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Background: Poly (ADP- ribose) polymerase inhibitors (PARPi) has been increasingly adopted for metastatic castration-resistance prostate cancer (mCRPC) patients with homologous recombination repair deficiency (HRD). However, it is unclear which PARPi is optimal in mCRPC patients with HRD in 2nd -line setting. Method: We conducted a systematic review of trials regarding PARPi- based therapies on mCRPC in 2nd -line setting and performed a Bayesian network meta-analysis (NMA). Radiographic progression-free survival (rPFS) was assessed as primary outcome. PSA response and adverse events (AEs) were evaluated as secondary outcomes. Subgroup analyses were performed according to specific genetic mutation. Results: Four RCTs comprised of 1024 patients (763 harbored homologous recombination repair (HRR) mutations) were identified for quantitative analysis. Regarding rPFS, olaparib monotherapy, rucaparib and cediranib plus olaparib showed significant improvement compared with ARAT. Olaparib plus cediranib had the highest surface under cumulative ranking curve (SUCRA) scores (87.5%) for rPFS, followed by rucaparib, olaparib and olaparib plus abiraterone acetate prednisone. For patients with BRCA 1/2 mutations, olaparib associated with the highest probability (98.1%) of improved rPFS. For patients with BRCA-2 mutations, olaparib and olaparib plus cediranib had similar efficacy. However, neither olaparib nor rucaparib showed significant superior effectiveness to androgen receptor-axis-targeted therapy (ARAT) in patients with ATM mutations. For safety, olaparib showed significantly lower ≥ 3 AE rate compared with cediranib plus olaparib (RR: 0.72, 95% CI: 0.51, 0.97), while olaparib plus cediranib was associated with the highest risk of all-grade AE. Conclusion: PARPi-based therapy showed considerable efficacy for mCRPC patients with HRD in 2nd -line setting. However, patients should be treated accordingly based on their genetic background as well as the efficacy and safety of the selected regimen. Trial registration: : CRD42023454079. [ABSTRACT FROM AUTHOR]

Purpose: Olaparib, an inhibitor of poly-(adenosine diphosphate-ribose) polymerase (PARP), has been shown to have anticancer benefits in patients with pancreatic cancer who have a germline mutation in BRCA1/2. However, resistance acquired on long-term exposure to olaparib significantly impedes clinical efficacy. Methods: In this study, the chromatin accessibility and differentially expressed transcripts of parental and olaparib-resistant pancreatic cancer cell lines were assessed using the Assay for Transposase Accessible Chromatin with sequencing (ATAC-seq) and mRNA-seq. Detection of downstream genes regulated by transcription factors using ChIP (Chromatin immunoprecipitation assay). Results: According to pathway enrichment analysis, differentially expressed genes in olaparib-resistant cells were remarkably enriched in the NF-κB signaling pathway. With ATAC-seq, we identified chromatin regions with higher accessibility in olaparib-resistant cells and predicted a series of important transcription factors. Among them, activating transcription factor 3 (ATF3) was significantly highly expressed. Functional experiments verified that inhibition of ATF3 suppressed the NF-κB pathway significantly and restored olaparib sensitivity in olaparib-resistant cells. Conclusion: Experiments in vitro and in vivo indicate ATF3 enhances olaparib resistance through the NF-κB signaling pathway, suggesting that ATF3 could be employed as an olaparib sensitivity and prognostic indicator in patients with pancreatic cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: An inhibitor of BUB1 increases the cytotoxic ability of different classes of chemotherapy, targeted agents, and radiotherapy in triple-negative breast cancer, which is the most difficult subtype of breast cancer to treat due to its lack of expression of targetable genes. The data presented here demonstrate that the cell cycle checkpoint kinase BUB1 can serve as a novel molecular target for the treatment of triple-negative breast cancer and form the basis for the development of rational combinatorial treatment approaches. BUB1 is overexpressed in most human solid cancers, including breast cancer. Higher BUB1 levels are associated with a poor prognosis, especially in patients with triple-negative breast cancer (TNBC). Women with TNBC often develop resistance to chemotherapy and radiotherapy, which are still the mainstay of treatment for TNBC. Our previous studies demonstrated that a BUB1 kinase inhibitor (BAY1816032) reduced tumor cell proliferation and significantly enhanced radiotherapy efficacy in TNBC. In this study, we evaluated the effectiveness of BAY1816032 with a PARP inhibitor (olaparib), platinum agent (cisplatin), and microtubule poison (paclitaxel) alone or in combination with radiotherapy using cytotoxicity and clonogenic survival assays. BUB1 inhibitors sensitized BRCA1/2 wild-type SUM159 and MDA-MB-231 cells to olaparib, cisplatin, and paclitaxel synergistically (combination index; CI < 1). BAY1816032 significantly increased the radiation sensitization of SUM159 and MDA-MB-231 by olaparib, cisplatin, or paclitaxel at non-toxic concentrations (doses well below the IC50 concentrations). Importantly, the small molecular inhibitor of BUB1 synergistically (CI < 1) sensitized the BRCA mutant TNBC cell line HCC1937 to olaparib. Furthermore, the BUB1 inhibitor significantly increased the radiation enhancement ratio (rER) in HCC1937 cells (rER 1.34) compared to either agent alone (BUB1i rER 1.19; PARPi rER 1.04). The data presented here are significant as they provide proof that inhibition of BUB1 kinase activity sensitizes TNBC cell lines to a PARP inhibitor and radiation, irrespective of BRCA1/2 mutation status. Due to the ability of the BUB1 inhibitor to sensitize TNBC to different classes of drugs (platinum, PARPi, microtubule depolarization inhibitors), this work strongly supports the role of BUB1 as a novel molecular target to improve chemoradiation efficacy in TNBC and provides a rationale for the clinical evaluation of BAY1816032 as a chemosensitizer and chemoradiosensitizer in TNBC. [ABSTRACT FROM AUTHOR]

Background: The prospective phase III multi-centre L-MOCA trial (NCT03534453) has demonstrated the encouraging efficacy and manageable safety profile of olaparib maintenance therapy in the Asian (mainly Chinese) patients with platinum-sensitive relapsed ovarian cancer (PSROC). In this study, we report the preplanned exploratory biomarker analysis of the L-MOCA trial, which investigated the effects of homologous recombination deficiency (HRD) and programmed cell death ligand 1 (PD-L1) expression on olaparib efficacy. Methods: HRD status was determined using the ACTHRD assay, an enrichment-based targeted next-generation sequencing assay. PD-L1 expression was assessed by SP263 immunohistochemistry assay. PD-L1 expression positivity was defined by the PD-L1 expression on ≥ 1% of immune cells. Kaplan–Meier method was utilised to analyse progression-free survival (PFS). Results: This exploratory biomarker analysis included 225 patients and tested HRD status [N = 190; positive, N = 125 (65.8%)], PD-L1 expression [N = 196; positive, N = 56 (28.6%)], and BRCA1/2 mutation status (N = 219). The HRD-positive patients displayed greater median PFS than the HRD-negative patients [17.9 months (95% CI: 14.5–22.1) versus 9.2 months (95% CI: 7.5–13.8)]. PD-L1 was predominantly expressed on immune cells. Positive PD-L1 expression on immune cells was associated with shortened median PFS in the patients with germline BRCA1/2 mutations [14.5 months (95% CI: 7.4–18.2) versus 22.2 months (95% CI: 18.3–NA)]. Conversely, positive PD-L1 expression on immune cells was associated with prolonged median PFS in the patients with wild-type BRCA1/2 [20.9 months (95% CI: 13.9–NA) versus 8.3 months (95% CI: 6.7–13.8)]. Conclusions: HRD remained an effective biomarker for enhanced olaparib efficacy in the Asian patients with PSROC. Positive PD-L1 expression was associated with decreased olaparib efficacy in the patients with germline BRCA1/2 mutations but associated with improved olaparib efficacy in the patients with wild-type BRCA1/2. Trial registration: NCT03534453. Registered at May 23, 2018. [ABSTRACT FROM AUTHOR]

Resistance to olaparib is the major obstacle in targeted therapy for ovarian cancer (OC) with poly(ADP-ribose) polymerase inhibitors (PARPis), prompting studies on novel combination therapies to enhance olaparib efficacy. Despite identifying various mechanisms, understanding how OC cells acquire PARPi resistance remains incomplete. This study investigated microRNA (miRNA) expression in olaparib-sensitive (PEO1, PEO4) and previously established olaparib-resistant OC cell lines (PEO1-OR) using high-throughput RT-qPCR and bioinformatic analyses. The role of miRNAs was explored regarding acquired resistance and resensitization with the ATR/CHK1 pathway inhibitors. Differentially expressed miRNAs were used to construct miRNA–mRNA regulatory networks and perform functional enrichment analyses for target genes with miRNet 2.0. TCGA-OV dataset was analyzed to explore the prognostic value of selected miRNAs and target genes in clinical samples. We identified potential processes associated with olaparib resistance, including cell proliferation, migration, cell cycle, and growth factor signaling. Resensitized PEO1-OR cells were enriched in growth factor signaling via PDGF, EGFR, FGFR1, VEGFR2, and TGFβR, regulation of the cell cycle via the G2/M checkpoint, and caspase-mediated apoptosis. Antibody microarray analysis confirmed dysregulated growth factor expression. The addition of the ATR/CHK1 pathway inhibitors to olaparib downregulated FGF4, FGF6, NT-4, PLGF, and TGFβ1 exclusively in PEO1-OR cells. Survival and differential expression analyses for serous OC patients revealed prognostic miRNAs likely associated with olaparib resistance (miR-99b-5p, miR-424-3p, and miR-505-5p) and resensitization to olaparib (miR-324-5p and miR-424-3p). Essential miRNA–mRNA interactions were reconstructed based on prognostic miRNAs and target genes. In conclusion, our data highlight distinct miRNA profiles in olaparib-sensitive and olaparib-resistant cells, offering molecular insights into overcoming resistance with the ATR/CHK1 inhibitors in OC. Moreover, some miRNAs might serve as potential predictive signature molecules of resistance and therapeutic response. [ABSTRACT FROM AUTHOR]

