Natalie Y.L. Ngoi

Durvalumab versus Physician’s Choice Chemotherapy in Recurrent Ovarian Clear Cell Adenocarcinoma (MOCCA/APGOT-OV2/GCGS-OV3): A Multicenter, Randomized, Phase 2 Trial

Abstract Purpose: The optimal treatment of recurrent ovarian clear cell carcinoma (rOCCC) remains unknown. This is the first randomized trial to compare durvalumab with chemotherapy in rOCCC. Patients and Methods: MOCCA is a randomized, phase 2 trial conducted in Singapore, Korea, and Australia. Eligible patients had rOCCC with recurrence after platinum-based chemotherapy, Eastern Cooperative Oncology Group performance status ≤2, and no prior immune checkpoint blockade. Patients were randomly assigned (2:1) to durvalumab (1,500 mg every 4 weeks) or chemotherapy. Patients progressing on chemotherapy were allowed to cross over to durvalumab. The primary outcome was progression-free survival. Secondary outcomes included overall survival, objective response rates, and safety. Results: Forty-eight eligible women were assigned to durvalumab (N = 31) or chemotherapy (N = 17). The median progression-free survival was 7.6 [95% confidence interval (CI), 7.0–16.0] and 14.0 (95% CI, 7.0–32.9) weeks with durvalumab and chemotherapy, respectively (HR = 1.6; 95% CI, 0.8–3.0; P = 0.92). The median overall survival was 37.9 (95% CI, 21.7–143.0) and 40.6 (95% CI, 25.0–not reached) weeks, respectively (HR = 1.5; 95% CI, 0.7–3.3; P = 0.85). The difference in objective response rates between the groups was not statistically significant (durvalumab 9.7% vs. physician’s choice chemotherapy 18.8%; difference −9.1%; 95% CI, −31.3% to 12.9%; P = 0.83). Fewer all-grade (35.5% vs. 68.8%) and high-grade (9.7% vs. 31.3%) treatment-related adverse events were observed for durvalumab. PD-L1 combined positive score (CPS)+ was observed in 28.9% (CPS ≥1%) and 10.5% (CPS ≥10%) of patients. PIK3CA mutations were associated with time to progression on durvalumab ≥12 weeks [relative risk (mutated vs. wild-type) 2.83; 95% CI, 1.16–14.17]. Conclusions: Durvalumab was well-tolerated but did not improve efficacy outcomes compared with chemotherapy in rOCCC.

Clinical and biological characteristics associated with loss-of-heterozygosity in endometrial cancer

Genomic instability has been identified in a subgroup of endometrial cancers (ECs) that are predominantly We conducted a retrospective analysis of EC patients from France and Singapore. All patients underwent comprehensive molecular profiling using the tumor based FoundationOne CDX panel. The degree of LOH was correlated with molecular and clinicopathologic findings. LOH-high, intermediate and low were defined as ≥14%, 4%-14%, and <4%, respectively. One hundred twelve patients were identified, including 66% Asian and 34% Caucasian. Fifty nine percent had International Federation of Gynecology and Obstetrics III/IV diseases, 34% low-grade endometrioid, 19% high-grade endometrioid, and 15% serous. The 63% and 50% of tumors expressed estrogen receptor (ER) and progesterone receptor (PR). One percent had a In this large multiethnic cohort, 17% of EC exhibited high LOH and correlated with hormone-receptor-negative tumors and poorer survival rates. LOH may serve as a tool for identifying EC cases with high genomic instability that could potentially benefit from PARP inhibitors.

A multicenter phase II randomized trial of durvalumab (MEDI-4736) versus physician’s choice chemotherapy in recurrent ovarian clear cell adenocarcinoma (MOCCA)

The optimal treatment of recurrent ovarian clear cell carcinoma remains unknown. There is increasing rationale to support the role of immune checkpoint inhibitors targeting the programmed cell death protein 1 (PD To evaluate the efficacy of durvalumab (MEDI-4736) compared with standard chemotherapy in patients with recurrent ovarian clear cell carcinoma. Patients with recurrent ovarian clear cell carcinoma treated with durvalumab will have improved progression-free survival compared with those treated with chemotherapy of physician's choice. The MOCCA study is a multicenter, open-label, randomized phase II trial in patients with recurrent ovarian clear cell carcinoma, which recruited from eight sites across Gynecologic Cancer Group Singapore (GCGS), Korean Gynecologic-Oncology Group (KGOG), and Australia New Zealand Gynecological Oncology Group (ANZGOG). Enrolled patients were randomized in a 2:1 ratio to receive durvalumab or physician's choice of chemotherapy until disease progression, intolerable toxicity, or withdrawal of patient consent. Eligible patients required histologically documented diagnosis of recurrent ovarian clear cell carcinoma, as evidenced by WT1 negativity. All patients must have been of Eastern Cooperative Oncology Group (ECOG) performance status 2 or better, and have had previous treatment with, and progressed or recurred after prior platinum-based chemotherapy. No more than four prior lines of treatment were allowed and prior immune checkpoint inhibitor treatment was not permitted. The primary endpoint was the median progression-free survival following treatment with durvalumab, compared with physician's choice of chemotherapy. Progression-free survival was defined as the time from the first day of treatment to the first observation of disease progression, or death due to any cause, or last follow-up. The target sample size was 46 patients. Accrual has been completed and results are expected to be presented by mid-2021. Clinicaltrials.gov: NCT03405454.

