Niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer: final overall survival results from the PRIMA/ENGOT-OV26/GOG-3012 trial.

BACKGROUND: The phase III PRIMA/ENGOT-OV26/GOG-3012 trial met its primary endpoint. Niraparib first-line maintenance significantly prolonged progression-free survival (PFS) among patients with newly diagnosed advanced ovarian cancer that responded to first-line platinum-based chemotherapy, regardless of homologous recombination deficiency (HRD) status. Final overall survival (OS) results are reported. PATIENTS AND METHODS: Patients were randomized 2:1 to niraparib or placebo, stratified by response to first-line treatment, receipt of neoadjuvant chemotherapy, and tumor HRD status. After reaching 60% target maturity, OS was evaluated via a stratified log-rank test using randomization stratification factors and summarized using Kaplan-Meier methodology. OS testing was hierarchical [overall population first, then the homologous recombination-deficient (HRd) population]. Other secondary outcomes and long-term safety were assessed; an updated, ad hoc analysis of investigator-assessed PFS was also conducted (cut-off date, 8 April 2024). RESULTS: The median follow-up was 73.9 months. In the overall population, the OS hazard ratio was 1.01 [95% confidence interval (CI) 0.84-1.23; P = 0.8834] for niraparib (n = 487) versus placebo (n = 246). In the HRd (n = 373) and homologous recombination-proficient (n = 249) populations, the OS hazard ratios were 0.95 (95% CI 0.70-1.29) and 0.93 (95% CI 0.69-1.26), respectively. Subsequent poly(ADP-ribose) polymerase inhibitor therapy was received by 11.7% and 15.8% of niraparib patients and 37.8% and 48.4% of placebo patients in the overall and HRd populations, respectively. The 5-year PFS rate numerically favored niraparib in the overall (niraparib, 22%; placebo, 12%) and HRd populations (niraparib, 35%; placebo, 16%). Myelodysplastic syndromes/acute myeloid leukemia incidence was <2.5% (niraparib, 2.3%; placebo, 1.6%). No new safety signals were observed. CONCLUSIONS: In patients with newly diagnosed advanced ovarian cancer at high risk of recurrence, there was no difference in OS between treatment arms. In the HRd population, patients alive at 5 years were two times as likely to be progression free with niraparib treatment than placebo. Long-term safety remained consistent with the established niraparib safety profile.

Talazoparib Plus Enzalutamide in Patients With HRR-Deficient mCRPC: Practical Implementation Steps for Oncology Nurses and Advanced Practice Providers.

BACKGROUND: About one-quarter of patients with advanced prostate cancer have alterations in homologous recombination repair (HRR) genes. In a global phase 3 study, talazoparib plus enzalutamide significantly improved progression-free survival in patients with HRR-deficient metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVES: This article reviews the role of oncology nurses and advanced practice providers (APPs) in administering talazoparib plus enzalutamide in patients with mCRPC. METHODS: This review and hypothetical case study illustrate the role of oncology nurses and APPs in the administration of talazoparib plus enzalutamide and the management of adverse events to ensure safe and effective use in clinical practice. FINDINGS: Oncology nurses and APPs play an important role in the dosing and administration of talazoparib plus enzalutamide and can recognize and manage adverse events in patients with HRR-deficient mCRPC.

Development and Characterization of Olaparib-Loaded Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Pharmaceutical Applications.

