Olaparib Research Articles

Abstract P2-01-02: Clinicopathological characteristics, treatment patterns and disease outcomes of germline BRCA1/2 carriers with early stage HER2-negative breast cancer and potential eligibility for adjuvant Olaparib

Abstract Background: Approximately 5-10% of early breast cancers (eBC) occur in patients (pts) carrying a germline BRCA1/2 (gBRCA1/2) pathogenic (P) or likely P (LP) variant. In the OlympiA trial, 1-year (yr) adjuvant (adj) olaparib (OLA) improved both invasive disease-free survival (iDFS) and overall survival (OS) in gBRCA carriers with high-risk HER2- eBC. Whether benefit of adj OLA might extend beyond the high-risk population defined by the OlympiA criteria remains to be defined. Methods: Consecutive pts who underwent surgery for a first diagnosis of eBC at Dana-Farber Brigham Cancer Center between 1/2016 and 8/2021 were identified. Genetic data were retrieved from an institutional dataset to identify gBRCA1/2 P/LP carriers tested through Dana-Farber. Clinicopathological variables, treatment and outcomes were characterized. Eligibility for adj OLA was based on the OlympiA study criteria, as follows: triple-negative BC (TNBC) with ≥pT2 or ≥pN1 prior to adj chemotherapy (ACT) or non-pCR after neo-adj CT (NACT); hormone receptor (HR)+ eBC with ≥4 positive nodes prior to ACT or non-pCR and CPS+EG score ≥3 after NACT. Results: We identified 188 gBRCA (105 BRCA1, 83 BRCA2) carriers with newly diagnosed HER2- eBC. Median age was 42.5 years and 119 (63%) were premenopausal. Tumor stage, grade and subtype are reported in Table 1. Recurrence Score (RS) was performed on 46 pts, with a median value of 25 (2% 0-10 RS, 52% 11-25 RS, 46% ≥26 RS). 97 pts (52%) received NACT, 55 (29%) ACT only and 36 (19%) did not receive CT. Most pts received both anthracyclines and taxanes, either as NACT (68%) or ACT (53%). 19 (20%) and 8 (8%) received platinum as NACT or ACT, respectively. 4 pts received adj OLA. 43 (44%) pts had a pCR after NACT. The pCR rate was higher in BRCA1 than BRCA2 carriers (52 vs 25%, odds ratio (OR) 3.27, p=0.015) and in pts with TNBC than HR+ eBC (50 vs 32%, OR 2.10, p=0.101). After a median follow up for survival of 37 months, 16 iDFS events were recorded, including 4 second primary tumors (3 ovarian and 1 pancreatic cancer). 3-yr iDFS was 89% (95% CI, 84-95) in the overall cohort, with no significant difference according to BRCA status (BRCA2 vs BRCA1: 85% vs 93%, hazard ratio [HR] 2.65 (95% CI, 0.92-7.63), p=0.071) or tumor subtype (HR+ vs TNBC: 87 vs 93%, HR 1.72 (95% CI, 0.60-4.94), p=0.316). 3-yr relapse-free survival (RFS) was 92% (95% CI, 87-97). 54 (29%) pts were potentially eligible for adj OLA. Eligible pts more frequently had TNBC (67 vs 36%, p< 0.001), higher stage (stage I 9 vs 55%, stage II 63 vs 37%, stage III 28 vs 9%), and grade 3 disease (85 vs 69%, p=0.045), were less likely to have ODX performed (2 vs 34%, p< 0.001), and more likely to have received NACT (83 vs 39%, p< 0.001) and radiation therapy (78 vs 33%, p< 0.001). 3-yr iDFS was 87% and 90% for pts eligible vs not eligible (HR 1.36 (95% CI, 0.49-3.74), p=0.555). 10/16 iDFS events occurred among not eligible pts. 3-yr RFS was lower in eligible pts (87 vs 94%; HR 2.23 (95% CI, 0.72-6.92), p=0.165). Conclusions: In our cohort, approximately 30% of pts were eligible for adj OLA. 3-yr iDFS was similar between pts eligible and not eligible for adj OLA according to OlympiA criteria. Our findings raise a concern regarding proper selection of all gBRCA carriers who may benefit from adj OLA. Further research is needed to identify additional groups of pts who may benefit from adding OLA to CT in higher risk disease or potentially replacing CT in lower risk settings. Table 1: Characteristics and outcomes of gBRCA1 vs gBRCA2 Citation Format: Stefania Morganti, Qingchun Jin, Julie Vincuilla, Ryan Buehler, Sean Ryan, Samantha Stokes, Tonia Parker, Elizabeth A. Mittendorf, Tari King, Anna Weiss, Ann Partridge, Brittany Bychkovsky, Giuseppe Curigliano, Nabihah Tayob, Nancy U. Lin, Judy Garber, Sara Tolaney, Filipa Lynce. Clinicopathological characteristics, treatment patterns and disease outcomes of germline BRCA1/2 carriers with early stage HER2-negative breast cancer and potential eligibility for adjuvant Olaparib [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-01-02.

A Case of Recurrent Ovarian Cancer with Renal Dysfunction Associated with the Use of Olaparib

Olaparib (ORB) is known not to largely affect renal function due to its specific pharmacological mechanism, and there are no reports on renal dysfunction associated with the drug. The patient was found to have been diagnosed with recurrent ovarian cancer. She started therapy with bevacizumab (BEV). Unfortunately, BEV was discontinued due to the development of progressive renal dysfunction with proteinuria. Therefore, she started the administration of ORB. However, after switching to ORB, her renal dysfunction progressed. Renal histopathology revealed membranoproliferative glomerulonephritis (MPGN) and thrombotic microangiopathy (TMA). During the clinical course, her renal function deteriorated after the administration of ORB and improved after the drug was discontinued because of bone marrow suppression. Moreover, sustained improvement of renal function was observed after complete discontinuation of the drug. This case is considered to be the first report of renal dysfunction due to ORB. In the recent PAOLA-1 trial, the efficacy and toxicity profiles of the combination of BEV and ORB were superior to those of BEV alone. The combination of BEV and ORB is now the first-line treatment for ovarian cancer based on this result. In the present case, ORB was administered to a patient with BEV-induced renal dysfunction, resulting in further aggravation of the renal dysfunction. Here we report this case because of the adverse reaction that should be noted when ORB and BEV are used in combination therapy, which is expected to be more popular, based on the PAOLA-1 trial results.

