Chemo-Phosphoproteomic Profiling with ATR Inhibitors Berzosertib and Gartisertib Uncovers New Biomarkers and DNA Damage Response Regulators.

The ATR kinase protects cells against DNA damage and replication stress and represents a promising anti-cancer drug target. The ATR inhibitors (ATRi) berzosertib and gartisertib are both in clinical trials for the treatment of advanced solid tumors as monotherapy or in combination with genotoxic agents. We carried out quantitative phospho-proteomic screening for ATR biomarkers that are highly sensitive to berzosertib and gartisertib, using an optimized mass spectrometry pipeline. Screening identified a range of novel ATR-dependent phosphorylation events, which were grouped into three broad classes: (i) targets whose phosphorylation is highly sensitive to ATRi and which could be the next generation of ATR biomarkers; (ii) proteins with known genome maintenance roles not previously known to be regulated by ATR; (iii) novel targets whose cellular roles are unclear. Class iii targets represent candidate DNA damage response proteins and, with this in mind, proteins in this class were subjected to secondary screening for recruitment to DNA damage sites. We show that one of the proteins recruited, SCAF1, interacts with RNAPII in a phospho-dependent manner and recruitment requires PARP activity and interaction with RNAPII. We also show that SCAF1 deficiency partly rescues RAD51 loading in cells lacking the BRCA1 tumor suppressor. Taken together these data reveal potential new ATR biomarkers and new genome maintenance factors.

NRG-GY012: Randomized phase 2 study comparing olaparib, cediranib, and the combination of cediranib/olaparib in women with recurrent, persistent, or metastatic endometrial cancer.

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.

Biomarker-driven phase 2 umbrella trial: Clinical efficacy of olaparib monotherapy and combination with ceralasertib (AZD6738) in small cell lung cancer.

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.

Olaparib for childhood tumors harboring defects in DNA damage repair genes: arm H of the NCI-COG Pediatric MATCH trial.

BACKGROUND: The National Cancer Institute-Children's Oncology Group Pediatric Molecular Analysis for Therapy Choice (MATCH) precision oncology platform trial enrolled children aged 1-21 years with treatment-refractory solid tumors and predefined actionable genetic alterations. Patients with tumors harboring alterations in DNA damage repair (DDR) genes were assigned to receive olaparib. METHODS: Tumor and blood samples were submitted for centralized molecular testing. Tumor and germline sequencing were conducted in parallel. Olaparib was given twice daily for 28-day cycles starting at a dose 30% lower than the adult recommended phase 2 dose (RP2D). The primary endpoint was the objective response. RESULTS: Eighteen patients matched (1.5% of those screened) based on the presence of a deleterious gene alteration in BRCA1/2, RAD51C/D, or ATM detected by tumor sequencing without germline subtraction or analysis of loss of heterozygosity (LOH). Eleven (61%) harbored a germline mutation, with only one exhibiting LOH. Six patients enrolled and received the olaparib starting dose of 135 mg/m2/dose. Two participants were fully evaluable; 4 were inevaluable because <85% of the prescribed dose was administered during cycle 1. There were no dose-limiting toxicities or responses. Minimal hematologic toxicity was observed. CONCLUSION: Most DDR gene alterations detected in Pediatric MATCH were germline, monoallelic, and unlikely to confer homologous recombination deficiency predicting sensitivity to olaparib monotherapy. The study closed due to poor accrual. CLINICALTRIALS.GOV IDENTIFIER: NCT03233204. IRB approved: initial July 24, 2017.

Olaparib enhances sensitization of BRCA-proficient breast cancer cells to x-rays and protons.