This study aims to enhance the solubility of Olaparib, classified as biopharmaceutical classification system (BCS) class IV due to its low solubility and bioavailability using a solid self-nanoemulsifying drug delivery system (S-SNEDDS). For this purpose, SNEDDS formulations were created using Capmul MCM as the oil, Tween 80 as the surfactant, and PEG 400 as the co-surfactant. The SNEDDS formulation containing olaparib (OLS-352), selected as the optimal formulation, showed a mean droplet size of 87.0 ± 0.4 nm and drug content of 5.53 ± 0.09%. OLS-352 also demonstrated anticancer activity against commonly studied ovarian (SK-OV-3) and breast (MCF-7) cancer cell lines. Aerosil® 200 and polyvinylpyrrolidone (PVP) K30 were selected as solid carriers, and S-SNEDDS formulations were prepared using the spray drying method. The drug concentration in S-SNEDDS showed no significant changes (98.4 ± 0.30%, 25℃) with temperature fluctuations during the 4-week period, demonstrating improved storage stability compared to liquid SNEDDS (L-SNEDDS). Dissolution tests under simulated gastric and intestinal conditions revealed enhanced drug release profiles compared to those of the raw drug. Additionally, the S-SNEDDS formulation showed a fourfold greater absorption in the Caco-2 assay than the raw drug, suggesting that S-SNEDDS could improve the oral bioavailability of poorly soluble drugs like olaparib, thus enhancing therapeutic outcomes. Furthermore, this study holds significance in crafting a potent and cost-effective pharmaceutical formulation tailored for the oral delivery of poorly soluble drugs.

Abiraterone, Olaparib, or Abiraterone + Olaparib in First-Line Metastatic Castration-Resistant Prostate Cancer with DNA Repair Defects (BRCAAway).

PURPOSE: Deleterious germline/somatic homologous recombination repair mutations (HRRm) are present in ∼25% of patients with metastatic castration-resistant prostate cancer (mCRPC). Preclinically, poly(ADP-ribose) polymerase (PARP) inhibition demonstrated synergism with androgen receptor pathway (ARP)-targeted therapy. This trial evaluated the efficacy of ARP inhibitor versus PARP inhibitor versus their combination as first-line therapy in patients with mCRPC with HRRms. PATIENTS AND METHODS: BRCAAway is a biomarker preselected, randomized, phase 2 trial. Patients with BRCA1/2 and/or ATM alterations were randomized 1:1:1 to Arm1: abiraterone (1,000 mg)/prednisone (5 mg BID) (Abi/pred), Arm2: olaparib (300 mg BID) (Ola), or Arm3: abiraterone/prednisone + olaparib (Abi/pred + Ola). Single-agent arms could cross over at progression. Exploratory Arm4 patients with other HRRms received olaparib alone. The primary endpoint was progression-free survival (PFS), and secondary endpoints were objective response, PSA response, and safety. RESULTS: Sixty-one of 165 eligible patients had BRCA1/2 or ATM mutations: median age: 67 (IQR, 62-73) years. Mutations: BRCA1 n = 3, BRCA2 n = 46, ATM n = 11, and multiple n = 1; 33 germline and 28 somatic mutations. Median PFS [95% confidence interval (CI)]: Abi/pred, 8.6 months (m; 2.9, 17), Ola, 14 m (8.4, 20), and Abi/pred + Ola, 39 m [22, not reached (NR)]. There were no G4/5 adverse events; 8/19 patients on Abi/pred treatment crossed over to Ola, and 8/21 vice versa. Median PFS (95% CI) from crossover: Ola-after-Abi/pred, 8.3 m (5.5, 15) and Abi/pred-after-Ola, 7.2 m (2.8, NR). Median PFS (95% CI) from randomization: Ola-after-Abi/pred, 16 m (7.8, 25) and Abi/pred-after-Ola, 16 m (11, NR). Seventeen of 165 patients with other HRRms received olaparib: median PFS (95% CI): 5.5 m (2, 11). CONCLUSIONS: In patients with mCRPC with BRCA1/2 or ATM HRRm, Abi/pred + Ola was well tolerated and demonstrated longer PFS versus either agent alone or sequentially.

Olaparib plus trastuzumab in HER2-positive advanced breast cancer patients with germline BRCA1/2 mutations: The OPHELIA phase 2 study.