Characterization of the human <i>IDH1</i> gene promoter

<abstract> <p>In cancer, the production of ATP depends mainly on glycolysis, usually accompanied by the dysfunction of the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS). Nicotinamide adenine dinucleotide (NAD<sup>+</sup>) is a coenzyme for various biological enzymatic reactions such as those involved in the TCA cycle. To investigate the molecular mechanisms involved in carcinogenesis, the transcription system of genes associated with mitochondrial function should be elucidated. In this study, we isolated several mitochondrial function-associated bidirectional promoters and tested whether they responded to NAD<sup>+</sup>-metabolism regulating compounds, namely, <italic>trans</italic>-resveratrol (Rsv), 2-deoxy-D-glucose (2DG), 3-amino benzamide (3AB), and olaparib (OLA), in HeLa S3 cells. Transient transfection and luciferase (Luc) reporter assay showed that the <italic>IDH1</italic> promoter was prominently activated by these compounds. The <italic>IDH1</italic> gene, which encodes a nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>) dependent isocitrate dehydrogenase, is frequently mutated in glioma and leukemia cells. In this study, RT-PCR showed that <italic>IDH1</italic> gene and protein expression was induced in response to the NAD<sup>+</sup>-regulating drugs Rsv and 3AB. However, IDH1 protein amount was rather stable at control level. The result suggested that a post-transcriptional controlling system works to keep IDH1 at a stable level.</p> </abstract>

Nanocrystallization Improves the Solubilization and Cytotoxic Effect of a Poly (ADP-Ribose)-Polymerase-I Inhibitor.

Olaparib (OLA) is an anticancer agent that acts by inhibiting the poly (ADP-ribose)-polymerase-I (PARP-I). Due to its low solubility and low permeability, it has been placed as a BCS Class-IV drug and hence its clinical use is limited. In this study, we develop the nanocrystals of OLA as a way to improve its solubility and other performances. The OLA-NCs were prepared by antisolvent precipitation method through homogenization and probe sonication technique using a novel amphiphilic polymeric stabilizer (Soluplus®). Particle characterization resulted approximately 103.13 nm, polydispersity-index was 0.104 with positive zeta-potential of +8.67 mV. The crystal morphology by SEM of OLA-NCs (with and without mannitol) exhibited nano-crystalline prism-like structures as compared to the elongated OLA-pure. The DSC, XRD and FTIR were performed to check the interaction of Soluplus, mannitol and OLA did not exhibit any physical interaction among the OLA, Soluplus® and mannitol that is indicated by the presence of parent wave number peak. Two-fold increased solubility of OLA was found in PBS with Soluplus® from the NCs (69.3 ± 6.2 µgmL-1) as compared to pure drug (35.6 ± 7.2 µgmL-1). In vitro release of drug from OLA-NCs was higher (78.2%) at 12 h at pH 6.8 and relatively lower (53.1%) at pH 1.2. In vitro cellular cytotoxicity and anticancer effects were examined on MCF-7 cells. OLA-NCs were found effectively potent to MCF-7 cells compared with OLA-pure with approximately less than half IC50 value during MTT assay. Estimation of p53, Caspase-3 and Caspase-9 in MCF-7 cells indicated that OLA-NCs have significantly (p < 0.05) increased their expressions. After single oral dose in rats, 12 h plasma drug concentration-time profile indicated approximately 2.06-, 2.29-, 2-25- and 2.62-folds increased Cmax, AUC0-12 h, AUC0-∞ and AUMC0-∞, respectively, from the NCs as compared to OLA-pure. Storage stability indicated that the OLA-NCs was physically and chemically stable at 4 °C, 25 °C and 40 °C up to 6-months. Overall, OLA-NCs were deliberated; its potential feasibility to overwhelm the formulation challenges related to poorly soluble drugs and its future clinical applications.

PARP1 inhibition by Olaparib reduces the lethality of pancreatic cancer cells and increases their sensitivity to Gemcitabine

Pancreatic cancer (PC) is one of the tumors with the lowest survival rates due to the poor efficacy of the treatments currently used. Gemcitabine (GMZ), one of the chemotherapeutic agents employed when the tumor is unresectable, frequently fails due to the development of drug resistance. PARP1 is a relevant protein in this phenomenon and appears to be related to cancer progression in several types of tumors, including PC. To determine the relevance of PARP1 in the development and treatment of PC, we used the Panc02 cell line to generate modified PC cells with stably inhibited PARP1 expression (Panc02-L) and used GMZ, Olaparib (OLA) and GMZ+OLA as therapeutic strategies. Viability, radiosensitization, angiogenesis, migration, colony formation, TUNEL, cell cycle, multicellular tumorsphere induction and in vivo assays were performed to test the influence of PARP1 inhibition on resistance phenomena and tumor progression. We demonstrated that stable inhibition or pharmacological blockade of PARP1 using OLA-sensitized Panc02 cells against GMZ significantly decreased their IC50, reducing colony formation capacity, cell migration and vessel formation (angiogenesis) in vitro. Furthermore, in vivo analyses revealed that Panc02-L-derived (PARP1-inhibited) tumors showed less growth and lethality, and that GMZ+OLA treatment significantly reduced tumor growth. In conclusion, PARP1 inhibition, both alone and in combination with GMZ, enhances the effectiveness of this chemotherapeutic agent and represents a promising strategy for the treatment of PC.

