Platinum-sensitive Relapsed Ovarian Cancer Research Articles

781P Olaparib maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and a BRCA mutation (C-PATROL): Overall survival (OS) in predefined subgroups

781P Olaparib maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and a BRCA mutation (C-PATROL): Overall survival (OS) in predefined subgroups

Exploring the impact of BRCA1 and BRCA2 mutation type and location on Olaparib maintenance therapy in platinum-sensitive relapsed ovarian Cancer patients: A single center report

ObjectiveIn patients with platinum-sensitive relapsed ovarian cancer (PSROC) harboring pathogenic/likely pathogenic variants (PV) in BRCA1 and BRCA2 genes, olaparib maintenance monotherapy (OMT) is a viable option. Our study aimed to evaluate the impact of different BRCA1/2 PV in survival outcomes and safety of OMT in BRCA1/2-mutated PSROC patients, focusing on the type and location of PV. MethodsWe assessed the outcomes of 100 BRCA1/2-mutated PSROC patients treated at our institute, analyzing progression-free survival (PFS) and overall survival (OS). Germline and tumor BRCA1/2 genotyping was conducted using Illumina's next-generation sequencing (NGS). ResultsPFS and OS were significantly shorter in PSROC patients with PV in BRCA1 compared to those with PV in BRCA2 (PFS:14.0 vs. 38.8 months, p = 0.007, OS: 21.8 vs. 62.0 months, p = 0.011). Notably, there was a significant difference in PFS based on the intragenic location of BRCA1 PV, with shorter PFS in patients with 1st/2nd relapse, harboring PV in BRCA1 RING domain compared to those with PV in the DNA binding domain (DBD) and BRCT domains (12.4 vs. 23.0 months, p = 0.046). No differences in PFS and OS were observed between patients with germline versus somatic BRCA1/2 PV (PFS:14.9 vs.19.3, p = 0.316, OS: not reached vs. 25.8 months; p = 0.224). However, there were significant differences in the reasons for OMT discontinuation between patients with germline and somatic BRCA1/2 PV, primarily due to adverse side effects. ConclusionsIn summary, the type and location of BRCA1 and BRCA2 PV provide additional insight into the expected survival outcomes of olaparib MT in PSROC patients.Trial registration number: ISRCTN42408038, Name of registry: ISRCTN registry, Date of registration: 24/11/2015.

Targeted Nanocarrier-Based Drug Delivery Strategies for Improving the Therapeutic Efficacy of PARP Inhibitors against Ovarian Cancer.

The current focus of ovarian cancer (OC) research is the improvement of treatment options through maximising drug effectiveness. OC remains the fifth leading cause of cancer-induced mortality in women worldwide. In recent years, nanotechnology has revolutionised drug delivery systems. Nanoparticles may be utilised as carriers in gene therapy or to overcome the problem of drug resistance in tumours by limiting the number of free drugs in circulation and thereby minimising undesired adverse effects. Cell surface receptors, such as human epidermal growth factor 2 (HER2), folic acid (FA) receptors, CD44 (also referred to as homing cell adhesion molecule, HCAM), and vascular endothelial growth factor (VEGF) are highly expressed in ovarian cancer cells. Generation of active targeting nanoparticles involves modification with ligands that recognise cell surface receptors and thereby promote internalisation by cancer cells. Several poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are currently used for the treatment of high-grade serous ovarian carcinomas (HGSOC) or platinum-sensitive relapsed OC. However, PARP resistance and poor drug bioavailability are common challenges, highlighting the urgent need to develop novel, effective strategies for ovarian cancer treatment. This review evaluates the utility of nanoparticles in ovarian cancer therapy, with a specific focus on targeted approaches and the use of PARPi nanocarriers to optimise treatment outcomes.

Surgery versus no surgery in platinum-sensitive relapsed ovarian cancer: final overall survival analysis of the SOC-1 randomized phase 3 trial.