Aim Methods Results Conclusion In this study, we aimed to investigate patient characteristics, efficacy, prognostic factors, and safety of olaparib maintenance therapy for platinum‐sensitive recurrent ovarian cancer at our institution.Patients responding to platinum‐based therapy and starting olaparib maintenance therapy for recurrent epithelial ovarian, fallopian tube, or peritoneal cancer at Kurume University Hospital between January 2018 and November 2021 were enrolled in the study. Their data were extracted retrospectively from medical records.In all, 50 patients were included. The median (range) age of the patients, follow‐up time, and duration of olaparib maintenance therapy were 62 (39–87) years, 21.6 (2.2–45.9) months, and 7.2 (2–45.9) months, respectively. Among the 29 patients tested for homologous recombination (HR) status, 22 (75.9%) were positive for HR deficiency (HRD), 12 (54.5%) of whom had BRCA‐positive tumors. The median progression‐free survival was 8.9 months (95% confidence interval: 6.2–12.6), and the median overall survival was 27.1 months (95% confidence interval: 22.5–40.3). Multivariate analysis of prognostic factors revealed that HRD was an independent prognostic factor for both progression‐free survival and overall survival. The most common adverse event was nausea (any grade, n = 30, 60%), resulting in drug interruption (n = 23, 46%), dose reduction (n = 17, 34%), and discontinuation of treatment (n = 1, 2%).Olaparib maintenance therapy for recurrent platinum‐sensitive ovarian cancer at our institution was effective, with acceptable adverse events. HRD was the most significant prognostic factor for patients with recurrent platinum‐sensitive ovarian cancer. [ABSTRACT FROM AUTHOR]

AbstractWe investigated predictors of olaparib discontinuation owing to adverse effects. Patients with ovarian, peritoneal, or fallopian tube cancers treated with olaparib at Osaka Medical and Pharmaceutical University Hospital between April 2018 and September 2022 were included in this study. The exclusion criteria were as follows: discontinuation of treatment due to disease progression, use of anaemia medications, and use of cytochrome P450 (CYP3A4) inhibitors. The follow-up period was 90 d. Of the 46 eligible patients, 21 patients discontinued olaparib, including 15 patients with grade 3 or higher anaemia, eight patients with grade 3 or higher neutropenia, and four patients with non-haematological toxicity (including multiple onset). Multivariate logistic regression analysis showed that grade 4 neutropenia and anaemia progression to grades 2–3 due to chemotherapy administered before olaparib administration were predictors of olaparib discontinuation. The severity of neutropenia and anaemia due to chemotherapy before olaparib administration may be a potential marker for its discontinuation. [ABSTRACT FROM AUTHOR]

PARP inhibitors have been developed as anti-cancer agents based on synthetic lethality in homologous recombination deficient cancer cells. However, resistance to PARP inhibitors such as olaparib remains a problem in clinical use, and the mechanisms of resistance are not fully understood. To investigate mechanisms of PARP inhibitor resistance, we established a BRCA1 knockout clone derived from the pancreatic cancer MIA PaCa-2 cells, which we termed C1 cells, and subsequently isolated an olaparib-resistant C1/OLA cells. We then performed RNA-sequencing and pathway analysis on olaparib-treated C1 and C1/OLA cells. Our results revealed activation of cell signaling pathway related to NAD+ metabolism in the olaparib-resistant C1/OLA cells, with increased expression of genes encoding the NAD+ biosynthetic enzymes NAMPT and NMNAT2. Moreover, intracellular NAD+ levels were significantly higher in C1/OLA cells than in the non-olaparib-resistant C1 cells. Upregulation of intracellular NAD+ levels by the addition of nicotinamide also induced resistance to olaparib and talazoparib in C1 cells. Taken together, our findings suggest that upregulation of intracellular NAD+ is one of the factors underlying the acquisition of PARP inhibitor resistance. [ABSTRACT FROM AUTHOR]

Purpose: This paper reports the efficacy of the poly (ADP‐ribose) polymerase inhibitor olaparib alone and in combination with the antiangiogenesis agent cediranib compared with cediranib alone in patients with advanced endometrial cancer. Methods: This was open‐label, randomized, phase 2 trial (NCT03660826). Eligible patients had recurrent endometrial cancer, received at least one (<3) prior lines of chemotherapy, and were Eastern Cooperative Oncology Group performance status 0 to 2. Patients were randomly assigned (1:1:1), stratified by histology (serous vs. other) to receive cediranib alone (reference arm), olaparib, or olaparib and cediranib for 28‐day cycles until progression or unacceptable toxicity. The primary end point was progression‐free survival in the intention‐to‐treat population. Homologous repair deficiency was explored using the BROCA‐GO sequencing panel. Results: A total of 120 patients were enrolled and all were included in the intention‐to‐treat analysis. Median age was 66 (range, 41–86) years and 47 (39.2%) had serous histology. Median progression‐free survival for cediranib was 3.8 months compared with 2.0 months for olaparib (hazard ratio, 1.45 [95% CI, 0.91‐2.3] p =.935) and 5.5 months for olaparib/cediranib (hazard ratio, 0.7 [95% CI, 0.43–1.14] p =.064). Four patients receiving the combination had a durable response lasting more than 20 months. The most common grade 3/4 toxicities were hypertension in the cediranib (36%) and olaparib/cediranib (33%) arms, fatigue (20.5% olaparib/cediranib), and diarrhea (17.9% cediranib). The BROCA‐GO panel results were not associated with response. Conclusion: The combination of cediranib and olaparib demonstrated modest clinical efficacy; however, the primary end point of the study was not met. The combination was safe without unexpected toxicity. Randomized study of cediranib compared with olaparib and the combination for advanced or recurrent endometrial cancer demonstrated progression‐free survival of 3.8, 2.0, and 5.5 months respectively. The treatment toxicities were manageable but the study did not meet its primary end point. [ABSTRACT FROM AUTHOR]

Objective: To assess the cost-effectiveness and budget impact of olaparib as a maintenance therapy in platinum-responsive, metastatic pancreatic cancer patients harboring a germline BRCA1/2 mutation, using the Swiss context as a model. Methods: Based on data from the POLO trial, published literature and local cost data, we developed a partitioned survival model of olaparib maintenance including full costs for BRCA1/2 germline testing compared to FOLFIRI maintenance chemotherapy and watch-and-wait. We calculated the incremental cost-effectiveness ratio (ICER) for the base case and several scenario analyses and estimated 5-year budget impact. Results: Comparing olaparib with watch-and wait and maintenance chemotherapy resulted in incremental cost-effectiveness ratios of CHF 2,711,716 and CHF 2,217,083 per QALY gained, respectively. The 5-year costs for the olaparib strategy in Switzerland would be CHF 22.4 million, of which CHF 11.4 million would be accounted for by germline BRCA1/2 screening of the potentially eligible population. This would amount to a budget impact of CHF 15.4 million (USD 16.9 million) versus watch-and-wait. Conclusions: Olaparib is not a cost-effective maintenance treatment option. Companion diagnostics are an equally important cost driver as the drug itself. [ABSTRACT FROM AUTHOR]

Patients with glioblastoma who are older or have poor performance status (PS) experience particularly poor clinical outcomes. At the time of study initiation, these patients were treated with short-course radiation therapy (40 Gy in 15 fractions). Olaparib is an oral inhibitor of the DNA repair enzyme poly (ADP-ribose) polymerase (PARP) that is well tolerated as a single agent but exacerbates acute radiation toxicity in extracranial sites. Preclinical data predicted that PARP inhibitors would enhance radiosensitivity in glioblastoma without exacerbating adverse effects on the normal brain. Phase 1 of the PARADIGM trial was a 3+3 dose-escalation study testing olaparib in combination with radiation therapy (40 Gy 15 fractions) in patients with newly diagnosed glioblastoma who were unsuitable for radical treatment either because they were aged 70 years or older (World Health Organization PS 0-1) or aged 18 to 69 years with PS 2. The primary outcome was the recommended phase 2 dose of olaparib. Secondary endpoints included safety and tolerability, overall survival, and progression-free survival. Effects on cognitive function were assessed via the Mini Mental State Examination. Of 16 eligible patients (56.25% male; median age, 71.5 years [range, 44-78]; 75% PS 0-1), 1 dose-limiting toxicity was reported (grade 3 agitation). Maximum tolerated dose was not reached and the recommended phase 2 dose was determined as 200 mg twice daily. Median overall survival and progression-free survival were 10.8 months (80% CI, 7.3-11.4) and 5.5 months (80% CI, 3.9-5.9), respectively. Mini Mental State Examination plots indicated that cognitive function was not adversely affected by the olaparib–radiation therapy combination. Olaparib can be safely combined with hypofractionated brain radiation therapy and is well tolerated in patients unsuitable for radical chemoradiation. These results enabled initiation of a randomized phase 2 study and support future trials of PARP inhibitors in combination with radiation therapy for patients with brain tumors. [ABSTRACT FROM AUTHOR]

Key Clinical Message: In a patient with metastatic breast cancer, an acquired BRCA mutation in the BRCA gene was detected, resulting in benefits from olaparib treatment. This underscores the importance of ongoing genetic phenotype testing after paclitaxel chemotherapy. Triple‐negative breast cancer (TNBC) is associated with a poor prognosis and elevated mortality risk. BRCA mutations are commonly regarded as prevalent mutations in TNBC patients, strongly associated with congenital familial heredity. Dynamic changes in mutation sites, however, are rarely reported. In this case report, we report a 59‐year‐old TNBC patient who developed pulmonary metastases post‐chemoradiotherapy. No BRCA mutations were detected through NGS. After 7.6 months of nab‐paclitaxel treatment, the patient experienced progression of lung metastases, and BRCA mutations were detected through NGS testing. Subsequent administration of olaparib resulted in a reduction in lung metastasis, demonstrating significant therapeutic efficacy. This case underscores the infrequent occurrence of treatment‐induced BRCA mutations and emphasizes the significance of dynamic NGS genetic testing for real‐time assessment of a patient's mutational status. [ABSTRACT FROM AUTHOR]

