Phase 1b study to assess the safety, tolerability, and clinical activity of pamiparib in combination with temozolomide in patients with locally advanced or metastatic solid tumors.

BACKGROUND: Pamiparib is a potent, selective, poly (ADP-ribose) polymerase 1/2 inhibitor that demonstrates synthetic lethality in cells with breast cancer susceptibility gene mutations or other homologous recombination deficiency. This two-stage phase 1b study (NCT03150810) assessed pamiparib in combination with temozolomide (TMZ) in adult patients with histologically confirmed locally advanced and metastatic solid tumors. METHODS: Oral pamiparib 60 mg was administered twice daily. During the dose-escalation stage, increasing doses of TMZ (40-120 mg once daily pulsed or 20-40 mg once daily continuous) were administered to determine the recommended dose to be administered in the dose-expansion stage. The primary objectives were to determine safety and tolerability, maximum tolerated/administered dose, recommended phase 2 dose and schedule, and antitumor activity of pamiparib in combination with TMZ. Pharmacokinetics of pamiparib and TMZ and biomarkers were also assessed. RESULTS: Across stages, 139 patients were treated (dose escalation, n = 66; dose expansion, n = 73). The maximum tolerated dose of TMZ, which was administered during dose expansion, was 7-day pulsed 60 mg once daily. The most common treatment-emergent adverse events (TEAEs) were anemia (dose escalation, 56.1%; dose expansion, 63.0%), nausea (dose escalation, 54.5%; dose expansion, 49.3%), and fatigue (dose escalation, 48.5%; dose expansion, 47.9%). In the dose-escalation stage, four patients experienced dose-limiting toxicities (three neutropenia and one neutrophil count decreased). No TEAEs considered to be related to study drug treatment resulted in death. Antitumor activity was modest, indicated by confirmed overall response rate (dose escalation, 13.8%; dose expansion, 11.6%), median progression-free survival (3.7 and 2.8 months), and median overall survival (10.5 and 9.2 months). Administration of combination therapy did not notably impact pamiparib or TMZ pharmacokinetics. CONCLUSIONS: Pamiparib in combination with TMZ had a manageable safety profile. Further investigation of the efficacy of this combination in tumor types with specific DNA damage repair deficiencies is warranted.

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.

Synthetic Lethality Beyond BRCA: A Phase I Study of Rucaparib and Irinotecan in Metastatic Solid Tumors With Homologous Recombination-Deficiency Mutations Beyond BRCA1/2.

PURPOSE: Combining poly ADP-ribose polymerase (PARP) and topoisomerase I inhibitors has demonstrated synergistic effects in in vivo models. This phase I trial evaluated rucaparib and irinotecan in metastatic solid tumors with homologous recombination deficiency. METHODS: This study enrolled patients in three cohorts to determine the tolerability and preliminary efficacy of (1) rucaparib 400 mg PO twice a day (days 1-7, 15-21) and irinotecan 65 mg/m2 intravenously once every 2 weeks; (2) rucaparib 400 mg PO twice a day (D1-7, 15-21) and irinotecan 100 mg/m2 once every 2 weeks; and (3) rucaparib 400 mg per os twice a day (D1-7) and irinotecan 100 mg/m2 once every 3 weeks. RESULTS: Twenty patients were enrolled: 95% with previous platinum, 40% with previous irinotecan, and 20% with previous PARP inhibitor. The maximally tolerated was determined as rucaparib 400 mg twice a day days 1-7 and irinotecan 100 mg/m2 once every 3 weeks. Four dose-limiting toxicities (all grade 3-4 neutropenia) occurred during dose escalation with only neutropenia as other grade 3-4 toxicities (25%; grade 3 [n = 3], grade 4 [n = 2]). Treatment-related grade 1-2 adverse events included neutropenia (45%), diarrhea (45%), nausea (40%), and fatigue (30%). Of 17 patients with evaluable disease, six patients (35%) derived clinical benefit (n = 2 with PR, n = 4 with stable disease for over 6 months). Three patients remained on study >1 year: two with ATM mutations (small bowel carcinoma and pancreatic neuroendocrine tumor) and one patient with a PALB2 mutation (primary peritoneal cancer). CONCLUSION: Pulse dosing of rucaparib and once every 3 weeks irinotecan was well tolerated for up to 18 months with durable responses in BRCA-, PALB2-, and ATM-mutated cancers despite progression on previous platinum.

"Having cancer is very expensive": A qualitative study of patients with ovarian cancer and PARP inhibitor treatment.