PURPOSE: To evaluate the efficacy and safety of the combination of olaparib plus trastuzumab in patients with HER2-positive advanced breast cancer (ABC) and germinal BRCA mutations (gBRCAm). METHODS: OPHELIA (NCT03931551) was a single-arm, open-label, phase 2 clinical trial. Patients aged ≥18 years diagnosed with HER2-positive ABC with germinal deleterious mutations in BRCA1 or BRCA2 who had received at least one prior systemic regimen for advanced disease were enrolled. Patients received olaparib plus trastuzumab until disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was investigator-assessed clinical benefit rate for at least 24 weeks as per RECIST v.1.1. Key secondary endpoints included overall response rate (ORR) and safety profile. RESULTS: A total of 68 pre-treated HER2-positive ABC patients were screened. Due to slow accrual the trial was stopped after enrolling 5 patients instead of the planned sample size of 20. Four patients achieved clinical benefit (80.0 %, 95 % CI; 28.4-99.5, p < 0.001) and the primary endpoint was met. The ORR was 60.0 % (95 % CI; 14.7-94.7), including one complete response. Four (80.0 %) patients experienced at least one treatment-related treatment-emergent adverse event (TEAE). Most TEAEs were grade 1 or 2. There were no treatment-related deaths and no new safety signals were identified. CONCLUSIONS: This study suggests that the combination of olaparib plus trastuzumab may be effective and safe in pre-treated patients with HER2-positive gBRCAm ABC. This ABC patient population should be further studied and not be pre-emptively excluded from clinical trials of targeted therapy for BRCA1/2-driven cancers.

Evaluation of Anticancer Efficacy of D-α-Tocopheryl Polyethylene-Glycol Succinate and Soluplus® Mixed Micelles Loaded with Olaparib and Rapamycin Against Ovarian Cancer.

Purpose: Ovarian cancer has the highest mortality rate and lowest survival rate among female reproductive system malignancies. There are treatment options of surgery and chemotherapy, but both are limited. In this study, we developed and evaluated micelles composed of D-α-tocopheryl polyethylene-glycol (PEG) 1000 succinate (TPGS) and Soluplus® (SOL) loaded with olaparib (OLA), a poly(ADP-ribose)polymerase (PARP) inhibitor, and rapamycin (RAPA), a mammalian target of rapamycin (mTOR) inhibitor in ovarian cancer. Methods: We prepared micelles containing different molar ratios of OLA and RAPA embedded in different weight ratios of TPGS and SOL (OLA/RAPA-TPGS/SOL) were prepared and physicochemical characterized. Furthermore, we performed in vitro cytotoxicity experiments of OLA, RAPA, and OLA/RAPA-TPGS/SOL. In vivo toxicity and antitumor efficacy assays were also performed to assess the efficacy of the mixed micellar system. Results: OLA/RAPA-TPGS/SOL containing a 4:1 TPGS:SOL weight ratio and a 2:3 OLA:RAPA molar ratio showed synergistic effects and were optimized. The drug encapsulation efficiency of this formulation was >65%, and the physicochemical properties were sustained for 180 days. Moreover, the formulation had a high cell uptake rate and significantly inhibited cell migration (**p < 0.01). In the in vivo toxicity test, no toxicity was observed, with the exception of the high dose group. Furthermore, OLA/RAPA-TPGS/SOL markedly inhibited tumor spheroid and tumor growth in vivo. Conclusion: Compared to the control, OLA/RAPA-TPGS/SOL showed significant tumor inhibition. These findings lay a foundation for the use of TPGS/SOL mixed micelles loaded with OLA and RAPA in the treatment of ovarian cancer.

Low-dose abiraterone plus Olaparib as a late-line treatment for mCRPC patients without BRCA1/2 mutations: a multicenter retrospective pilot study.

Although overall survival data are still premature, the PROpel study found radiological progression-free survival (PFS) benefits of abiraterone and olaparib in patients with metastatic castration-resistant prostate cancer (mCRPC). However, for patients who have not been genetically tested or lack BRCA1/2 mutations (BRCAm), this combination therapy has been questioned as a first-line conventional treatment for mCRPC, mainly due to significant health economics and side effects. In our retrospective study, we found that treatment with low-dose abiraterone plus olaparib as a late-line treatment for mCRPC could lead to prostate-specific antigen (PSA) and symptom PFS in selective cases even without BRCAm. The median PSA-PFS was 8 months (IQR: 6.5-11.5), with a median follow-up duration of 39.0 months (IQR: 27.5-64.5). Gene tests were conducted in all patients, identifying non-BRCA mutations through ctDNA testing (24%), tumor tissue testing (12%), or both (64%). Adverse events occurred in 72% of patients, with 16% experiencing Grade ≥ 3 events. Common adverse events included anemia (64%), decreased appetite (48%), and fatigue (25%). Our findings support low-dose abiraterone plus olaparib as a potential option for mCRPC patients without BRCAm, offering manageable safety and efficacy profiles.

