Ovarian cancer in the older patient: where are we now? What to do next?

In recent years, major advances have been made toward the individualization of epithelial ovarian cancer care, leading to an overall improvement of patient outcomes. However, real-life data indicate that the oldest populations do not benefit from this, due to aspects related to cancer (more aggressive histopathological features), treatment (i.e. frequently suboptimal), and the host (increased toxicities in patients with lower physiological reserve). A specific risk-benefit perspective should therefore be taken when considering surgery, chemotherapy, and maintenance treatments: the decision for cytoreductive surgery should include geriatric vulnerability and surgical complexity, neo-adjuvant chemotherapy being an option when primary surgery appears at high risk; carboplatin paclitaxel association remains the standard even in vulnerable older patients; and bevacizumab and poly(ADP-ribose) polymerase inhibitors maintenance are interesting options provided they are prescribed according to their indications with a close monitoring of their toxicities. Future studies should aim to individualize care without limiting access of older patients to innovation. A specific focus is needed on age-specific translational analyses (focusing on tumor mutational burden and impaired biological pathways), a better patient stratification according to geriatric parameters, an adaptation of both oncological treatment and geriatric interventions, and treatment adaptations not a priori but according to formal pharmacokinetic data.

Treatment With Niraparib Maintenance Therapy in Patients With Newly Diagnosed Advanced Ovarian Cancer: A Phase 3 Randomized Clinical Trial

Importance

The efficacy of niraparib maintenance therapy with an individualized starting dose (ISD) warrants further investigation in a broad population with newly diagnosed advanced ovarian cancer (aOC), including patients without postoperative residual disease.

Objective

To evaluate the efficacy and safety of niraparib with an ISD in a broad population with newly diagnosed aOC (R0 resection permitted).

Design, Setting, and Participants

This multicenter, randomized, double-blind, placebo-controlled, phase 3 study was conducted in China and enrolled 384 patients with newly diagnosed aOC who received primary or interval debulking surgery and responded to treatment with first-line platinum-based chemotherapy. By data cutoff (September 30, 2021), median follow-up for progression-free survival (PFS) was 27.5 (IQR, 24.7-30.4) months.

Interventions

Patients were randomized 2:1 to receive niraparib or placebo with ISD (200 mg/d for those with a body weight of <77 kg and/or platelet count of <150 ×103/μL [to convert to ×109/μL, multiply by 1] at baseline; 300 mg/d otherwise) stratified by germline BRCA variant status, tumor homologous recombination deficiency status, neoadjuvant chemotherapy, and response to first-line platinum-based chemotherapy.

Main Outcomes and Measurements

The primary end point was blinded, independent central review-assessed PFS in the intention-to-treat population.

Results

A total of 384 patients were randomized (255 niraparib [66.4%]; median [range] age, 53 [32-77] years; 129 placebo [33.6%]; median [range] age, 54 [33-77] years), and 375 (247 niraparib [65.9%], 128 placebo [34.1%]) received treatment at a dose of 200 mg per day. Median PFS with niraparib vs placebo was 24.8 vs 8.3 months (hazard ratio [HR], 0.45; 95% CI, 0.34-0.60; P < .001) in the intention-to-treat population; not reached vs 10.8 months (HR, 0.40; 95% CI, 0.23-0.68) and 19.3 vs 8.3 months (HR, 0.48; 95% CI, 0.34-0.67) in patients with and without germline BRCA variants, respectively; not reached vs 11.0 months (HR, 0.48; 95% CI, 0.34-0.68) and 16.6 vs 5.5 months (HR, 0.41; 95% CI, 0.22-0.75) in homologous recombination deficient and proficient patients, respectively; and 24.8 vs 8.3 months (HR, 0.44; 95% CI, 0.32-0.61) and 16.5 vs 8.3 months (HR, 0.27; 95% CI, 0.10-0.72) in those with optimal and suboptimal debulking, respectively. Similar proportions of niraparib-treated and placebo-treated patients (6.7% vs 5.4%) discontinued treatment due to treatment-emergent adverse events.