OBJECTIVE: To examine patient barriers and facilitators to PARP inhibitor (PARP-I) maintenance therapy in ovarian cancer. PARP-I improves survival in ovarian cancer, but these multi-year therapies cost around $100,000 annually and are under-prescribed. METHODS: We recruited patients with ovarian cancer treated with PARP-I maintenance therapy at an academic health system for a semi-structured interview. Patient demographics, including genetics and PARP-I cost, were self-reported. We assessed patient experiences with barriers and facilitators of PARP-I usage. Two team members used a thematic approach to analyze and identify key themes. RESULTS: In May 2022, we interviewed 10 patients (mean age = 65 years; 80% White; 60% with a germline genetic mutation). Patients paid on average $227.50 monthly for PARP-I, straining resources for some participants. While sampled patients were insured, all patients identified having no or inadequate insurance as a major barrier to PARP-I. At the same time, all participants prioritized clinical effectiveness over costs of care. Patients identified PARP-I delivery from specialty pharmacies, separate and different from other medications, as a potential barrier, but each had been able to navigate delivery. Patients expressed significant initial side effects of PARP-I as a potential barrier yet reported clinician communication and prompt dose reduction as facilitating continuation. CONCLUSIONS: Patients identified cost, restrictive pharmacy benefits, and initial side effects as barriers to PARP-I usage. Having insurance and a supportive care team were identified as facilitators. Enhancing communication about PARP-I cost and side effects could improve patient experience and receipt of evidence-based maintenance therapy in ovarian cancer.

Safety and hematological toxicities of PARP inhibitors in patients with cancer: a systematic review of randomized controlled trials and a pharmacovigilance analysis.

INTRODUCTION: This study aimed to estimate the toxicities of PARP inhibitors (PARPis), based on randomized controlled trials (RCTs) and the FDA Adverse Event Reporting System (FAERS) database. METHODS: Four electronic databases were searched from inception to 16 April 2024, for RCTs of approved PARPis. The primary and secondary outcomes were grade 3-5 adverse events (AEs) and grade 3-5 hematological AE, respectively. We conducted network meta-analyses to calculate the relative risks (RRs) and 95% confidence intervals (CIs) of outcomes. A disproportionality analysis was conducted to estimate the signals of hematological AEs associated with PARPis from the FAERS database. RESULTS: Overall, 27 RCTs involving 11,067 patients with cancer were included. Olaparib had the best safety profile for any grade 3-5 AEs and hematological AEs among four approved PARPis. Olaparib did not increase the risk of thrombocytopenia (RR: 1.48; 95%CI: 0.64-3.39), but other PARPis did. Furthermore 14,780 hematological AE reports associated with PARPis were identified in the FAERS database, and all PARPis were associated with strong hematological AE signals. Hematological AEs mainly occurred within the first 3 months (80.84%) after PARPi initiation. CONCLUSION: Olaparib had the best safety profile among five PARPis. PARPi-associated hematological AEs mainly occurred within the first 3 months. REGISTRATION: PROSPERO (CRD42022385274).

Senaparib as first-line maintenance therapy in advanced ovarian cancer: a randomized phase 3 trial.

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors as maintenance therapy after first-line chemotherapy have improved progression-free survival in women with advanced ovarian cancer; however, not all PARP inhibitors can provide benefit for a biomarker-unselected population. Senaparib is a PARP inhibitor that demonstrated antitumor activity in patients with solid tumors, including ovarian cancer, in phase 1 studies. The multicenter, double-blind, phase 3 trial FLAMES randomized (2:1) 404 females with advanced ovarian cancer (International Federation of Gynecology and Obstetrics stage III-IV) and response to first-line platinum-based chemotherapy to senaparib 100 mg (n = 271) or placebo (n = 133) orally once daily for up to 2 years. The primary endpoint was progression-free survival assessed by blinded independent central review. At the prespecified interim analysis, the median progression-free survival was not reached with senaparib and was 13.6 months with placebo (hazard ratio 0.43, 95% confidence interval 0.32-0.58; P < 0.0001). The benefit with senaparib over placebo was consistent in the subgroups defined by BRCA1 and BRCA2 mutation or homologous recombination status. Grade ≥3 treatment-emergent adverse events occurred in 179 (66%) and 27 (20%) patients, respectively. Senaparib significantly improved progression-free survival versus placebo in patients with advanced ovarian cancer after response to first-line platinum-based chemotherapy, irrespective of BRCA1 and BRCA2 mutation status and with consistent benefits observed between homologous recombination subgroups, and was well tolerated. These results support senaparib as a maintenance treatment for patients with advanced ovarian cancer after a response to first-line chemotherapy. ClinicalTrials.gov identifier: NCT04169997 .

