Efficacy and safety of olaparib according to age in BRCA1/2-mutated patients with recurrent platinum-sensitive ovarian cancer: Analysis of the phase III SOLO2/ENGOT-Ov21 study

Efficacy and safety of niraparib in patients aged 65 years and older with advanced ovarian cancer: Results from the PRIMA/ENGOT-OV26/GOG-3012 trial

OBJECTIVE

To evaluate the impact of age on the efficacy and safety of niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer with a complete/partial response to first-line platinum-based chemotherapy.

METHODS

Post hoc analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study (NCT02655016). Patients in the intent-to-treat population were categorized according to age at baseline (<65 years vs ≥65 years), and progression-free survival (PFS), safety, and health-related quality of life (HRQOL) were evaluated for each age subgroup (clinical cutoff date, May 17, 2019). Safety findings were also evaluated according to a fixed starting dose (FSD) or an individualized starting dose (ISD).

RESULTS

Of 733 randomized patients, 289 (39.4%) were ≥65 years (190 niraparib, 99 placebo) at baseline. Median PFS (niraparib vs placebo) and hazard ratios (95% CI) were similar in patients aged <65 years (13.9 vs 8.2 months; HR, 0.61 [0.47-0.81]) and ≥65 years (13.7 vs 8.1 months; HR, 0.53 [0.39-0.74]). The incidences of any-grade and grade ≥3 treatment-emergent adverse events (TEAEs) were similar across age subgroups; in the niraparib arm, TEAEs leading to dose discontinuation occurred in 7.8% of patients <65 years and 18.4% of patients ≥65 years. ISD use lowered the incidence of grade ≥3 thrombocytopenia events in niraparib-treated patients compared with the FSD (<65 years: 42.8% vs 18.0%; ≥65 years 57.0% vs 26.1%). HRQOL was comparable across age subgroups.

CONCLUSION

Niraparib efficacy, safety, and HRQOL were generally comparable across age subgroups, although patients ≥65 years had a higher rate of discontinuations due to TEAEs. ISD use reduced grade ≥3 thrombocytopenia events regardless of age.

PARP Inhibitors: Strategic Use and Optimal Management in Ovarian Cancer

Poly (ADP-ribose) polymerase (PARP) inhibitors have become an established part of the anticancer armamentarium. Discovered in the 1980s, PARP inhibitors (PARPis) were initially developed to exploit the presence of BRCA mutations, which disrupt the homologous recombination repair of deoxyribonucleic acid (DNA) via synthetic lethality, an intrinsic vulnerability caused by the cell's dependence on other DNA repair mechanisms for which PARP is an essential contributor. PARPi use expanded with the demonstration of clinical benefit when other mechanisms of high-fidelity DNA damage response were present in cancer cells called homologous repair deficiency (HRD). Recently, new data have resulted in the voluntary withdrawal of later-line treatment indications for all the available PARPis used in ovarian cancer because of a negative impact on overall survival (OS). PARPi switch maintenance to consolidate a response to platinum-based therapy is recommended for earlier treatment lines to have the greatest impact on the chance of cure and length of survival. This article reviews the clinical utility of PARPis and how to integrate them into best practices.

Efficacy and safety of PARP inhibitors for maintenance treatment of ovarian cancer, regardless of BRCA or HRD status: a comprehensive updated meta-analysis

Without taking into account existing biomarkers like genetic mutations (BRCA mutation, Homologous recombination deficiency) with advanced ovarian cancer (OC), the overall survival (OS), progress-free survival (PFS) of the aggregate all groups that have been classified were hazard ratio (HR): 0.72, 95% confidence intervals (CI): 0.66-0.79 and HR: 0.48, 95%CI: 0.44-0.52, respectively. Meanwhile, the OS and PFS of the whole population (regardless of existing genetic mutation markers) were HR: 0.74, 95%CI: 0.64-0.87 and HR: 0.52, 95%CI: 0.42-0.65, separately. Furthermore, the OS and PFS of positive gene mutation markers were HR: 0.71, 95%CI: 0.61-0.83 (HRD and BRACm) and HR: 0.47, 95%CI: 0.42-0.52 (HRD and BRACm), individually. The poly ADP-ribose polymers (PARP) inhibitors have desired efficiency and security in the maintenance treatment of advanced OC patients with BRCAm or BRCAwt, HRD or HRP and unknown gene status.