Conclusion and Relevance

This randomized clinical trial found that niraparib maintenance therapy prolonged PFS in patients with newly diagnosed aOC regardless of postoperative residual disease or biomarker status. The ISD was effective and safe in the first-line maintenance setting.

Trial Registration

ClinicalTrials.gov Identifier: NCT03709316.

PARP Inhibitors in Ovarian Cancer: A Review

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) have transformed the ovarian cancer (OC) treatment landscape. This narrative review provides a comprehensive overview of data for the PARPis olaparib, niraparib, and rucaparib in patients with OC and discusses their role in disease management, with a focus on the use of PARPis as maintenance therapy in the United States (US). Olaparib was the first PARPi to be approved as first-line maintenance monotherapy in the US, with maintenance niraparib subsequently approved in the first-line setting. Data also support the efficacy of rucaparib as first-line maintenance monotherapy. PARPi maintenance combination therapy (olaparib plus bevacizumab) also provides benefit in patients with newly diagnosed advanced OC whose tumors tested positive for homologous recombination deficiency (HRD). Biomarker testing is critical in the newly diagnosed setting to identify patients most likely to benefit from PARPi maintenance therapy and guide treatment decisions. Clinical trial data support the use of PARPis (olaparib, niraparib, rucaparib) as second-line or later maintenance therapy in patients with platinum-sensitive relapsed OC. Although distinct differences in tolerability profile were observed between PARPis, they were generally well tolerated, with the majority of adverse events managed by dose modification. PARPis had no detrimental effect on patients' health-related quality of life. Real-world data support the use of PARPis in OC, although some differences between PARPis are apparent. Data from trials investigating novel combination strategies, such as PARPis plus immune checkpoint inhibitors, are awaited with interest; the optimal sequencing of novel therapies in OC remains to be established.

Managing Adverse Effects Associated With Poly (ADP-ribose) Polymerase Inhibitors in Ovarian Cancer: A Synthesis of Clinical Trial and Real-World Data

The use of poly (ADP-ribose) polymerase (PARP) inhibitor therapy is standard care in the management of patients with various malignancies including ovarian, breast, prostate, and pancreatic cancers. PARP inhibitors have been approved in different settings for patients with specific hereditary pathogenic variants, most notably homologous recombination repair pathways such as BRCA1 and BRCA2 genes. The vast experience with PARP inhibitors (olaparib, niraparib, rucaparib) has been in the management of epithelial ovarian cancer. There have not been any head-to-head comparisons of PARP inhibitors in randomized trials, and we can only perform cross-comparison on the basis of the reported literature. The three approved PARP inhibitors share several common adverse effects because of a class effect including nausea, fatigue, and anemia, but there are notable differences likely because of variations in their poly-pharmacology and off-target effects. Finally, patients included in clinical trials are often younger with a good performance status and less comorbidities than the real-world population, and hence, the potential benefits and adverse effects may not be superimposable. In this review, we describe these differences and discuss strategies to mitigate and manage adverse side effects effectively.