Epithelial ovarian cancer and brain metastases: might the BRCA status, PARP inhibitor administration, and surgical treatment impact the survival?

OBJECTIVE: To evaluate disease characteristics and survival according to BRCA status, administration of poly-(ADP-ribose) polymerase inhibitors (PARPi), and surgery in patients with ovarian cancer and brain metastases. METHODS: This is a monocentric retrospective cohort of patients with ovarian cancer and brain metastases treated between 2000 and 2021. Data were collected by a retrospective review of medical records and analyzed according to: (1) BRCA mutation; (2) PARPi before and after brain metastases; (3) surgery for brain metastases. RESULTS: Eighty-five patients with ovarian cancer and brain metastasis and known BRCA status (31 BRCA mutated (BRCAm), 54 BRCA wild-type (BRCAwt)) were analyzed. Twenty-two patients had received PARPi before brain metastases diagnosis (11 BRCAm, 11 BRCAwt) and 12 after (8 BRCAm, 4 BRCAwt). Brain metastases occurred >1 year later in patients who had received previous PARPi. Survival was longer in the BRCAm group (median post-brain metastasis survival: BRCAm 23 months vs BRCAwt 8 months, p=0.0015). No differences were found based on BRCA status analyzing the population who did not receive PARPi after brain metastasis (median post-brain metastasis survival: BRCAm 8 months vs BRCAwt 8 months, p=0.31). In the BRCAm group, survival was worse in patients who had received previous PARPi (median post-brain metastasis survival: PARPi before, 7 months vs no-PARPi before, 24 months, p=0.003). If PARPi was administered after brain metastases, survival of the overall population improved (median post-brain metastasis survival: PARPi after, 46 months vs no-PARPi after, 8 months, p=0.00038).In cases of surgery for brain metastases, the prognosis seemed better (median post-brain metastasis survival: surgery 13 months vs no-surgery 8 months, p=0.036). Three variables were significantly associated with prolonged survival at multivariate analysis: BRCA mutation, multimodal treatment, and ≤1 previous chemotherapy line. CONCLUSIONS: BRCA mutations might impact brain metastasis occurrence and lead to better outcomes. In a multimodal treatment, surgery seems to affect survival even in cases of extracranial disease. PARPi use should be considered as it seems to prolong survival if administered after brain metastasis.

Comparing niraparib versus platinum-taxane doublet chemotherapy as neoadjuvant treatment in patients with newly diagnosed homologous recombination-deficient stage III/IV ovarian cancer: study protocol for cohort C of the open-label, phase 2, randomized controlled multicenter OPAL trial.

BACKGROUND: Maintenance therapy with niraparib, a poly(ADP-ribose) polymerase inhibitor, has been shown to extend progression-free survival in patients with newly diagnosed advanced ovarian cancer who responded to first-line platinum-based chemotherapy, regardless of biomarker status. However, there are limited data on niraparib's efficacy and safety in the neoadjuvant setting. The objective of Cohort C of the OPAL trial (OPAL-C) is to evaluate the efficacy, safety, and tolerability of neoadjuvant niraparib treatment compared with neoadjuvant platinum-taxane doublet chemotherapy in patients with newly diagnosed stage III/IV ovarian cancer with confirmed homologous recombination-deficient tumors. METHODS: OPAL is an ongoing global, multicenter, randomized, open-label, phase 2 trial. In OPAL-C, patients will be randomized 1:1 to receive three 21-day cycles of either neoadjuvant niraparib or platinum-taxane doublet neoadjuvant chemotherapy per standard of care. Patients with a complete or partial response per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) will then undergo interval debulking surgery; patients with stable disease may proceed to interval debulking surgery or alternative therapy at the investigator's discretion. Patients with disease progression will exit the study treatment and proceed to alternative therapy at the investigator's discretion. After interval debulking surgery, all patients will receive up to three 21-day cycles of platinum-taxane doublet chemotherapy followed by niraparib maintenance therapy for up to 36 months. Adult patients with newly diagnosed stage III/IV ovarian cancer eligible to receive neoadjuvant platinum-taxane doublet chemotherapy followed by interval debulking surgery may be enrolled. Patients must have tumors that are homologous recombination-deficient. The primary endpoint is the pre-interval debulking surgery unconfirmed overall response rate, defined as the investigator-assessed percentage of patients with unconfirmed complete or partial response on study treatment before interval debulking surgery per RECIST v1.1. DISCUSSION: OPAL-C explores the use of niraparib in the neoadjuvant setting as an alternative to neoadjuvant platinum-taxane doublet chemotherapy to improve postsurgical residual disease outcomes for patients with ovarian cancer with homologous recombination-deficient tumors. Positive findings from this approach could significantly impact preoperative ovarian cancer therapy, particularly for patients who are ineligible for primary debulking surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT03574779. Registered on February 28, 2022.