Background: Poly (ADP‐ribose) polymerase (PARP) inhibitors have been increasingly used in the treatment of ovarian cancer, with BRCA positivity and homologous recombination deficiency (HRD) being common biomarkers used for predicting their efficacy. However, given the limitations of these biomarkers, new ones need to be explored. Methods: This retrospective study included 181 ovarian cancer patients who received olaparib or niraparib at two independent hospitals in Japan between May 2018 and December 2022. Clinical information and blood sampling data were collected. Patient characteristics, treatment history, and predictability of treatment duration based on blood data before treatment initiation were examined. Results: High‐grade serous carcinoma, BRCA positivity, HRD, and maintenance therapy after recurrence treatment were observed more frequently in the olaparib group than in the niraparib group. The most common reasons for treatment interruption were anemia, fatigue, and nausea in the olaparib group and thrombocytopenia in the niraparib group. Regarding response to olaparib treatment, complete response to the most recent treatment, maintenance therapy after the first chemotherapy, high‐grade serous carcinoma, and germline BRCA positivity were observed significantly more frequently among responders than among non‐responders. Furthermore, neutrophil counts were significantly higher among responders than among non‐responders. Conclusions: Inflammation‐related blood data, such as neutrophil count, obtained at the initial pre‐treatment visit might serve as potential predictors for prolonged olaparib treatment. While this study offers valuable insights into potential indicators for prolonged olaparib treatment, it underscores the need for more expansive research to strengthen our understanding of PARP inhibitors and optimize treatment strategies in ovarian cancer. [ABSTRACT FROM AUTHOR]

A 66‐year‐old woman was found to have abnormal shadows on a chest radiograph at a previous hospital 4 years ago, which led to a diagnosis of lung adenocarcinoma, cT2aN1M1b stage IVA. First‐line treatment included carboplatin and paclitaxel plus thoracic radiotherapy and stereotactic radiation therapy for brain metastases. The patient later underwent second‐line pemetrexed treatment, followed by third‐line nivolumab, fourth‐line docetaxel and bevacizumab, fifth‐line tegafur‐gimeracil‐oteracil, and sixth‐line gemcitabine. Two years ago, after observing an increase in the primary lesion and carcinoembryonic antigen levels (104.0 ng/mL), a computed tomography‐guided biopsy was performed from the primary site of lung cancer. A cancer genomic profiling test (FoundationOne® CDx cancer genome profile) revealed a breast cancer susceptibility (BRCA) 2 gene mutation. Therefore, she started taking olaparib. The treatment led to stable disease for approximately 2 years. [ABSTRACT FROM AUTHOR]

Simple Summary: Poly (ADP-ribose) polymerase (PARP) inhibitors have become an essential part of the anticancer armamentarium in ovarian cancer. As maintenence therapy they have been shown to extend survival, and may improve the chance of cure in first line. However, later line treatmewnt is associated with a negative impact on survivaL and limited their use outside trials to first line and secondline in patients with a BRCA mutated cancer. Poly (ADP-ribose) polymerase (PARP) inhibitors have become an established part of the anticancer armamentarium. Discovered in the 1980s, PARP inhibitors (PARPis) were initially developed to exploit the presence of BRCA mutations, which disrupt the homologous recombination repair of deoxyribonucleic acid (DNA) via synthetic lethality, an intrinsic vulnerability caused by the cell's dependence on other DNA repair mechanisms for which PARP is an essential contributor. PARPi use expanded with the demonstration of clinical benefit when other mechanisms of high-fidelity DNA damage response were present in cancer cells called homologous repair deficiency (HRD). Recently, new data have resulted in the voluntary withdrawal of later-line treatment indications for all the available PARPis used in ovarian cancer because of a negative impact on overall survival (OS). PARPi switch maintenance to consolidate a response to platinum-based therapy is recommended for earlier treatment lines to have the greatest impact on the chance of cure and length of survival. This article reviews the clinical utility of PARPis and how to integrate them into best practices. [ABSTRACT FROM AUTHOR]

Background: Ovarian cancer is the eighth leading cause of cancer-related death among women, characterized by late diagnosis and a high relapse rate. In randomized controlled trials, we aimed to evaluate the efficacy and safety of PARP inhibitors (PARPi) in treating advanced ovarian cancer. Methods: This review was registered on PROSPERO (CRD42021283150), included all phase II and phase III randomized controlled trials (RCTs) assessing the effect of PARPi on ovarian cancer until the 13th of April, 2022. The main outcomes were progression- free survival (PFS), overall survival (OS), and adverse events (AEs). Pooled hazard ratios (HRs), and risk ratios (RRs) were calculated with 95% confidence intervals (95% CI). The random-effects model was applied in all analyses. Results: In the meta-analysis, 16 eligible RCTs were included, with a total of 5,815 patients. In recurrent ovarian cancer, PARPi maintenance therapy showed a significant PFS benefit over placebo in the total population (HR 0.34, CI 0.29–0.40), BRCA mutant (HR 0.24, CI 0.18–0.31), germline BRCA mutant (HR 0.23, CI 0.18–0.30), and BRCA wild-type cases (HR 0.50, CI 0.39–0.65). PARPi monotherapy also improved PFS (HR 0.62, CI 0.51–0.76) compared with chemotherapy in BRCAm patients with recurrent ovarian cancer. The use of PARPi maintenance therapy resulted in an improvement in PFS over placebo in newly-diagnosed cancers in the overall population (HR 0.46, CI 0.30–0.71) and the BRCAm population (HR 0.36, CI 0.29–0.44). Although the risk of severe AEs was increased by PARPi therapy compared to placebo in most settings investigated, these side effects were controllable with dose modification, and treatment discontinuation was required in the minority of cases. Conclusions: PARPis are an effective therapeutic option for newly-diagnosed and recurrent ovarian cancer. Despite a minor increase in the frequency of serious adverse effects, they are generally well tolerated. [ABSTRACT FROM AUTHOR]

Background: Based on a high incidence of genomic alteration in the cell cycle and DNA damage and response (DDR)‐related pathways in small cell lung cancer (SCLC), the clinical efficacy of the DDR‐targeting agent olaparib (PARP inhibitor) as monotherapy and in combination with ceralasertib (ATR inhibitor) in relapsed or refractory SCLC was evaluated. Methods: As part of a phase 2 biomarker driven umbrella study, patients with SCLC and predefined DDR gene alterations who failed to benefit from prior platinum‐based regimens were allocated to the olaparib monotherapy arm and nonbiomarker‐selected patients were allocated to the olaparib and ceralasertib combination arm. Results: In the olaparib monotherapy arm (n = 15), the objective response rate was 6.7% (one partial response), and the disease control rate was 33.3%, including three patients with stable disease. The median progression‐free survival was 1.3 months (95% CI, 1.2–NA). In the combination arm (n = 26), the objective response rate and disease control rate were 3.8% and 42.3%, respectively, with one partial response and 10 patients with stable disease. The median progression‐free survival was 2.8 months (95% CI, 1.8–5.4). Treatment was generally well tolerated except for one fatal case of neutropenic fever in the combination arm. Conclusions: Targeting DDR pathways with olaparib as a single agent or in combination with ceralasertib did not meet the predefined efficacy end point. However, disease stabilization was more evident in the combination arm. Further investigation of the combination of olaparib in SCLC should be performed with diverse combinations and patient selection strategies to maximize efficacy. This study provides clinical evidence that current approaches targeting DNA damage and response pathway as either olaparib alone or in combination with ceralasertib therapy are insufficient to achieve a satisfactory response in small cell lung cancer. However, this study supports the evidence for further investigation, searching for an appropriate combination partner of DNA damage and response pathway targeting agent and relevant predictive biomarkers in small cell lung cancer. [ABSTRACT FROM AUTHOR]

Poly-(ADP-ribose) polymerases (PARPs) are a protein family that make ADP-ribose modifications on target genes and proteins. PARP family members contribute to the pathogenesis of chronic inflammatory diseases, including atherosclerosis, in which monocytes/macrophages play important roles. PARP inhibition is protective against atherosclerosis. However, the mechanisms by which PARP inhibition exerts this beneficial effect are not well understood. Here we show that in THP-1 monocytes, inhibition of PARP by olaparib attenuated oxidized low-density lipoprotein (oxLDL)-induced protein expressions of nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing-3 (NLRP3) inflammasome components: NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), and caspase-1. Consistent with this effect, olaparib decreased oxLDL-enhanced interleukin (IL)-1β and IL-18 protein expression. Olaparib also decreased the oxLDL-mediated increase in mitochondrial reactive oxygen species. Similar to the effects of the NLRP3 inhibitor, MCC950, olaparib attenuated oxLDL-induced adhesion of monocytes to cultured human umbilical vein endothelial cells and reduced foam cell formation. Furthermore, olaparib attenuated the oxLDL-mediated activation of nuclear factor (NF)-κB through the oxLDL-mediated increase in IκBα phosphorylation and assembly of NF-κB subunits, demonstrated by co-immunoprecipitation of IκBα with RelA/p50 and RelB/p52 subunits. Moreover, PARP inhibition decreased oxLDL-mediated protein expression of a NF-κB target gene, VCAM1, encoding vascular cell adhesion molecule-1. This finding indicates an important role for NF-κB activity in PARP-mediated activation of the NLRP3 inflammasome. Thus, PARP inhibition by olaparib attenuates NF-κB and NLRP3 inflammasome activities, lessening monocyte cell adhesion and macrophage foam cell formation. These inhibitory effects of olaparib on NLRP3 activity potentially protect against atherosclerosis. [ABSTRACT FROM AUTHOR]