Safety and management of niraparib monotherapy in ovarian cancer clinical trials

Niraparib is a poly (ADP-ribose) polymerase inhibitor that has shown a significant improvement in progression-free survival irrespective of biomarker status in patients with advanced epithelial ovarian cancer. This review focuses on the adverse events associated with niraparib and their management to maintain efficacy of niraparib treatment and improve quality of life for patients. In five trials assessing efficacy of niraparib in patients with advanced epithelial ovarian cancer (PRIMA, NOVA, NORA, QUADRA, and PRIME), treatment-emergent adverse events of any grade were reported in nearly all patients (≥99%) receiving niraparib; the events were grade ≥3 in 51-74% of patients. Across all lines of therapy, treatment-emergent adverse events led to dose interruptions in 62-80% of patients receiving niraparib and dose reductions in 47-71%. Hematologic events were most frequently reported, including thrombocytopenia, anemia, and neutropenia. Common non-hematologic events included gastrointestinal events, which were generally low grade (<5% were grade ≥3). Clinical strategies to manage these and other events, such as fatigue and insomnia, cognitive behavioral therapy and pharmacologic agents, are summarized. Once-daily niraparib dosing may be advantageous for some patients for many reasons, including night-time dosing which may help alleviate gastrointestinal symptoms. An individualized starting dose (determined by baseline body weight and platelet count) of niraparib demonstrated an improved safety profile while maintaining efficacy. Patients receiving the niraparib individualized starting dose had fewer grade ≥3 adverse events, dose interruptions, and dose reductions than patients receiving a fixed starting dose. The safety profile of niraparib across five pivotal studies in advanced epithelial ovarian cancer was consistent across multiple lines of treatment, including as maintenance therapy in first-line and recurrent settings and as treatment in heavily pre-treated patients. Long-term safety data from the NOVA trial confirmed that, with appropriate and early dose modifications, niraparib is well tolerated.

A Randomized, Phase III Trial to Evaluate Rucaparib Monotherapy as Maintenance Treatment in Patients With Newly Diagnosed Ovarian Cancer (ATHENA-MONO/GOG-3020/ENGOT-ov45)

PURPOSE

ATHENA (ClinicalTrials.gov identifier: NCT03522246) was designed to evaluate rucaparib first-line maintenance treatment in a broad patient population, including those without BRCA1 or BRCA2 (BRCA) mutations or other evidence of homologous recombination deficiency (HRD), or high-risk clinical characteristics such as residual disease. We report the results from the ATHENA-MONO comparison of rucaparib versus placebo.

METHODS

Patients with stage III-IV high-grade ovarian cancer undergoing surgical cytoreduction (R0/complete resection permitted) and responding to first-line platinum-doublet chemotherapy were randomly assigned 4:1 to oral rucaparib 600 mg twice a day or placebo. Stratification factors were HRD test status, residual disease after chemotherapy, and timing of surgery. The primary end point of investigator-assessed progression-free survival was assessed in a step-down procedure, first in the HRD population (BRCA-mutant or BRCA wild-type/loss of heterozygosity high tumor), and then in the intent-to-treat population.

RESULTS

As of March 23, 2022 (data cutoff), 427 and 111 patients were randomly assigned to rucaparib or placebo, respectively (HRD population: 185 v 49). Median progression-free survival (95% CI) was 28.7 months (23.0 to not reached) with rucaparib versus 11.3 months (9.1 to 22.1) with placebo in the HRD population (log-rank P = .0004; hazard ratio [HR], 0.47; 95% CI, 0.31 to 0.72); 20.2 months (15.2 to 24.7) versus 9.2 months (8.3 to 12.2) in the intent-to-treat population (log-rank P < .0001; HR, 0.52; 95% CI, 0.40 to 0.68); and 12.1 months (11.1 to 17.7) versus 9.1 months (4.0 to 12.2) in the HRD-negative population (HR, 0.65; 95% CI, 0.45 to 0.95). The most common grade ≥ 3 treatment-emergent adverse events were anemia (rucaparib, 28.7% v placebo, 0%) and neutropenia (14.6% v 0.9%).

CONCLUSION

Rucaparib monotherapy is effective as first-line maintenance, conferring significant benefit versus placebo in patients with advanced ovarian cancer with and without HRD.