Secondary cytoreductive surgery and oncologic outcomes in the era of targeted maintenance therapy for recurrent, platinum-sensitive ovarian cancer.

OBJECTIVES: To compare oncologic outcomes of secondary cytoreductive surgery (SCS) before and after FDA approval of Poly(ADP-ribose) polymerase inhibitor (PARPi) and bevacizumab maintenance therapies for platinum-sensitive recurrent ovarian cancer (PS-ROC). METHODS: Patients who underwent SCS for first recurrence of PS-ROC from 1/1/2013-1/1/2020 were identified. Exclusion criteria included prior chemotherapy for recurrence, bowel obstruction procedures, and palliative surgery. Data were dichotomized pre/post 1/2017, relative to FDA approval of PARPi and bevacizumab maintenance for ROC. Second progression-free survival (PFS2), the primary endpoint, was estimated using Kaplan-Meier method. RESULTS: Overall, 245 patients underwent SCS-131 (53%) pre- and 114 (47%) post-approval. Most patients had high-grade serous tumors (83% and 90%, respectively; p = 0.13). Deleterious BRCA1/2 alterations were identified in 27% (32/120) and 28% (32/113) of tested patients, respectively (p = 0.88). Disease-free intervals pre- and post-approval were: 6-12 months, 16% and 18%; 12-30 months, 56% and 59%; and >30 months, 28% and 24%, respectively (p = 0.73). Overall, 85% and 86% of patients, respectively, achieved complete gross resection (CGR; p > 0.99). PARPi maintenance use increased from 3.8% to 27% (p < 0.001) following approval, and bevacizumab from 1.5% to 12% (p < 0.001). Median PFS2 was 19 and 20.1 months, respectively. In the post group, 1-year PFS2 rate was 84.5% (95% CI, 75.7-90.4%) for patients with CGR vs 56.2% (95% CI, 29.5-76.2%) for those with residual disease; 3-year PFS2 rates were 31.3% (95% CI, 21.6-41.4%) and 12.5% (95% CI, 2.1-32.8%), respectively (p = 0.001). CONCLUSIONS: CGR during SCS is associated with improved PFS2 compared to suboptimal resection. Prospective randomized trials are warranted to elucidate the role of SCS as more therapeutics become available.

Radiation therapy for triple-negative breast cancer: from molecular insights to clinical perspectives.

INTRODUCTION: Triple-negative breast cancer (TNBC) lacks three common receptors, making traditional treatments less effective. This review highlights the importance of radiotherapy and emerging therapeutic strategies to enhance treatment outcomes in TNBC. AREAS COVERED: We conducted a literature search on PubMed for publications from 2000 to 2023 to discuss the critical role of radiotherapy in managing TNBC, emphasizing its applications from locoregional control to improving survival rates. The review explores molecular mechanisms underlying TNBC's radiotherapy response, including DNA damage repair and apoptosis, with a focus on BRCA1/2 mutations and Poly (ADP-ribose) polymerase (PARP) inhibition. We summarize preclinical and clinical research on radiosensitization strategies, from gene-targeted therapies to immunotherapy combinations, and the impact of post-mastectomy radiation therapy on locoregional control. The potential of personalized treatment approaches, integrating molecular profiling, targeted radiosensitizers, and the synergistic effects of radiotherapy with immunotherapy, is also discussed. EXPERT OPINION: Future TNBC treatment strategies should focus on precision medicine, integrating immunotherapy, developing novel radiosensitizers, and targeting biological pathways to overcome radioresistance. The integration of radiomics and artificial intelligence offers promising avenues for enhancing treatment personalization and efficacy, aiming to improve patient outcomes in TNBC.

Health-related quality of life in patients with newly diagnosed advanced ovarian cancer treated with niraparib vs placebo: Results from the phase 3 randomized PRIMA/ENGOT-OV26/GOG-3012 trial.