Safety of PARP inhibitors as maintenance therapy in ovarian cancer

INTRODUCTION

Antiangiogenic agents and poly(ADP-ribose) polymerase inhibitors (PARP-Is) have improved the outcome of patients suffering from ovarian cancer. However, as they are associated with many adverse events (AEs), it is important to be aware of their safety and toxicity profiles.

AREAS COVERED

We reviewed PARP-I therapeutical indications, mechanism of action, metabolism, and interactions. We reported on all major and minor AEs that have emerged from clinical trials (SOLO1, PRIMA, PAOLA1, ATHENA, SOLO2, NOVA, ARIEL3, NORA), their follow-ups, meta-analyses, and real-world studies, particularly hematologic toxicities and their management, and secondary malignancies (myelodysplastic syndrome and acute myeloid leukemia). We also addressed gastrointestinal, neurological, respiratory, hepatic, and renal toxicity and the use of PARP-Is in older, pregnant, and lactating patients. No specific research strategy in terms of keywords, inclusive dates and databases was used.

EXPERT OPINION

PARP-Is benefits largely outweigh the risks associated with potential AEs. Randomized controlled trials produced strong good, quality data, but they enrolled a selected population and failed to capture rare events. More pharmacovigilance data and real-life studies on a larger and more heterogeneous sample are needed to understand PARP-Is differences and to clarify the incidence of late AEs to balance the risk/benefit ratio.

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.

Efficacy and safety of maintenance olaparib and bevacizumab in ovarian cancer patients aged ≥65 years from the PAOLA-1/ENGOT-ov25 trial

BACKGROUND

The phase III PAOLA-1/ENGOT-ov25 study (NCT02477644) showed that addition of olaparib to bevacizumab maintenance improved progression-free survival (PFS) in patients with newly diagnosed advanced ovarian cancer. We evaluated maintenance olaparib plus bevacizumab in older patients in PAOLA-1.

METHODS

Baseline clinical and molecular data, and PFS, were compared between older (aged ≥65 years) and younger patients (<65 years). Factors associated with olaparib efficacy, and safety in age subgroups, were also assessed.

RESULTS

Of 806 randomised patients, 292 (36.2%) were ≥65 years. A lower proportion of older versus younger patients had an Eastern Cooperative Oncology Group performance status of 0 (61.0% versus 76.2%) and upfront surgery (42.0% versus 55.7%). Older patients were less likely to have a BRCA1/2 mutation (17.1% versus 36.7%) or homologous recombination deficiency-positive status (34.1% versus 55.7%). After median follow-up of 22.1 months, median PFS was 21.6 months with olaparib versus 16.6 months with placebo in the older population (hazard ratio [HR] 0.55, 95% confidence interval [CI] 0.41-0.75), comparable with the younger population (median 22.9 versus 16.9 months; HR 0.61, 95% CI 0.49-0.77). PFS benefits were observed in patients with a BRCA mutation or homologous recombination deficiency-positive tumours. Incidence of olaparib-related grade ≥3 adverse events in older patients was comparable with that of younger patients (36.8% versus 31.7%) although hypertension and anaemia were more common in older patients. No treatment-related deaths occurred in older patients receiving olaparib.

CONCLUSION

Older patients enrolled in PAOLA-1 achieved similar PFS benefits compared with younger patients, with a similar safety profile.

