Phase II study of niraparib in recurrent or persistent rare fraction of gynecologic malignancies with homologous recombination deficiency (JGOG2052)

Background

Poly (adenosine diphosphate)-ribose polymerase (PARP) inhibitors for tumors with homologous recombination deficiency (HRD), including pathogenic mutations in BRCA1/2, have been developed. Genomic analysis revealed that about 20% of uterine leiomyosarcoma (uLMS) have HRD, including 7.5%–10% of BRCA1/2 alterations and 4%–6% of carcinomas of the uterine corpus, and 2.5%–4% of the uterine cervix have alterations of BRCA1/2. Preclinical and clinical case reports suggest that PARP inhibitors may be effective against those targets. The Japanese Gynecologic Oncology Group (JGOG) is now planning to conduct a new investigator-initiated clinical trial, JGOG2052.

Methods

JGOG2052 is a single-arm, open-label, multi-center, phase 2 clinical trial to evaluate the efficacy and safety of niraparib monotherapy for a recurrent or persistent rare fraction of gynecologic malignancies with BRCA1/2 mutations except for ovarian cancers. We will independently consider the effect of niraparib for uLMS or other gynecologic malignancies with BRCA1/2 mutations (cohort A, C) and HRD positive uLMS without BRCA1/2 mutations (cohort B). Participants must have 1–3 lines of previous chemotherapy and at least one measurable lesion according to RECIST (v.1.1). Niraparib will be orally administered once a day until lesion exacerbation or unacceptable adverse events occur. Efficacy will be evaluated by imaging through an additional computed tomography scan every 8 weeks. Safety will be measured weekly in cycle 1 and every 4 weeks after cycle 2 by blood tests and physical examinations. The sample size is 16–20 in each of cohort A and B, and 31 in cohort C. Primary endpoint is the objective response rate.

Trial Registration

Japan Primary Registries Network (JPRN) Identifier: jRCT2031210264

[PARP Inhibitors: From the Mechanism of Action to Clinical Practice]

Repairing damage and errors that occur in the DNA molecule is essential to maintain the integrity of the genome and cell viability. Deficits in DNA repair mechanisms lead to an increased risk of genetic instability and contribute to neoplastic transformation. Poly (ADP-ribose) polymerases (PARP) are a group of enzymes that play a key role in signalling and repairing DNA errors. The inhibition of its activity is a therapeutic strategy that takes advantage of the mechanism of synthetic lethality and that can be used in the treatment of tumours with specific defects in DNA repair pathways, namely in tumours with mutations in the tumour suppressor genes BRCA1 and BRCA2. There are several PARP inhibitors (iPARP), already approved by the USA Food and Drug Administration and the European Medicines Agency used in the treatment of breast, ovarian, pancreatic and prostate cancer. However, as with other target therapies, despite being well tolerated and widely used in the clinical practice, iPARP resistance is common and can be developed through various molecular mechanisms. In this article, we intend to make an updated review on iPARP and its main role in tumour cells, highlighting the several resistance mechanisms that have been recently revealed, as well as the current clinical applications and toxicity associated with this target therapy.

A single-arm, phase II study of niraparib and bevacizumab maintenance therapy in platinum-sensitive, recurrent ovarian cancer patients previously treated with a PARP inhibitor: Korean Gynecologic Oncology Group (KGOG 3056)/NIRVANA-R trial

Background

Given the expanding clinical use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPis), there is a significant need for optimal strategies with which to treat patients whose cancer progresses while using a PARPi. However, the treatment consensus after PARPi has not been established. The aim of the Korean Gynecologic Oncology Group (KGOG) 3056/NIRVANA-R trial is to investigate the efficacy of niraparib in combination with bevacizumab as a maintenance therapy in platinum-sensitive ovarian cancer patients who were previously treated with a PARPi.