PURPOSE: This study aimed to compare the radiosensitizing effect of the PARP inhibitor, Olaparib, between proton and X-rays irradiations in BRCA-proficient breast cancer (BC) cells. METHODS: Two BRCA-proficient BC cell lines, MDA-MB-231 and T47D BC, were used. Cell proliferation was assessed using the CCK-8 assay, and radiosensitivity was determined through the clonogenic survival assay. Flow cytometry was employed to analyze cell cycle distribution and apoptosis. The kinetics of DNA damage repair were evaluated using γH2AX immunofluorescence imaging and the comet assay. Tumor spheroid assays were conducted to test radiosensitivity in a three-dimensional culture condition. RESULTS: Olaparib sensitized both MDA-MB-231 and T47D cells to proton and X-ray irradiation in the clonogenic assay. MDA-MB-231 cells exhibited a higher dose enhancement factor for Olaparib than T47D cells. Olaparib increased radiation-induced G2/M cell cycle arrest and apoptosis specifically in MDA-MB-231 cells. γH2AX immunostaining and the comet assay showed Olaparib augmented radiation-induced DNA damage and apoptosis. The enhancement effect of Olaparib was more pronounced in proton irradiation than in X-ray irradiation, particularly in MDA-MB-231 cells than T47D cells. Both radiation and Olaparib dose-dependently inhibited spheroid growth in both cell lines. The synergy scores demonstrated that Olaparib interacted more strongly with protons than X-rays. The addition of an ATR inhibitor further enhanced Olaparib-induced proton radiosensitization in MDA-MB-231 cells. CONCLUSION: This study found that Olaparib enhanced radiation efficacy in BRCA-proficient breast cancer cells, with a more pronounced effect observed with proton irradiation compared to X-ray irradiation. Combining Olaparib with an ATR inhibitor increased the radiosensitizing effect of protons.

Clinical effectiveness and safety of olaparib in BRCA-mutated, HER2-negative metastatic breast cancer in a real-world setting: final analysis of LUCY.

PURPOSE: The interim analysis of the phase IIIb LUCY trial demonstrated the clinical effectiveness of olaparib in patients with germline BRCA-mutated (gBRCAm), human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (mBC), with median progression-free survival (PFS) of 8.11 months, which was similar to that in the olaparib arm of the phase III OlympiAD trial (7.03 months). This prespecified analysis provides final overall survival (OS) and safety data. METHODS: The open-label, single-arm LUCY trial of olaparib (300 mg, twice daily) enrolled adults with gBRCAm or somatic BRCA-mutated (sBRCAm), HER2-negative mBC. Patients had previously received a taxane or anthracycline for neoadjuvant/adjuvant or metastatic disease and up to two lines of chemotherapy for mBC. RESULTS: Of 563 patients screened, 256 (gBRCAm, n = 253; sBRCAm, n = 3) were enrolled. In the gBRCAm cohort, median investigator-assessed PFS (primary endpoint) was 8.18 months and median OS was 24.94 months. Olaparib was clinically effective in all prespecified subgroups: hormone receptor status, previous chemotherapy for mBC, previous platinum-based chemotherapy (including by line of therapy), and previous cyclin-dependent kinase 4/6 inhibitor use. The most frequent treatment-emergent adverse events (TEAEs) were nausea (55.3%) and anemia (39.2%). Few patients (6.3%) discontinued olaparib owing to a TEAE. No deaths associated with AEs occurred during the study treatment or 30-day follow-up. CONCLUSION: The LUCY patient population reflects a real-world population in line with the licensed indication of olaparib in mBC. These findings support the clinical effectiveness and safety of olaparib in patients with gBRCAm, HER2-negative mBC. CLINICAL TRIAL REGISTRATION: Clinical trials registration number: NCT03286842.

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

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.

Auger emitter in combination with Olaparib suppresses tumor growth via promoting antitumor immune responses in pancreatic cancer.