A Pan-Canadian Consensus Statement on First-Line PARP Inhibitor Maintenance for Advanced, High-Grade Serous and Endometrioid Tubal, Ovarian, and Primary Peritoneal Cancers

The majority of patients with advanced, high-grade epithelial-tubo ovarian cancer (EOC) respond well to initial treatment with platinum-based chemotherapy; however, up to 80% of patients will experience a recurrence. Poly(ADP-ribose) Polymerase (PARP) inhibitors have been established as a standard of care maintenance therapy to prolong remission and prevent relapse following a response to first-line platinum-chemotherapy. Olaparib and niraparib are the PARP inhibitors currently approved for use in the first-line maintenance setting in Canada. Selection of maintenance therapy requires consideration of patient and tumour factors, presence of germline and somatic mutations, expected drug toxicity profile, and treatment access. This paper discusses the current clinical evidence for first-line PARP inhibitor maintenance therapy in patients with advanced, high-grade EOC and presents consensus statements and a treatment algorithm to aid Canadian oncologists on the selection and use of PARP inhibitors within the Canadian EOC treatment landscape.

Individualization in the first-line treatment of advanced ovarian cancer based on the mechanism of action of molecularly targeted drugs

With the development of poly(ADP-ribose) polymerase inhibitors, the treatment of advanced ovarian cancer is changing dramatically. The purpose of this narrative review is to provide a direction for the individualization of advanced ovarian cancer treatment based on the mechanism of action of molecularly targeted drugs currently used in Japan. The PAOLA-1 study showed very good progression-free survival in patients with homologous recombination deficiency tumors who underwent complete surgery with primary debulking surgery and who received olaparib plus bevacizumab. Niraparib has high intratumor penetration, and in a subgroup analysis of the PRIMA study, it was most effective in patients with residual tumors after interval debulking surgery. These data suggest the importance of achieving complete surgery and aiming for cure in the treatment of ovarian cancer and how the use of bevacizumab, olaparib, and niraparib should be individualized.

Appropriate Selection of PARP Inhibitors in Ovarian Cancer

OPINION STATEMENT

Poly-ADP-ribose polymerase inhibitors (PARPi) are a class of anti-cancer drugs that target DNA repair pathways and have shown promising efficacy in patients with ovarian cancer in recent clinical trials. To date, there have been 9 FDA PARPi approvals/indications in ovarian cancer since 2014, highlighting the importance of this class of agents in the treatment of ovarian cancer. BRCA1/2-mutated tumors or other forms of homologous recombination deficient (HRD) tumors are particularly susceptible to PARP inhibition and have seen the greatest benefits of improvement in response rate and progression-free survival (PFS) in clinical trials. Patients with homologous recombination-proficient tumors also receive benefit, especially when a nice response to paltinum is noted, but to a lesser extent. PARP inhibitors now have FDA approval and indications in first-line and recurrent maintenance, and treatment. PARP inhibitor use as maintenance therapy in the front-line setting is now considered the standard of care in patients with BRCA1/2 mutations based on the SOLO-1/GOG-3004/ENGOT study. PARP inhibitors are also recommended per ASCO guidelines in all patients with ovarian cancer as front-line maintenance therapy based on the PRIMA/ENGOT-OV26/GOG-3012 trial. The combination of PARP inhibitor, olaparib, and the anti-angiogenesis inhibitor bevacizumab is also approved as maintenance therapy after front-line chemotherapy treatment in patients with HRD tumors and is an option for patients who have initiated bevacizumab with their chemotherapy treatment. PARPi are also FDA approved and can be utilized as a treatment in third-line and beyond in recurrent ovarian cancer patients with BRCA1/2 mutations and HRD tumors. In this review, we will cover in detail when PARP inhibitor use is appropriate in ovarian cancer, as well as the various clinical factors to take into consideration when selecting a PARP inhibitor regimen.