Methods

The KGOG 3056/NIRVANA-R is a multi-centre, investigator-initiated, single-arm, phase II trial of patients with platinum-sensitive recurrent ovarian cancer recruited from seven KGOG sites. This study included patients with platinum-sensitive recurrent epithelial ovarian cancer who received at least 2 previous courses of platinum-containing therapy and had been treated with a PARPi. Mucinous histology type was excluded. Patients who had responded to the last platinum regimen (either complete or partial response) were eligible to participate in this study. Forty-four patients will be recruited. All enrolled patients are treated with niraparib and bevacizumab for maintenance therapy until disease progression, unacceptable toxicity, or withdrawal of patient consent. The primary endpoint of the study is 6-month progression-free survival rate. Accrual is expected to be completed in 2022, followed by presentation of results in 2023.

Trial Registration

ClinicalTrials.gov Identifier: NCT04734665

A phase II trial of cytoreductive surgery combined with niraparib maintenance in platinum-sensitive, secondary recurrent ovarian cancer: SGOG SOC-3 study

Background

In China, secondary cytoreductive surgery (SCR) has been widely used in ovarian cancer (OC) over the past two decades. Although Gynecologic Oncology Group-0213 trial did not show its overall survival benefit in first relapsed patients, the questions on patient selection and effect of subsequent targeting therapy are still open. The preliminary data from our pre-SOC1 phase II study showed that selected patients with second relapse who never received SCR at recurrence may still benefit from surgery. Moreover, poly(ADP-ribose) polymerase inhibitors (PARPi) maintenance now has been a standard care for platinum sensitive relapsed OC. To our knowledge, no published or ongoing trial is trying to answer the question if patient can benefit from a potentially complete resection combined with PARPi maintenance in OC patients with secondary recurrence.

Methods

SOC-3 is a multi-center, open, randomized, controlled, phase II trial of SCR followed by chemotherapy and niraparib maintenance vs chemotherapy and niraparib maintenance in patients with platinum-sensitive second relapsed OC who never received SCR at recurrence. To guarantee surgical quality, if the sites had no experience of participating in any OC-related surgical trials, the number of recurrent lesions evaluated by central-reviewed positron emission tomography–computed tomography image shouldn't be more than 3. Eligible patients are randomly assigned in a 1:1 ratio to receive either SCR followed by 6 cycles of platinum-based chemotherapy and niraparib maintenance or 6 cycles of platinum-based chemotherapy and niraparib maintenance alone. Patients who undergo at least 4 cycles of chemotherapy and must be, in the opinion of the investigator, without disease progression, will be assigned niraparib maintenance. Major inclusion criteria are secondary relapsed OC with a platinum-free interval of no less than 6 months and a possibly complete resection. Major exclusion criteria are borderline tumors and non-epithelial ovarian malignancies, received debulking surgery at recurrence and impossible to complete resection. The sample size is 96 patients. Primary endpoint is 12-month non-progression rate.

Trial Registration

ClinicalTrials.gov Identifier: NCT03983226

A single-arm phase II study of olaparib maintenance with pembrolizumab and bevacizumab in BRCA non-mutated patients with platinum-sensitive recurrent ovarian cancer (OPEB-01)

Background

The optimal treatment of BRCA wild-type patients with platinum-sensitive recurrent ovarian cancer remains unknown. Recently, there is an increase in the evidence to support the role of the combination of a poly(adenosine diphosphate-ribose) polymerase inhibitor, anti-angiogenic agents, and immunotherapy as maintenance therapy in BRCA wild-type patients with platinum-sensitive recurrence. We hypothesized that adding pembrolizumab and bevacizumab to olaparib maintenance can increase progression-free survival (PFS) in BRCA wild-type patients with platinum-sensitive recurrent ovarian cancer.

Methods

BRCA wild-type patients who received two previous courses of platinum-containing therapy, achieved complete or partial response to last treatment, and the treatment-free interval is >6 months after the penultimate platinum-based chemotherapy offered olaparib maintenance with pembrolizumab and bevacizumab. Forty-four patients will be included from 4 sites across Singapore and Korea. The primary endpoint of the study is 6-month PFS rate.

