scholarly journals Differential Activity of PARP Inhibitors in BRCA1- Versus BRCA2-Altered Metastatic Castration-Resistant Prostate Cancer

2021 ◽  
pp. 1200-1220
Author(s):  
Fadi Taza ◽  
Albert E. Holler ◽  
Wei Fu ◽  
Hao Wang ◽  
Nabil Adra ◽  
...  

PURPOSE Two poly (ADP-ribose) polymerase (PARP) inhibitors (olaparib and rucaparib) are US Food and Drug Administration–approved for patients with metastatic castration-resistant prostate cancer (mCRPC) harboring BRCA1/ 2 mutations, but the relative efficacy of PARP inhibition in BRCA1- versus BRCA2-altered mCRPC is understudied. METHODS We conducted a multicenter retrospective analysis involving 12 sites. We collected genomic and clinical data from 123 patients with BRCA1/ 2-altered mCRPC who were treated with PARP inhibitors. The primary efficacy end point was the prostate-specific antigen (PSA) response (≥ 50% PSA decline) rate. Secondary end points were PSA progression-free survival (PSA-PFS), clinical or radiographic PFS, and overall survival. We compared clinical outcomes, and other genomic characteristics, among BRCA1- versus BRCA2-altered mCRPC. RESULTS A total of 123 patients (13 BRCA1 and 110 BRCA2) were included. PARP inhibitors used were olaparib (n = 116), rucaparib (n = 3), talazoparib (n = 2), and veliparib (n = 2). At diagnosis, 72% of patients had Gleason 8-10 disease. BRCA1 patients were more likely to have metastatic disease at presentation (69% v 37%; P = .04). Age, baseline PSA, metastatic distribution, and types of previous systemic therapies were similar between groups. There were equal proportions of germline mutations (51% v 46%; P = .78) in both groups. BRCA1 patients had more monoallelic (56% v 41%; P = .49) and concurrent TP53 (55% v 36%; P = .32) mutations. PSA50 responses in BRCA1- versus BRCA2-altered patients were 23% versus 63%, respectively ( P = .01). BRCA2 patients achieved longer PSA-PFS (HR, 1.94; 95% CI, 0.92 to 4.09; P = .08), PFS (HR, 2.08; 95% CI, 0.99 to 4.40; P = .05), and overall survival (HR, 3.01; 95% CI, 1.32 to 6.83; P = .008). Biallelic (compared with monoallelic) mutations, truncating (compared with missense) mutations, and absence of a concurrent TP53 mutation were associated with PARP inhibitor sensitivity. CONCLUSION PARP inhibitor efficacy is diminished in BRCA1- versus BRCA2-altered mCRPC. This is not due to an imbalance in germline mutations but might be related to more monoallelic mutations and/or concurrent TP53 alterations in the BRCA1 group.

2021 ◽  
Author(s):  
Shotaro Nakanishi ◽  
Masato Goya ◽  
Mitsuyoshi Tamaki ◽  
Takuma Oshiro ◽  
Seiichi Saito

Abstract Objective: To date, there are no useful markers for predicting the prognosis of metastatic hormone-sensitive prostate cancer (mHSPC). We evaluated the effect of early changes in prostate-specific antigen (PSA) levels after androgen deprivation therapy (ADT) on castration-resistant prostate cancer (CRPC) progression and overall survival (OS) in mHSPC patients. Results: In 71 primary mHSPC patients treated with ADT, the median times to CRPC and OS were 15 months and 92 months, respectively. In multivariate analysis, a Gleason score of ≥8 (p = 0.004), an extent of disease value (EOD) of ≥2 (p = 0.004), and a 3-month PSA level >1% of the pretreatment level (p = 0.017) were independent predictors of shorter time to CRPC. The area under the receiver operating characteristic curve was feasible at 0.822. For OS, a 3-month PSA level >1% of the pretreatment level was an independent predictor of time to CRPC (p = 0.004).Three factors were independent predictors of shorter time to CRPC. A 3-month PSA level >1% of the pretreatment level correlated with poor a prognosis.