The present study aimed to clarify the hypothesis that auger emitter 125I particles in combination with PARP inhibitor Olaparib could inhibit pancreatic cancer progression by promoting antitumor immune response. Pancreatic cancer cell line (Panc02) and mice subcutaneously inoculated with Panc02 cells were employed for the in vitro and in vivo experiments, respectively, followed by 125I and Olaparib administrations. The apoptosis and CRT exposure of Panc02 cells were detected using flow cytometry assay. QRT-PCR, immunofluorescence, immunohistochemical analysis, and western blot were employed to examine mRNA and protein expression. Experimental results showed that 125I combined with Olaparib induced immunogenic cell death and affected antigen presentation in pancreatic cancer. 125I in combination with Olaparib influenced T cells and dendritic cells by up-regulating CD4, CD8, CD69, Caspase3, CD86, granzyme B, CD80, and type I interferon (IFN)-γ and down-regulating Ki67 in vivo. The combination also activated the cyclic GMP-AMP synthase stimulator of IFN genes (Sting) pathway in Panc02 cells. Moreover, Sting knockdown alleviated the effect of the combination of 125I and Olaparib on pancreatic cancer progression. In summary, 125I in combination with Olaparib inhibited pancreatic cancer progression through promoting antitumor immune responses, which may provide a potential treatment for pancreatic cancer.

A phase 2 trial exploring the significance of homologous recombination status in patients with platinum sensitive or platinum resistant relapsed ovarian cancer receiving combination cediranib and olaparib.

OBJECTIVE: Combination cediranib/olaparib has reported activity in relapsed ovarian cancer. This phase 2 trial investigated the activity of cediranib/olaparib in relapsed ovarian cancer and its association with homologous recombination deficiency (HRD). METHODS: Seventy patients were enrolled to cohorts of either platinum-sensitive or platinum-resistant ovarian cancer and received olaparib tablets 200 mg twice daily and cediranib tablets 30 mg once daily under a continuous dosing schedule. HRD testing was performed on pre-treatment, on-treatment and archival biopsies by sequencing key homologous recombination repair (HRR) genes and by genomic LOH analysis. The primary objective for the platinum-sensitive cohort was the association of HRD, defined as presence of HRR gene mutation, with progression-free survival (PFS). The primary objective for the platinum-resistant cohort was objective response rate (ORR), with a key secondary endpoint evaluating the association of HRD status with activity. RESULTS: In platinum-sensitive ovarian cancer (N = 35), ORR was 77.1% (95% CI 59.9-89.6%) and median PFS was 16.4 months (95% CI 13.2-18.6). Median PFS in platinum-sensitive HRR-HRD cancers (N = 22) was 16.8 months (95% CI 11.3-18.6), and 16.4 months (95% CI 9.4-NA) in HRR-HR proficient cancers (N = 13; p = 0.57). In platinum-resistant ovarian cancer (N = 35), ORR was 22.9% (95% CI 10.4-40.1%) with median PFS 6.8 months (95% CI 4.2-9.1). Median PFS in platinum-resistant HRR-HRD cancers (N = 7) was 10.5 months (95% CI 3.6-NA) and 5.6 months (95% CI 3.6-7.6) in HRR-HR proficient cancers (N = 18; p = 0.23). CONCLUSIONS: Cediranib/olaparib had clinical activity in both platinum-sensitive and -resistant ovarian cancer. Presence of HRR gene mutations was not associated with cediranib/olaparib activity in either setting.

Low-dose Olaparib improves septic cardiac function by reducing ferroptosis via accelerated mitophagy flux.

Sepsis is a dysregulated response to infection that can result in life-threatening organ failure, and septic cardiomyopathy is a serious complication involving ferroptosis. Olaparib, a classic targeted drug used in oncology, has demonstrated potential protective effects against sepsis. However, the exact mechanisms underlying its action remain to be elucidated. In our study, we meticulously screened ferroptosis genes associated with sepsis, and conducted comprehensive functional enrichment analyses to delineate the relationship between ferroptosis and mitochondrial damage. Eight sepsis-characterized ferroptosis genes were identified in sepsis patients, including DPP4, LPIN1, PGD, HP, MAPK14, POR, GCLM, and SLC38A1, which were significantly correlated with mitochondrial quality imbalance. Utilizing DrugBank and molecular docking, we demonstrated a robust interaction of Olaparib with these genes. Lipopolysaccharide (LPS)-stimulated HL-1 cells and monocytes were used to establish an in vitro sepsis model. Additionally, an in vivo model was developed using mice subjected to cecal ligation and perforation (CLP). Intriguingly, low-dose Olaparib (5 mg/kg) effectively targeted and mitigated markers associated with ferroptosis, concurrently improving mitochondrial quality. This led to a marked enhancement in cardiac function and a significant increase in survival rates in septic mice (p < 0.05). The mechanism through which Olaparib ameliorates ferroptosis in cardiac and leukocyte cells post-sepsis is attributed to its facilitation of mitophagy, thus favoring mitochondrial integrity. In conclusion, our findings suggest that low-dose Olaparib can improve mitochondrial quality by accelerating mitophagy flux, consequently inhibiting ferroptosis and preserving cardiac function after sepsis.