This multicenter retrospective cohort study aimed to compare survival outcomes and adverse events between maintenance therapy with two poly (ADP-ribose) polymerase (PARP) inhibitors, olaparib and niraparib, in patients with BRCA -mutated, newly diagnosed advanced epithelial ovarian cancer (EOC) who responded to platinum-based chemotherapy. We enrolled stage III-IV EOC patients with germline and/or somatic BRCA1/2 mutations that had received maintenance therapy with olaparib or niraparib. A 3:1 propensity score matching was conducted using two variables: residual disease size and the presence of germline variants. The primary outcome was progression-free survival (PFS), and the secondary outcomes were time to first subsequent therapy (TFST), overall survival (OS), and treatment-emergent adverse events (TEAEs). In the propensity score-matched analysis, 80 patients who received olaparib and 31 patients who received niraparib were matched (3:1). In the propensity score-matched cohort, median PFS with olaparib vs. niraparib was not reached vs 31.5 months (HR, 1.08; 95% CI, 0.47–2.52; p = 0.854). The median TFST was not reached vs 31.8 months (HR, 1.20; 95% CI, 0.51–2.81; p = 0.682), and neither olaparib nor niraparib reached the median OS (HR, 0.42; 95% CI, 0.01–17.61; p = 0.649). In terms of the incidence rates of any-grade hematologic or non-hematologic TEAEs, higher rates of thrombocytopenia (p = 0.021) and neutropenia (p = 0.011) were observed in the niraparib group. Advanced EOC patients with BRCA1/2 mutations exhibited no significant difference in OS between olaparib and niraparib, indicating the need to consider individualized strategies for selecting PARP inhibitors based on adverse event profiles. • This multicenter study compared olaparib and niraparib in newly diagnosed BRCA-mutated ovarian cancer. • The study found no significant difference in PFS, TFST, or OS between two groups in the matched cohort. • Higher thrombocytopenia and neutropenia rates with niraparib suggest individualized PARP inhibitor selection. [ABSTRACT FROM AUTHOR]

This article discusses a case report of a pharmacokinetic drug-drug interaction between olaparib and apixaban in a cancer patient. The patient was receiving off-label treatment with olaparib and also taking apixaban for the prevention of deep vein thrombosis recurrence. The study found that the concurrent use of olaparib and apixaban resulted in a 2.1-fold increase in apixaban concentration. This interaction could potentially increase the risk of bleeding in patients. The authors recommend a multidisciplinary approach and therapeutic drug monitoring for cancer patients receiving both apixaban and olaparib. [Extracted from the article]

Objective: Olaparib is a PARP (poly-ADP-ribose polymerase) inhibitor used for maintenance therapy in BRCA-mutated cancers. Metformin is a first-choice drug used in the treatment of type 2 diabetes. Both drugs are commonly co-administered to oncologic patients with add-on type 2 diabetes mellitus. Olaparib is metabolized by the CYP3A4 enzyme, which may be inhibited by metformin through the Pregnane X Receptor. In vitro studies have shown that olaparib inhibits the following metformin transporters: OCT1, MATE1, and MATE2K. The aim of the study was to assess the influence of 'the perpetrator drug' on the pharmacokinetic (PK) parameters of 'the victim drug' after a single dose. To evaluate the effect, the AUC0→∞ (area under the curve) ratio was determined (the ratio between AUC0→∞ in the presence of the perpetrator and AUC0→∞ without the presence of the perpetrator). Methods: Male Wistar rats were assigned to three groups (eight animals in each group), which were orally administered: metformin and olaparib (IMET+OLA), vehiculum with metformin (IIMET), and vehiculum with olaparib (IIIOLA). Blood samples were collected after 24 h. HPLC was applied to measure the concentrations of olaparib and metformin. The PK parameters were calculated in a non-compartmental model. Results: Metformin did not affect the olaparib PK parameters. The AUC0→∞ IMET+OLA/IIIOLA ratio was 0.99. Olaparib significantly increased the metformin Cmax (by 177.8%), AUC0→t (by 159.8%), and AUC0→∞ (by 74.1%). The AUC0→∞ IMET+OLA/IIMET ratio was 1.74. Conclusions: A single dose of metformin did not affect the PK parameters of olaparib, nor did it inhibit the olaparib metabolism, but olaparib significantly changed the metformin pharmacokinetics, which may be of clinical importance. [ABSTRACT FROM AUTHOR]

We present the case of a 75-year-old female with simultaneous EGFR-mutated stage IV lung cancer and advanced BRCA2-mutated ovarian cancer, treated with a unique regimen. In this case report, the patient was treated with alternating months of osimertinib and olaparib to control her lung and ovarian cancers, respectively. When both diseases showed progression, the patient underwent a trial of concurrent therapy with both drugs, yet this was discontinued due to patient-reported adverse side effects. Combination targeted drug therapy may be required to treat complex diagnoses such as dual malignancies. However, combination drug therapy consisting of osimertinib and olaparib has not previously been explored. This case report represents the first to demonstrate osimertinib and olaparib combination therapy as a unique treatment regimen for concurrent lung and ovarian cancers. These two drugs can either be given in an alternating way or given together, short-term, with a higher but tolerable toxicity profile. [ABSTRACT FROM AUTHOR]

Objective: The PAOLA-1 trial (NCT02477644) reported final survival benefit associated with olaparib plus bevacizumab maintenance treatment of patients with advanced ovarian cancer (AOC) based on molecular status. Our aimed to compare the cost-effectiveness of olaparib plus bevacizumab for overall patients, patients with a breast cancer susceptibility genes (BRCA) mutation, homologous recombination deficiency (HRD), or HRD without BRCA mutations AOC from the context of the American healthcare system. Methods: Analysis of health outcomes in life-years (LYs), quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER) in various molecular status-based AOC patient at a $150,000/QALY of willingness-to-pay was performed using a state-transitioned Markov model with a 20-year time horizon. Meanwhile, sensitivity analyses assessments were also used to gauge the model's stability. Results: The ICERs of olaparib plus bevacizumab versus bevacizumab alone were $487,428 ($374,758), $249,579 ($191,649), $258,859 ($198,739), and $270,736 ($206,640) per QALY (LY) in the overall patients, patients with BRCA mutations, patients with HRD, and patients with HRD without BRCA mutations AOC, respectively, which indicated that The ICERs was higher than $150,000/QALY in the US. Progression-free survival (PFS) value and olaparib cost emerged as the primary influencing factors of these findings in the sensitivity analysis. Conclusion: At current cost levels, olaparib plus bevacizumab treatment is not a cost-effective treatment for patients with AOC regardless of their molecular status in the US. However, this maintenance treatment may be more favorable health advantages for patients with BRAC mutations AOC. [ABSTRACT FROM AUTHOR]

This study concerned with assessing the effect of restoring p53 using PRIMA-1 on the anti-cancer activity of olaparib against TP53-mutant triple negative breast cancer (TNBC) cells and exploring the optimum synergistic concentrations and the underlying mechanism. Human BC cell lines, MDA-MB-231 with mutated TP53 gene, and MCF-7 with wild-type TP53 gene were treated with olaparib and/or PRIMA-1. The IC50 value for olaparib was significantly decreased by PRIMA-1 in MDA-MB-231 cells compared to MCF-7 cells. Contrary to MCF-7 cells, co-treatment with olaparib and PRIMA-1 had a synergistic anti-proliferative effect in MDA-MB-231 at all tested concentrations with the best synergistic combination at 45 and 8.5 µM, respectively, and furthermore PRIMA-1 enhanced olaparib-induced apoptosis. This synergistic apoptotic effect was associated with a significant boost in mRNA expression of TP53 gene, cell cycle arrest at G2/M phase, modulation of BRCA-1, BAX and Bcl2 proteins expressions, and induction of active caspase-3. These results present a clue for the utility of combined olaparib and PRIMA-1 in treatment of TP53-mutant TNBC invitro. PRIMA-1 triggers olaparib-induced MDA-MB-231 cell death in a synergistic manner via restoring TP53, decreasing BRCA-1 expression, cell cycle arrest, and enhancement of apoptosis via p53/BAX/Bcl2/caspase 3 pathway. [ABSTRACT FROM AUTHOR]

Myeloproliferative neoplasms (MPN) are rare hematologic disorders characterized by clonal hematopoiesis. Familial clustering is observed in a subset of cases, with a notable proportion exhibiting heterozygous germline mutations in DNA double-strand break repair genes (e.g., BRCA1). We investigated the therapeutic potential of targeting BRCA1 haploinsufficiency alongside the JAK2V617F driver mutation. We assessed the efficacy of combining the PARP inhibitor olaparib with interferon-alpha (IFNα) in CRISPR/Cas9-engineered Brca1+/− Jak2V617F-positive 32D cells. Olaparib treatment induced a higher number of DNA double-strand breaks, as demonstrated by γH2AX analysis through Western blot (p = 0.024), flow cytometry (p = 0.013), and confocal microscopy (p = 0.071). RAD51 foci formation was impaired in Brca1+/− cells compared to Brca1+/+ cells, indicating impaired homologous recombination repair due to Brca1 haploinsufficiency. Importantly, olaparib enhanced apoptosis while diminishing cell proliferation and viability in Brca1+/− cells compared to Brca1+/+ cells. These effects were further potentiated by IFNα. Olaparib induced interferon-stimulated genes and increased endogenous production of IFNα in Brca1+/− cells. These responses were abrogated by STING inhibition. In conclusion, our findings suggest that the combination of olaparib and IFNα presents a promising therapeutic strategy for MPN patients by exploiting the synthetic lethality between germline BRCA1 mutations and the JAK2V617F MPN driver mutation. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficacy and safety of olaparib for the treatment of advanced ovarian cancer. All studies that assessed the efficacy and safety of olaparib in advanced ovarian cancer were searched in PubMed, Embase, and Web of Science from their inception to 20 September 2022. The analysis included six studies and 2016 patients. Olaparib could significantly prolong the progression-free survival (PFS) of patients compared to that of the control group (HR = 0.49, 95% CI = 0.36 − 0.68). However, no statistically significant differences were detected in overall survival (OS) and objective response rate (ORR) between the olaparib and control groups. Olaparib treatment increased the number of grade ≥3 adverse events (AEs) in patients with advanced ovarian cancer compared with that in the control group. Olaparib significantly prolonged PFS in patients with advanced ovarian cancer; however, no statistically significant differences were detected in OS and ORR. In terms of safety, olaparib has manageable adverse effects. [ABSTRACT FROM AUTHOR]