Multi-Disciplinary Care Planning of Ovarian Cancer in Older Patients: General Statement-A Position Paper from SOFOG-GINECO-FRANCOGYN-SFPO

Simple Summary

This position paper aims to provide practitioners a proposal for multidisciplinary care planning for older patients with ovarian cancer from the time of suspected diagnosis. The first-line treatment of advanced ovarian cancer involves several interdependent sequences: cytoreductive surgery, (neo)adjuvant chemotherapy and maintenance targeted treatments. In older patients, care planning must be adapted to their geriatric parameters and consider the geriatric impact of each treatment sequence to allow treatment completion. Care planning should be centered on patient motivation and imply multidisciplinarity. Each step of treatment plan should be reconsidered in light of a geriatric assessment and follow-up. Studies are needed to prospectively evaluate the impact of geriatric vulnerability parameters at each step of the treatment agenda and the impact of geriatric interventions on patient outcomes.

Abstract

In this position paper the Société Francophone d’OncoGériatrie (SOFOG; French-speaking oncogeriatric society), the Société Française de Pharmacie Oncologique (SFPO, French society for oncology pharmacy), the Groupe d’Investigateurs Nationaux pour l’Étude des Cancers de l’Ovaire et du sein (GINECO, National Investigators’ Group for Studies in Ovarian and Breast Cancer) and the Groupe Français de chirurgie Oncologique et Gynécologique (FRANCOGYN) propose a multi-disciplinary care planning of ovarian cancer in older patients. The treatment pathway is based on four successive decisional nodes (diagnosis, resectability assessment, operability assessment, adjuvant, and maintenance treatment decision) implying multidisciplinarity and adaptation of the treatment plan according to the patient’s geriatric covariates and her motivation towards treatment. Specific attention must be paid to geriatric intervention, supportive care and pharmaceutical conciliation. Studies are needed to prospectively evaluate the impact of geriatric vulnerability parameters at each step of the treatment agenda and the impact of geriatric interventions on patient outcomes.

Pharmacokinetics and Pharmacodynamics of PARP Inhibitors in Oncology

Olaparib, niraparib, rucaparib, and talazoparib are poly (ADP-ribose) polymerase (PARP) inhibitors approved for the treatment of ovarian, breast, pancreatic, and/or prostate cancer. Poly (ADP-ribose) polymerase inhibitors are potent inhibitors of the PARP enzymes with comparable half-maximal inhibitory concentrations in the nanomolar range. Olaparib and rucaparib are orally dosed twice a day, extensively metabolized by cytochrome P450 enzymes, and inhibitors of several enzymes and drug transporters with a high risk for drug-drug interactions. Niraparib and talazoparib are orally dosed once a day with a lower risk for niraparib and a minimal risk for talazoparib to cause drug-drug interactions. All four PARP inhibitors show moderate-to-high interindividual variability in plasma exposure. Higher exposure is associated with an increase in toxicity, mostly hematological toxicity. For talazoparib, exposure-efficacy relationships have been described, but for olaparib, niraparib, and rucaparib this relationship remains inconclusive. Further studies are required to investigate exposure-response relationships to improve dosing of PARP inhibitors, in which therapeutic drug monitoring could play an important role. In this review, we give an overview of the pharmacokinetic properties of the four PARP inhibitors, including considerations for patients with renal dysfunction or hepatic impairment, the effect of food, and drug-drug interactions. Furthermore, we focus on the pharmacodynamics and summarize the available exposure-efficacy and exposure-toxicity relationships.

Maintenance Treatment of Newly Diagnosed Advanced Ovarian Cancer: Time for a Paradigm Shift?