Effects of thiostrepton alone or in combination with selumetinib on triple-negative breast cancer metastasis.

FoxM1 transcription factor contributes to tumor metastasis and poor prognosis in many cancers including triple-negative breast cancer (TNBC). In this study, we examined the effects of FoxM1 inhibitor Thiostrepton (THIO) alone or in combination with MEK inhibitor Selumetinib (SEL) on metastatic parameters in vitro and in vivo. Cell viability was determined by MTT assay. Immunoblotting and immunohistochemistry was used to assess metastasis-related protein expressions in 4T1 cells and its allograft tumor model in BALB/c mice. In vivo uPA activity was determined by enzymatic methods. Both inhibitors were effective on the expressions of FoxM1, ERK, p-ERK, Twist, E-cadherin, and Vimentin alone or in combination in vitro. THIO significantly decreased 4T1 cell migration and changed the cell morphology from mesenchymal-like to epithelial-like structure. THIO was more effective than in combination with SEL in terms of metastatic protein expressions in vivo. THIO alone significantly inhibited mean tumor growth, decreased lung metastasis rate and tumor foci, however, no significant changes in these parameters were observed in the combined group. Immunohistochemically, FoxM1 expression intensity was decreased with THIO and its combination with SEL in the tumors. This study suggests that inhibiting FoxM1 as a single target is more effective than combined treatment with MEK in theTNBC allograft model. The therapeutic efficacy of THIO should be investigated with further studies on appropriate drug delivery systems.

Olaparib enhances the Resveratrol-mediated apoptosis in breast cancer cells by inhibiting the homologous recombination repair pathway

Although sensitization of BRCA-mutated, homologous recombination (HR)-deficient breast cancer cells through PARP inhibitor is widely studied, not much is known about the treatment of BRCA-wild-type, HR-proficient breast cancer. Here, we aim to investigate whether a bioactive compound, Resveratrol (RES), can induce DNA double-strand breaks in HR-proficient breast cancer cells and Olaparib (OLA), a PARP inhibitor, can enhance the RES-mediated apoptosis by deregulating the HR repair pathway. The detailed mechanism of anti-cancer action of RES + OLA combination in breast cancer has been evaluated using in vitro, ex vivo, and in vivo preclinical model systems. OLA increased RES-mediated DNA damage, downregulated the HR pathway proteins, caused a late S/G2 cell cycle arrest, enhanced apoptosis and cell death in RES pre-treated breast cancer cells at much lower concentrations than their individual treatments. Direct measurement of HR pathway activity using a GFP plasmid-based assay demonstrated reduced HR efficiency in I-SceI endonuclease-transfected cells treated with OLA. Moreover, RES + OLA treatment also caused significant reduction in PARP1-mediated PARylation and efficiently trapped PARP1 at the DNA damage site. Upon RES treatment, PARylated PARP1 was found to interact with BRCA1, which then activated other HR pathway proteins. But after addition of OLA in RES pre-treated cells, PARP1 could not interact with BRCA1 due to inhibition of PARylation. This resulted in deregulation of HR pathway. To further confirm the role of BRCA1 in PARP1-mediated HR pathway activation, BRCA1 was knocked down that caused complete inhibition of HR pathway activity, and further enhanced apoptosis after RES + OLA treatment in BRCA1-silenced cells. In agreement with in vitro data, similar experimental results were obtained in ex vivo patient-derived breast cancer cells and in vivo xenograft mice. Thus, RES + OLA combination treatment enhanced breast cancer cell death by causing excessive DNA damage and also simultaneously inhibiting the HR pathway.

583P Aurora kinase overexpression may play a role in PARPi resistance in tumor samples of patients with high grade ovarian cancer and its inhibition with alisertib overcomes resistance to olaparib in a PARPi-resistant cell line model

Despite benefit of PARP inhibitors (PARPi) in high grade ovarian cancer (HGOC) a proportion of patients will become resistant. The aim of our study was to assess if AURKA overexpression is a mechanism of PARPi resistant and if the inhibition with alisertib (ALI) could overcome resistance to olaparib (OLA) in cell line models.

Modeling the impact of sequencing approaches and contribution of therapies on clinical outcomes in patients with advanced ovarian cancer (487.5)