OBJECTIVE: To assess patient-reported health-related quality of life (HRQoL) in patients with ovarian cancer (OC) who received niraparib as first-line maintenance therapy. METHODS: PRIMA/ENGOT-OV26/GOG-3012 (NCT02655016) enrolled patients with newly diagnosed advanced OC who responded to first-line platinum-based chemotherapy. Patients were randomized (2:1) to niraparib or placebo once daily in 28-day cycles until disease progression, intolerable toxicity, or death. HRQoL was assessed as a prespecified secondary end point using patient-reported responses to the European Organisation for Research and Treatment of Cancer QOL Questionnaire (EORTC QLQ-C30), the EORTC QLQ Ovarian Cancer Module (EORTC QLQ-OV28), the Functional Assessment of Cancer Therapy-Ovarian Symptom Index (FOSI), and EQ-5D-5L questionnaires. Assessments were collected at baseline and every 8 weeks (±7 days) for 56 weeks, beginning on cycle 1/day 1, then every 12 weeks (±7 days) thereafter while the patient received study treatment. RESULTS: Among trial participants (niraparib, n = 487; placebo, n = 246), PRO adherence exceeded 80% for all instruments across all cycles. Patients reported no decline over time in HRQoL measured via EORTC QLQ-C30 Global Health Status/QoL and FOSI overall scores. Scores for abdominal/gastrointestinal symptoms (EORTC QLQ-OV28) and nausea and vomiting, appetite loss, and constipation (EORTC QLQ-C30) were higher (worse symptoms) in niraparib-treated patients than placebo-treated patients; except for constipation, these differences resolved over time. Patients did not self-report any worsening from baseline of fatigue, headache, insomnia, or abdominal pain on questionnaires. CONCLUSIONS: Despite some early, largely transient increases in gastrointestinal symptoms, patients with OC treated with niraparib first-line maintenance therapy reported no worsening in overall HRQoL.

Real-world Study on the Effect of PARPi as Maintenance Therapy on Platinum Sensitivity after First- and Second-line Chemotherapy in Patients with Recurrent High-grade Serous Epithelial Ovarian Cancer.

BACKGROUND: This study investigated the effect of poly(ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy after first- and second-line chemotherapy on platinum sensitivity in patients with recurrent high-grade serous epithelial ovarian cancer (rHGSOC). METHODS: This study retrospectively analyzed 172 patients with rHGSOC treated at Zhejiang Cancer Hospital and Jiaxing Maternity and Child Health Care Hospital between January 2017 and December 2021. The 1st-PARPi group comprised patients who received a PARPi as maintenance therapy after first-line chemotherapy (n=23), and the 1st-control group comprised those who did not (n = 105). Similarly, the 2nd-PARPi group comprised patients not given a PARPi in their first-line treatment (n = 30), and the 2nd-control group comprised those who were given a PARPi (n = 89). RESULTS: Among the 23 patients in the 1st-PARPi group and the 105 patients in the 1st-control group, nine and 99 were platinum-sensitive, and 14 and six were platinum-resistant, respectively (hazard ratio [HR]: 14.46, P < 0.0001). Among the 30 patients in the 2nd-PARPi group and 89 patients in the 2nd-control group, 10 and 71 were platinum-sensitive, and 20 and 18 were platinumresistant, respectively (HR: 4.37, P < 0.0001). Age, stage, residual tumor, the courses of platinumbased chemotherapy, and breast cancer susceptibility gene mutations were not associated with platinum sensitivity when using a PARPi as maintenance therapy after first- and second-line chemotherapy. CONCLUSION: Patients with rHGSOC using a PARPi were more likely to be platinum-sensitive and develop platinum resistance independent of PARPi duration. Care should be taken when using a PARPi as maintenance therapy after first- and second-line chemotherapy.

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

OBJECTIVE: PARP (poly adenosine diphosphate [ADP]-ribose polymerase) inhibitors are approved as maintenance therapy in platinum sensitive ovarian cancer (OC), in first line and in the recurrent setting, regardless of BRCA mutational status. Real-world data after the introduction of these agents are needed to evaluate whether the benefit observed in phase III randomized clinical trials can be translated into clinical practice. The aim of our study was to provide real-life data on efficacy and safety of niraparib administered as maintenance in platinum sensitive relapsed OC patients (PSROC). METHODS: This retrospective/prospective observational study included relapsed OC patients that received niraparib as maintenance, at the time of platinum sensitive recurrence within the Italian expanded-access program. Clinical data at the time of diagnosis and at the time of recurrence were collected and analyzed. Median progression free survival (PFS) and overall survival (OS) were calculated as the time from start of niraparib treatment to subsequent radiologically confirmed relapse and death or last contact, respectively. RESULTS: Among 304 eligible patients, 260 (85%) had BRCA wild-type tumor and 36. (11.9%) were BRCA mutated. Median PFS was 9.1 months (95% CI: 6.9-11.2) and 10.3 months (95% CI: 7.0-13.5) in the BRCAwt and BRCAmut cohorts, respectively. Furthermore, median OS was 41.7 months (95% CI: 31.6-41.9) and 34.6 months (95% CI: N.E.) in the BRCAwt and BRCAmut cohorts, respectively. CONCLUSION: Data from this large real-life dataset suggested that maintenance with niraparib in the real-life setting of platinum sensitive OC recurrence is effective and well tolerated.