2019 ◽  
Vol 37 (5) ◽  
pp. 403-410 ◽  
Author(s):  
Susan Halabi ◽  
Sandipan Dutta ◽  
Catherine M. Tangen ◽  
Mark Rosenthal ◽  
Daniel P. Petrylak ◽  
...  

Purpose Several studies have reported that among patients with localized prostate cancer, black men have a shorter overall survival (OS) time than white men, but few data exist for men with advanced prostate cancer. The primary goal of this analysis was to compare the OS in black and white men with metastatic castration-resistant prostate cancer (mCRPC) who were treated in phase III clinical trials with docetaxel plus prednisone (DP) or a DP-containing regimen. Methods Individual participant data from 8,820 men with mCRPC randomly assigned in nine phase III trials to DP or a DP-containing regimen were combined. Race was based on self-report. The primary end point was OS. The Cox proportional hazards regression model was used to assess the prognostic importance of race (black v white) adjusted for established risk factors common across the trials (age, prostate-specific antigen, performance status, alkaline phosphatase, hemoglobin, and sites of metastases). Results Of 8,820 men, 7,528 (85%) were white, 500 (6%) were black, 424 (5%) were Asian, and 368 (4%) were of unknown race. Black men were younger and had worse performance status, higher testosterone and prostate-specific antigen, and lower hemoglobin than white men. Despite these differences, the median OS was 21.0 months (95% CI, 19.4 to 22.5 months) versus 21.2 months (95% CI, 20.8 to 21.7 months) in black and white men, respectively. The pooled multivariable hazard ratio of 0.81 (95% CI, 0.72 to 0.91) demonstrates that overall, black men have a statistically significant decreased risk of death compared with white men ( P < .001). Conclusion When adjusted for known prognostic factors, we observed a statistically significant increased OS in black versus white men with mCRPC who were enrolled in these clinical trials. The mechanism for these differences is not known.


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 39-39 ◽  
Author(s):  
Steven Xu ◽  
Charles J. Ryan ◽  
Kim Stuyckens ◽  
Matthew R. Smith ◽  
Fred Saad ◽  
...  

39 Background: Abiraterone, the active metabolite of abiraterone acetate (AA), is an effective androgen biosynthesis inhibitor for patients with metastatic castration-resistant prostate cancer (mCRPC). We conducted a sequential exposure-biomarker-survival modeling analysis to explore the relationship between prostate-specific antigen (PSA) kinetics and overall survival (OS) and to establish the exposure response for PSA kinetics and OS in chemotherapy-naïve and -pretreated patients with mCRPC following AA administration. Methods: The exposure-PSA-survival modeling framework was based on two phase III studies, COU-AA-301 (chemotherapy-pretreated, N = 1184) and COU-AA-302 (chemotherapy-naïve, N = 1081), and included a mixed-effects tumor growth inhibition (TGI) model to describe PSA dynamics in response to AA and a Cox proportional hazards survival model to evaluate the relationship between relative risk of death and PSA dynamic end points. Results: The TGI model best described the longitudinal PSA dynamics following AA treatment. Abiraterone exposure significantly increased PSA decay rate (maximum effect of 2.72, p < 0.0001). The estimated concentration for 50% of the maximum effect (EC50) was 4.75 ng/mL. The abiraterone effect on PSA kinetics was similar in chemotherapy-naïve and -pretreated subjects, and approximately 90% of subjects had a steady-state concentration greater than the EC50. All model-predicted PSA metrics were strongly associated with OS in both populations; model-based post-treatment PSA doubling time showed the strongest association (hazard ratios approximately 0.9 in both populations). Simulations showed that the modeling framework could accurately predict the survival outcome for both studies. Conclusions: The analysis revealed a similar effect of abiraterone on PSA kinetics and association between PSA kinetics and OS in chemotherapy-naïve and -pretreated subjects, providing additional evidence for surrogacy of PSA kinetics and the use of PSA end points to indicate clinical benefit of abiraterone in subjects with mCRPC regardless of prior chemotherapy. Furthermore, the study confirmed that the recommended 1,000 mg/d dose of AA leads to adequate clinical exposure above the effective level. Clinical trial information: NCT00638690, NCT00887198.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. TPS5087-TPS5087 ◽  
Author(s):  
Sumit Kumar Subudhi ◽  
Ana Aparicio ◽  
Amado J. Zurita ◽  
Bernard Doger ◽  
William Kevin Kelly ◽  
...  