Recent data have demonstrated substantial efficacy with poly (ADP-ribose) polymerase (PARP) inhibitors as treatment and/or maintenance therapy in patients with newly diagnosed advanced epithelial ovarian cancer (EOC). Here, we review efficacy and safety results from four recent Phase III trials in newly diagnosed EOC: SOLO1 (olaparib), PAOLA-1 (olaparib in combination with bevacizumab), PRIMA (niraparib), and VELIA (veliparib). The implications of these data for current clinical practice and areas for future research are discussed, including ongoing studies of targeted agents in the newly diagnosed setting. Data from SOLO1, PAOLA-1, PRIMA, and VELIA confirm the benefit of PARP inhibitors (olaparib, niraparib, veliparib) for women with newly diagnosed EOC. The greatest benefit was seen in patients with a BRCA1 and/or BRCA2 mutation or in the homologous recombination deficiency (HRD)-test positive subgroup. These four well-conducted studies have generated practice-changing data. However, deciding how to apply these results in clinical practice is challenging, and substantial differences in trial design impede cross-trial comparisons. Recent PARP inhibitor approvals (olaparib, niraparib) in the newly diagnosed EOC setting have provided new maintenance treatment options for a broader patient population. The results of these studies call for personalized medicine based on biomarker profile and other factors, including tolerability, cost considerations, and physician and patient preference. Important areas for future research include appropriate use of both BRCA mutation and HRD testing to inform magnitude of PARP inhibitor benefit as well as exploring further options for patients who are HRD-test negative and for those who become PARP inhibitor resistant.

Niraparib: A Review in First-Line Maintenance Therapy in Advanced Ovarian Cancer

Niraparib (Zejula™) is a PARP inhibitor which is approved for maintenance therapy in adults with advanced ovarian cancer in complete or partial response to platinum-based chemotherapy. In a placebo-controlled phase III trial in patients with newly diagnosed advanced ovarian cancer, niraparib significantly extended progression free survival in two predefined populations, namely a patient population with altered homologous-recombination DNA repair pathways [i.e. homologous-recombination deficiency positive (HRd)] and the overall trial population. A prespecified exploratory subgroup analysis indicated that niraparib was also efficacious in patients who were homologous recombination deficiency negative or homologous recombination proficient (HRp). Niraparib has a manageable tolerability profile with myelosuppression as the main safety concern. Haematological reactions were managed with monitoring and dose reduction or interruption. A weight- and platelet count-based individualised dosage regimen introduced during the trial (and subsequently approved) appeared to improve haematological tolerability. Niraparib is a useful option for first-line maintenance therapy for advanced ovarian cancer in adults who responded to platinum-based chemotherapy, regardless of homologous-recombination deficiency status and is a promising option for HRp patients, for whom maintenance treatment options are limited.

Population-adjusted indirect treatment comparison of maintenance PARP inhibitor with or without bevacizumab versus bevacizumab alone in women with newly diagnosed advanced ovarian cancer

BACKGROUND

In patients with newly diagnosed ovarian cancer, bevacizumab and poly(ADP-ribose) polymerase (PARP) inhibitors, alone or in combination, have shown benefit as maintenance treatment following platinum-based chemotherapy. However, no trials have compared a PARP inhibitor plus bevacizumab versus a PARP inhibitor, or a PARP inhibitor versus bevacizumab. We performed an unanchored population-adjusted indirect treatment comparison to estimate the relative efficacy and safety of maintenance treatments for newly diagnosed advanced ovarian cancer.

METHODS

Analyses were performed using aggregate data from the PRIMA trial and patient-level data from a subset of patients from the PAOLA-1 trial that met surgery and staging eligibility criteria of PRIMA. Propensity weights were used to match baseline characteristics of the PAOLA-1 subset to those of the PRIMA population. Analysis was performed in overall (biomarker-unselected) and homologous recombination repair deficiency (HRD)-positive populations.

RESULTS

A total of 595/806 (266/387 HRD-positive) PAOLA-1 patients were included. After matching, the effective sample size for PAOLA-1 was 532 (242 HRD-positive). Maintenance olaparib plus bevacizumab reduced the risk of disease progression or death by 43% [hazard ratio (HR) 0.57; 95% confidence interval (CI): 0.47-0.69] versus niraparib and by 40% (HR 0.60; 95% CI: 0.49-0.74) versus bevacizumab in the biomarker-unselected population and by 43% (HR 0.57; 95% CI: 0.41-0.79) and 60% (HR 0.40; 95% CI: 0.29-0.55), respectively, in the HRD-positive population. Progression-free survival (PFS) benefits of maintenance niraparib and bevacizumab arms were comparable in the biomarker-unselected population (HR 1.07; 95% CI: 0.87-1.32); however, niraparib showed a 30% reduced risk compared with bevacizumab (HR 0.70; 95% CI: 0.51-0.97) in the HRD-positive population.