PARP inhibition promotes endothelial-like traits in melanoma cells and modulates pericyte coverage dynamics during vasculogenic mimicry.

Vasculogenic mimicry (VM) describes the ability of highly aggressive tumor cells to develop pseudovascular structures without the participation of endothelial cells. PARP1 is implicated in the activation of hypoxia-inducible factors, which are crucial in tumor neovascularization. We have explored the role of hypoxia and PARP inhibition in VM. In uveal melanoma xenografts, the PARP inhibitor olaparib improved in vivo pericyte coverage specifically of VM channels. This was concomitant with reduced metastasis in olaparib-treated VM+ tumors. PARP inhibition and hypoxia modulated melanoma tube formation in vitro, inducing a more sparse and regular tubular architecture. Whole-transcriptome profiling revealed that olaparib treatment under hypoxic conditions modulated the expression of genes implicated in vasculogenesis during tube formation, enhancing the endothelial-like phenotype of VM+ uveal melanoma cells. PARP inhibition, especially during hypoxia, upregulated PDGFß, which is essential for pericyte recruitment. Our study indicates that PARP inhibitors may enhance the endothelial characteristics of VM+ cells, modulate pericyte coverage, and reduce metastatic spread in VM+ melanoma. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Addressing Residual Disease in HER2-Positive and Triple-Negative Breast Cancer: What Is Next?

PURPOSE OF REVIEW: To summarize the treatment strategies for patients with human epidermal growth factor receptor 2 (HER2)-positive disease and triple-negative breast cancer (TNBC) who have residual disease after preoperative systemic therapy. RECENT FINDINGS: There has been a shift towards neoadjuvant systemic therapy for selected patients with HER2-positive and TNBC. Assessing the tumor's response to therapy provides prognostic information and allows individualization of the postoperative treatment for these patients based on the tumor response to neoadjuvant therapy. Patients with TNBC with residual disease after neoadjuvant therapy can be treated with pembrolizumab, capecitabine, or olaparib. Those with HER2-positive disease are treated with adjuvant trastuzumab emtansine. The treatment of early breast cancer has evolved significantly, and patient outcomes continue to improve. As better treatments are developed, we will need biomarkers to determine which patients may benefit from certain therapies to continue to improve outcomes by right-sizing treatments and limiting toxicities.

Efficacy and safety of olaparib, olaparib plus bevacizumab and niraparib maintenance treatment in Japanese patients with platinum-sensitive advanced ovarian cancer.

OBJECTIVE: To investigate whether maintenance treatment could be safely and effectively performed with olaparib, olaparib plus bevacizumab and niraparib in platinum-sensitive advanced ovarian cancer at multiple institutions in Japan. METHODS: We investigated progression-free survival and adverse events in 117 patients with platinum-sensitive advanced ovarian cancer treated with maintenance therapy. RESULTS: The median progression-free survival of 117 patients was 20.1 months. Patients with germline BRCA pathogenic variants had a significantly better prognosis than the other groups (P < 0.001). Furthermore, in the multivariate analysis, stage IV (P = 0.016) and germline BRCA wild-type (P ≤ 0.001) were significantly associated with worse progression-free survival in patients with advanced ovarian cancer. Regarding adverse events, all three types of maintenance treatment were significantly worse than chemotherapy given before maintenance treatment with respect to renal function (olaparib, P = 0.037; olaparib plus bevacizumab, P < 0.001; and niraparib, P = 0.016). CONCLUSION: Maintenance treatment was performed effectively and safely. Renal function deterioration is likely to occur during maintenance treatment, and careful administration is important in platinum-sensitive advanced ovarian cancer.

