Olaparib Maintenance Monotherapy in Asian Patients with Platinum-Sensitive Relapsed Ovarian Cancer: Phase III Trial (L-MOCA)

Exploratory biomarker analysis in the phase III L-MOCA study of olaparib maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer

BACKGROUND

The prospective phase III multi-centre L-MOCA trial (NCT03534453) has demonstrated the encouraging efficacy and manageable safety profile of olaparib maintenance therapy in the Asian (mainly Chinese) patients with platinum-sensitive relapsed ovarian cancer (PSROC). In this study, we report the preplanned exploratory biomarker analysis of the L-MOCA trial, which investigated the effects of homologous recombination deficiency (HRD) and programmed cell death ligand 1 (PD-L1) expression on olaparib efficacy.

METHODS

HRD status was determined using the ACTHRD assay, an enrichment-based targeted next-generation sequencing assay. PD-L1 expression was assessed by SP263 immunohistochemistry assay. PD-L1 expression positivity was defined by the PD-L1 expression on ≥ 1% of immune cells. Kaplan-Meier method was utilised to analyse progression-free survival (PFS).

RESULTS

This exploratory biomarker analysis included 225 patients and tested HRD status [N = 190; positive, N = 125 (65.8%)], PD-L1 expression [N = 196; positive, N = 56 (28.6%)], and BRCA1/2 mutation status (N = 219). The HRD-positive patients displayed greater median PFS than the HRD-negative patients [17.9 months (95% CI: 14.5-22.1) versus 9.2 months (95% CI: 7.5-13.8)]. PD-L1 was predominantly expressed on immune cells. Positive PD-L1 expression on immune cells was associated with shortened median PFS in the patients with germline BRCA1/2 mutations [14.5 months (95% CI: 7.4-18.2) versus 22.2 months (95% CI: 18.3-NA)]. Conversely, positive PD-L1 expression on immune cells was associated with prolonged median PFS in the patients with wild-type BRCA1/2 [20.9 months (95% CI: 13.9-NA) versus 8.3 months (95% CI: 6.7-13.8)].

CONCLUSIONS

HRD remained an effective biomarker for enhanced olaparib efficacy in the Asian patients with PSROC. Positive PD-L1 expression was associated with decreased olaparib efficacy in the patients with germline BRCA1/2 mutations but associated with improved olaparib efficacy in the patients with wild-type BRCA1/2.

TRIAL REGISTRATION

NCT03534453. Registered at May 23, 2018.

Current treatment strategies for ovarian cancer in the East Asian Gynecologic Oncology Trial Group (EAGOT)

Ovarian cancer, notable for its severe prognosis among gynecologic cancers, has seen substantial progress in treatment approaches recently. Enhanced protocols in chemotherapy and the introduction of poly (ADP-ribose) polymerase (PARP) inhibitors for maintenance therapy have markedly improved outcomes for patients with specific genetic profiles, such as those positive for BRCA mutations or exhibiting homologous recombination deficiency (HRD). Additionally, the method of intraperitoneal chemotherapy administration has emerged as a valuable alternative to traditional transvenous routes, showing promise for wider clinical adoption. The field of surgery has also evolved, with increasing exploration into the benefits and feasibility of laparoscopic methods over more invasive traditional surgeries, aiming for complete tumor removal but with reduced patient impact. The hereditary nature of ovarian cancer underscores the importance of genetic testing, which has become integral in tailoring treatment strategies, particularly in determining suitability for PARP inhibitors. The formation of the East Asian Gynecologic Oncology Trial Group (EAGOT) aims to optimize treatment across Japan, Korea, China, and Taiwan. The ovarian cancer committee of EAGOT shared the current policies, focusing on 5 topics: 1) strategies for maintenance therapy after initial surgery and chemotherapy, 2) drug regimens for platinum-sensitive and platinum-resistant recurrence, 3) intraperitoneal chemotherapy, 4) laparoscopic surgery as an alternative to laparotomy, and 5) current status of genetic testing (BRCA, HRD, and panel tests) for ovarian cancer and its prospects. EAGOT's multi-national trials aim to harmonize these evolving treatment strategies, ensuring that the latest and most effective protocols are accessible across the region, thereby significantly impacting patient outcomes in East Asia.

A real-world study of PARP inhibitors in 75 patients with platinum-sensitive recurrent ovarian cancer from China

Objective

The aim of this study is to assess the efficacy and safety of poly (ADP-ribose) polymerase inhibitor (PARPi) as a maintenance therapy for patients with platinum-sensitive recurrent epithelial ovarian cancer (PSROC) at the largest center of gynecologic oncology in Western China.

