inhibitors have shown promise for OvCa chemoprevention.

SUMMARY

Currently, no agent is proven by interventional trials to possess chemopreventive properties against OvCa. The key opportunities in the chemoprevention of OvCa include the development of surrogate biomarkers for OvCa, the molecular definition of OvCa risk that will help select those who may benefit the most from chemoprevention, the identification of additional agents likely driven by understanding the molecular pathogenesis of OvCa, and the development of dedicated resources and support mechanisms for OvCa. Overall, there is significant optimism for the future of OvCa chemoprevention.

Rucaparib: a new treatment option for ovarian cancer

INTRODUCTION

Approximately 50% of high-grade serous ovarian cancers present a deficiency in the pathways involved in homologous recombination (HR). PARP inhibitors prevent single-strand DNA damage repair and determine a progression of the defect towards double-strand breaks, which results in a process known as 'synthetic lethality'. Areas covered: In this review, the authors discuss the efficacy and toxicity of rucaparib either as a single agent or as a maintenance treatment for ovarian cancer. This includes the NGS Foundation Medicine evaluation of the role of this drug in the treatment algorithm of ovarian cancer. Moreover, perspectives on the future development of this drug are presented. Expert opinion: The FDA has approved this drug for the treatment of recurrent BRCA-mutated ovarian cancers, which were previously treated with at least two chemotherapies and has accepted the supplemental new drug application for maintenance use in patients who respond to platinum-based chemotherapy via the Prescription Drug User Fee Act (PDUFA) on 6 April 2018. European Medicines Agency (EMA) approval in the same setting is awaited. The possibility of using PARP inhibitors as a maintenance therapy, as a front-line therapy to combat recurrence, and in combination with anti-angiogenic agents and immune-therapies appears to be of particular interest.

Administration of the Tablet Formulation of Olaparib in Patients with Ovarian Cancer: Practical Guidance and Expectations

Olaparib is a poly(ADP-ribose) polymerase enzyme inhibitor that is approved for use in patients with advanced ovarian cancer (OC) and genetic BRCA1/2 mutations who have received three or more prior lines of chemotherapy for maintenance treatment of recurrent OC that is in response to platinum-based chemotherapy regardless of BRCA mutation status and for human epidermal growth receptor factor 2-negative metastatic breast cancer with deleterious or suspected deleterious germline BRCA mutations who have previously been treated with chemotherapy in the neoadjuvant, adjuvant, or metastatic setting. Because olaparib is poorly soluble and requires advanced drug delivery techniques to ensure bioavailability, the originally approved 400 mg dose is taken as eight 50 mg capsules twice daily. An alternative melt-extrusion tablet formulation was developed to improve the pharmacokinetic and pharmacodynamic profile of olaparib and reduce the pill burden for patients. The recommended tablet dose is 300 mg twice daily (two 150 mg tablets). Phase III studies with the tablet formulation are ongoing for multiple tumor types. Two studies conducted with the olaparib tablet formulation have reported results: one in platinum-sensitive, BRCA-mutated recurrent OC (SOLO-2) and one that included patients with germline BRCA-mutated metastatic breast cancer (OlympiAD). The tablet is the approved formulation based on the SOLO-2 trial results. Because the capsule and tablet formulations have different bioavailability, physicians must strictly adhere to the dosing instructions provided in the prescribing information. The tablet offers greater convenience for most patients, especially when using olaparib for maintenance therapy. This review discusses the differences between the two formulations, dose determination, and guidance for use of olaparib tablets by patients with OC. Prior to implementing any changes in therapy, health care providers should engage their patients in discussion to support an informed transition between the formulations.

IMPLICATIONS FOR PRACTICE

Olaparib has recently been approved for maintenance treatment of recurrent ovarian cancer (OC) that is in response to platinum-based chemotherapy. The originally approved capsule formulation was dosed as 400 mg twice daily (eight 50 mg capsules). The recommended olaparib tablet dose is 300 mg twice daily (two 150 mg tablets). The tablet is the new approved formulation based on the SOLO-2 trial results. Because the capsule and tablet formulations have different bioavailability, physicians must strictly adhere to the dosing instructions provided in the prescribing information. The tablet offers greater convenience for most patients, especially when using olaparib for maintenance therapy. This review discusses the differences between the two formulations, dose determination, and guidance for use of olaparib tablets by patients with OC.