Purpose: PARP inhibitors have revolutionized the treatment landscape for advanced prostate cancer (PCa) patients who harboring mutations in homologous recombination repair (HRR) genes. However, the molecular mechanisms underlying PARP inhibitors function beyond DNA damage repair pathways remain elusive, and identifying novel predictive targets that favorably respond to PARP inhibitors in PCa is an active area of research. Methods: The expression of GSDME in PCa cell lines and human PCa samples was determined by western blotting. Targeted bisulfite sequencing, gene enrichment analysis (GSEA), clone formation, construction of the stably transfected cell lines, lactate dehydrogenase (LDH) assay, western blotting as well as a mouse model of subcutaneous xenografts were used to investigate the role of GSDME in PCa. The combinational therapeutic effect of olaparib and decitabine was determined using both in vitro and in vivo experiments. Results: We have found low expression of GSDME in PCa. Interestingly, we demonstrated that GSDME activity is robustly induced in olaparib-treated cells undergoing pyroptosis, and that high methylation of the GSDME promoter dampens its activity in PCa cells. Intriguingly, genetically overexpressing GSDME does not inhibit tumor cell proliferation but instead confers sensitivity to olaparib. Furthermore, pharmacological treatment with the combination of olaparib and decitabine synergistically induces GSDME expression and cleavage through caspase-3 activation, thus promoting pyroptosis and enhancing anti-tumor response, ultimately resulting in tumor remission. Conclusion: Our findings highlight a novel therapeutic strategy for enhancing the long-term response to olaparib beyond HRR-deficient tumors in PCa, underscoring the critical role of GSDME in regulating tumorigenesis. [ABSTRACT FROM AUTHOR]

Aim: Although the advent of a poly polymerase inhibitors has greatly advanced the tailoring of cancer treatment, there is a dearth of real‐world evidence on the actual use of olaparib in aging populations, especially those using national‐level data. Methods: We extracted and analyzed all prescriptions of olaparib in female outpatients from the National Database Open Data Japan (NDB Open Data) from April 2019 to March 2021. The recommended standard dose of olaparib is four tablets of the 150 mg formulation per day, while the 100 mg formulation of olaparib can be considered as an alternative dose in the occurrence of hematologic toxicity. We calculated the proportion of 100 mg compared to the 150 mg prescriptions across age groups. A Cochrane–Armitage trend test was used to examine the association of age groups with the proportion of 100 mg prescriptions. Results: The total number of prescriptions of the 100 mg formulation and the 150 mg formulation were 1449 222, and 4233 625, respectively. Overall, 45.1% (2567 513/5682 847 prescriptions) of olaparib were prescribed for patients 65 years of age or older in females. Stratified by age group, the proportion of 100 mg compared to the 150 mg prescriptions significantly increased with age (p < 0.0001). Conclusions: Given that the 100 mg formulation of olaparib can be considered as an alternative dose in Japan in the occurrence of hematologic toxicity, our observations indicate the dose reduction of olaparib in older patients in Japan. Further investigations are necessary to assess its efficacy and safety at a reduced dose. [ABSTRACT FROM AUTHOR]

Aim: Ovarian cancer is a gynecological malignancy with a poor prognosis. For platinum‐sensitive relapsed ovarian cancer, maintenance therapy with poly‐ADP ribose polymerase (PARP) inhibitors after chemotherapy is considered; however, olaparib treatment does not always lead to sufficient progression‐free survival (PFS). This study aimed to identify factors that predict the efficacy of maintenance therapy using olaparib in platinum‐sensitive relapsed ovarian cancer. Methods: Twenty‐seven patients with platinum‐sensitive relapsed ovarian cancer, who received initial treatment and showed complete or partial response to prior chemotherapy at our hospital, were included. The primary outcome was the time from the end of previous platinum‐based chemotherapy to disease progression (PFS). The Kaplan–Meier method was used to generate time‐to‐event curves for PFS; multivariate analysis was performed using the Cox proportional hazards regression model. Results: The median PFS was 12 months (95% confidence interval [CI]: 8.3–15.8). Before olaparib administration, the median PFS was 12 months in the <4.1 neutrophil‐to‐lymphocyte ratio group and 4 months in the ≥4.1 group, with PFS being significantly better in the <4.1 group (log‐rank: p = 0.023). When comparing serum cancer antigen 125 (CA125) levels, the median PFS was 13 months in the <18 U/mL group and 6 months in the >18 U/mL group (log‐rank: p = 0.022). Multivariate Cox regression analysis revealed that CA125 was the factor affecting PFS (hazard ratio: 4.85; 95% CI: 1.53–15.38). Conclusions: Serum CA125 levels at olaparib initiation in patients with platinum‐sensitive relapsed ovarian cancer may predict PFS as an effect of maintenance therapy using olaparib to treat recurrent disease. [ABSTRACT FROM AUTHOR]

Background: Endometrial cancer (EC) is one of the most prevalent gynecologic cancers, which poses a serious threat to women's health worldwide. Olaparib, the first FDA-approved PARP inhibitor for the treatment of BRCA-mutated breast, ovarian and pancreatic cancers, triggers apoptosis of cancer cells through synthetic lethality by inhibiting PARP1/2 enzymatic activity and BRCA1/2-dependent homologous recombination (HR) repair deficiency. However, the synergistic lethal effects between Olaparib and inhibitors of other DNA damage response proteins, such as ATM, PTEN and RAD51, are still unknown.Aim: Exploring the synergistic lethal effect between Olaparib and KU-55933 on EC.Methods: The GEPIA database was used to test EC patient survival rate. CCK8 was used for cell viability assays. Western blot was used for examining gene levels. The wound healing assay was used to detect cell migration ability. Flow cytometry was used for detecting the apoptosis rate. All experimental conditions were repeated independently in triplicate and analyzed in three separate experiments.Results: In this study, we discovered that the frequency of ATM alterations in endometrial cancer reaches nearly 20% and that there is a positive correlation between ATM alterations and prognosis. Furthermore, we discovered that endometrial cells with low expression levels of ATM are sensitive to Olaparib. Treatment with KU-55933, a specific inhibitor of ATM, significantly enhanced the sensitivity of endometrial cancer cells to Olaparib, as evidenced by colony formation, cell migration and apoptosis assay. Further analysis revealed that KU-55933 potentiates Olaparib-induced cell apoptosis by inhibiting ATM phosphorylation.Conclusion: Our study demonstrates that inhibiting ATM could enhance the sensitivity of endometrial cancer to Olaparib, thereby providing a potential alternative treatment for the clinical treatment of endometrial cancer. [ABSTRACT FROM AUTHOR]

Olaparib is a small-molecule inhibitor of poly(ADP)-ribose polymerase (PARP) used as maintenance therapy for recurrent ovarian cancer and newly diagnosed advanced ovarian cancer after initial chemotherapy. An exposure-toxicity correlation has been reported between the probability of anemia, a common adverse event associated with olaparib, and the steady-state minimum plasma concentration (Cmin) as well as the predicted maximum plasma concentration (Cmax). On the other hand, olaparib exhibits high interpatient variability with regard to the area under the concentrationtime curve, Cmax, and Cmin. Therefore, we developed a simple and sensitive assay based on highperformance liquid chromatography with ultraviolet light (HPLC-UV) for the therapeutic drug monitoring of olaparib. The analysis was performed on an octadecylsilyl column with a mobile phase consisting of 0.5% KH2PO4 (pH 4.5) and acetonitrile (71:29, v/v), at a flow rate of 0.8 mL/min. Olaparib and an internal standard (imatinib) were well separated from the co-extracted material, with retention times of 13.6 and 11.5 min, respectively. The calibration curve for olaparib showed linearity over the concentration range of 0.10-10.0 μg/mL (r² = 0.9998). The intra- and interday validation coefficients ranged from 1.79 to 4.13% and 1.37 to 3.55%, respectively. Measurement accuracy ranged from - 6.07 to 3.26%, with a recovery rate of more than 91.06%. The developed method was then applied to evaluate the plasma olaparib concentrations in patients with ovarian cancer. Our findings demonstrate that HPLC-UV is an economical, simple, and sensitive method for clinical application and holds promise for the effective drug monitoring of olaparib during ovarian cancer treatment. [ABSTRACT FROM AUTHOR]