Patients and methods

The efficacy of PARPi was evaluated by progression-free survival (PFS) and overall survival (OS) in this real-world single-center retrospective cohort study conducted at West China Second University Hospital. The safety of PARPi was assessed using Common Terminology Criteria for Adverse Events Version 5.0.

Results

In this study, we included a total of 75 eligible patients, of which 54 (72.0%) received olaparib and 21 (28.0%) received niraparib. Among these patients, 24 (32.0%) had breast cancer susceptibility gene (BRCA) mutations, 27 (36.0%) achieved complete response after their last platinum-based therapy, and 22 (29.3%) had previously received ≥3rd-line chemotherapy. The median progression-free survival (mPFS) was 19.1 months (95% CI 8.5-29.7), and the median overall survival (mOS) had not been reached. Log-rank analysis revealed that age (<65 years old V.S. ≥65 years old) and previous lines of chemotherapy (2nd-line V.S. 3rd-line V.S. ≥4th-line) were associated with prolonged PFS (P <0.05). However, multivariate COX regression analysis did not identify any independent factors associated with prognosis (P >0.05). The most common grade≥3 adverse events in the olaparib group were anemia, thrombocytopenia, and leukopenia, while in the niraparib group, they were anemia and thrombocytopenia.

Conclusion

This study confirmed that olaparib and niraparib are effective and tolerate for PSROC in real-world settings. At the follow-up endpoint, no independent prognostic factor associated with prolonged PFS was identified.

Biology and Development of DNA-Targeted Drugs, Focusing on Synthetic Lethality, DNA Repair, and Epigenetic Modifications for Cancer: A Review

DNA-targeted drugs constitute a specialized category of pharmaceuticals developed for cancer treatment, directly influencing various cellular processes involving DNA. These drugs aim to enhance treatment efficacy and minimize side effects by specifically targeting molecules or pathways crucial to cancer growth. Unlike conventional chemotherapeutic drugs, recent discoveries have yielded DNA-targeted agents with improved effectiveness, and a new generation is anticipated to be even more specific and potent. The sequencing of the human genome in 2001 marked a transformative milestone, contributing significantly to the advancement of targeted therapy and precision medicine. Anticipated progress in precision medicine is closely tied to the continuous development in the exploration of synthetic lethality, DNA repair, and expression regulatory mechanisms, including epigenetic modifications. The integration of technologies like circulating tumor DNA (ctDNA) analysis further enhances our ability to elucidate crucial regulatory factors, promising a more effective era of precision medicine. The combination of genomic knowledge and technological progress has led to a surge in clinical trials focusing on precision medicine. These trials utilize biomarkers for identifying genetic alterations, molecular profiling for potential therapeutic targets, and tailored cancer treatments addressing multiple genetic changes. The evolving landscape of genomics has prompted a paradigm shift from tumor-centric to individualized, genome-directed treatments based on biomarker analysis for each patient. The current treatment strategy involves identifying target genes or pathways, exploring drugs affecting these targets, and predicting adverse events. This review highlights strategies incorporating DNA-targeted drugs, such as PARP inhibitors, SLFN11, methylguanine methyltransferase (MGMT), and ATR kinase.

Regeneration and anti-inflammatory effects of stem cells and their extracellular vesicles in gynecological diseases

There are many gynecological diseases, among which breast cancer (BC), cervical cancer (CC), endometriosis (EMs), and polycystic ovary syndrome (PCOS) are common and difficult to cure. Stem cells (SCs) are a focus of regenerative medicine. They are commonly used to treat organ damage and difficult diseases because of their potential for self-renewal and multidirectional differentiation. SCs are also commonly used for difficult-to-treat gynecological diseases because of their strong directional differentiation ability with unlimited possibilities, their tendency to adhere to the diseased tissue site, and their use as carriers for drug delivery. SCs can produce exosomes in a paracrine manner. Exosomes can be produced in large quantities and have the advantage of easy storage. Their safety and efficacy are superior to those of SCs, which have considerable potential in gynecological treatment, such as inhibiting endometrial senescence, promoting vascular reconstruction, and improving anti-inflammatory and immune functions. In this paper, we review the mechanisms of the regenerative and anti-inflammatory capacity of SCs and exosomes in incurable gynecological diseases and the current progress in their application in genetic engineering to provide a foundation for further research.