Surgery for platinum-sensitive, relapsed ovarian cancer (PSROC) is widely practiced but had contradictory survival outcomes in previous studies. In this multicenter, open-label, phase 3 trial, women with PSROC, and having had one previous therapy and no platinum-based chemotherapy (platinum-free interval) of 6 months or more, were randomly assigned to either the surgery group (182 patients) or the no-surgery group (control) (175 patients). Patients with resectable diseases were eligible according to the international model (iMODEL), combined with a positron emission tomography-computed tomography imaging. Overall survival (OS) and progression-free survival were coprimary endpoints in hierarchical testing, and a significantly longer progression-free survival with surgery was previously reported. Final analysis of OS was planned at data maturity of 59%. Between 19 July 2012 and 3 June 2019, 357 patients were enrolled. Median follow-up was 82.5 months. Median OS was 58.1 months with surgery and 52.1 months for control (hazard ratio (HR) 0.80, 95% confidence interval (CI) 0.61-1.05, P = 0.11). The predefined threshold for statistical significance was not met, but prespecified sensitivity analysis was performed. Overall, 61 of 175 (35%) patients in control had crossed over to surgery following subsequent relapse, and adjusted HR for death in the surgery group compared with control was 0.76, 95% CI 0.58-0.99. In subgroup analysis of relapse sites by imaging, median survival was not estimable in the surgery group and was 69.5 months in control in patients with <20 sites (HR 0.69, 95% CI 0.46-1.03). Patients with a complete resection had the most favorable outcome, with a median OS of 73.0 months. Twenty-four of 182 (13.2%) patients remained relapse free and alive >60 months in the surgery group as compared with five of 175 (2.9%) patients in the control group. In patients with PSROC, surgery did not increase OS in the intention-to-treat population but resulted in a prolongation of survival following adjustment of crossover.ClinicalTrials.gov registration: NCT01611766 .

Overall survival in patients with BRCA-mutated platinum-sensitive relapsed ovarian cancer (PSROC) treated with olaparib maintenance: Real-world data of the C-PATROL study.

e17542 Background: Maintenance monotherapy with PARP-inhibitor (PARPi), olaparib has previously shown good effectiveness and tolerability in total population of patients with PSROC who were in response to platinum-based chemotherapy (PBC) in the C-PATROL study. Here we present the overall survival (OS) data in different subgroups. Methods: The prospective German non-interventional study C-PATROL (NCT02503436) captured routine clinical data of olaparib maintenance according to label in patients with BRCA-mutated PSROC treated with PBC. The primary endpoint was PFS, relevant secondary endpoints included OS and safety. Data were analyzed by descriptive statistics. Results: Between 10/2015 and 10/2019, 277 patients were enrolled. The ITT set (study selection criteria fulfilled) comprised 267 patients (median age: 60 yrs; ECOG ≤1: 93%; ≥2 relapses: 32%; ≥3 prior PBC: 29%). Median follow-up was 23.5 months (range 0.0–80.5) and median olaparib treatment duration was 13.6 months (0.1–80.9). 10% of patients received olaparib for ≥ 5 years and 8% of patients received further PARPi also as subsequent treatment. Median OS was 35.4 months (95% CI 29.2–49.9). The longest median OS was observed in patients with a complete debulking after the surgery at current relapse, a complete response (CR) to the current PBC and a BRCA2 mutation. Adverse events (AEs) were consistent with the known tolerability profile of olaparib (safety set: n=274; any AE: 95%, AE of CTCAE grade ≥ 3: 40%, olaparib discontinuation due to AE: 11%; most common AE any CTCAE: nausea (46%), fatigue (39%), anaemia (31%), and vomiting (17%); most common AE CTCAE grade ≥ 3: anaemia (14%)). Conclusions: Olaparib is effective and safe in the real-world setting. In olaparib-treated patients with BRCA-mutated PSROC longer OS was observed mainly with respect to resection status after debulking surgery at current relapse, to tumor burden at the therapy start and BRCA mutation type. Our data underline the role of cytoreduction and platinum response in the context of PARPi maintenance therapy. Clinical trial information: NCT02503436 . [Table: see text]

Overall survival (OS) in patients with platinum-sensitive relapsed ovarian cancer (PSROC) treated with olaparib maintenance monotherapy: Update from the L-MOCA trial.

Overall survival (OS) in patients with platinum-sensitive relapsed ovarian cancer (PSROC) treated with olaparib maintenance monotherapy: Update from the L-MOCA trial.

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

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. 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). 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 wasassociated 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)]. 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. NCT03534453. Registered at May 23, 2018.