Poly(ADP-ribose) polymerase (PARP) inhibitor maintenance therapy is the standard of care for some patients with advanced ovarian cancer. We evaluated the efficacy and safety of PARP inhibitor rechallenge. This randomized, double-blind, multicenter trial (NCT03106987) enrolled patients with platinum-sensitive relapsed ovarian cancer who had received one prior PARP inhibitor therapy for ≥18 and ≥12 months in the BRCA-mutated and non-BRCA-mutated cohorts, respectively, following first-line chemotherapy or for ≥12 and ≥6 months, respectively, following a second or subsequent line of chemotherapy. Patients were in response following their last platinum-based chemotherapy regimen and were randomized 2 : 1 to maintenance olaparib tablets 300 mg twice daily or placebo. Investigator-assessed progression-free survival (PFS) was the primary endpoint. Seventy four patients in the BRCA-mutated cohort were randomized to olaparib and 38 to placebo, and 72 patients in the non-BRCA-mutated cohort were randomized to olaparib and 36 to placebo; >85% of patients in both cohorts had received ≥3 prior lines of chemotherapy. In the BRCA-mutated cohort, the median PFS was 4.3 months with olaparib versus 2.8 months with placebo [hazard ratio (HR) 0.57; 95% confidence interval (CI) 0.37-0.87; P = 0.022]; 1-year PFS rates were 19% versus 0% (Kaplan–Meier estimates). In the non-BRCA-mutated cohort, median PFS was 5.3 months for olaparib versus 2.8 months for placebo (HR 0.43; 95% CI 0.26-0.71; P = 0.0023); 1-year PFS rates were 14% versus 0% (Kaplan–Meier estimates). No new safety signals were identified with olaparib rechallenge. In ovarian cancer patients previously treated with one prior PARP inhibitor and at least two lines of platinum-based chemotherapy, maintenance olaparib rechallenge provided a statistically significant, albeit modest, PFS improvement over placebo in both the BRCA-mutated and non-BRCA-mutated cohorts, with a proportion of patients in the maintenance olaparib rechallenge arm of both cohorts remaining progression free at 1 year. • OReO is the first study to show that maintenance olaparib rechallenge provides a PFS benefit in relapsed ovarian cancer. • Statistically significant PFS benefit is seen with olaparib rechallenge over placebo independent of BRCA mutation status. • A proportion of the OReO population was still progression free at 1 year. • No new safety signals were observed with maintenance olaparib rechallenge. • Further investigation may reveal identifiable characteristics of those patients deriving the most clinical benefit. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) is effectively treated with tyrosine kinase inhibitors (TKIs), targeting the BCR::ABL1 oncoprotein. Still, resistance to therapy, relapse after treatment discontinuation, and side effects remain significant issues of long-term TKI treatment. Preliminary studies have shown that targeting oxidative phosphorylation (oxPhos) and the unfolded protein response (UPR) are promising therapeutic approaches to complement CML treatment. Here, we tested the efficacy of different TKIs, combined with the ATP synthase inhibitor oligomycin and the ER stress inducer thapsigargin in the CML cell lines K562, BV173, and KU812 and found a significant increase in cell death. Both, oligomycin and thapsigargin, triggered the upregulation of the UPR proteins ATF4 and CHOP, which was inhibited by imatinib. We observed comparable effects on cell death when combining TKIs with the ATP synthase inhibitor 8-chloroadenosine (8-Cl-Ado) as a potentially clinically applicable therapeutic agent. Stress-related apoptosis was triggered via a caspase cascade including the cleavage of caspase 3 and the inactivation of poly ADP ribose polymerase 1 (PARP1). The inhibition of PARP by olaparib also increased CML death in combination with TKIs. Our findings suggest a rationale for combining TKIs with 8-Cl-Ado or olaparib for future clinical studies in CML. [ABSTRACT FROM AUTHOR]

Background: Lack of Schlafen family member 11 (SLFN11) expression has been recently identified as a dominant genomic determinant of response to DNA damaging agents in numerous cancer types. Thus, several strategies aimed at increasing SLFN11 are explored to restore chemosensitivity of refractory cancers. In this study, we examined various approaches to elevate SLFN11 expression in breast cancer cellular models and confirmed a corresponding increase in chemosensitivity with using the most successful efficient one. As oncogenic transcriptomic downregulation is often driven by methylation of the promotor region, we explore the demethylation effect of 5-aza-2′-deoxycytidine (decitabine), on the SLFN11 gene. Since SLFN11 has been reported as an interferon inducible gene, and interferon is secreted during an active anti-tumor immune response, we investigated the in vitro effect of IFN-γ on SLFN11 expression in breast cancer cell lines. As a secondary approach to pick up cross talk between immune cells and SLFN11 expression we used indirect co-culture of breast cancer cells with activated PBMCs and evaluated if this can drive SLFN11 upregulation. Finally, as a definitive and specific way to modulate SLFN11 expression we implemented SLFN11 dCas9 (dead CRISPR associated protein 9) systems to specifically increase or decrease SLFN11 expression. Results: After confirming the previously reported correlation between methylation of SLFN11 promoter and its expression across multiple cell lines, we showed in-vitro that decitabine and IFN-γ could increase moderately the expression of SLFN11 in both BT-549 and T47D cell lines. The use of a CRISPR-dCas9 UNISAM and KRAB system could increase or decrease SLFN11 expression significantly (up to fivefold), stably and specifically in BT-549 and T47D cancer cell lines. We then used the modified cell lines to quantify the alteration in chemo sensitivity of those cells to treatment with DNA Damaging Agents (DDAs) such as Cisplatin and Epirubicin or DNA Damage Response (DDRs) drugs like Olaparib. RNAseq was used to elucidate the mechanisms of action affected by the alteration in SLFN11 expression. In cell lines with robust SLFN11 promoter methylation such as MDA-MB-231, no SLFN11 expression could be induced by any approach. Conclusion: To our knowledge this is the first report of the stable non-lethal increase of SLFN11 expression in a cancer cell line. Our results show that induction of SLFN11 expression can enhance DDA and DDR sensitivity in breast cancer cells and dCas9 systems may represent a novel approach to increase SLFN11 and achieve higher sensitivity to chemotherapeutic agents, improving outcome or decreasing required drug concentrations. SLFN11-targeting therapies might be explored pre-clinically to develop personalized approaches. [ABSTRACT FROM AUTHOR]

A scalable total synthesis of a potent poly(ADP-ribose) polymerase (PARP) enzyme inhibitor, Olaparib (Lynparza), approved by U.S. FDA and EMA for ovarian cancer, is disclosed. The process is operationally simple, highly atom economical and environmentally benign as compared to the existing literature route of Olaparib. Herein, we report an eco-friendly synthesis of Olaparib using commercially available inexpensive starting materials, in only four steps with 51% overall yield. This synthesis comprises the key steps of generation of conjugated enolate from 2-acetylbenzoic acid to produce α-arylated product under transition metal-free conditions followed by ring construction of the final phthalazinone scaffold affording Olaparib. An alternative synthesis of another PARP inhibitor, AZD2461, using the same protocol is also reported. Highlighting this work is the phosphonate-free synthesis, as opposed to the Horner–Wadsworth–Emmons olefination reaction utilized previously which requires the synthesis of a phosphonate precursor. [ABSTRACT FROM AUTHOR]

This study aimed to develop a physiologically-based pharmacokinetic (PBPK) model to predict the maximum plasma concentration (Cmax) and trough concentration (Ctrough) at steady-state of olaparib (OLA) in Caucasian, Japanese and Chinese. Furthermore, the PBPK model was combined with mean and 95% confidence interval to predict optimal dosing regimens of OLA when co-administered with CYP3A4 modulators and administered to patients with hepatic/renal impairment. The dosing regimens were determined based on safety and efficacy PK threshold Cmax (< 12,500 ng/mL) and Ctrough (772–2500 ng/mL). The population PBPK model for OLA was successfully developed and validated, demonstrating good consistency with clinically observed data. The ratios of predicted to observed values for Cmax and Ctrough fell within the range of 0.5 to 2.0. When OLA was co-administered with a strong or moderate CYP3A4 inhibitor, the recommended dosing regimens should be reduced to 100 mg BID and 150 mg BID, respectively. Additionally, the PBPK model also suggested that OLA could be not recommended with a strong or moderate CYP3A4 inducer. For patients with moderate hepatic and renal impairment, the dosing regimens of OLA were recommended to be reduced to 200 mg BID and 150 mg BID, respectively. In cases of severe hepatic and renal impairment, the PBPK model suggested a dosing regimen of 100 mg BID for OLA. Overall, this present PBPK model can determine the optimal dosing regimens for various clinical scenarios involving OLA. [ABSTRACT FROM AUTHOR]

Simple Summary: Castration-resistant prostate cancer (CRPC) treatments include next-generation anti-androgen therapies (NGATs), taxane therapy, and PARP inhibitors (PARPi). However, resistance often occurs across and within therapeutic classes, which can complicate sequential treatment options. We developed acquired resistant models to study therapeutic resistance. Our findings indicate that while NGAT-resistant cells are cross-resistant to other NGATs, they remain sensitive to taxanes and olaparib. Cells resistant to docetaxel display cross-resistance to cabazitaxel and olaparib but respond to NGATs. Olaparib-resistant cells are cross-resistant to other PARPi but still sensitive to NGATs and docetaxel. Our research underscores the significance of rationale drug sequencing in CRPC treatment and underlying mechanisms of resistance. Current common treatments for castration-resistant prostate cancer (CRPC) typically belong to one of three major categories: next-generation anti-androgen therapies (NGAT) including enzalutamide, abiraterone acetate, apalutamide, and darolutamide; taxane therapy represented by docetaxel; and PARP inhibitors (PARPi) like olaparib. Although these treatments have shown efficacy and have improved outcomes for many patients, some do not survive due to the emergence of therapeutic resistance. The clinical landscape is further complicated by limited knowledge about how the sequence of treatments impacts the development of therapeutic cross-resistance in CRPC. We have developed multiple CRPC models of acquired therapeutic resistance cell sublines from C4-2B cells. These include C4-2B MDVR, C4-2B AbiR, C4-2B ApaR, C4-2B DaroR, TaxR, and 2B-olapR, which are resistant to enzalutamide, abiraterone, apalutamide, darolutamide, docetaxel, and olaparib, respectively. These models are instrumental for analyzing gene expression and assessing responses to various treatments. Our findings reveal distinct cross-resistance characteristics among NGAT-resistant cell sublines. Specifically, resistance to enzalutamide induces resistance to abiraterone and vice versa, while maintaining sensitivity to taxanes and olaparib. Conversely, cells with acquired resistance to docetaxel exhibit cross-resistance to both cabazitaxel and olaparib but retain sensitivity to NGATs like enzalutamide and abiraterone. OlapR cells, significantly resistant to olaparib compared to parental cells, are still responsive to NGATs and docetaxel. Moreover, OlapR models display cross-resistance to other clinically relevant PARP inhibitors, including rucaparib, niraparib, and talazoparib. RNA-sequencing analyses have revealed a complex network of altered gene expressions that influence signaling pathways, energy metabolism, and apoptotic signaling, pivotal to cancer's evolution and progression. The data indicate that resistance mechanisms are distinct among different drug classes. Notably, NGAT-resistant sublines exhibited a significant downregulation of androgen-regulated genes, contrasting to the stable expression noted in olaparib and docetaxel-resistant sublines. These results may have clinical implications by showing that treatments of one class can be sequenced with those from another class, but caution should be taken when sequencing drugs of the same class. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, based on the results of chemotherapy or poly(ADP-ribose) polymerase (PARP) inhibitor (PARPi) maintenance in other tumors, we explore whether olaparib, a PARP inhibitor, could be useful in terms of prolonging radiographic progression of the disease in patients with metastatic castration-resistant prostate cancer with specific mutations whose illness had not progressed under treatment with docetaxel—A standard chemotherapy for these patients. In the 14 patients included in this study harboring mutations in homologous recombination genes, olaparib maintenance was an effective option, stabilizing the metastasis and extending the radiographic and clinical progression of the disease with tolerable and manageable adverse events. Overall, the results suggest this alternative could be useful for selected patients. The SOGUG-IMANOL trial was a phase 2, uncontrolled, Spanish multicenter study to assess the effect of maintenance treatment with olaparib on radiographic progression-free survival (PFS) in patients with metastatic castration-resistant prostate cancer (mCRPC) who achieved partial or complete response or disease stabilization on docetaxel treatment and had a documented germline/somatic mutation in any of the homologous recombination repair (HRR) genes. Patients received olaparib 300 mg orally twice daily. From the screened population (n = 134), 26 (19.4%) somatic mutations were found, and 14 patients were included in the study. The median radiographic PFS was 11.1 (95%CI, 5.7 to 16.5) months. The median PSA-PFS was 3.5 (95%CI, 1.0 to 6.0) months, and the median clinical PFS was 14.7 (95%CI, 1.8 to 27.5 months). Clinical benefit was observed in 12 patients (85.7%, 95%CI 67.4% to 100%), including two patients with partial response and 10 with stable disease. Six patients reported grade 3–5 adverse events: asthenia (n = 3), anemia (n = 2) and neutropenia (n = 1). In this setting, olaparib has been shown to be an efficacious maintenance treatment in terms of radiographic PFS and clinical benefit, becoming a therapeutic option for some patients harboring an HRR gene mutation and in scenarios where further investigation is needed. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is one of the most aggressive diseases with a very poor outcome. Olaparib, a PARP inhibitor, as maintenance therapy showed benefits in patients with metastatic pancreatic adenocarcinoma bearing germline BRCA1/2 mutations. However, germline BRCA mutation has been described in only 4–7% of patients with pancreatic adenocarcinoma. A CRISPR/Cas9-mediated system was used to knock-in the c.763G > T p.(Glu255*) and c.2133C > A p.(Cys711*) mutations in cell lines to obtain truncated BRCA1 and BRCA2 proteins, respectively. A CRISPR/Cas9 ribonucleoprotein complex was assembled for each mutation and transfected into two pancreatic cell lines (T3M4 and Capan-2) and into a breast cancer cell lines (MCF7) as control. BRCA protein levels were significantly decreased in all BRCA-depleted cells (P < 0.05), proving the transfection efficiency of our CRISPR/Cas9 systems. As expected, the calculated olaparib IC50 were significantly reduced for all cell lines harbored BRCA1 or BRCA2 mutations compared to wild-type BRCA1/2 cells (P < 0.01). Furthermore, we observed a higher induction of apoptosis after 72 h olaparib treatment in BRCA-depleted cells than in wild-type cells. This strategy might offer new insights into the management of patients with pancreatic cancer and open up new perspectives based on the in vivo use of CRISPR/Cas9 strategy. [ABSTRACT FROM AUTHOR]