Olaparib monotherapy or in combination with abiraterone for treating mutated metastatic castration-resistant prostate cancer: alone or stronger together?

INTRODUCTION: Prostate cancer has entered the era of precision medicine with the introduction of PARP inhibitors for patients with specific mutations in genes associated with DNA damage repair. Recent studies have shown benefit in combination therapy with PARP inhibitors like olaparib and antiandrogens like abiraterone. AREAS COVERED: This review discusses the pharmacodynamics and pharmacokinetics of olaparib as well as the data supporting combination therapy with olaparib and abiraterone. EXPERT OPINION: Co-targeting the androgen receptor and PARP pathway has shown clear clinical benefit in the management of patients with metastatic castration resistant prostate cancer and mutations in BRCA1, BRCA2, and ATM. The benefit in patients without these mutations is less clear, and the benefit of olaparib combination therapy in the management of hormone sensitive disease remains to be seen.

Novel Combinations of Immunotherapies or DNA Damage Repair Inhibitors in Platinum-Refractory Extensive-Stage Small Cell Lung Cancer: The Phase II BALTIC Study.

PURPOSE: The phase II, multiarm, signal-searching BALTIC study (NCT02937818) assessed novel treatment combinations for platinum-refractory/resistant extensive-stage small cell lung cancer (ES-SCLC). PATIENTS AND METHODS: Patients with ES-SCLC with progressive disease during or within 90 days of completing first-line platinum-based chemotherapy received one of three regimens: durvalumab plus tremelimumab followed by durvalumab monotherapy (arm A), adavosertib plus carboplatin (arm B), or ceralasertib plus olaparib (arm C). The primary endpoint was the objective response rate. Prespecified exploratory biomarker analyses were conducted in arms A and C. RESULTS: In arm A (n = 41), arm B (n = 10), and arm C (n = 21), the confirmed objective response rates were 7.3%, 0%, and 4.8%, respectively. Safety profiles in all arms were consistent with those of the individual drugs. In arm A, patients with PD-L1 expression (tumor cells or immune cells) ≥1% seemed to have a greater likelihood of achieving disease control with durvalumab plus tremelimumab than those with PD-L1 (tumor cells and immune cells) <1%, and lower baseline ctDNA and reduction in the on-treatment ctDNA level were both associated with longer overall survival. Among patients treated with ceralasertib plus olaparib in arm C, specific immune response-relevant circulating chemokines and cytokines were identified as early biomarkers of survival and pharmacodynamic biomarkers. CONCLUSIONS: In BALTIC, all combination regimens demonstrated tolerable safety profiles, but antitumor activity was limited in refractory/resistant ES-SCLC. Among patients treated with durvalumab plus tremelimumab, an association of on-treatment reduction in ctDNA with longer overall survival suggests the potential use of ctDNA as a surrogate of treatment response, warranting further investigation.

Feasibility of Indirect Treatment Comparisons Between Niraparib Plus Abiraterone Acetate and Other First-Line Poly ADP-Ribose Polymerase Inhibitor Treatment Regimens for Patients with BRCA1/2 Mutation-Positive Metastatic Castration-Resistant Prostate Cancer.