PARP inhibitors: risk factors for toxicity and matching patients to the proper poly (ADP-ribose) polymerase inhibitor (PARPi) therapy

The past 5 years have seen several fundamental advances in ovarian cancer, with important new insights towards novel therapeutic opportunities within the DNA repair pathway. With the incorporation of poly (ADP-ribose) polymerase inhibitors (PARPi) into maintenance treatment regimens, the management of short- and long-term adverse events are key clinical priorities. Currently, three different PARPi are clinically beneficial and have been approved for primary and recurrent ovarian cancer: olaparib, niraparib, and rucaparib. The duration of treatment with PARPi in patients with ovarian cancer varies; patients can receive treatment for up to 2 or 3 years in first-line setting, or continue treatment until unacceptable toxicity or progression occurs in recurrent disease. Despite their similar mechanisms of action, these three inhibitors have specific toxicity profiles, which may lead to dose interruptions or discontinuation of treatment. This review summarizes the current indications for PARPi, including their role in recurrent and first-line maintenance treatment for advanced ovarian cancer. We also outline dose modifications leading to treatment disruption and potential changes in quality of life after prolonged treatment. Finally, we highlight the patient groups most likely to benefit from each of the three different PARPi.

Myeloid neoplasms post PARP inhibitors for ovarian cancer

The incidence of myeloid neoplasms following treatment with poly (ADP-ribose) polymerase inhibitors (PARPi) in patients with ovarian cancer has been gradually increasing over the last few years. The cumulative exposure to PARPi and the improved overall survival of patients with ovarian cancer may represent key underlying explanations behind such trend. Fortunately, the earlier introduction of PARPi in the frontline setting reduces the risk of developing secondary myeloid neoplasms. The etiopathogenesis is still unclear but is likely to be multifactorial. The first 2 years of PARPi exposure seem to be the critical window for the onset of myeloid neoplasms post PARPi, with persistent cytopenia recognized as an early warning sign. Despite intensive treatment strategies, the outcome remains poor. There is an unmet clinical need to learn how to minimize risk, make an early diagnosis, and manage myeloid neoplasms post PARPi. First, decision making regarding the optimal maintenance treatment should avoid a 'PARPi-for-all' strategy. PARPi should be used cautiously in cases of high baseline risk for myeloid neoplasms and/or patients who are less likely to have a benefit. Active surveillance, accurate differential diagnosis, and prompt hematological referral are key management pillars. This review discusses what is known on this emerging issue as well as unresolved questions.

Expression pattern and prognostic potential of histamine receptors in epithelial ovarian cancer

PURPOSE

Despite recent advances in the treatment of ovarian cancer (OC), long-term remissions remain scarce. For a targeted approach, prognostic markers are indispensable for predicting survival and treatment response. Given their association with multiple hallmarks of cancer, histamine receptors (HR) are emerging as promising candidates. Here, we investigate their expression pattern and prognostic value in OC.

METHODS

Specimens of 156 epithelial OC patients were collected during cytoreductive surgery at the Department of Obstetrics and Gynecology, LMU, between 1990 and 2002 and combined in a tissue microarray. Immunohistochemical staining of the HR H1, H2, H3 and H4 was quantified by an immunoreactive score and linked with clinico-pathological data by Spearman's correlation. Via ROC curve analysis, optimal cut-off values for potential prognostic markers were defined. Overall survival (OS) was visualized in Kaplan-Maier curves and significances determined by log-rank testing. A Cox regression model was applied for multivariate analysis.

RESULTS

HR H3 and H4 expression was restricted to the cytosol of OC cells, while H1 was also present in the nucleus. A significant association between HR H1, H3 and H4 expression with several clinico-pathological parameters was revealed. In addition, HR H1 and H3 expression correlated positively, HR H4 expression negatively with OS. In addition, HR H3 was identified as independent prognostic marker for OS. HR H2 expression had no prognostic value.

CONCLUSIONS

HR H1, H3 and H4 could serve as potential predictors for OS of OC patients. Further research is warranted to elucidate their pathophysiologic role and their predictive and therapeutic potential in OC.