Exploiting replicative stress in gynecological cancers as a therapeutic strategy

Elevated levels of replicative stress in gynecological cancers arising from uncontrolled oncogenic activation, loss of key tumor suppressors, and frequent defects in the DNA repair machinery are an intrinsic vulnerability for therapeutic exploitation. The presence of replication stress activates the DNA damage response and downstream checkpoint proteins including ataxia telangiectasia and Rad3 related kinase (ATR), checkpoint kinase 1 (CHK1), and WEE1-like protein kinase (WEE1), which trigger cell cycle arrest while protecting and restoring stalled replication forks. Strategies that increase replicative stress while lowering cell cycle checkpoint thresholds may allow unrepaired DNA damage to be inappropriately carried forward in replicating cells, leading to mitotic catastrophe and cell death. Moreover, the identification of fork protection as a key mechanism of resistance to chemo- and poly (ADP-ribose) polymerase inhibitor therapy in ovarian cancer further increases the priority that should be accorded to the development of strategies targeting replicative stress. Small molecule inhibitors designed to target the DNA damage sensors, such as inhibitors of ataxia telangiectasia-mutated (ATM), ATR, CHK1 and WEE1, impair smooth cell cycle modulation and disrupt efficient DNA repair, or a combination of the above, have demonstrated interesting monotherapy and combinatorial activity, including the potential to reverse drug resistance and have entered developmental pipelines. Yet unresolved challenges lie in balancing the toxicity profile of these drugs in order to achieve a suitable therapeutic index while maintaining clinical efficacy, and selective biomarkers are urgently required. Here we describe the premise for targeting of replicative stress in gynecological cancers and discuss the clinical advancement of this strategy.

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)

The optimal treatment of ClinicalTrials.gov Identifier: NCT04361370, Clinical Research Information Service Identifier: KCT0005144.

Comprehensive characterization of genomic features and clinical outcomes following targeted therapy and secondary cytoreductive surgery in OCCC: a single center experience

Ovarian clear cell carcinoma (OCCC) is associated with chemoresistance. Limited data exists regarding the efficacy of targeted therapies such as immune checkpoint inhibitors (ICI) and bevacizumab, and the role of secondary cytoreductive surgery (SCS). We retrospectively analyzed genomic features and treatment outcomes of 172 OCCC patients treated at our institution from January 2000 to May 2022. Next-generation sequencing (NGS) was performed where sufficient archival tissue was available. 64.0% of patients were diagnosed at an early stage, and 36.0% at an advanced stage. Patients with advanced/relapsed OCCC who received platinum-based chemotherapy plus bevacizumab followed by maintenance bevacizumab had a median first-line progression-free survival (PFS) of 12.2 months, compared with 9.3 months for chemotherapy alone (hazard ratio=0.69; 95% confidence interval [CI]=0.33, 1.45). In 27 patients who received an ICI, the overall response rate was 18.5% and median duration of response was 7.4 months (95% CI=6.5, 8.3). In 17 carefully selected patients with fewer than 3 sites of relapse, median PFS was 35 months (95% CI=0, 73.5) and median overall survival was 96.8 months (95% CI=44.6, 149.0) after SCS. NGS on 58 tumors revealed common mutations in Our study demonstrates encouraging outcomes with bevacizumab and ICI, and SCS in select relapsed OCCC patients. Prospective trials are warranted.

Olaparib Maintenance With Pembrolizumab & Bevacizumab in BRCA Non-mutated Patients With Platinum-sensitive Recurrent Ovarian Cancer

This study is phase II, open label, clinical trial to determine the efficacy of Olaparib maintenance with Bevacizumab and Pembrolizumab by assessment progression-free survival(6 months PFS rate) in BRCA non-mutated patients with platinum-sensitive recurrent ovarian cancer.