CONCLUSIONS

In biomarker-unselected and HRD-positive patients, combination treatment with olaparib plus bevacizumab as maintenance treatment improves PFS for women with newly diagnosed advanced ovarian cancer compared with either bevacizumab or niraparib alone. Results are hypothesis generating and could guide randomised trial design.

First-line PARP inhibitors in ovarian cancer: summary of an ESMO Open - Cancer Horizons round-table discussion

Poly(ADP-ribose) polymerase (PARP) inhibitor maintenance therapy is the latest breakthrough in the management of newly diagnosed advanced ovarian cancer. The results of the SOLO-1 trial in 2018 led to European Medicines Agency and Food and Drug Administration approval of olaparib as first-line maintenance therapy in patients with BRCA1/2 mutation, establishing a new standard of care. Subsequently, the results of three phase III trials (PRIMA, PAOLA-1, VELIA) evaluating the use of first-line PARP inhibitors beyond patients with BRCA1/2 mutations and as combination strategies were presented in 2019, leading to the recent approval of maintenance niraparib irrespective of biomarker status and olaparib in combination with bevacizumab in homologous recombination deficiency-positive-associated advanced ovarian cancer. An ESMO Open - Cancer Horizons round-table expert panel discussed the four phase III trials of first-line PARP inhibitor therapy and how they are changing the clinical management of advanced ovarian cancer.

Population exposure-efficacy and exposure-safety analyses for rucaparib in patients with recurrent ovarian carcinoma from Study 10 and ARIEL2

OBJECTIVE

To evaluate correlations between rucaparib exposure and selected efficacy and safety endpoints in patients with recurrent ovarian carcinoma using pooled data from Study 10 and ARIEL2.

METHODS

Efficacy analyses were limited to patients with carcinomas harboring a deleterious BRCA1 or BRCA2 mutation who had received ≥2 prior lines of chemotherapy. Safety was evaluated in all patients who received ≥1 rucaparib dose. Steady-state daily area under the concentration-time curve (AUCss) and maximum concentration (Cmax,ss) for rucaparib were calculated for each patient and averaged by actual dose received over time (AUCavg,ss and Cmax,avg,ss) using a previously developed population pharmacokinetic model.

RESULTS

Rucaparib exposure was dose-proportional and not associated with baseline patient weight. In the exposure-efficacy analyses (n = 121), AUCavg,ss was positively associated with independent radiology review-assessed RECIST response in the subgroup of patients with platinum-sensitive recurrent disease (n = 75, p = 0.017). In the exposure-safety analyses (n = 393, 40 mg once daily to 840 mg twice daily [BID] starting doses), most patients received a 600 mg BID rucaparib starting dose, with 27% and 21% receiving 1 or ≥2 dose reductions, respectively. Cmax,ss was significantly correlated with grade ≥2 serum creatinine increase, grade ≥3 alanine transaminase/aspartate transaminase increase, platelet decrease, fatigue/asthenia, and maximal hemoglobin decrease (p < 0.05).

CONCLUSION

The exposure-response analyses provide support for the approved starting dose of rucaparib 600 mg BID for maximum clinical benefit with subsequent dose modification only following the occurrence of a treatment-emergent adverse event in patients with BRCA-mutated recurrent ovarian carcinoma.