INTRODUCTION: Poly(ADP-ribose) polymerase inhibitors (PARPi) are a novel option to treat patients with metastatic castration-resistant prostate cancer (mCRPC). Niraparib plus abiraterone acetate and prednisone (AAP) is indicated for BRCA1/2 mutation-positive mCRPC. Niraparib plus AAP demonstrated safety and efficacy in the phase 3 MAGNITUDE trial (NCT03748641). In the absence of head-to-head studies comparing PARPi regimens, the feasibility of conducting indirect treatment comparisons (ITC) to inform decisions for patients with first-line BRCA1/2 mutation-positive mCRPC has been explored. METHODS: A systematic literature review was conducted to identify evidence from randomized controlled trials on relevant comparators to inform the feasibility of conducting ITCs via network meta-analysis (NMA) or population-adjusted indirect comparisons (PAIC). Feasibility was assessed based on network connectivity, data availability in the BRCA1/2 mutation-positive population, and degree of within- and between-study heterogeneity or bias. RESULTS: NMAs between niraparib plus AAP and other PARPi regimens (olaparib monotherapy, olaparib plus AAP, and talazoparib plus enzalutamide) were inappropriate due to the disconnected network, differences in trial populations related to effect modifiers, or imbalances within BRCA1/2 mutation-positive subgroups. The latter issue, coupled with the lack of a common comparator (except for olaparib plus AAP), also rendered anchored PAICs infeasible. Unanchored PAICs were either inappropriate due to lack of population overlap (vs. olaparib monotherapy) or were restricted by unmeasured confounders and small sample size (vs. olaparib plus AAP). PAIC versus talazoparib plus enzalutamide was not possible due to lack of published arm-level baseline characteristics and sufficient efficacy outcome data in the relevant population. CONCLUSION: The current randomized controlled trial evidence network does not permit robust comparisons between niraparib plus AAP and other PARPi regimens for patients with 1L BRCA-positive mCRPC. Decision-makers should scrutinize any ITC results in light of their limitations. Real-world evidence combined with clinical experience should inform treatment recommendations in this indication.

A Phase II, Open-Label, Randomized Trial of Durvalumab With Olaparib or Cediranib in Patients With Mismatch Repair-Proficient Colorectal or Pancreatic Cancer.

BACKGROUND: The use of immunotherapy in mismatch repair proficient colorectal cancer (pMMR-CRC) or pancreatic adenocarcinoma (PDAC) is associated with limited efficacy. DAPPER (NCT03851614) is a phase 2, basket study randomizing patients with pMMR CRC or PDAC to durvalumab with olaparib (durvalumab + olaparib) or durvalumab with cediranib (durvalumab + cediranib). METHODS: PDAC or pMMR-CRC patients were randomized to either durvalumab+olaparib (arm A), or durvalumab + cediranib (arm B). Co-primary endpoints included pharmacodynamic immune changes in the tumor microenvironment (TME) and safety. Objective response rate, progression-free survival (PFS) and overall survival (OS) were determined. Paired tumor samples were analyzed by multiplexed immunohistochemistry and RNA-sequencing. RESULTS: A total of 31 metastatic pMMR-CRC patients were randomized to arm A (n = 16) or B (n = 15). In 28 evaluable patients, 3 patients had stable disease (SD) (2 patients treated with durvalumab + olaparib and 1 patient treated with durvalumab + cediranib) while 25 had progressive disease (PD). Among patients with PDAC (n = 19), 9 patients were randomized to arm A and 10 patients were randomized to arm B. In 18 evaluable patients, 1 patient had a partial response (unconfirmed) with durvalumab + cediranib, 1 patient had SD with durvalumab + olaparib while 16 had PD. Safety profile was manageable and no grade 4-5 treatment-related adverse events were observed in either arm A or B. No significant changes were observed for CD3+/CD8+ immune infiltration in on-treatment biopsies as compared to baseline for pMMR-CRC and PDAC independent of treatment arms. Increased tumor-infiltrating lymphocytes at baseline, low baseline CD68+ cells and different immune gene expression signatures at baseline were associated with outcomes. CONCLUSIONS: In patients with pMMR-CRC or PDAC, durvalumab + olaparib and durvalumab + cediranib showed limited antitumor activity. Different immune components of the TME were associated with treatment outcomes.