Trial Registration

ClinicalTrials.gov Identifier: NCT04361370, Clinical Research Information Service Identifier: KCT0005144

Cost-effectiveness of olaparib versus routine surveillance in the maintenance setting for patients with BRCA-mutated advanced ovarian cancer after response to first-line platinum-based chemotherapy in Singapore

Objective

To evaluate the cost-effectiveness of olaparib as a maintenance treatment versus routine surveillance (RS) in patients with BRCA mutated (BRCAm) advanced ovarian cancer (OC) following response to first-line platinum-based chemotherapy in Singapore.

Methods

A 4-health state partitioned survival model was developed to simulate the lifetime (50 years) incremental cost-effectiveness ratio (ICER) of olaparib versus RS from a healthcare payer perspective. Progression-free survival, time to second disease progression, and overall survival were estimated using SOLO-1 data and extrapolated beyond the trial period using parametric survival models. Any patient who remained progression-free at year 7 was assumed to be no longer at risk of progression. Mortality rates were based on all-cause mortality, adjusted based on BRCA1/2 mutation. Health state utilities and adverse event frequencies were from SOLO-1. Drug costs were from local public healthcare institutions. Healthcare resource usage and costs were from local clinician input and publications. A 3% discount rate was applied to costs and outcomes. Deterministic and probabilistic sensitivity analyses (PSA) were performed to assess the robustness of results.

Results

The base-case analysis of olaparib maintenance therapy versus RS resulted in an ICER of Singapore dollar (SGD) 19,822 per quality-adjusted life-year (QALY) gained. The ICER was most sensitive to variations in the discount rate. PSA demonstrated that olaparib had an 87% probability of being cost-effective versus RS at a willingness-to-pay of SGD 60,000 per QALY gained.

Conclusion

Olaparib has a high potential of being a cost-effective maintenance treatment versus RS for patients with BRCA1/2m advanced OC after response to first-line chemotherapy in Singapore.

BET, SRC, and BCL2 family inhibitors are synergistic drug combinations with PARP inhibitors in ovarian cancer

BACKGROUND

Homologous recombination deficiencies (HRD) are present in approximately half of epithelial ovarian cancers, for which PARP inhibitors (PARPi) are becoming a preferred treatment option. However, a considerable proportion of these carcinomas acquire resistance or harbour de novo resistance, posing a significant challenge to treatment.

METHODS

To identify new combinatorial therapeutics to overcome resistance to PARPi, we employed high-throughput conditional RNAi and drug screening of patient-derived ovarian cancer cells. To prioritise clinically relevant drug combinations, we integrated empirical validation with analysis of The Cancer Genome Atlas (TCGA) and Genomics of Drug Sensitivity in Cancer (GDSC) datasets to nominate candidate targets and drugs, reaching three main findings.

FINDINGS

Firstly, we found that the PARPi rucaparib enhanced the effect of BET inhibitors (CPI-203 & CPI-0610) irrespective of clinical subtype or HRD status. Additional drug combination screens identified that dasatinib, a non-receptor tyrosine kinase inhibitor, augmented the effects of rucaparib and BET inhibitors, proposing a potential broadly applicable triple-drug combination for high-grade serous and clear cell ovarian carcinomas. Secondly, rucaparib synergised with the BCL2 family inhibitor navitoclax, with preferential activity in ovarian carcinomas that harbour alterations in BRCA1/2, BARD1, or MSH2/6. Thirdly, we identified potentially antagonistic drug combinations between the PARPi rucaparib and vinca alkaloids, anthracyclines, and antimetabolites, cautioning their use in the clinic.

INTERPRETATION

These findings propose therapeutic strategies to address PARP inhibitor resistance using agents that are already approved or are in clinical development, with the potential for rapid translation to benefit a broad population of ovarian cancer patients.