Poor Concordance Between Cancer Antigen-125 and RECIST Assessment for Progression in Patients With Platinum-Sensitive Relapsed Ovarian Cancer on Maintenance Therapy With a Poly(ADP-ribose) Polymerase Inhibitor.

Cancer antigen-125 (CA-125) is recommended by treatment guidelines and widely used to diagnose ovarian cancer recurrence. The value of CA-125 as a surrogate for disease progression (PD) and its concordance with radiologic progression are unclear, particularly for women with platinum-sensitive relapsed ovarian cancer (PSROC) who have responded to chemotherapy and treated with maintenance poly(ADP-ribose) polymerase inhibitor (PARPi). In this pooled analysis of four randomized trials of maintenance PARPi or placebo (Study 19, SOLO2, ARIEL3, and NOVA), we extracted data on CA-125 PD as defined by Gynecologic Cancer InterGroup criteria and RECIST v1.1. We evaluated the concordance between CA-125 and RECIST PD and reported on the negative predictive value (NPV) and positive predictive value (PPV). Of 1,262 participants (n = 818 PARPi, n = 444 placebo), 403 (32%) had CA-125 PD, and of these, 366 had concordant RECIST PD (PPV, 91% [95% CI, 88 to 93]). However, of 859 (68%) without CA-125 PD, 382 also did not have RECIST PD (NPV, 44% [95% CI, 41 to 48]). Within the treatment arms, PPV remained high (PARPi, 91% [95% CI, 86 to 94]; placebo, 91% [95% CI, 86 to 95]) but NPV was lower on placebo (PARPi, 53% [95% CI, 49 to 57]; placebo, 25% [95% CI, 20 to 31]). Of 477 with RECIST-only PD, most (95%) had a normal CA-125 at the start of maintenance therapy and the majority (n = 304, 64%) had CA-125 that remained within normal range. Solid organ recurrence without peritoneal disease was more common in those with RECIST-only PD than in those with CA-125 and RECIST PD (36% v 24%; P < .001). In patients with PSROC treated with maintenance PARPi, almost half with RECIST PD did not have CA-125 PD, challenging current guidelines. Periodic computed tomography imaging should be considered as part of surveillance, particularly in those with a normal CA-125 at the start of maintenance therapy and on treatment.

768P Preliminary results of an open-label, multicentric, phase Ib/II study to assess the safety and efficacy of AsiDNA, a DNA repair inhibitor, in addition to PARP inhibitor in patients with relapsed platinum sensitive ovarian cancer already treated with PARPi for at least 6 months (RevoCAN)

768P Preliminary results of an open-label, multicentric, phase Ib/II study to assess the safety and efficacy of AsiDNA, a DNA repair inhibitor, in addition to PARP inhibitor in patients with relapsed platinum sensitive ovarian cancer already treated with PARPi for at least 6 months (RevoCAN)

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.

Consensus on the management of platinum-sensitive high-grade serous epithelial ovarian cancer in Lebanon

Ovarian cancer is the most lethal gynecologic cancer. The high grade serous epithelial (HGSE) subtype is the most aggressive and it often presents at advanced stages, while screening programs have not proven beneficial. Management of the advanced stages (FIGO III and IV), which constitute the majority of diagnoses, usually consists of platinum-based chemotherapy and cytoreductive surgery (primary or interval) followed by maintenance therapy. Currently, the standard-of-care for advanced newly diagnosed HGSE ovarian cancer, as per international medical societies, starts with upfront cytoreductive surgery, followed by platinum-based chemotherapy (mostly carboplatin and paclitaxel) and/or anti-angiogenic agent bevacizumab, then maintenance therapy with a poly(ADP-ribose) polymerase (PARP) inhibitor with/without/or bevacizumab (continued). PARP inhibitor use depends on the patient’s genetic signature, mainly the breast cancer gene (BRCA) mutation and the homologous recombination deficiency (HRD) status. Therefore, genetic testing is recommended at diagnosis to inform treatment and prognosis.In line with the evolving standard-of-care for ovarian cancer, a panel of experts in treating advanced ovarian cancer convened to lay down practical recommendations on the management of advanced ovarian cancer in Lebanon; since the currently applicable guidelines by the Lebanese Ministry of Public Health for cancer treatment have not been updated yet to reflect the treatment paradigm shift brought upon by the development and approval of PARP inhibitors. The current work reviews the leading clinical trials on PARP inhibitors (as maintenance for newly diagnosed advanced and platinum-sensitive relapsed ovarian cancer), presents international recommendations, and proposes treatment algorithms for optimal local practice.