Patterns of initial ovarian cancer recurrence on niraparib maintenance monotherapy in patients with no baseline evidence of disease after first-line chemotherapy: An ad hoc subgroup analysis of PRIMA/ENGOT-OV26/GOG-3012.

OBJECTIVES: Patterns of disease recurrence on poly(ADP-ribose) polymerase inhibitor maintenance therapy are unclear and may affect subsequent treatment. This ad hoc subgroup analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study evaluated patterns of initial recurrence in patients with advanced ovarian cancer (AOC). METHODS: PRIMA included participants at high risk for disease progression. This ad hoc analysis only evaluated participants randomized to niraparib maintenance without evidence of disease at baseline. The number and site(s) of initial recurrent lesions at investigator-assessed progressive disease (PD) were evaluated. RESULTS: Of the 314 niraparib-treated patients analyzed, 190 developed ≥1 new lesion (median number of new lesions, 1.0; interquartile range, 1-2). In total, 93.2% (177/190) of patients developed 1-3 lesions at first disease progression. The most common sites of recurrence were the peritoneum (30.0% [57/190]), lymph nodes (26.3% [50/190]), and liver (20.5% [39/190]). Similar results were observed when patients with PD were stratified by biomarker status, disease stage at diagnosis, and type of debulking surgery. Patients with homologous recombination-proficient tumors, stage III disease, or a history of primary debulking developed a median of 2.0 new lesions at first progression; patients with homologous recombination-deficient tumors, stage IV disease, or a history of interval debulking developed a median of 1.0 new lesion. CONCLUSIONS: Many patients with AOC without lesions at first-line maintenance treatment initiation develop oligometastatic disease at first recurrence. Prospective evaluation is required to determine whether these patients have improved outcomes when local therapies are combined with continuous, systemic, targeted maintenance therapy.

Plain language summary of the results from the TALAPRO-2 study: Talazoparib plus enzalutamide versus placebo plus enzalutamide for patients with advanced prostate cancer.

WHAT IS THIS SUMMARY ABOUT?: This summary describes the results from the TALAPRO-2 research study (also known as a clinical trial). The TALAPRO-2 study tested the combination of two medicines called talazoparib plus enzalutamide. This combination of medicines was used as the first treatment for adult patients with metastatic castration-resistant prostate cancer. The combination of talazoparib plus enzalutamide was compared with a placebo plus enzalutamide. WHAT IS METASTATIC CASTRATION-RESISTANT PROSTATE CANCER?: Metastatic castration-resistant prostate cancer is a type of cancer that starts in the prostate and has spread to other parts of the body. Castration-resistant means that the cancer continues to grow even when testosterone levels in the blood are reduced to very low levels. Taking medicines to lower testosterone levels in the blood is a standard treatment for men with advanced prostate cancer. WHAT ARE THE AIMS OF THE TALAPRO-2 TRIAL?: TALAPRO-2 looked at if combining talazoparib plus enzalutamide would increase the length of time patients lived before their cancer got worse or they died compared with a placebo plus enzalutamide. Researchers looked at how treatment affected the size and number of tumors and the length of time before patients needed to change to a new cancer medicine. Researchers also looked at any side effects patients had during the study. WHAT ARE THE KEY TAKEAWAYS?: A total of 805 patients with metastatic castration-resistant prostate cancer took part in the study. Compared with patients who took a placebo plus enzalutamide, the group of patients who took talazoparib plus enzalutamide had a 37% reduced risk of their cancer getting worse or dying. Some patients had tumors that at the start of the study could be measured with scans. Sixty-two percent of patients who took talazoparib plus enzalutamide had their tumors decrease or shrink to the point that they could no longer be seen on scans versus 44% of patients who took a placebo plus enzalutamide. Patients who took talazoparib plus enzalutamide were more likely to have a longer time before they needed to change to a new cancer medicine. The most common side effects of talazoparib plus enzalutamide were low levels of red blood cells (66% of patients) and neutrophils (36% of patients), and excessive tiredness or exhaustion (34% of patients).Clinical Trial Registration: NCT03395197 (TALAPRO-2) (ClinicalTrials.gov).