Primary results and characterization of patients with exceptional outcomes in a phase 1b study combining PARP and MEK inhibition, with or without anti-PD-L1, for BRCA wild-type, platinum-sensitive, recurrent ovarian cancer.

BACKGROUND: This phase 1b study (ClinicalTrials.gov identifier NCT03695380) evaluated regimens combining PARP and MEK inhibition, with or without PD-L1 inhibition, for BRCA wild-type, platinum-sensitive, recurrent ovarian cancer (PSROC). METHODS: Patients with PSROC who had received one or two prior treatment lines were treated with 28-day cycles of cobimetinib 60 mg daily (days 1-21) plus niraparib 200 mg daily (days 1-28) with or without atezolizumab 840 mg (days 1 and 15). Stage 1 assessed safety before expansion to stage 2, which randomized patients who had BRCA wild-type PSROC to receive either doublet or triplet therapy, stratified by genome-wide loss of heterozygosity status (<16% vs. ≥16%; FoundationOne CDx assay) and platinum-free interval (≥6 to <12 vs. ≥12 months). Coprimary end points were safety and the investigator-determined objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (RECIST). Potential associations between genetic parameters and efficacy were explored, and biomarker profiles of super-responders (complete response or those with progression-free survival [PFS] >15 months) and progressors (disease progression as the best response) were characterized. RESULTS: The ORR in patients who had BRCA wild-type PSROC was 35% (95% confidence interval, 20%-53%) with the doublet regimen (n = 37) and 27% (95% confidence interval, 14%-44%) with the triplet regimen (n = 37), and the median PFS was 6.0 and 7.4 months, respectively. Post-hoc analyses indicated more favorable ORR and PFS in the homologous recombination-deficiency-signature (HRDsig)-positive subgroup than in the HRDsig-negative subgroup. Tolerability was consistent with the known profiles of individual agents. NF1 and MKNK1 mutations were associated with sustained benefit from the doublet and triplet regimens, respectively. CONCLUSIONS: Chemotherapy-free doublet and triplet therapy demonstrated encouraging activity, including among patients who had BRCA wild-type, HRDsig-positive or HRDsig-negative PSROC harboring NF1 or MKNK1 mutations.

A phase I study of veliparib with cyclophosphamide and veliparib combined with doxorubicin and cyclophosphamide in advanced malignancies.

PURPOSE: Veliparib (V), an oral poly(ADP-ribose) polymerase (PARP) inhibitor, potentiates effects of alkylating agents and topoisomerase inhibitors in preclinical tumor models. We conducted a phase I trial of V with iv cyclophosphamide (C) and V plus iv doxorubicin (A) and C. METHODS: Objectives were to establish the maximum tolerated dose (MTD) of the combinations, characterize V pharmacokinetics (PK) in the presence and absence of C, measure PAR in peripheral blood mononuclear cells (PBMCs) and γH2AX in circulating tumor cells (CTCs). In Group 1, dose escalations of V from 10 to 50 mg every 12 h Days 1-4 plus C 450 to 750 mg/m2 Day 3 in 21-day cycles were evaluated. In Group 2, V doses ranged from 50 to 150 mg every 12 h Days 1-4 with AC (60/600 mg/m2) Day 3 in 21-day cycles. In Group 3, patients received AC Day 1 plus V Days 1-7, and in Group 4, AC Day 1 plus V Days 1-14 was given in 21-day cycles to evaluate effects on γH2AX foci. RESULTS: Eighty patients were enrolled. MTD was not reached for V and C. MTD for V and AC was V 100 mg every 12 h Days 1-4 with AC (60/600 mg/m2) Day 3 every 21 days. V PK appears to be dose-dependent and has no effect on the PK of C. Overall, neutropenia and anemia were the most common adverse events. Objective response in V and AC treated groups was 22% (11/49). Overall clinical benefit rate was 31% (25/80). PAR decreased in PBMCs. Percentage of γH2AX-positive CTCs increased after treatment with V and AC. CONCLUSION: V and AC can be safely combined. Activity was observed in patients with metastatic breast cancer.