Clinical characterization of patients with gBRCA1/2 mutation-positive unresectable pancreatic cancer: a multicenter prospective study.

BACKGROUND: Accumulating evidence has demonstrated platinum-based chemotherapy followed by maintenance therapy with a poly Adenosine diphosphate (ADP)-ribose polymerase inhibitor (olaparib) show benefits in unresectable pancreatic cancer with a germline (g)BRCA1/2 mutation. Evaluation of the germline BRCA1 and BRCA2 mutation is essential for making decisions on a treatment strategy for patients with unresectable pancreatic cancer. However, the detection rates of germline BRCA1 and BRCA2 mutations and efficacy of maintenance with olaparib remain undetermined, prospectively, in Japan. METHODS & RESULTS: In this prospective analysis, the rate of germline BRCA1 and BRCA2 mutations and efficacy of chemotherapy were analyzed in 136 patients with pancreatic cancer who underwent BRACAnalysis® (85 patients) or FoundationOne® CDx (51 patients) between January 2020 and July 2022. A total of six patients (4.4%) had a germline BRCA1 and BRCA2 mutation. Five patients were treated with modified FOLFIRINOX and one with fluorouracil and oxaliplatin. All patients continued platinum-based chemotherapy for ˃4 months and were subsequently treated with olaparib as a maintenance therapy. The response rate to platinum-based chemotherapy in the germline BRCA1 and BRCA2 mutation-positive group was significantly better than that of the germline BRCA1 and BRCA2 mutation-negative group (66% vs 23%, P = 0.04). All patients harbouring a germline BRCA1 and BRCA2 mutation were able to switch to olaparib. The median progression-free survival using olaparib was 5.7 months (range 3.0-9.2). CONCLUSIONS: The rate of germline BRCA1 and BRCA2 mutations found in patients with unresectable pancreatic cancer was comparable to those of previous studies.An analysis of germline BRCA1 and BRCA2 mutations has benefits for all patients with unresectable pancreatic cancer with regard to decisions on therapeutic strategies in a clinical practice setting.

m6A reader HNRNPA2B1 destabilization of ATG4B regulates autophagic activity, proliferation and olaparib sensitivity in breast cancer.

N6-methyladenosine RNA (m6A) is the most extensive epigenetic modification in mRNA and influences tumor progression. However, the role of m6A regulators and specific mechanisms in breast cancer still need further study. Here, we investigated the significance of the m6A reader HNRNPA2B1 and explored its influence on autophagy and drug sensitivity in breast cancer. HNRNPA2B1 was selected by bioinformatics analysis, and its high expression level was identified in breast cancer tissues and cell lines. HNRNPA2B1 was related to poor prognosis. Downregulation of HNRNPA2B1 reduced proliferation, enhanced autophagic flux, and partially reversed de novo resistance to olaparib in breast cancer. ATG4B was determined by RIP and MeRIP assays as a downstream gene of HNRNPA2B1, by which recognized the m6A site in the 3'UTR. Overexpression of ATG4B rescued the malignancy driven by HNRNPA2B1 in breast cancer cells and increased the olaparib sensitivity. Our study revealed that the m6A reader HNRNPA2B1 mediated proliferation and autophagy in breast cancer cell lines by facilitating ATG4B mRNA decay and targeting HNRNPA2B1/m6A/ATG4B might enhance the olaparib sensitivity of breast cancer cells.

PRIMA-1 synergizes olaparib-induced cell death in p53 mutant triple negative human breast cancer cell line via restoring p53 function, arresting cell cycle, and inducing apoptosis.

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.

The cost-effectiveness of germline BRCA testing-guided olaparib treatment in metastatic castration resistant prostate cancer.