Niraparib maintenance therapy in patients with platinum-sensitive recurrent ovarian cancer using an individualized starting dose (NORA): a randomized, double-blind, placebo-controlled phase III trial☆

BACKGROUND

This study evaluated maintenance treatment with niraparib, a potent inhibitor of poly(ADP-ribose) polymerase 1/2, in patients with platinum-sensitive recurrent ovarian cancer.

PATIENTS AND METHODS

In this phase III, double-blind, placebo-controlled study conducted at 30 centers in China, adults with platinum-sensitive recurrent ovarian cancer who had responded to their most recent platinum-containing chemotherapy were randomized 2 : 1 to receive oral niraparib (300 mg/day) or matched placebo until disease progression or unacceptable toxicity (NCT03705156). Following a protocol amendment, patients with a bodyweight <77 kg or a platelet count <150 × 10³/μl received 200 mg/day, and all other patients 300 mg/day, as an individualized starting dose (ISD). Randomization was carried out by an interactive web response system and stratified by BRCA mutation, time to recurrence following penultimate chemotherapy, and response to most recent chemotherapy. The primary endpoint was progression-free survival (PFS) assessed by blinded independent central review.

RESULTS

Between 26 September 2017 and 2 February 2019, 265 patients were randomized to receive niraparib (n = 177) or placebo (n = 88); 249 patients received an ISD (300 mg, n = 14; 200 mg, n = 235) as per protocol. In the intention-to-treat population, median PFS was significantly longer for patients receiving niraparib versus placebo: 18.3 [95% confidence interval (CI), 10.9-not evaluable] versus 5.4 (95% CI, 3.7-5.7) months [hazard ratio (HR) = 0.32; 95% CI, 0.23-0.45; P < 0.0001], and a similar PFS benefit was observed in patients receiving an ISD, regardless of BRCA mutation status. Grade ≥3 treatment-emergent adverse events occurred in 50.8% and 19.3% of patients who received niraparib and placebo, respectively; the most common events were neutrophil count decreased (20.3% versus 8.0%) and anemia (14.7% versus 2.3%).

CONCLUSIONS

Niraparib maintenance treatment reduced the risk of disease progression or death by 68% and prolonged PFS compared to placebo in patients with platinum-sensitive recurrent ovarian cancer. Individualized niraparib dosing is effective and safe and should be considered standard practice in this setting.

Therapeutic options following second-line platinum-based chemotherapy in patients with recurrent ovarian cancer: Comparison of active surveillance and maintenance treatment

Most women with advanced ovarian cancer respond to initial treatment, consisting of surgical resection and ≈6 cycles of platinum-based chemotherapy. However, disease recurrence occurs in most patients, and subsequent therapies become necessary. Historically, close monitoring following treatment (active surveillance) was the only available option, as continued maintenance chemotherapy treatment led to increased toxicity without providing any meaningful clinical benefit. Recently, targeted therapy with the angiogenesis inhibitor bevacizumab and the poly(ADP-ribose) polymerase (PARP) inhibitors olaparib, niraparib, and rucaparib have demonstrated significant clinical benefits as maintenance treatment for recurrent disease. Despite consensus guidelines recommending their use, maintenance treatments are currently underutilized. Here, we review evidence from pivotal clinical trials of approved second-line maintenance treatments demonstrating efficacy in terms of progression-free survival and postprogression efficacy outcomes for patients with recurrent ovarian cancer. Adverse events frequently associated with bevacizumab include hypertension, proteinuria, and non-central nervous system bleeding, whereas PARP inhibitors are associated with nausea, vomiting, fatigue, and anemia. Patient-centered outcomes analyses show that PARP inhibitors provide significant benefits to patient health status, even when accounting for the toxicities associated with treatment. Many factors influence the selection of second-line maintenance treatment for patients with recurrent ovarian cancer, including the maintenance treatment received in the first-line setting. Overall, targeted maintenance treatment represents a new standard of care for patients with ovarian cancer, and we recommend that maintenance treatment should be offered to all eligible patients with recurrent ovarian cancer.