<b>Objectives:</b> Evolution in the therapeutic landscape and guidelines for advanced ovarian cancer (AOC)—including increased utilization of poly (ADP-ribose) polymerase inhibitors (PARPi) and bevacizumab (BEV)—has resulted in multiple available treatment sequences. Prior studies have compared interventions in specific populations and lines of therapy, but this approximates the downstream impacts of earlier treatment choices. This study assessed the impact of adding BEV to platinum-based chemotherapy (PBC) over multiple treatment lines in frontline (1L) induction and alongside olaparib (OLAP) in 1L maintenance (per the PAOLA-1 trial), offering a complete picture of the incremental clinical value of BEV and OLAP. <b>Methods:</b> A discrete event simulation model was developed to simulate overall survival (OS) and intermediate clinical outcomes (e.g., time to IL/second-line (2L) treatment discontinuation, progression, and/or death; response to 1L/2L induction; platinum sensitivity) based on patient characteristics and treatment history, explicitly tracking events experienced by initially identical patient cohorts progressing through multiple treatment lines. Electronic medical record data from Tempus were used to inform patient characteristics (age at diagnosis, age, race, stage at diagnosis, among others) and derive predictive equations for two 1L reference pathways: PBC followed by no maintenance and PBC + BEV followed by BEV. In 2L, both sequences administered PBC or non-PBC (if platinum-resistant), with or without BEV, followed by maintenance consisting of OLAP, BEV, or no maintenance, depending on outcomes in 1L and treatment history. After 2L, patients received the best supportive care. Hazard ratios from published trials of OLAP and/or BEV were applied to progression-free survival, and OS was estimated from the predictive risk equations to capture other sequences. <b>Results:</b> Results for all sequences in the model are presented in Table 1. Patients receiving PBC and no maintenance in frontline (S0) accrued 4.0 life-years (LYs) on average. Treating a subset of patients with <i>BRCA</i> mutations (30% as per PAOLA-1) with OLAP maintenance and the remaining patients with no maintenance (S1) resulted in 0.3 incremental LYs versus S0 (total: 4.3 LYs). Treating all patients with PBC + BEV followed by BEV (S2) added 1.0 LYs versus S1 (total: 5.2 LYs). Adding OLAP maintenance to S2 for patients with tumors positive for homologous recombination deficiency (HRD) (S3; 48%, as per PAOLA-1), with HRD negative patients receiving BEV only maintenance, contributed another 0.7 LYs versus S2 (total: 5.9 LYs). Results were robust to variability in treatment effects, hazard ratios, and treatment utilization assumptions. <b>Conclusions:</b> Results reflect a combination of the independent impacts of BEV and OLAP in 1L on OS and their influence on the likelihood of response to 1L induction and platinum sensitivity, both of which are linked to improved patient outcomes. Treatment sequences, adding both BEV and OLAP during 1L, improved intermediate outcomes and OS compared to other sequences for AOC treatment.

Development of Chitosan-Coated PLGA-Based Nanoparticles for Improved Oral Olaparib Delivery: In Vitro Characterization, and In Vivo Pharmacokinetic Studies

Olaparib (OLP) is an orally active poly (ADP-ribose) polymerase enzyme inhibitor, approved for treatment for the metastatic stage of prostate, pancreatic, breast and ovarian cancer. Due to its low bioavailability, an increase in dose and frequency is required to achieve therapeutic benefits, which also results in associated toxicity in patients. In the current study, OLP-loaded poly (d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) (OLP-PLGA NPs) and a coating of OLP-PLGA NPs with chitosan (CS) (OLP-CS-PLGA NPs) were prepared successfully in order to improve the dissolution rate and bioavailability. The developed OLP-PLGA NPs were evaluated for hydrodynamic particle size (392 ± 5.3 nm), PDI (0.360 ± 0.03), ZP (−26.9 ± 2.1 mV), EE (71.39 ± 5.5%) and DL (14.86 ± 1.4%), and OLP-CS-PLGA NPs, hydrodynamic particle size (622 ± 9.5 nm), PDI (0.321 ± 0.02), ZP (+36.0 ± 1.7 mV), EE (84.78 ± 6.3%) and DL (11.05 ± 2.6%). The in vitro release profile of both developed NPs showed a sustained release pattern. Moreover, the pharmacokinetics results exhibited a 2.0- and 4.75-fold increase in the bioavailability of OLP-PLGA NPs and OLP-CS-PLGA NPs, respectively, compared to normal OLP suspension. The results revealed that OLP-CS-PLGA NPs could be an effective approach to sustaining and improving the bioavailability of OLP.

VP1-2022: Pre-specified event driven analysis of Overall Survival (OS) in the OlympiA phase III trial of adjuvant olaparib (OL) in germline BRCA1/2 mutation (gBRCAm) associated breast cancer

OlympiA is the first phase III randomised clinical trial (RCT) testing a PARP inhibitor as adjuvant therapy. At the first event driven interim analysis [Data CutOff 1 (DCO1), 27/03/20; median follow up (MFU) 2.5 years] OL significantly improved the primary endpoint of invasive disease-free survival (IDFS) and secondary endpoint of distant DFS (DDFS) compared with placebo (PL) [both p<0.001]. OS did not cross the pre-specified boundary (p<0.01) (Tutt et al NEJM 2021). The second pre-specified analysis of OS and updated IDFS, DDFS and safety descriptive analyses was planned after 330 IDFS events [DCO2 12/07/21; MFU 3.5 years].

PH-Responsive Hyaluronic Acid Nanoparticles for Enhanced Triple Negative Breast Cancer Therapy.

PurposeThis study emphasized that dasatinib (DAS) and olaparib (OLA) have synergistic effects on triple negative breast cancer, by inducing DNA damage and inhibiting DNA damage repair. However, poor water solubility, short half-life of drugs, and low drug concentration in tumor tissue limit the clinical application.MethodsIn this research, acid-sensitive ester bonds were used to connect hydrophobic DAS and hydrophilic hyaluronic acid (HA) to form the amphiphilic polymer prodrug HA-DAS, and then OLA was added as the core, the HA-DAS was used as the carrier to form nanomicelles (HDO-NPs) in aqueous. The characterization and drug release of HDO-NPs were studied, and the cytotoxicity, targeting effect, and intracellular transport behavior of HDO-NPs were evaluated in MDA-MB-231. In addition, the pharmacokinetic and therapeutic effect of HDO-NPs were further verified in vivo.ResultsIn vitro characterizations showed that HDO-NPs were spherical with uniform particle size, good stability and anti-dilution ability, and displayed favorable pH-responsive drug release behavior. In addition, the cell experiments showed that HDO-NPs could be effectively taken up by binding to the overexpressed CD44 proteins of MDA-MB-231 cells, resulting in increased intracellular drug concentration. In vivo experiments showed that HDO-NPs can effectively target tumor tissues, have excellent therapeutic effects on tumor, significantly prolong the circulation time of drugs in vivo, and effectively improved the bioavailability of drugs.ConclusionDAS and OLA were designed into micelles, the efficacy of HDO-NPs was higher than that of free drugs. Therefore, HDO-NPs have good application prospects in the treatment of triple negative breast cancer.