TPS5087 Background: Assessing multiple therapies in a single clinical trial can facilitate the rapid identification of new agents for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). Niraparib (Nirap) is a highly selective PARP inhibitor, with potent activity against PARP-1 and PARP-2 deoxyribonucleic acid (DNA)-repair polymerases. PARP inhibition may be especially lethal in tumor cells with genetic DNA damage response deficits (DRD). Based on promising preclinical and clinical data, this study is designed as a master protocol with nirap as a backbone therapy. Combination 1 assesses the safety and efficacy of nirap plus JNJ-63723283 (JNJ-283), an anti-PD-1 monoclonal antibody. Combination 2 assesses nirap plus abiraterone acetate and prednisone (AA-P). Methods: This multicenter, global, open-label study is currently open at 18 sites in 5 countries of the planned XX sites, and is enrolling patients with mCRPC who have progressed on ≥1 androgen-receptor targeted therapy for mCRPC. Enrollment at time of abstract submission was 25 for combination 1. When combined with AA-P, the RP2D has been determined to be nirap 200 mg. The recommended phase-2 dose (RP2D) of nirap plus JNJ-283 was determined in Part 1 based on the incidence of specified adverse events and PK data to be 480 mg every 4 weeks. For Part 2 of the study, patients are assigned to receive oral niraparib daily plus JNJ-283 infusions once every four weeks until disease progression, unacceptable toxicity, death, study termination. Part 2 is described in the table. Clinical trial information: NCT03431350. [Table: see text]


2010 ◽  
Vol 28 (12) ◽  
pp. 2070-2076 ◽  
Author(s):  
Yang-Min Ning ◽  
James L. Gulley ◽  
Philip M. Arlen ◽  
Sukyung Woo ◽  
Seth M. Steinberg ◽  
...  

Purpose We previously demonstrated that thalidomide appears to add to the activity of docetaxel in metastatic castration-resistant prostate cancer (CRPC). Phase II studies combining docetaxel with bevacizumab have had substantial antitumor activity. We hypothesized that the combination of docetaxel plus these antiangiogenic drugs with different targets would have substantial clinical activity. To explore safety and efficacy, this was tested in mice and in human patients. Patients and Methods Preclinical efficacy of the combination therapy was evaluated in PC3 xenograft mice. Sixty patients with progressive metastatic CRPC received intravenous docetaxel and bevacizumab plus oral thalidomide and prednisone. The primary end point was a prostate-specific antigen (PSA) decline of ≥ 50%. Secondary end points included time to progression, overall survival, and safety. Results In the mouse model, combination therapy of docetaxel, bevacizumab, and thalidomide inhibited tumor growth most effectively. In the clinical trial, 90% of patients receiving the combination therapy had PSA declines of ≥ 50%, and 88% achieved a PSA decline of ≥ 30% within the first 3 months of treatment. The median time to progression was 18.3 months, and the median overall survival was 28.2 months in this group with a Halabi-predicted survival of 14 months. While toxicities were manageable, all patients developed grade 3/4 neutropenia. Conclusion The addition of bevacizumab and thalidomide to docetaxel is a highly active combination with manageable toxicities. The estimated median survival is encouraging, given the generally poor prognosis of this patient population. These results suggest that definitive clinical trials combining antiangiogenic agent combinations with docetaxel are warranted to improve treatment outcomes for patients with metastatic CRPC.


2015 ◽  
Vol 33 (7_suppl) ◽  
pp. 260-260
Author(s):  
Martin Boegemann ◽  
Phillip Mikah ◽  
Okyaz Eminaga ◽  
Edwin Herrmann ◽  
Philipp Marius Papavassilis ◽  
...  