Phase 1A/1B dose-escalation and -expansion study to evaluate the safety, pharmacokinetics, food effects and antitumor activity of pamiparib in advanced solid tumours.

BACKGROUND: Pamiparib, a PARP1/2 inhibitor, demonstrated antitumor activity in preclinical models. METHODS: This Phase 1A/1B dose-escalation/dose-expansion study enrolled adults (≥18 years) with advanced/metastatic cancer. The dose-escalation phase evaluated the recommended Phase 2 dose (RP2D), maximum tolerated dose (MTD), and pharmacokinetics; the dose-expansion phase evaluated the antitumor activity and food effects. RESULTS: Patients (N = 101) were enrolled in dose-escalation (n = 64) and dose-expansion (n = 37). During BID dose-escalation, dose-limiting toxicities were Grade 2 nausea (n = 1, 40 mg; n = 1, 80 mg); Grade 2 nausea and Grade 2 anorexia (n = 1, 120 mg), Grade 2 nausea, Grade 3 fatigue and Grade 3 paraesthesia (n = 1, 120 mg); MTD was 80 mg BID and RP2D was 60 mg BID. Common adverse events (AEs) were nausea (69.3%), fatigue (48.5%) and anaemia (35.6%); the most common Grade ≥3 AE was anaemia (24.8%). There was a dose-proportional increase in pamiparib exposure; no food effects on pharmacokinetics were observed. In the efficacy-evaluable population (n = 77), objective response rate (ORR) was 27.3% (95% CI, 17.7-38.6%). Median duration of response was 14.9 months (95% CI, 8.7-26.3). In the epithelial ovarian cancer (EOC)-evaluable population (n = 51), ORR was 41.2% (95% CI, 27.6-55.8%). CONCLUSIONS: Pamiparib was tolerated with manageable AEs, and antitumor activity was observed in patients with EOC. CLINICALTRIALS. GOV IDENTIFIER: NCT02361723.

Repurposing Ceritinib Induces DNA Damage and Enhances PARP Inhibitor Responses in High-Grade Serous Ovarian Carcinoma.

PARP inhibitors (PARPi) have activity in homologous recombination (HR) repair-deficient, high-grade serous ovarian cancers (HGSOC). However, even responsive tumors develop PARPi resistance, highlighting the need to delay or prevent the appearance of PARPi resistance. Here, we showed that the ALK kinase inhibitor ceritinib synergizes with PARPis by inhibiting complex I of the mitochondrial electron transport chain, which increases production of reactive oxygen species (ROS) and subsequent induction of oxidative DNA damage that is repaired in a PARP-dependent manner. In addition, combined treatment with ceritinib and PARPi synergized in HGSOC cell lines irrespective of HR status, and a combination of ceritinib with the PARPi olaparib induced tumor regression more effectively than olaparib alone in HGSOC patient-derived xenograft (PDX) models. Notably, the ceritinib and olaparib combination was most effective in PDX models with preexisting PARPi sensitivity and was well tolerated. These findings unveil suppression of mitochondrial respiration, accumulation of ROS, and subsequent induction of DNA damage as novel effects of ceritinib. They also suggest that the ceritinib and PARPi combination warrants further investigation as a means to enhance PARPi activity in HGSOC, particularly in tumors with preexisting HR defects. SIGNIFICANCE: The kinase inhibitor ceritinib synergizes with PARPi to induce tumor regression in ovarian cancer models, suggesting that ceritinib combined with PARPi may be an effective strategy for treating ovarian cancer.

Evaluation of patterns of progression on poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance in ovarian cancer: a cross-sectional study.

INTRODUCTION: Despite improvement in progression-free survival with poly (ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy for ovarian cancer, many patients will eventually progress on therapy. Oligoprogression is uniquely suited to considerations of local consolidation therapy in this setting, but not commonly used in ovarian cancer. In this study we evaluated the proportion of patients on PARPi maintenance who developed limited sites of disease, the location of progression, and their natural history. METHODS: From January 2006 to December 2020, natural language processing software (DEEP6AI) was used to identify 58 patients with ovarian cancer treated with PARPi maintenance after complete or partial response after surgery and platinum-based chemotherapy at our institution. Patients were assessed for presence and location of recurrence based on radiologic findings. RESULTS: The median patient age was 65 (IQR 57-71) years. Patients had a median of two lines of chemotherapy prior to starting PARPi. With a median follow-up of 48 (range 12-149) months, 32 (55%) patients had a recurrence on maintenance olaparib and 11 (34%) patients developed oligoprogression (≤3 sites). For the 11 patients with oligoprogression, three patients developed recurrence in one site, five in two sites, and three in three sites. The sites of oligoprogression were pelvic/periaortic nodal (27%), peritoneal (27%), liver (27%), lung/mediastinal (14%), and brain (5%). The median progression-free survival for the entire cohort was 6.0 months (95% CI 4.2 to 7.8); median overall survival was not met. There were no significant differences in overall survival (p=0.81) or progression-free survival (p=0.95) between patients with and without oligoprogression. CONCLUSIONS: One-third of patients on PARPi maintenance experienced oligoprogression defined as limited to ≤3 sites. These patients may benefit from local consolidation therapy. A larger dataset is needed to validate these findings to assess if trials investigating local therapy for these patients is of value.