Abstract GS4-09: Quality of life results from OlympiA: A phase III, multicenter, randomized, placebo-controlled trial of adjuvant olaparib after (neo)-adjuvant chemotherapy in patients with germline BRCA1/2 mutations and high-risk HER-2 negative early breast cancer

Abstract Background: The primary results from the OlympiA trial were recently reported (NEJM, 2021) after an interim analysis demonstrated statistically significant invasive disease-free survival (DFS) benefit from 1 year of olaparib (OL) vs. placebo (PL) after 2.5 yrs median follow-up. Although there were fewer deaths with OL than PL, overall survival (OS) did not reach the statistical significance threshold prespecified for interim analysis. The initial publication also reported on the adverse event profile, which was similar to that previously reported, as well as Global Health Status/Quality of Life (GHQ), a secondary endpoint for the Patient-Reported Outcome (PRO) sub-study. The full protocol-specified PRO analyses are presented here. Methods: The OlympiA randomized phase III trial (NCT02032823, BIG 6-13, NSABP B-55) tested the role of 1 year of adjuvant OL after completion of (neo)adjuvant chemotherapy and definitive local therapy on invasive DFS, distant DFS and OS, and sought to collect PRO data from all eligible patients (pts) prior to randomization, on treatment (trt) (6 and 12 months [mos]), and after trt (18 and 24 mos) using validated questionnaires available in multiple languages. Fatigue, the primary PRO endpoint, was measured with the FACIT-Fatigue Scale in which a clinically meaningful (CM) difference is ≥3 points. Secondary PRO endpoints included gastrointestinal (GI) symptoms (nausea and vomiting [NV], diarrhea) and multiple quality of life (QOL) domains assessed with the EORTC QLQ-C-30 questionnaire (CM differences: small 5-10 points, moderate 10-20 points [Osoba, 1998]). The primary protocol-specified PRO hypothesis was that during trt pts treated with OL may experience greater fatigue severity at 6 and 12 mos. Secondary PRO hypotheses included: a) pts receiving OL may experience greater severity of GI symptoms at 6 and 12 mos with no difference by 24 mos; b) no difference in fatigue severity post-trt at 18 and 24 mos; and c) no difference in QOL over duration of the PRO sub-study between OL and PL as measured by the GHQ score and other EORTC QLQ-C30 subscales. A mixed model for repeated measures analysis compared the primary and secondary endpoints scores. Separate analyses were performed for neoadjuvant (NAC) and adjuvant (AC) chemotherapy subgroups due to differences in interval from NAC and AC to randomization. Two-sided p-values &amp;lt;0.05 were considered statistically significant. Results: Of 1,836 randomized pts, 1,751 (NAC: 875 [OL:440, PL: 435], AC: 876 [OL:436, PL:440]) were included in the PRO sub-study. Baseline QOL and symptom scores did not differ between OL and PL. Fatigue severity was statistically significantly greater in pts treated with OL than with PL at 6 mos (diff OL vs. PL: NAC -1.3 [95%CI -2.4, -0.2], p=0.024; AC -1.3 [-2.3,-0.2], p=0.017) and 12 mos (NAC -1.5 [-2.8,-0.2] p=0.025; AC -1.3 [-2.4,-0.1] p=0.027); however, the differences did not meet the pre-specified criterion for CM with the FACIT-Fatigue Scale. There were no meaningful differences in fatigue severity at 18 and 24 mos. NV symptom severity was worse in pts treated with OL than with PL with small differences at 6 mos (NAC: 6.0 [4.0, 8.0], p&amp;lt;0.001, AC: 5.3 [3.4,7.2], p&amp;lt;0.001) and 12 mos (NAC: 6.3 [4.4, 8.2], p&amp;lt;0.001, AC: 4.5 [2.8,6.2], p&amp;lt;0.001), and no differences at 18 and 24 mos. In general, there were no CM differences between OL and PL in terms of other symptoms and QOL subscales with improvements in functioning over time. Conclusions: Increased trt-emergent symptoms with OL were small and resolved after trt. QOL scores were similar and slowly improved during the 24 mos after (neo) adjuvant chemotherapy. Support: U10CA180868, -180822, UG1CA189867, AstraZeneca, Merck and Co, Inc. NCT02032823 Citation Format: Patricia A Ganz, Hanna Bandos, Tanja Spanic, Sue Friedman, Volkmar Müller, Sherko Kümmel, Suzette Delaloge, Etienne Brain, Masakazu Toi, Hideko Yamauchi, Eduardo-Martínez de Dueñas, Anne Armstrong, Seock-Ah Im, Chuangui Song, Hong Zheng, Tomasz Sarosiek, Priyanka Sharma, Giovanna Rossi, Priya Rastogi, Anitra Fielding, Richard D Gelber, Christine Campbell, Judy E Garber, Charles E Geyer, Jr, Andrew NJ Tutt, On behalf of the OlympiA Trial Steering Committeeand Investigators. Quality of life results from OlympiA: A phase III, multicenter, randomized, placebo-controlled trial of adjuvant olaparib after (neo)-adjuvant chemotherapy in patients with germline BRCA1/2 mutations and high-risk HER-2 negative early breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS4-09.