52P Real-world data of niraparib in platinum sensitive relapsed ovarian cancer: A multicenter experience of the MITO group

PARP (poly ADP–ribose polymerase) inhibitors are approved as maintenance therapy in platinum sensitive ovarian cancer (OC), in first line and in the recurrent setting, regardless BRCA mutational status. Real-world data after the introduction of these agents are needed to evaluate whether the benefit observed in phase III trials can be translated into clinical practice. The aim of our study was to provide real-life data on efficacy and safety of niraparib administered as maintenance in platinum sensitive relapsed OC patients (PSROC). This retrospective/prospective multicenter study included relapsed OC patients treated in 17 MITO centers and receiving niraparib as maintenance, according to the label, at the time of first or subsequent platinum sensitive recurrence. Clinical data at the time of diagnosis and at the time of recurrence before Niraparib treatment were collected from the patients´ medical records at each institution, centralized into an electronic CRF at the coordinating center (Fondazione Policlinico Gemelli) and analyzed. The efficacy and safety analysis, as primary objectives, was performed. Median progression free survival (PFS) and overall survival (OS) were calculated as the time from start of niraparib treatment to subsequent radiologically confirmed relapse and death or last contact, respectively. The study included 304 patients with median age of 58 years (range 51-66). 260 (85%) enrolled patients were BRCA wild-type and 36 (11.9%) were BRCA mutated. At the time of diagnosis, most of patients (65.8%) underwent complete debulking surgery and were diagnosed with III-IV FIGO stage (78.8%). At the time of recurrence before niraparib maintenance 179 patients (58.9%) had received 2 previous lines of platinum-based chemotherapy and carboplatin in combination with PDL was the most frequent administered regimen (31.3%). Complete and partial radiological response to platinum-based CT was recorded in 44.4% and 27.0% of patients, respectively. Median PFS was 9.1 months (95% CI: 7.6-10.7) and median OS was 41.7 months (95% CI: 32.4-51.1). In a real-life setting, niraparib maintenance in patients with PSROC showed efficacy comparable with the published phase III data.

203TiP Autophagy as a target for therapy in ovarian cancer: A phase II randomized trial with biomarker correlation (ATOC Trial)

Epithelial ovarian cancer (EOC) is gynecologic cancer with one of the highest mortalities. First-line treatment usually involves cytoreductive surgery and six cycles of platinum and taxane chemotherapy. With this treatment, most (70-80%) patients with stage III/IV disease relapse after one year. Patients who require re-treatment >6 months after previous platinum exposure [platinum sensitive relapsed ovarian cancer (PS-ROC)] are usually treated with a combination containing platinum agent. Autophagy pathways are activated in relapsed ovarian cancer allowing cancer cells to survive chemotherapy-induced stress.

Final overall survival results from SOLO3: Phase III trial assessing olaparib monotherapy versus non-platinum chemotherapy in heavily pretreated patients with germline BRCA1 - and/or BRCA2-mutated platinum-sensitive relapsed ovarian cancer (026)