BACKGROUND: Olaparib targets the DNA repair pathways and has revolutionized the management of metastatic castration resistant prostate cancer (mCRPC). Treatment with the drug should be guided by genetic testing; however, published economic evaluations did not consider olaparib and genetic testing as codependent technologies. This study aims to assess the cost-effectiveness of BRCA germline testing to inform olaparib treatment in mCRPC. METHODS: We conducted a cost-utility analysis of germline BRCA testing-guided olaparib treatment compared to standard care without testing from an Australian health payer perspective. The analysis applied a decision tree to indicate the germline testing or no testing strategy. A Markov multi-state transition approach was used for patients within each strategy. The model had a time horizon of 5 years. Costs and outcomes were discounted at an annual rate of 5 percent. Decision uncertainty was characterized using probabilistic and scenario analyses. RESULTS: Compared to standard care, BRCA testing-guided olaparib treatment was associated with an incremental cost of AU$7,841 and a gain of 0.06 quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was AU$143,613 per QALY. The probability of BRCA testing-guided treatment being cost effective at a willingness-to-pay threshold of AU$100,000 per QALY was around 2 percent; however, the likelihood for cost-effectiveness increased to 66 percent if the price of olaparib was reduced by 30 percent. CONCLUSION: This is the first study to evaluate germline genetic testing and olaparib treatment as codependent technologies in mCRPC. Genetic testing-guided olaparib treatment may be cost-effective with significant discounts on olaparib pricing.

Case report of penile squamous cell carcinoma continuous treatment with BRCA2 mutation.

BACKGROUND: Penile squamous cell carcinoma (PSCC) is a highly aggressive malignancy with a poor prognosis. BRCA1/2 mutations are associated with impaired DNA double-strand break repair and are among the common mutations in penile cancer, potentially paving the way for poly ADP-ribose polymerase inhibitor therapy. CASE PRESENTATION: We report a 65-year-old male with PSCC who progressed to thigh metastasis at 10 months after partial penectomy. Next-generation sequencing showed that the penis primary lesion and metastatic thigh lesion harboured a BRCA2 mutation. Chemotherapy plus immunotherapy was used for treatment, and the thigh metastasis was found to involve no tumour. Progression-free survival (PFS) lasted for 8 months until the appearance of lung metastasis. Afterwards, the patient benefited from second-line therapy of olaparib with pembrolizumab and anlotinib, and his disease was stable for 9 months. The same BRCA2 was identified in the lung biopsy. Given the tumour mutation burden (TMB, 13.97 mutation/Mb), the patient received third-line therapy with nivolumab plus ipilimumab, but PFS only lasted for 3 months, with the appearance of right frontal brain metastasis. Then, the patient was treated with radiation sequential fluzoparib therapy as fourth-line treatment, and the treatment efficacy was evaluated as PR. Currently, this patient is still alive. CONCLUSIONS: This is the first report of penile cancer with BRCA2 mutation, receiving a combination treatment with olaparib and experiencing a benefit for 9 months. This case underscores the pivotal role of BRCA2 in influencing treatment response in PSCC, providing valuable insights into the application of targeted therapies in managing recurrent PSCC with BRCA2 alterations. This elucidation establishes a crucial foundation for further research and clinical considerations in similar cases.

Olaparib maintenance therapy for platinum-sensitive relapsed ovarian cancer at a single institution: A retrospective study.

AIM: 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. METHODS: 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. RESULTS: 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%). CONCLUSION: 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.

Synergistic effect of PARP inhibitor and BRD4 inhibitor in multiple models of ovarian cancer.

Ovarian cancer has the highest facility rate among gynaecological tumours. Current therapies including PARP inhibitors have a defect that ovarian tumour is easy to recurrent and become resistant to therapy. To solve this problem, we found that BRD4 inhibitor AZD5153 and PARP inhibitor olaparib had a widespread synergistic effect in multiple models with different gene backgrounds. AZD5153 sensitizes cells to olaparib and reverses the acquired resistance by down-regulating PTEN expression levels to destabilize hereditary materials. In this study, we used the following multiple ovarian cancer models PDX, PDO and 3D/2D cell lines to elucidate the co-effect of AZD5153 and olaparib in vivo and in vitro. The similar results of these models further proved that the mechanism identified was consistent with the biological process occurring in ovarian cancer patients after drug treatment. This consistency between the results of different models suggests the possibility of translating these laboratory research findings into clinical studies towards developing treatments.