Randomized CLIO/BGOG-ov10 trial of olaparib monotherapy versus physician's choice chemotherapy in relapsed ovarian cancer

ObjectiveComparison of olaparib (OLA) monotherapy versus chemotherapy in patients with platinum-sensitive (PSOC) or platinum-resistant ovarian cancer (PROC). MethodsPatients with measurable disease and ≥ 1 prior line of chemotherapy (CT) were randomized 2:1 to OLA (300 mg tablets, BID) or physician's choice CT.: for PSOC: Carboplatin-Pegylated-Liposomal-Doxorubicin (PLD) or Carboplatin-Gemcitabine; for PROC: PLD, Topotecan, Paclitaxel or Gemcitabine. Results160 patients (60 with PSOC and 100 with PROC) were randomized 2:1 to OLA (n = 107) or CT (n = 53). Baseline characteristics were similar between both arms. Overall objective response rate (ORR) for OLA and CT were similar (24.3% (26/107) and 28.3% (15/53), respectively). Clinical benefit rate (≥ 12 weeks) was similar with 54.2% (58/107) and 56.6% (30/53), respectively. In PSOC, ORR was 35.0% (14/40) and 65.0% (13/20) for OLA and CT (p = 0.053); in PROC, ORR was 17.9% (12/67) and 6.1% (2/33) for OLA and CT (p = 0.134). ORR in heavily pretreated PROC (>4 prior lines) was 22.9% (8/35) with OLA versus 0% (0/14) for CT. ORR of 35.7% (5/14) and 13.2% (7/53) was observed in BRCA-mutated and -wildtype PROC cases, respectively. Median PFS in PROC was not significantly different with 2.9 months (95% CI 2.8–5.1 in the OLA group versus 3.8 months (95% CI 3.0–6.4) in the CT group (hazard ratio [HR] 1.11 [95% CI 0.72–1.78]; log-rank p = 0.600). ConclusionOLA monotherapy showed overall an equal response rate in relapsed ovarian cancer compared with CT. In PROC, ORR and TFST tended to be higher with OLA than with CT. In heavily pretreated patients (four lines or more) with PROC disease, OLA treatment seemed to be more effective than CT.

734P Neutrophil-lymphocyte ratio predicts survival in platinum-resistant ovarian cancer patients treated with olaparib and pegylated liposomal doxorubicin (PLD): Stratified analysis from the phase II clinical trial ROLANDO, GEICO-1601

Identifying prognostic biomarkers of Olaparib (OLA) plus PLD efficacy is relevant to optimize the clinical benefit of this therapy in PROC pts. Neutrophil/lymphocyte (NLR), Lymphocyte/monocyte (LMR) and Platelet/lymphocyte (PLR) ratios have been identified as prognostic factors for survival but evidence at PROC is scarce.

Tumor extracelluar hyroxyapatite: a potential biomarker for imaging ovarian cancer

<h3>Objectives:</h3> Identifying new strategies to improve response to poly ADP-ribose polymerase inhibitors (PARPi) in women with homologous recombination (HR)-proficient ovarian cancer is a key clinical challenge. The nuclear orphan receptor NR4A1 has pro-tumor effects in ovarian cancer cells through transcriptional regulation of key genes promoting growth, survival and HR DNA repair. NR4A1 is also expressed in immune cells in the tumor microenvironment and may play a role in inhibiting re-polarization of pro-tumor M2-like tumor-associated macrophages (TAMs) to a more effective anti-tumor M1-like TAM phenotype. Our group has shown that the NF-kappaB (NF-ĸB) pathway is a key regulator of TAM phenotype, with upregulated NF-ĸB signaling promoting M1-like functions. Our goal therefore was to determine whether inhibition of NR4A1 can improve responses to PARPi both by increased tumor DNA damage and apoptosis, and by promoting an anti-tumor M1 phenotype in TAMs by modulating NF-ĸB activity. <h3>Methods:</h3> Cultured HR-proficient ID8 mouse ovarian cancer cells, mouse ovarian TAMs and mouse bone marrow-derived macrophages were treated with the established NR4A1 antagonist C-DIM-pPHOH (C-DIM) and/or the PARPi olaparib (OLA) for 24-72 hours. C57BL/6 mice with established intra-peritoneal ID8 tumors were treated with vehicle, C-DIM, OLA or combined C-DIM/OLA for 3 weeks. Standard techniques were used to determine cell growth (Sulforhodamine B assay), HR efficiency (<i>BRCA1</i> and RAD51 foci formation), NF-ĸB activity (nuclear p65, luciferase reporter activity), and expression of markers of DNA damage (pH2AX), apoptosis (cleaved PARP), proliferation (PCNA), and macrophage M1 (CCL3, iNOS) and M2 (CD206, arginase-1) polarization. Statistical significance (p<0.05) between group means was determined by Student's t test for <i>in vitro</i> studies and Mann-Whitney test for mouse studies. <h3>Results:</h3> In ID8 cells, co-treatment with C-DIM and OLA significantly reduced cell growth and HR efficiency, and increased DNA-damage-induced apoptosis, compared to OLA treatment alone. NR4A1 was highly expressed in macrophages, and C-DIM increased NF-ĸB activity and induced M1 polarization alone and when combined with olaparib. Similar effects of combined treatment were observed <i>in vivo.</i> Compared to mice treated with OLA alone, there was significantly reduced ascites volume and omental tumor mass in C-DIM/OLA mice at the time of sacrifice. Combined treatment also reduced proliferation and increased DNA damage and apoptosis in harvested tumors, and increased M1 polarization of TAMs in ascites fluid, compared to OLA mice. <h3>Conclusions:</h3> NR4A1 inhibition sensitizes ovarian tumors to PARPi though direct effects on tumors by targeting the HR pathway, and by modulating TAM function towards an anti-tumor phenotype. These findings have important implications for expanding the use of PARPi in women with HR-proficient ovarian tumors, which would benefit a substantial number of women with this devastating disease.