260 Background: Significant progress in treatment of metastatic castration resistant prostate cancer (mCRPC) has been made. Biomarkers to tailor therapy are scarce. To facilitate decision-making we evaluated dynamic changes of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and prostate specific antigen (PSA) under Abiraterone acetate (AA). ALP-Bouncing can be observed during very early AA-therapy. Methods: Men with bone mCRPC (bmCRPC) on AA 12/2009-01/2014 were analyzed. Dynamic ALP-, LDH- and PSA-changes were analyzed as predictors of best clinical benefit (BCB) and overall survival (OS) with logistic-regression, Cox-regression and Kaplan-Meier-analysis. Results: 39 pre- and 45 post-chemotherapy patients with median follow up of 14.0 months were analyzed. In univariate analysis failure of PSA-reduction ≥50% (PSA-red≥50%) and failure of ALP-Bouncing were the strongest predictors of progressive disease (p=0.003 and 0.021). Rising ALP at 12 weeks (ALP12), no PSA-red≥50% and no ALP-Bouncing were strongest predictors of poor OS, (all p<0.001). Kaplan-Meier-analysis showed worse OS for ALP12, no PSA-red≥50% and no ALP-Bouncing (p<0.001). In subgroup-analysis of oligosymptomatic patients all parameters remained significant predictors of poor OS, no PSA-red≥50% and ALP12 being the strongest (p<0.001). In multivariate analysis PSA-red≥50% remained independent predictor of OS for the whole cohort and for the oligosymptomatic subgroup (p=0.014). No patient with ALP-Bouncing had PD for BCB. Patients with ALP12 had no further benefit of AA. Conclusions: Dynamic changes of ALP, LDH and PSA during AA-therapy are associated with BCB and OS in bmCRPC. ALP-Bouncing occurring earlier than PSA-changes and rising ALP12 under AA may help to decide whether to discontinue AA.


2019 ◽  
Vol 37 (7_suppl) ◽  
pp. TPS328-TPS328
Author(s):  
Simon Chowdhury ◽  
Joaquin Mateo ◽  
Mitchell Gross ◽  
Andrew J. Armstrong ◽  
Marcia Cruz-Correa ◽  
...  

TPS328 Background: Men with metastatic castration-resistant prostate cancer (mCRPC) who have a BRCA1/2 mutation ( BRCA1/2mut) or mutations in other HRD genes have a poor prognosis. The EPIC liquid biopsy test is a novel assay that can identify circulating tumor cells (CTC) with HRD associated phenotypes. Preliminary studies have shown that these men may respond to treatment with a PARP inhibitor. Pamiparib is an investigational PARP1/2 inhibitor that has shown brain penetration and potent PARP–DNA complex trapping in nonclinical studies. In early phase clinical studies (NCT02361723; NCT03333915), pamiparib was generally well tolerated and showed preliminary antitumor activity; 60 mg orally twice daily (BID) was established as the recommended investigational dose. Methods: This open-label, global, phase 2 study (NCT03712930) will evaluate antitumor activity and safety of pamiparib in mCRPC pts with CTC-HRD, assessed by the EPIC CTC-HRD assay, or deleterious germline/somatic BRCA1/2mut status. Patients must have progressed on/after ≥1 androgen receptor-targeted therapy, have received ≥1 taxane-based therapy, and have prostate-specific antigen (PSA) progression per PCWG3 criteria. Four cohorts of patients will receive pamiparib 60 mg BID in 28-day cycles. Cohort 1 will include ~50 pts with CTC-HRD+ +/- BRCA1/2mut mCRPC with measurable metastatic disease; Cohort 2 will include ~30 pts with CTC-HRD+ +/- BRCA1/2mut mCRPC with bone-only disease; Cohorts 3 & 4 will include ~20 pts with CTC-HRD-/unknown + BRCA1/2mut mCRPC with measurable metastatic disease (Cohort 3), or bone-only disease (Cohort 4). Disease status will be assessed every 8 wks for 24 wks, then every 12 wks; PSA levels will be tested every 4 wks. Co-primary endpoints are radiographic ORR assessed by IRC (pts with measurable disease) and confirmed PSA response rate per PCWG3 criteria (pts +/- measurable disease). Secondary endpoints include ORR, time to PSA response/progression, duration of PSA response, time to symptomatic skeletal event, radiographic progression-free survival, overall survival, and safety. Clinical trial information: NCT03712930.


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