<b>Objectives:</b> In the open-label Phase III SOLO3 trial (NCT02282020), olaparib monotherapy provided clinically relevant and statistically significant improvements in objective response rate (ORR; primary endpoint) and progression-free survival (PFS; secondary endpoint), compared with single-agent non-platinum chemotherapy, in patients (pts) with germline <i>BRCA1</i> and/or <i>BRCA2</i>-mutated (g<i>BRCA</i>m) platinum-sensitive relapsed ovarian cancer (PSROC) who had received ≥2 prior lines of platinum-based chemotherapy (Penson <i>et al. JCO</i> 2020). We report final overall survival (OS) and second disease progression results from SOLO3. <b>Methods:</b> Pts were randomized (2:1) to olaparib tablets (300 mg bid) or single-agent non-platinum chemotherapy treatment of physician's choice (TPC; paclitaxel [P], topotecan [T], gemcitabine [G], or pegylated liposomal doxorubicin [PLD]). Study treatment continued until objective radiological disease progression, unacceptable toxicity, or other discontinuation criteria were met. The time from randomization to second progression or death (PFS2) and OS were secondary endpoints. As prespecified, this analysis was performed at approximately 60% data maturity for OS. <b>Results:</b> 266 pts were randomized (olaparib, <i>n</i>=178; TPC, <i>n</i>=88 [PLD, <i>n</i>=47; P, <i>n</i>=20; G, <i>n</i>=13; T, <i>n</i>=8]); 12 (14%) TPC pts withdrew before receiving study treatment. At the final data cut-off (DCO; April 16, 2021), 19 (11%) olaparib pts versus no TPC pts were still receiving study treatment. The percentage of pts who left the study prior to death was approximately 2.3 times higher in the TPC arm (22 pts [25%]) than in the olaparib arm (19 pts [11%]). Following disease progression, the majority of pts received subsequent anticancer therapy (119 of 178 [67%] olaparib pts vs 54 of 88 [61%] TPC pts received ≥1 subsequent anticancer regimen); three of 178 (2%) olaparib pts versus 23 of 88 (26%) TPC pts received a PARP inhibitor in their first subsequent line of therapy, with nine of 178 (5%) versus 33 of 88 (38%) pts, respectively, receiving a PARP inhibitor in any subsequent line of therapy. At the final DCO, PFS2 favored olaparib over TPC, although the between-group difference was not statistically significant, and OS was similar in the olaparib and TPC groups (see Table). Adverse events (AEs) were consistent with the known safety profile of olaparib and with previous SOLO3 analyses; no new safety signals were identified. Discontinuation of study treatment due to AEs occurred in 18 of 178 (10%) olaparib pts versus 15 of 76 (20%) TPC pts in the safety analysis set. Circulating tumor DNA analyses are ongoing. <b>Conclusions:</b> In the primary analysis of SOLO3, olaparib monotherapy improved ORR and PFS compared with single-agent non-platinum chemotherapy in heavily pretreated pts with g<i>BRCA</i>m PSROC. In the final analysis, PFS2 favored olaparib monotherapy over TPC, and OS was similar in both treatment groups, supporting the use of olaparib as a chemotherapy-free treatment option in this pt population. No new safety signals were identified.

Olaparib treatment for platinum-sensitive relapsed ovarian cancer by BRCA mutation and homologous recombination deficiency status: Phase II LIGHT study primary analysis

ObjectiveOlaparib treatment resulted in significant improvement in objective response rates (ORRs) and progression-free survival (PFS) over non‑platinum chemotherapy in patients with BRCA1/BRCA2-mutated (BRCAm) platinum-sensitive relapsed ovarian cancer (PSROC) and ≥2 prior lines of platinum-based chemotherapy in the phase III SOLO3 study. LIGHT (NCT02983799) prospectively evaluated olaparib treatment for patients with PSROC and known BRCAm and homologous recombination deficiency (HRD) status. MethodsIn this phase II open-label multicenter study, patients with PSROC and ≥1 prior line of platinum-based chemotherapy were assigned to cohorts by presence of germline BRCAm (gBRCAm), somatic BRCAm (sBRCAm), HRD-positive tumors without BRCAm, or HRD-negative tumors. The primary endpoint was investigator-assessed ORR. Secondary endpoints included disease control rate (DCR) and PFS. Tumors were analyzed using Myriad BRACAnalysis CDx and myChoice HRD assays; HRD-positive tumors were defined using a genomic instability score of ≥42. ResultsOf 272 enrolled patients, 271 received olaparib and 270 were included in efficacy analyses. At data cut-off, ORRs in the gBRCAm, sBRCAm, HRD-positive, and HRD-negative cohorts were 69.3%, 64.0%, 29.4%, and 10.1%, respectively. DCRs were 96.0%, 100.0%, 79.4%, and 75.3% in each cohort, respectively. Median PFS was 11.0, 10.8, 7.2, and 5.4 months, respectively. The most common (≥ 20%) treatment-emergent adverse events included nausea, fatigue/asthenia, vomiting, anemia, constipation, diarrhea, and decreased appetite. ConclusionsOlaparib treatment demonstrated activity across all cohorts. The greatest efficacy was observed in the BRCAm cohorts, regardless of gBRCAm/sBRCAm. For patients without a BRCAm, greater efficacy was observed in the HRD-positive than the HRD-negative cohorts. The safety profile was consistent with that established in previous olaparib studies.