The efficacy and safety of PARP inhibitors in mCRPC with HRR mutation in second-line treatment: a systematic review and bayesian network meta-analysis.

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.

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.

Neoadjuvant talazoparib in patients with germline BRCA1/2 mutation-positive, early-stage triple-negative breast cancer: exploration of tumor BRCA mutational status.

BACKGROUND: Talazoparib monotherapy in patients with germline BRCA-mutated, early-stage triple-negative breast cancer (TNBC) showed activity in the neoadjuvant setting in the phase II NEOTALA study (NCT03499353). These biomarker analyses further assessed the mutational landscape of the patients enrolled in the NEOTALA study. METHODS: Baseline tumor tissue from the NEOTALA study was tested retrospectively using FoundationOne®CDx. To further hypothesis-driven correlative analyses, agnostic heat-map visualizations of the FoundationOne®CDx tumor dataset were used to assess overall mutational landscape and identify additional candidate predictive biomarkers of response. RESULTS: All patients enrolled (N = 61) had TNBC. In the biomarker analysis population, 75.0% (39/52) and 25.0% (13/52) of patients exhibited BRCA1 and BRCA2 mutations, respectively. Strong concordance (97.8%) was observed between tumor BRCA and germline BRCA mutations, and 90.5% (38/42) of patients with tumor BRCA mutations evaluable for somatic-germline-zygosity were predicted to exhibit BRCA loss of heterozygosity (LOH). No patients had non-BRCA germline DNA damage response (DDR) gene variants with known/likely pathogenicity, based on a panel of 14 non-BRCA DDR genes. Ninety-eight percent of patients had TP53 mutations. Genomic LOH, assessed continuously or categorically, was not associated with response. CONCLUSION: The results from this exploratory biomarker analysis support the central role of BRCA and TP53 mutations in tumor pathobiology. Furthermore, these data support assessing germline BRCA mutational status for molecular eligibility for talazoparib in patients with TNBC.

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.

Antibody-Drug Conjugate Sacituzumab Govitecan Enables a Sequential TOP1/PARP Inhibitor Therapy Strategy in Patients with Breast Cancer.

PURPOSE: The antibody-drug conjugate (ADC) sacituzumab govitecan (SG) comprises the topoisomerase 1 (TOP1) inhibitor (TOP1i) SN-38, coupled to a monoclonal antibody targeting trophoblast cell surface antigen 2 (TROP-2). Poly(ADP-ribose) polymerase (PARP) inhibition may synergize with TOP1i and SG, but previous studies combining systemic PARP and TOP1 inhibitors failed due to dose-limiting myelosuppression. Here, we assess the proof-of-mechanism and clinical feasibility for SG and talazoparib (TZP) employing an innovative sequential dosing schedule. PATIENTS AND METHODS: In vitro models tested pharmacodynamic endpoints, and in a phase 1b clinical trial (NCT04039230), 30 patients with metastatic triple-negative breast cancer (mTNBC) received SG and TZP in a concurrent (N = 7) or sequential (N = 23) schedule. Outcome measures included safety, tolerability, preliminary efficacy, and establishment of a recommended phase 2 dose. RESULTS: We hypothesized that tumor-selective delivery of TOP1i via SG would reduce nontumor toxicity and create a temporal window, enabling sequential dosing of SG and PARP inhibition. In vitro, sequential SG followed by TZP delayed TOP1 cleavage complex clearance, increased DNA damage, and promoted apoptosis. In the clinical trial, sequential SG/TZP successfully met primary objectives and demonstrated median progression-free survival (PFS) of 7.6 months without dose-limiting toxicities (DLT), while concurrent dosing yielded 2.3 months PFS and multiple DLTs including severe myelosuppression. CONCLUSIONS: While SG dosed concurrently with TZP is not tolerated clinically due to an insufficient therapeutic window, sequential dosing of SG followed by TZP proved a viable strategy. These findings support further clinical development of the combination and suggest that ADC-based therapy may facilitate novel, mechanism-based dosing strategies.

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.