Introduction: Over the last few years, targeted therapy has become the mainstay maintenance treatment of patients with ovarian cancer including patients with BRCA1/BRCA2 mutations. Poly ADP ribose polymerase inhibitors (PARPi) are effective in the treatment of patients who are in complete or partial remission. PARPi are known to cause hematological adverse events (AEs), but have not been compared directly to each other. Objective: Primary objective was to compare the incidence of hematological and non-hematological AEs associated with the use of PARPi. Methods: This was a single institution, retrospective study evaluating patients who were treated with PARPi for ovarian cancer from January 2017 to October 2020. Patients were stratified according to which PARP inhibitor they received. Results: Ninety-two patients were included in final analysis. Thirty-one (33.7%) patients received niraparib and 61 (66.3%) patients received olaparib. Median age of patients were 64.3 (range, 33.8 to 92.3) years, 66 (71.7%) were white, and 84 (91.3%) had an ECOG PS of 0/1. Patients in the niraparib group experienced a higher rate of hematologic AEs, with 11 (35.5%), 20 (64.5%), and 18 (58.1%) experiencing neutropenia, anemia, and thrombocytopenia, respectively. Eight (13.1%), 24 (39.3%), and 16 (26.2%) patients in the olaparib group experienced neutropenia, anemia, and thrombocytopenia, respectively. Conclusion: This single institution retrospective study outlines the hematological toxicities observed between two PARPi. Our results suggested that niraparib tended to be associated with a higher risk for hematologic toxicities than olaparib. Anemia was the most common hematologic toxicity which was consistent with what has been widely documented in the literature. [ABSTRACT FROM AUTHOR]

Poly ADP-ribose polymerase inhibitors (PARPis) have clinical activity in several cancers. The rationale of their therapeutic use in urothelial cancer (UC) resides in the high homologous-recombination repair (HRR) deficiency (HRD) prevalence and potential cross-sensitivity with platinum-based chemotherapy (PBCT). This review aims to summarize and analyze trials exploring the activity of PARPis in UC, focusing on patients who may benefit from those agents, the best clinical setting for the treatment and the benefit of the association with immune-checkpoint inhibitors (ICIs). We included all the available trials analyzing the activity of PARPis in UC in neoadjuvant, adjuvant, first or subsequent lines, and maintenance setting. We included PARPis in monotherapy and in association with other agents. The results in the maintenance setting are intr iguing: ATLANTIS tr ial showed signals of improved progression-free survival in patients with known HRR aberrations, although the Meet-URO12 trial, with its negative results, suggested the failure of clinical selection based on platinum sensitivity only. Single-agent PARPis in pretreated patients showed discouraging results in an unselected population of chemo-refractory patients. Concerning the association of PARPis with ICIs, several trials are exploring their role in platinum-naïve setting; the results in the advanced setting were globally negative. Prior selection of HRD status is essential to identify patients who might benefit from PARPis. The ideal clinical settings seem to be the maintenance treatment and the combination with ICIs in platinum-naïve patients. Definitive results of ongoing and further trials will delineate the position for PARPis, if any, in UC therapy. [ABSTRACT FROM AUTHOR]

PROpel met its primary endpoint showing statistically significant improvement in radiographic progression-free survival with olaparib plus abiraterone versus placebo plus abiraterone in patients with first-line metastatic castration-resistant prostate cancer (mCRPC) unselected by homologous recombination repair mutation (HRRm) status, with benefit observed in all prespecified subgroups. Here we report the final prespecified overall survival analysis. This was a randomised, double-blind, phase 3 trial done at 126 centres in 17 countries worldwide. Patients with mCRPC aged at least 18 years, Eastern Cooperative Oncology Group performance status 0–1, a life expectancy of at least 6 months, with no previous systemic treatment for mCRPC and unselected by HRRm status were randomly assigned (1:1) centrally by means of an interactive voice response system–interactive web response system to abiraterone acetate (orally, 1000 mg once daily) plus prednisone or prednisolone with either olaparib (orally, 300 mg twice daily) or placebo. The patients, the investigator, and study centre staff were masked to drug allocation. Stratification factors were site of metastases and previous docetaxel at metastatic hormone-sensitive cancer stage. Radiographic progression-free survival was the primary endpoint and overall survival was a key secondary endpoint with alpha-control (alpha-threshold at prespecified final analysis: 0·0377 [two-sided]), evaluated in the intention-to-treat population. Safety was evaluated in all patients who received at least one dose of a study drug. This study is registered with ClinicalTrials.gov , NCT03732820 , and is completed and no longer recruiting. Between Oct 31, 2018 and March 11, 2020, 1103 patients were screened, of whom 399 were randomly assigned to olaparib plus abiraterone and 397 to placebo plus abiraterone. Median follow-up for overall survival in patients with censored data was 36·6 months (IQR 34·1–40·3) for olaparib plus abiraterone and 36·5 months (33·8–40·3) for placebo plus abiraterone. Median overall survival was 42·1 months (95% CI 38·4–not reached) with olaparib plus abiraterone and 34·7 months (31·0–39·3) with placebo plus abiraterone (hazard ratio 0·81, 95% CI 0·67–1·00; p=0·054). The most common grade 3–4 adverse event was anaemia reported in 64 (16%) of 398 patients in the olaparib plus abiraterone and 13 (3%) of 396 patients in the placebo plus abiraterone group. Serious adverse events were reported in 161 (40%) in the olaparib plus abiraterone group and 126 (32%) in the placebo plus abiraterone group. One death in the placebo plus abiraterone group, from interstitial lung disease, was considered treatment related. Overall survival was not significantly different between treatment groups at this final prespecified analysis. Supported by AstraZeneca and Merck Sharp & Dohme. [ABSTRACT FROM AUTHOR]