Randomized phase III trial on niraparib-TSR-042 (dostarlimab) versus physician's choice chemotherapy in recurrent ovarian, fallopian tube, or primary peritoneal cancer patients not candidate for platinum retreatment: NItCHE trial (MITO 33).

BACKGROUND: Platinum-resistant ovarian cancer patients have a poor prognosis and few treatment options are available. Preclinical and clinical data demonstrated that the combination of poly-ADP ribose polymerase inhibitors with immune checkpoint inhibitors could have a synergistic antitumor activity in this setting of patients. PRIMARY OBJECTIVE: The primary objective is to assess the efficacy of niraparib plus dostarlimab compared with chemotherapy in recurrent ovarian cancer patients not suitable for platinum treatment. STUDY HYPOTHESIS: This trial will assess the hypothesis that niraparib plus dostarlimab therapy is effective to increase overall survival, progression-free survival, and time to first subsequent therapy respect to chemotherapy alone, with an acceptable toxicity profile. TRIAL DESIGN: This is a phase III, multicenter trial, where recurrent ovarian cancer patients not eligible for platinum re-treatment will be randomized 1:1 to receive niraparib plus dostarlimab vs physician's choice chemotherapy until disease progression, intolerable toxicity, or withdrawal of patient consent. The study will be performed according to European Network for Gynaecological Oncological Trial groups (ENGOT) model B and patients will be recruited from 40 sites across MITO, CEEGOG, GINECO, HeCOG, MANGO, and NOGGO groups. MAJOR INCLUSION/EXCLUSION CRITERIA: Eligible patients must have recurrent epithelial ovarian cancer not eligible for platinum retreatment. Patients who received previous treatment with poly-ADP ribose polymerase inhibitors and/or immune checkpoint inhibitors will be eligible. No more than two prior lines of treatment are allowed. PRIMARY ENDPOINT: The primary endpoint is overall survival defined as the time from the randomization to the date of death by any cause. SAMPLE SIZE: 427 patients will be randomized. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: June 2024 TRIAL REGISTRATION NUMBER: NCT04679064.

Active Targeted Nanoparticles for Delivery of Poly(ADP-ribose) Polymerase (PARP) Inhibitors: A Preliminary Review.

Nanotechnology has revolutionized novel drug delivery strategies through establishing nanoscale drug carriers, such as niosomes, liposomes, nanomicelles, dendrimers, polymeric micelles, and nanoparticles (NPs). Owing to their desirable cancer-targeting efficacy and controlled release, these nanotherapeutic modalities are broadly used in clinics to improve the efficacy of small-molecule inhibitors. Poly(ADP-ribose) polymerase (PARP) family members engage in various intracellular processes, including DNA repair, gene transcription, signal transduction, cell cycle regulation, cell division, and antioxidant response. PARP inhibitors are synthetic small-molecules that have emerged as one of the most successful innovative strategies for targeted therapy in cancer cells harboring mutations in DNA repair genes. Despite these advances, drug resistance and unwanted side effects are two significant drawbacks to using PARP inhibitors in the clinic. Recently, the development of practical nanotechnology-based drug delivery systems has tremendously improved the efficacy of PARP inhibitors. NPs can specifically accumulate in the leaky vasculature of the tumor and cancer cells and release the chemotherapeutic moiety in the tumor microenvironment. On the contrary, NPs are usually unable to permeate across the body's normal organs and tissues; hence the toxicity is zero to none. NPs can modify the release of encapsulated drugs based on the composition of the coating substance. Delivering PARP inhibitors without modulation often leads to the toxic effect; therefore, a delivery vehicle is essential to encapsulate them. Various nanocarriers have been exploited to deliver PARP inhibitors in different cancers. Through this review, we hope to cast light on the most innovative advances in applying PARP inhibitors for therapeutic purposes.