Efficacy of subsequent chemotherapy for patients with BRCA1/2-mutated recurrent epithelial ovarian cancer progressing on olaparib versus placebo maintenance: post-hoc analyses of the SOLO2/ENGOT Ov-21 trial

In the SOLO2 trial (ENGOT Ov-21; NCT01874353), maintenance olaparib in patients with platinum-sensitive relapsed ovarian cancer (PSROC) and BRCA mutation significantly improved progression-free survival (PFS) and prolonged overall survival (OS). Following disease progression on olaparib, efficacy of subsequent chemotherapy remains unknown. We conducted a post-hoc hypothesis-generating analysis of SOLO2 data to determine the efficacy of different chemotherapy regimens following RECIST disease progression in patients who received olaparib or placebo. We evaluated time to second progression (TTSP) calculated from the date of RECIST progression to the next progression/death. The study population comprised 147 patients who received chemotherapy as their first subsequent treatment after RECIST progression. Of these, 69 (47%) and 78 (53%) were originally randomized to placebo and olaparib arms, respectively. In the placebo-treated cohort, 27/69 and 42/69 received non-platinum and platinum-based chemotherapy, respectively, compared with 24/78 and 54/78, respectively, in the olaparib-treated cohort. Among patients treated with chemotherapy (N= 147), TTSP was significantly longer in the placebo than in the olaparib arm: 12.1 versus 6.9 months [hazard ratio (HR) 2.17, 95% confidence interval (CI) 1.47-3.19]. Similar result was obtained on multivariable analysis adjusting for prognostic factors at RECIST progression (HR 2.13, 95% CI 1.41-3.22). Among patients treated with platinum-based chemotherapy (n = 96), TTSP was significantly longer in the placebo arm: 14.3 versus 7.0 months (HR 2.89, 95% CI 1.73-4.82). Conversely, among patients treated with non-platinum-based chemotherapy (n= 51), the TTSP was comparable in the placebo and olaparib arms: 8.3 versus 6.0 months (HR 1.58, 95% CI 0.86-2.90). Following progression from maintenance olaparib in the recurrent setting, the efficacy of platinum-based subsequent chemotherapy seems to be reduced in BRCA1/2-mutated patients with PSROC compared to patients not previously receiving poly (ADP-ribose) polymerase inhibitors (PARPi). The optimal strategy for patients who relapse after PARPi is an area of ongoing research.

Randomized phase III trial on trabectedin (ET-743) single agent versus clinician’s choice chemotherapy in recurrent ovarian, primary peritoneal, or fallopian tube cancers of BRCA-mutated or BRCAness phenotype patients (MITO23).

LBA5504 Background: Trabectedin demonstrated antitumor activity when administered as single agent in relapsed platinum sensitive ovarian cancer (OC), with an overall response rate (ORR) ranging from 26 to 43% and a median PFS of 5 months. In addition, trabectedin showed 39.4% RR, 4.5 months median progression free survival (PFS) and 18 months median overall survival (OS) in a single arm phase 2 trial in recurrent BRCA mutated and/or the BRCAness phenotype OC patients. Methods: In this open-label, phase III, randomized trial, we assigned recurrent OC patients harboring BRCA 1/2 mutations or with BRCAness phenotype (defined as patients who had received and responded to at least 2 previous platinum-based treatments) to receive trabectedin 1.3 mg/mq q 21d or physician’s choice chemotherapy (among carboplatin, gemcitabine, weekly paclitaxel, pegylated liposomal doxorubicine or topotecan). The primary endpoint was OS. Secondary endpoints were PFS, ORR and Duration of Response (DoR). The sample size was calculated based on the assumption that trabectedin would increase median OS from 10 to 15 months (two-sided log-rank test at the error alfa= 0.05 and a power of 80%). Medians and lifetables were computed using the Kaplan-Meier method and analyzed using the log-rank test. Cox proportional hazards model was used to assess the effect of treatment. Results: Two hundred and forty-four patients were randomized and analyzed based on the intent-to-treat principle. At a median follow up of 40 months, the median PFS was 4.4 and 4.9 months (HR= 1.03 p=0.848) and median OS was 17.9 and 15.8 months (HR=1.15 p=0.304), in the control and experimental arm, respectively. ORR was 20.2% in the group of patients receiving standard chemotherapies and 15.4% in the group of patients treated with trabectedin. No superior effect was reported for Trabectedin in the pre-specified sub-group analysis according to BRCA mutational status, type of chemotherapy and platinum-free interval. No new signal of toxicity were reported for all the chemotherapies employed. Conclusions: Trabectedin as single agent does not improve survival outcomes when compared to standard chemotherapy in BRCA mut and BRCAness phenotype OC patients. Clinical trial information: NCT02993705.