Abstract 1606: Potentiating effect of olaparib on anti-PD-1 treatment in colorectal cancer

Abstract Immune checkpoint inhibitors (ICIs) are approved for microsatellite unstable colorectal cancer (CRC), however, microsatellite stable (MSS) CRC that make up the majority of tumors in clinical practice have not seen any benefit with ICI. This is in part due to the lack of sufficient tumor infiltrating immune cells, particularly CD8+ T cells, in the milieu. Immunogenic cell death (ICD) is a particular form of cell death that elicits robust cross-priming of CD8 T cells against antigens expressed by dying cells in the absence of exogenous adjuvants. ICD-inducing drugs such as poly (ADP-ribose) polymerase inhibitors (PARPis) are poised to enhance cancer cell killing, boost tumor immunogenicity, increase in vivo immune infiltration, and thereby accelerate a tumor response to ICI treatment. Here, we tested the combinatorial therapeutic efficacy of a PARPi, olaparib (OLA), and an ICI, anti-PD-1, in in vitro and in vivo conditions. Combined treatment of OLA and anti-mouse PD-1 reduced tumor growth and increased survival in an immunocompetent, syngeneic animal model of BALB/c carrying allograft CT26 tumor that is MSS. Flow cytometry analysis revealed that the combo treatment significantly reduced percentages of anti-inflammatory macrophages and increased inflammatory monocytes. There was no significant difference in dendritic cell populations. We observed increased anti-tumor lymphocyte response via activation of CD4 and CD8 T cell populations upon combo treatment with OLA and anti-mouse PD-1. In addition, we noticed an increased association of expression of PD-L1 and its receptor PD-1 with OLA treatment in CRC cell lines and CT26 tumors. Our preliminary data suggests altered expressions of the CD8+ T cell exhaustion marker TIM-3 and its ligands galectin-9 and high mobility group protein 1 (HMGB1), an indicator of ICD. The pilot studies also revealed increased levels of STING-dependent type I interferon signaling initiator cGAS upon treatment with OLA in vivo. Mechanistically, OLA might induce DNA damage among tumor cells and trigger innate immune signaling including NF-κB activation and STING-dependent type I interferon signaling, both of which contribute to the maturation of myeloid antigen-presenting cells and subsequent activation of T cells. In conclusion, OLA potentiated the antitumor efficacy of anti-PD-1 in CT26 induced syngeneic CRC mouse model. Our findings indicate that OLA might trigger tumor immunogenicity, and enable a potential targeted-immunotherapeutic angle for exercising ICD and activating cytotoxic T lymphocytes in CT26 syngeneic CRC mouse model; however, further studies are needed to elucidate the mechanism. Despite ICD markers' identification as immuno-stimulating characteristics of dead cells, whether ICD-associated molecules can be used as a prognostic biomarker or therapeutic target, and the rational for such markers on tumor cells in eliciting antitumor immunity are still under investigation. Citation Format: Chintal Bhavsar, Peter John, Magnolia Abreu, Laura Bencosme, Radhashree Maitra, Sanjay Goel, Titto Augustine. Potentiating effect of olaparib on anti-PD-1 treatment in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1606.

Abstract 21: LiP-MS, a machine learning-based chemoproteomic approach to identify drug targets in complex proteomes

Abstract Background Target identification is a critical step in elucidating the mechanism of action (MoA) for bioactive compounds. For target-based and phenotypic drug discovery pipelines, extensive potential target knowledge for a lead compound provides essential insights that enable potency and selectivity optimization. The tedious process of target deconvolution for a compound often necessitates a plethora of biochemical and biophysical techniques. To expand the toolbox of unbiased target ID approaches, we developed a novel workflow combining limited proteolysis with quantitative mass spectrometry (LiP-MS) that exploits the drug binding phenomena of protein structural alterations and steric hindrance. Advantageously, LiP-MS's unique peptide-centric focus exploits signature peptide detection to discern ligand binding. Additionally, the LiP-MS workflow enables binding affinity estimation (EC50) and binding site prediction. Here we demonstrate the performance of LiP-MS using two well-characterized kinase inhibitors (KIs), an AstraZeneca CDK9 inhibitor (AZ) and Selumetinib (SE). Methods Mechanically sheared HeLa or U2OS cell lysate was incubated with compound at multiple concentrations. Next, a limited proteolytic digest was performed using proteinase K. After quenching this digestion, lysate was trypsin digested to peptides for mass spectrometry analysis. The resulting peptides were analyzed quantitatively using data-independent acquisition (DIA)-MS. Results Herein, we use LiP-MS to unbiasedly identify unique peptides generated by the binding of two distinct classes of kinase inhibitors in human cell lysate. For the ATP-competitive inhibitor AZ, LiP-Quant shows a strong enrichment for CDKs in the target space defined by LiP score, including CDK1, 2, 4, 6, 9 and 11A. In addition, our data indicates that this KI targets members of the CDKs with different selectivity, with CDK9 displaying the highest compound affinity (nM range). For Selumetinib, a non-competitive allosteric inhibitor, LiP-MS clearly identified the direct targets MEK1/2 as the main hits by LiP score. Both cases represent a highly specific enrichment given that we quantified &amp;gt; 120,000 peptides in each of the experiments. These findings confirm our approach's ability to identify genuine drug targets regardless of drug MoA in a complex biological matrix. Importantly, in both KI target ID studies, identified LiP peptides could be successfully deployed to map compound binding site, demonstrating the potential of LiP-MS to pinpoint regions involved in drug-protein interactions. Conclusions Collectively, this data demonstrates that LiP-MS can be used to effectively identify protein drug targets and characterize the binding properties in complex proteomes independent of the compound's MoA and without compound modification or labeling. These capabilities make LiP-MS a powerful addition to the target ID toolbox. Citation Format: Nigel Beaton, Yuehan Feng, Roland Bruderer, Adam Hendricks, Ghaith Hamza, Eric Miele, Rick Davies, Kristina Beeler, Ilaria Piazza, Paola Picotti, Paola Castaldi, Lukas Reiter. LiP-MS, a machine learning-based chemoproteomic approach to identify drug targets in complex proteomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 21.