Background: The aim of the study is to investigate the role of serum inflammatory factors and T‐cell subsets in the diagnosis of recurrence in epithelial ovarian cancer patients and the effect of olaparib on inflammatory factor and T‐lymphocyte subsets in patients with recurrent epithelial ovarian cancer. Methods: In this study, 100 patients diagnosed as recurrent epithelial ovarian cancer in our hospital and 100 patients without recurrent epithelial ovarian cancer in the same period were selected. According to the treatment plan, the recurrent patients were divided into conventional therapy group (Paclitaxel and Carboplatin) and combined therapy group (Paclitaxel, Carboplatin, and olaparib). The levels of serum inflammatory factors were evaluated by enzyme‐linked immunosorbent assay. The peripheral blood T‐lymphocyte subsets in each group were detected by flow cytometry. Results: Compared with nonrecurrent patients, recurrent patients have higher serum interleukin‐6 (IL‐6) and tumor necrosis factor‐α (TNF‐α) levels (p <.05), and lower interferon‐γ (IFN‐γ) level and the CD4+/CD8+ ratio. After adjusting for confounding factors, the results showed that the serum IL‐6, IFN‐γ, and TNF‐α levels were influencing factors of recurrence in epithelial ovarian cancer patients. The area under the receiver operating curve and the sensitivity of serum TNF‐α in predicting ovarian cancer recurrence were higher than those of IL‐6 and IFN‐γ. After secondary chemotherapy and/or olaparib maintenance treatment, the IL‐6 (p <.001) and TNF‐α (p <.001) levels in combined therapy group were lower than those in the conventional therapy, whereas the IFN‐γ level (p <.001), the CD4+ T‐cell proportion (p =.0069) and the CD4+/CD8+ ratio (p =.0201) were higher than those in the conventional therapy. Conclusion: The serum IL‐6, TNF‐α, and IFN‐γ levels were closely related to the recurrence of ovarian cancer. Olaparib maintenance treatment can significantly decrease the IL‐6 and TNF‐α level, and increase IFN‐γ level and the CD4+/CD8+ ratio in patients with recurrent ovarian cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: Poly ADP-ribose polymerase inhibitors (PARPis) can be used in men with advanced prostate cancer. Unfortunately, this class of therapeutics has demonstrated the risk of developing hematological adverse events. We conducted a systematic review and meta-analysis of several PARPi clinical trials to further evaluate the incidence of anemia, thrombocytopenia, and neutropenia adverse events in prostate cancer patients. We found that this treatment is significantly associated with hematologic suppression. Further stratification suggests differences may exist between PARPis within this class of therapy. Background: Poly ADP-ribose polymerase inhibitors (PARPis) are an important class of therapeutics for metastatic castration-resistant prostate cancer (mCRPC). Unlike hormone-based treatments for mCRPC, PARPis are not without drug-related hematological adverse events. Objective: To review the evidence on hematological toxicities, including anemia, thrombocytopenia, and neutropenia from PARPis in prostate cancer. Study Methodology: A systematic review and meta-analysis using the PRISMA guidelines was performed for phase II and III randomized controlled trials (RCTs) of PARPis in prostate cancer. PubMed, Embase, and Ovid All EBM reviews—Cochrane were queried from inception to 9 June 2023. The Mantel–Haenszel method was used to report risk ratios (RR) and 95% confidence intervals (CI) for all-grade and high-grade anemia, thrombocytopenia, and neutropenia toxicities. Results: The systematic review retrieved eight phase II and III RCTs; specifically, eight were included in the anemia, five in the all-grade thrombocytopenia and neutropenia, and four in the high-grade thrombocytopenia and neutropenia outcomes. Compared to a placebo and/or other non-PARPi treatments, PARPi use was associated with an increased risk of all-grade anemia (RR, 3.37; 95% CI, 2.37–4.79; p < 0.00001), thrombocytopenia (RR, 4.54; 95% CI, 1.97–10.44; p = 0.0004), and neutropenia (RR, 3.11; 95% CI, 1.60–6.03; p = 0.0008). High-grade anemia (RR, 6.94; 95% CI, 4.06–11.86; p < 0.00001) and thrombocytopenia (RR, 5.52; 95% CI, 2.80–10.88; p < 0.00001) were also associated with an increased risk, while high-grade neutropenia (RR, 3.63; 95% CI, 0.77–17.23; p = 0.10) showed no significant association. Subgroup stratification analyses showed differences in various all-grade and high-grade toxicities. Conclusion: PARPis were associated with an increased risk of hematological AEs. Future studies with more pooled RCTs will enhance this understanding and continue to inform patient–physician shared decision-making. Future studies may also have a role in improving the current management strategies for these AEs. [ABSTRACT FROM AUTHOR]

Exceptional response to olaparib in a case with Fanconi anemia and metastatic esophageal carcinoma [ABSTRACT FROM AUTHOR]

Background: Although the clinical application of PARP inhibitors has brought hope to ovarian cancer, the problem of its resistance has become increasingly prominent. Therefore, clinical experts have been focused on finding specific indicators and therapeutic targets that can be used for resistance monitoring of PARP inhibitors. Results: By cfDNA detecting during Olaparib maintenance therapy in platinum-sensitive relapsed ovarian cancer, we found the presence of MRE11:p.K464R mutation was strongly associated with acquired Olaparib resistance. Structural analysis revealed that the MRE11:p.K464R mutation is situated at a critical site where the MRE11 protein interacts with other biomolecules, leading to potential structural and functional abnormalities of MRE11 protein. Functionally, MRE11:p.K464R mutation enhanced the tolerance of Olaparib by reducing the DNA damage. Mechanistically, MRE11:p.K464R mutation improved the efficiency of DNA damage repair and induce Olaparib resistance by enhancing its binding activity with the interacting proteins (including RAD50 and RPS3). Among them, the enhanced binding of MRE11:p.K464R mutation to RAD50/RPS3 facilitated non-homologous end joining (NHEJ) repair in tumor cells, thereby expanding the scope of research into acquired resistance to PARP inhibitors. Conclusions: Our findings provide a theoretical basis for MRE11:p.K464R mutation as a specific indicator of resistance monitoring in Olaparib treatment, and the exploration of its resistance mechanism provides a novel insights for the formulation of combination ther therapies after Olaparib resistance. [ABSTRACT FROM AUTHOR]

Background: The BRCA2 gene is a well-known tumor suppressor gene implicated in breast and ovarian cancers. BRCA1/2 mutations can be sensitive to poly ADP-ribose polymerase (PARP) inhibitors such as olaparib. However, some of these patients develop resistance to this treatment and an essential factor contributing to acquired insensitivity is the occurrence of reversion mutations in the BRCA1/2 genes. Case presentation: We report the case of a 65-year-old Brazilian female patient who had previously been diagnosed with metastatic lung carcinoma carrying a BRCA2 mutation that had extended to the central nervous system. Following disease progression, olaparib was administered, resulting in a stabilizing effect on her condition for ~ 30 months. During a routine follow-up, a new triple-negative breast tumor was found. Genetic testing revealed the presence of two distinct BRCA2 gene mutations in the breast tumor. The original mutation (p.Val220Ilefs4) led to a frameshift, culminating in the production of a truncated and non-functional BRCA2 protein; the second mutation, K437fs22, rectified the reading frame of exon 11. Consequently, Rad51 could properly bind to BRCA2—an essential protein crucial for DNA repair. This restoration resulted in a functional BRCA2 protein, effectively elucidating the clinical resistance observed in the new breast tumor in this case. Conclusions: This case report highlights the clinical significance of comprehensive next-generation sequencing analyses for lung adenocarcinomas, both at diagnosis and upon progression. Such analyses enable informed decisions regarding targeted therapies and facilitate a deeper comprehension of resistance mechanisms. [ABSTRACT FROM AUTHOR]

This study aimed to develop a physiologically-based pharmacokinetic (PBPK) model to predict the maximum plasma concentration (Cmax) and trough concentration (Ctrough) at steady-state of olaparib (OLA) in Caucasian, Japanese and Chinese. Furthermore, the PBPK model was combined with mean and 95% confidence interval to predict optimal dosing regimens of OLA when co-administered with CYP3A4 modulators and administered to patients with hepatic/renal impairment. The dosing regimens were determined based on safety and efficacy PK threshold Cmax (< 12,500 ng/mL) and Ctrough (772–2500 ng/mL). The population PBPK model for OLA was successfully developed and validated, demonstrating good consistency with clinically observed data. The ratios of predicted to observed values for Cmax and Ctrough fell within the range of 0.5 to 2.0. When OLA was co-administered with a strong or moderate CYP3A4 inhibitor, the recommended dosing regimens should be reduced to 100 mg BID and 150 mg BID, respectively. Additionally, the PBPK model also suggested that OLA could be not recommended with a strong or moderate CYP3A4 inducer. For patients with moderate hepatic and renal impairment, the dosing regimens of OLA were recommended to be reduced to 200 mg BID and 150 mg BID, respectively. In cases of severe hepatic and renal impairment, the PBPK model suggested a dosing regimen of 100 mg BID for OLA. Overall, this present PBPK model can determine the optimal dosing regimens for various clinical scenarios involving OLA. [ABSTRACT FROM AUTHOR]

Exceptional response to olaparib in a case with Fanconi anemia and metastatic esophageal carcinoma [ABSTRACT FROM AUTHOR]

Olaparib (OLA) is a PARP inhibitor drug which has been recently approved by the Food and Drug Administration (FDA) for the treatment of ovarian and breast cancer. A convenient analytical tool for the quantitation of OLA in its dosage form and plasma samples was urgently needed. This study describes, for the first time, the development of two different label-free and sensitive fluorescence-based platforms for the pharmaceutical and bioanalysis of OLA. These platforms were microwell-assisted with a fluorescence microplate reader (MW-FLR) and high-performance liquid chromatography with fluorescence detection (HPLC-FD). Both MW-FLR and HPLC-FD employed the native fluorescence of OLA as an analytical signal. The MW-FLR involved measuring the fluorescence signals in 96-well white-opaque plates. The HPLC-FD involved chromatographic separation of OLA and duvelisib (DUV), as an internal standard on a Nucleosil-CN HPLC column (250 mm length × 4.6 mm i.d., 5 µm particle diameter) with a mobile phase composed of acetonitrile: water (25:75, v/v) pumped at a flow rate of 1.7 mL/min. Elution of OLA and DUV was detected using a fluorescence detector. The optimal conditions of both MW-FLR and HPLC-FD were established, and they were validated according to the guidelines of the International Council for Harmonization for the validation of analytical procedures. The linear ranges of MW-FLR and HPLC-FD were 25–1000 and 5–200 ng/mL, respectively, with limits of detection of 15 and 1.7 ng/mL, respectively. The accuracy and precision of both platforms were confirmed as the recovery values were ≥98.2% and the relative standard deviations (RSD) were ≤2.89%. Both methodologies were satisfactorily applied to the quantitation of OLA in its commercial dosage form (Lynparza® tablets) and plasma samples with high accuracy and precision. The greenness of both MW-FLR and HPLC-FD was assessed using two different multiple parameter-based metric tools, and the results proved their greenness and adherence to the requirements of green analytical approaches. Both platforms have simple procedures and acceptable levels of analytical throughput. In conclusion, the proposed MW-FLR and HPLC-FD are valuable tools for routine use in quality control and clinical laboratories for the quantitation of OLA for the purposes of pharmaceutical quality control, pharmacokinetic studies, and bioequivalence testing. [ABSTRACT FROM AUTHOR]