Maintenance olaparib in patients (pts) with platinum-sensitive relapsed ovarian cancer (PSROC) by somatic (s) or germline (g) BRCA and other homologous recombination repair (HRR) gene mutation status: Overall survival (OS) results from the ORZORA study.

5519 Background: In the SOLO2 (NCT01874353) trial, maintenance olaparib provided clinically meaningful improvement in OS for PSROC pts with a gBRCA mutation (m) compared with placebo (median 51.7 vs 38.8 months [mo], respectively). The ORZORA trial (NCT02476968) assessed efficacy and safety of maintenance olaparib in PSROC pts with a BRCAm (s or g) or a non-BRCA HRRm. Median progression-free survival (18.0 mo, BRCAm; 16.4, non-BRCA HRRm) was reported at primary data cutoff (DCO). We report final OS analyses. Methods: We conducted an open-label, single-arm, multicenter study of PSROC pts in response to platinum-based chemotherapy (PBC) after ≥2 prior lines of PBC. Pts underwent prospective central screening for tumor BRCAm status (myChoice CDx, Myriad Genetic Laboratories, Inc.), then central gBRCAm testing (BRACAnalysis CDx, Myriad Genetic Laboratories, Inc.) to determine s or g status. An exploratory cohort comprised of pts with predefined non-BRCA HRRm (FoundationOne CDx, Foundation Medicine, Inc.). Pts received maintenance olaparib (400 mg bid; capsules) until progression. OS and time to second progression (PFS2) were secondary endpoints. Results: 181 pts were enrolled (BRCAm n = 145 [s, n = 55; g, n = 87; s/g status unknown, n = 3]; non-BRCA HRRm, n = 33; unassigned, n = 3). At DCO (June 25, 2021), median OS follow-up in censored pts was 42.6 mo in BRCAm and 39.3 mo in non-BRCA HRRm pts. OS and PFS2 are reported in the Table. PBC was received as a subsequent therapy by 33.1% BRCAm, 32.7% sBRCAm, 33.3% gBRCAm, and 45.5% non-BRCA HRRm pts. 177 pts received ≥1 dose of olaparib and were included in safety analyses; 6.2% of pts discontinued because of adverse events (AEs). 37.9% of pts reported grade ≥3 AEs, the most common being anemia (16.4%). Since primary DCO, one new primary malignancy and four myelodysplastic syndrome events occurred. Conclusions: In final OS analyses, maintenance olaparib capsules showed consistent clinical activity in BRCAm and sBRCAm PSROC pts. Exploratory analyses suggest similar activity in non-BRCA HRRm pts. No new safety signals were observed. Findings highlight that PSROC pts, beyond those with a gBRCAm, can benefit from maintenance olaparib. Clinical trial information: NCT02476968. [Table: see text]

Exploratory hrd and PD-L1 analysis of l-MOCA study: Olaparib maintenance monotherapy in Asian patients with platinum-sensitive relapsed ovarian cancer.