OlympiA: A phase III, multicenter, randomized, placebo-controlled trial of adjuvant olaparib after (neo)adjuvant chemotherapy in patients with germline BRCA1/2 mutations and high-risk HER2-negative early breast cancer.

LBA1 Background: PARP inhibitors (PARPi) target cancers with homologous recombination repair defects by synthetic lethality. The PARPi olaparib (OL) is licensed for metastatic HER2-negative breast cancer with BRCA1/2 germline mutation (gBRCAm). Despite (neo)adjuvant chemotherapy ([N]ACT), recurrence rates in patients (pts) with gBRCAm early breast cancer (EBC) can be high. Novel adjuvant treatments are needed. Methods: OlympiA (NCT02032823), a randomized, double-blind, phase III study, enrolled pts with gBRCAm and HER2-negative (TNBC or hormone-receptor+ [HR+]) high-risk EBC after primary local treatment and ACT/NACT. Eligible pts with TNBC had ≥pT2 or ≥pN1 disease prior to ACT or non-pCR after NACT; those with HR+ BC had ≥4 positive nodes prior to ACT or non-pCR and CPS&amp;EG score ≥3 after NACT. Pts were randomized 1:1 to 1 year of continuous oral OL (300 mg BID) or placebo (PL). Endocrine therapy and bisphosphonates were allowed. The primary endpoint was invasive disease-free survival (IDFS) in the ITT population. Secondary endpoints included distant DFS (DDFS), overall survival (OS) and safety. Safety analysis included adverse events of special interest (AESI) (myelodysplastic syndrome/ acute myeloid leukemia, new primary malignancy, pneumonitis). Per protocol IDMC interim analysis (IA) review was triggered at 165 IDFS events in the first 900 pts, with superiority boundaries based on a hierarchical multiple testing procedure: P &lt; 0.005 for IDFS, followed by P &lt; 0.005 for DDFS and p&lt;0.01 for OS. Results: 1836 pts were enrolled between 06/14–05/19; 49.9% had ACT, 50.1% NACT. Baseline demographics and tumor characteristics were balanced between arms. 82.2% had TNBC; 26.5% received a platinum agent. The IDMC recommended data unblinding as IA showed a significant benefit of OL vs PL for IDFS (hazard ratio [HR] 0.58; 99.5% CI 0.41, 0.82; P &lt; 0.0001) at 2.5 yrs median follow-up. IDFS events occurred in 106/921 and 178/915 pts assigned to OL and PL, respectively. 3-yr IDFS was 85.9% vs 77.1% (diff. 8.8%; 95% CI 4.5%, 13.0%). DDFS was significantly improved with OL (HR 0.57; 99.5% CI 0.39, 0.83; P&lt; 0.0001); 3-yr DDFS was 87.5% vs 80.4% (diff. 7.1%; 95% CI 3.0%, 11.1%). OS was greater for OL than PL but was not statistically significant at IA (HR 0.68; 99.0% CI 0.44, 1.05; P = 0.024); 3-yr OS% 92.0% vs 88.3% (diff. 3.7%; 95% CI 0.3%, 7.1%). Median intended OL exposure was 94.8%. AEs were consistent with the label. G3+ AEs in &gt;1% of OL pts were; anemia (8.7%), neutropenia (4.8%), leukopenia (3.0%), fatigue (1.8%), and lymphocytopenia (1.2%). SAEs and AESI were not increased by OL, SAE 8.7% vs 8.4% and AESI 3.3% vs 5.1%, OL vs PL respectively. Conclusions: Adjuvant OL following ACT or NACT significantly improved IDFS and DDFS with acceptable toxicity in pts with gBRCAm and high-risk HER2-negative EBC. Clinical trial information: NCT02032823.

A Highly Sensitive Nonextraction-Assisted HPLC Method with Fluorescence Detection for Quantification of Duvelisib in Plasma Samples and its Application to Pharmacokinetic Study in Rats.

BackgroundDuvelisib (DUV) is a new oral phosphoinositide-3-kinase (PI3K)-δ and PI3K-γ inhibitor. It has been recently granted an accelerated approval for treatment of adult patients with relapsed or refractory chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). It is also effective in therapy of T-cell lymphoma, solid tumors, and non-Hodgkin’s lymphoma. In literature, there is no method valid for quantitation of DUV in human plasma for its therapeutic monitoring and pharmacokinetic studies.PurposeThe purpose of this study is the establishment of a highly sensitive HPLC method with fluorescence detection for quantitation of DUV in plasma for its therapeutic monitoring and pharmacokinetic studies of DUV.MethodsThe resolution of DUV and the internal standard (IS) olaparib (OLA) was achieved on Nucleosil CN column, with a mobile phase composed of acetonitrile:water (25:75, v/v) at a flow rate of 1.7 mL min–1. The fluorescence of both DUV and OLA was detected at 410 nm after excitation at 280 nm. The method was validated according to the guidelines of bioanalytical method validation.ResultsThe method was linear in the range of 5–100 ng mL–1, and its limit of detection (LOD) and limit of quantitation (LOQ) were 2.12 ng mL–1 and 7 ng mL–1, respectively. The precisions of the method were ≤ 8.26%, and its accuracies were ≥ 95.32%. All the other validation parameters were satisfactory. The proposed method was successfully employed to the investigation of the pharmacokinetic profile of DUV in rats following a 25 mg/kg single dose of oral administration.ConclusionThe method is characterized with high sensitivity, accuracy, simple sample pretreatment, rapidity, eco-friendly as it consumes low volumes of organic solvent in the mobile phase and has high analysis throughput as its run time was short (~ 10 min).