Proteomic characterization of epithelial ovarian cancer delineates molecular signatures and therapeutic targets in distinct histological subtypes

Clear cell carcinoma (CCC), endometrioid carcinoma (EC), and serous carcinoma (SC) are the major histological subtypes of epithelial ovarian cancer (EOC), whose differences in carcinogenesis are still unclear. Here, we undertake comprehensive proteomic profiling of 80 CCC, 79 EC, 80 SC, and 30 control samples. Our analysis reveals the prognostic or diagnostic value of dysregulated proteins and phosphorylation sites in important pathways. Moreover, protein co-expression network not only provides comprehensive view of biological features of each histological subtype, but also indicates potential prognostic biomarkers and progression landmarks. Notably, EOC have strong inter-tumor heterogeneity, with significantly different clinical characteristics, proteomic patterns and signaling pathway disorders in CCC, EC, and SC. Finally, we infer MPP7 protein as potential therapeutic target for SC, whose biological functions are confirmed in SC cells. Our proteomic cohort provides valuable resources for understanding molecular mechanisms and developing treatment strategies of distinct histological subtypes.

Homologous Recombination Deficiency Score Determined by Genomic Instability in a Romanian Cohort

The Homologous Recombination Deficiency (HRD) Score, determined by evaluating genomic instability through the assessment of loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transitions (LST), serves as a crucial biomarker for identifying patients who might benefit from targeted therapies, such as PARP inhibitors (PARPi). This study aimed to investigate the efficacy of HRD testing in high-grade serous ovarian carcinoma, tubal, and peritoneal cancer patients who are negative for somatic BRCA1 and BRCA2 mutations and to evaluate the impact of HRD status on Bevacizumab and PARPi therapy response. A cohort of 100 Romanian female patients, aged 42-77, was initially selected. Among them, 30 patients had unsuitable samples for HRD testing due to insufficient tumor content or DNA integrity. Using the OncoScan C.N.V. platform, HRD testing was successfully performed on the remaining 70 patients, with 20 testing negative and 50 testing positive for HRD. Among the HRD-positive patients, 35 were eligible for and benefited from PARPi maintenance therapy, resulting in a median progression-free survival (PFS) increase from 4 months to 8.2 months. Our findings support the importance of HRD testing in ovarian cancer patients, demonstrating the potential therapeutic advantage of PARPi therapy in HRD-positive patients without somatic BRCA1/2 mutations.

A Retrospective Study Comparing Olaparib and Bevacizumab as a Maintenance Therapy for Platinum-Sensitive Recurrent Ovarian Cancer: Impact on Recurrence-Free Survival in Japanese and Asian Populations

The use of angiogenesis inhibitors and poly ADP-ribose polymerase inhibitors following multi-agent chemotherapy, including platinum-based agents, has become the standard treatment for platinum-sensitive recurrent ovarian cancer (PSROC). However, the optimal maintenance therapy and selection criteria for these patients remain unclear. Thus, this study aimed to optimize the treatment options and selection criteria for patients with PSROC. The clinical data of 51 patients with PSROC admitted to Nippon Medical School Chiba Hokusoh Hospital and Nippon Medical School Hospital were retrospectively collected. The log-rank test was used for the survival analysis, and Cox proportional hazard regression analysis was used for the multivariate survival analysis. Of the 51 patients, 17 received maintenance therapy with bevacizumab (Bev), and 34 received olaparib (Ola). Recurrence-free survival (RFS) was significantly prolonged in the Ola group (27 months; 95% confidence interval (CI), 19-NA months) compared with that in the Bev group (9 months; 95% CI, 5-22 months; p = 0.000103). The efficacy of Ola was independent of background factors, including response to previous chemotherapy, homologous recombination status, histological type, or laboratory data. Ola is superior to Bev as PSROC maintenance therapy, especially in Japanese and Asian populations.

Homologous recombination deficiency status predicts response to platinum-based chemotherapy in Chinese patients with high-grade serous ovarian carcinoma

BACKGROUND

Homologous Recombination Deficiency (HRD) is a predictive biomarker for ovarian cancer treated with PARP inhibitors or for breast cancer treated with first-line platinum-based chemotherapy. However, limited research is documented on platinum-based treatment prediction with HRD as a biomarker in ovarian cancer patients, especially in the Chinese population.

METHODS

We investigated the association between HRD status and the response of platinum-based chemotherapy in 240 Chinese HGSOC patients.