e17578 Background: Olaparib demonstrated its efficacy to prolong progression-free survival (PFS) in platinum-sensitive relapsed ovarian cancer (PSROC) patients (L-MOCA study). Almost half of OC patients harbor homologous recombination deficiencies (HRD). However, there is lack of the HRD prevalence in Asian PSR population. Meanwhile, Immunological processes play a key role in tumorigenesis and PD-L1 status may hinder an effective antitumor immune response in OC. Herein, we analyzed HRD and PD-L1 status in Asian patients with PSROC, and explored Olaparib response to different HRD status. Methods: In this exploratory analysis of L-MOCA trial, HRD and PD-L1 status were analyzed from patients with PSROC. Residual DNA samples of 193 patients were analyzed for HRD status with a local developed HRD assay (Teddy Laboratory, Shanghai, China, which determines two major components, tBRCA1/2 status and LOH score, HRD positive indicates the presence of a deleterious or suspected deleterious BRCA mutation or LOH score ≥0.4). The remaining formalin fixation and paraffin embedded samples were used for PD-L1 expression analysis by immunohistochemistry with SP263. Descriptive statistics were summarized for HRD status, PD-L1 expression status and PFS by different HRD status subgroups. Results: 193 of 224 patients had residual DNA for HRD test. Patients clinical characteristics were similar between those with and without residual DNA for HRD test, in terms of age (mean age 55.5y Vs 54.2y), FIGO stage (stage III 68.9% Vs 61.3%, stage IV 12.4% Vs 22.65%), and time to disease progression to Last prior Platinum Based Chemotherapy (6-12m: 39.9% Vs 41.9%; &gt; 12m: 59.6% Vs 54.8%). Among 193 patients with HRD test conducted, proportion of HRD+ BRCAm, HRD+ BRCAwt, HRD- and HRD unknown were 37.3%, 28.0%, 14.5% and 20.2%, separately. mPFS of the above subgroups was 20.1 months, 15.8 months, 9.2 months and 16.4 months, respectively (Table1). 200 of 224 patients were available for PD-L1 expression analysis. 184 (92%) with TC＜1%, 12 (6%) with TC among 1-25%. These results showed TC expression in all patients were less than 25%, suggesting that ovarian cancer may be an immunologically cold tumor. Conclusions: This is firstly showing the HRD and PD-L1 status in Asian OC patients. The results showed all the PSR patients could benefit from Olaparib treatment, regardless of HRD status. Meanwhile the numerically different mPFS observed across different HRD status subgroups also indicated potential clinical utility of locally developed HRD assay. Clinical trial information: NCT03534453. [Table: see text]

OReO/ENGOT Ov-38 trial: Impact of maintenance olaparib rechallenge according to ovarian cancer patient prognosis—An exploratory joint analysis of the BRCA and non-BRCA cohorts.

5558 Background: In the Phase IIIb OReO/ENGOT Ov-38 trial (NCT03106987), maintenance olaparib (O) rechallenge significantly improved progression-free survival (PFS) vs placebo in patients (pts) with platinum-sensitive relapsed ovarian cancer (PSROC) regardless of their BRCA status (Pujade-Lauraine, ESMO 2021). The impact of prognostic factors on this PFS benefit were unknown. Methods: Pts had PSROC, one prior line of PARP inhibitor (PARPi) maintenance and were in response to platinum-based chemotherapy (Cx). Pts were enrolled into two cohorts – BRCA mutated (BRCAm) and non-BRCAm – and randomized to receive maintenance O (300 mg bid) or placebo. Primary endpoint was PFS. Post-hoc individual patient data meta-analysis was used to combine both cohorts using fixed and random effect models, interaction, and stratified tests in the Cox model. Stepwise Cox multivariate model for PFS and logistic regression models were used for late relapse, defined as disease progression occurring &gt;24 weeks after randomization. Randomization stratification criteria and cohort effect were included in all models. Results: This study included 220 pts from the BRCAm (n=112) and non-BRCAm (n=108) cohorts recruited between October 3, 2017 and February 10, 2021. No heterogeneity was detected between cohorts: Cochran’s Q test P=0.53 (fixed and random); interaction test P=0.63. The O effect was consistent, and no significant interactions were observed between subgroups. In the multivariate PFS analyses, the main independent factors for prognosis were CA-125 level, visceral disease (liver, lung, pleura, brain), and treatment arm. These factors were independent predictive factors for late relapse among the 181 evaluable pts with the opportunity of at least 6 months of follow-up (Table). Conclusions: In the OReO/ENGOT Ov-38 trial, CA-125 level and presence of visceral disease at baseline were the best predictors of patient outcome. Maintenance olaparib rechallenge was effective overall regardless of prognostic subgroup. Clinical trial information: NCT03106987. [Table: see text]