Major clinical research advances in gynecologic cancer in 2019

In 2019, 12 topics were selected as the major research advances in gynecologic oncology. Herein, we first opted to introduce the significant clinical activity of pembrolizumab in women with advanced cervical cancer based on the results of the phase 2 KEYNOTE-158 trial. Thereafter, we reviewed 5 topics, including systemic lymphadenectomy in the advanced stage with no gross residual tumor, secondary cytoreductive surgery in recurrent ovarian cancer according to the results of Gynecologic Oncology Group-213 trial, dose-dense weekly paclitaxel scheduling as first-line chemotherapy, the utility of intraperitoneal therapy in the advanced stage, and an update on poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of ovarian cancer. Additionally, we conducted a thorough review of emerging data from several clinical trials on PARP inhibitors according to drug, target population, and combined usage. For uterine corpus cancer, we reviewed adjuvant therapy for high-risk disease and chemotherapy in advanced/recurrent disease. For the field of radiation oncology, we discussed the utility of neoadjuvant chemotherapy added to chemoradiotherapy and the treatment of radiation-induced cystitis using hyperbaric oxygen. Finally, we discussed the use of individualized therapy with humanized monoclonal antibodies (trastuzumab emtansine and sacituzumab govitecan-hziy) and combination therapy (fulvestrant plus alpesilib, fulvestrant plus anastrozole, and ribociclib plus endocrine therapy) for women with advanced breast cancer.

Major clinical research advances in gynecologic cancer in 2018

Nineteen topics were selected as major clinical research advances in gynecologic oncology in 2018. For cervical cancer, the importance of human papillomavirus (HPV) testing alone as primary cervical cancer screening method and negative survival impact of minimally invasive surgery in early-stage cervical cancer were addressed. For ovarian cancer, cost-effectiveness of genetic testing to prevent cancer, use of analgesics and oral pill to reduce cancer risk, efficacy of secondary cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, update in the use of poly (ADP-ribose) polymerase inhibitor, and efficacy of anti-angiogenic targeted treatments, including bevacizumab and tyrosine kinase inhibitors, were reviewed. For corpus cancer, sentinel lymph node mapping technique, adjuvant therapy in high-risk endometrial cancer (PORTEC-3), and targeted therapy in recurrent disease were covered. For the field of radiation oncology, survival outcomes of chemoradiation compared with chemotherapy alone in metastatic cervical cancer and new findings regarding the use of neoadjuvant chemotherapy in locally advanced cervical cancer were introduced. Lastly, for breast cancer, the use of talazoparib in patients with germline BRCA1/2 mutation, ovarian suppression for premenopausal patients, adjuvant chemotherapy guided by 21-gene assay, and combination therapy of atezolizumab and nab-paclitaxel for triple-negative cancer as well as promising overall survival results of palbociclib and fulvestrant in advanced breast cancer were briefly mentioned.

Major clinical research advances in gynecologic cancer in 2017

In 2017, 10 topics were selected as major clinical research advances in gynecologic oncology. For cervical cancer, efficacy and safety analysis results of a 9-valent human papillomavirus (HPV) vaccine and long-term impact of reduced dose of quadrivalent vaccine were updated. Brief introduction of KEYNOTE trials of pembrolizumab, a monoclonal antibody that blocks the interaction between programmed death (PD)-1 and its ligands, PD-L1 and PD-L2, followed. Tailored surveillance programs for gynecologic cancer related with Lynch syndrome and update on sentinel lymph node mapping were reviewed for uterine corpus cancer. For ovarian cancer, 5 topics were selected including poly(ADP-ribose) polymerases inhibitors and immunotherapy. The other potential practice changers covered in this review were lymphadenectomy in advanced disease, secondary cytoreductive surgery in recurrent disease, weekly dose-dense regimen for first-line chemotherapy, incorporation of bevacizumab maintenance in platinum-sensitive recurrent disease, and effect of platinum-free interval prolongation. Conflicting opinions of academic societies on periodic pelvic examination were introduced in conjunction with relevant literature review. For the field of radiation oncology, results of 2 big trials, The Postoperative Radiation Therapy in Endometrial Carcinoma-3 and Gynecologic Oncology Group-258, for endometrial cancer and recent advance in high-dose-rate brachytherapy for cervical cancer were reported. Topics for breast cancer covered adjuvant capecitabine after preoperative chemotherapy, adjuvant pertuzumab and trastuzumab in early human epidermal growth factor receptor 2-positive disease, olaparib for metastatic cancer in patients with a germline BRCA mutation, 20-year risks of recurrence after stopping endocrine therapy at 5 years, and contemporary hormonal contraception and the risk of breast cancer.