RESULTS

The Pt-sensitive patients showed higher HRD scores than Pt-resistant ones, but this was not significant(median: 42.6 vs. 31.6, p = 0.086). (Pt)-sensitive rate was higher in HRD + BRCAm tumors and in HRD + BRCAwt tumors (HRD + BRCAm: 97%, p = 0.004 and HRD + BRCAwt: 90%, p = 0.04) compared with 74% in the HRD-BRCAwt tumors. We also found Pt-sensitive patients tend to be enriched in patients with BRCA mutations or non-BRCA HRR pathway gene mutations (BRCA: 93.6% vs 75.4%, p < 0.001; non-BRCA HRR: 88.6% vs 75.4%, p = 0.062). Patients with HRD status positive had significantly improved PFS compared with those with HRD status negative (median PFS: 30.5 months vs. 16.8 months, Log-rank p = 0.001). Even for BRCAwt patients, positive HRD was also associated with better PFS than the HRD-negative group (median: 27.5 months vs 16.8 months, Log-rank p = 0.010). Further, we found patients with pathogenic mutations located in the DNA-binding domain (DBD) of BRCA1 had improved FPS, compared to those with mutations in other domains. (p = 0.03).

CONCLUSIONS

The HRD status can be identified as an independent significance in Chinese HGSOC patients treated with first-line platinum-based chemotherapy.

Current status and future promise of next-generation poly (ADP-Ribose) polymerase 1-selective inhibitor AZD5305

The family of poly (ADP-ribose) polymerases (PARPs) consists of 17 members, which have been demonstrated as having effects on a series of cellular processes, including DNA replication and repair. PARP inhibitors (PARPi) suppress DNA repair through "PARP trapping", thus, constitute an important treatment option for cancer nowadays. In addition, PARP inhibition and homologous recombination repair (HRR) defects are synthetically lethal, giving a promising therapeutic for homologous recombination repair deficient (HRD) tumors including BRCA mutation. However, overlapping hematologic toxicity causes PARPi to fail in combination with some first-line chemotherapies. Furthermore, recent literature has demonstrated that PARP1 inhibition and PARP1-DNA trapping are key for antitumor activity in HRD cancer models. Currently approved PARPi have shown varying levels of selectivity for the entire 17-member PARP family, hence contribute to toxicity. Together, these findings above have provided the necessity and feasibility of developing next-generation PARPi with improved selectivity for PARP1, expanding significant clinical values and wide application prospects both in monotherapy and combination with other anticancer agents. In this review, we summery the latest research of current approved PARPi, discuss the current status and future promise of next-generation PARP1-selective inhibitor AZD5305, including its reported progress up to now and anticipated impact on clinical.

Targeted therapy and immunotherapy: Diamonds in the rough in the treatment of epithelial ovarian cancer

Currently, for ovarian cancer, which has the highest mortality rate among all gynecological cancers, the standard treatment protocol is initial tumor cytoreductive surgery followed by platinum-based combination chemotherapy. Although the survival rate after standard treatment has improved, the therapeutic effect of traditional chemotherapy is very limited due to problems such as resistance to platinum-based drugs and recurrence. With the advent of the precision medicine era, molecular targeted therapy has gradually entered clinicians' view, and individualized precision therapy has been realized, surpassing the limitations of traditional therapy. The detection of genetic mutations affecting treatment, especially breast cancer susceptibility gene (BRCA) mutations and mutations of other homologous recombination repair defect (HRD) genes, can guide the targeted drug treatment of patients, effectively improve the treatment effect and achieve a better patient prognosis. This article reviews different sites and pathways of targeted therapy, including angiogenesis, cell cycle and DNA repair, and immune and metabolic pathways, and the latest research progress from preclinical and clinical trials related to ovarian cancer therapy.

Comprehensive Analysis of Adverse Events Induced by PARP Inhibitors Using JADER and Time to Onset

Poly (ADP-ribose) polymerase (PARP) inhibitors are effective against breast cancer susceptibility gene (BRCA) mutations. Clinical trials have reported hematologic toxicity and gastrointestinal symptoms as class effects of PARP inhibitors. However, information on adverse events (AEs) in a Japanese clinical cohort is currently lacking. In this study, we conducted a comprehensive survey of the AEs of two PARP inhibitors, olaparib and niraparib, using the Japanese Adverse Reaction Reporting (JADER) database provided by the Pharmaceuticals and Medical Devices Agency (PMDA). Moreover, we also analyzed the course and time to the onset of AEs. Signals were detected for 15 and 11 AEs for olaparib and niraparib, respectively. Most occurred within the first month of treatment with either agent. These results may indicate the importance of early response and monitoring after beginning PARP inhibitor therapy. The results of this study may be useful for managing side effects and suggesting supportive care for patients using PARP inhibitors in the future.