scholarly journals Homologous Recombination Repair Gene Mutation Characterization by Liquid Biopsy: A Phase II Trial of Olaparib and Abiraterone in Metastatic Castrate-Resistant Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5830
Author(s):  
T. Hedley Carr ◽  
Carrie Adelman ◽  
Alan Barnicle ◽  
Iwanka Kozarewa ◽  
Sally Luke ◽  
...  

Background: Phase III randomized trial data have confirmed the activity for olaparib in homologous recombination repair (HRR) mutated metastatic castration-resistant prostate cancer (mCRPC) post next-generation hormonal agent (NHA) progression. Preclinical data have suggested the potential for a combined effect between olaparib and NHAs irrespective of whether an HRR gene alteration was present. NCT01972217 was a randomised double-blind Phase II study which evaluated olaparib and abiraterone versus placebo and abiraterone in mCRPC patients who had received prior chemotherapy containing docetaxel. The study showed that radiologic progression was significantly delayed by the combination of olaparib and abiraterone regardless of homologous recombination repair mutation (HRRm) status. The study utilized tumour, blood (germline), and circulating tumour DNA (ctDNA) analysis to profile patient HRRm status, but tumour tissue provision was not mandated, leading to relatively low tissue acquisition and DNA sequencing success rates not representative of real-world testing. Patients and methods: Further analysis of germline and ctDNA samples has been performed for the trial to characterize HRRm status more fully and robustly analyse patient response to treatment. Results: Germline and plasma testing increased the HRRm characterized population from 27% to 68% of 142 randomized patients. Tumour-derived variants were detectable with high confidence in 78% of patients with a baseline plasma sample (71% of randomized patients). There was high concordance across methodologies (plasma vs. tumour; plasma vs. germline). The HR for the exploratory analysis of radiographic progression-free survival was 0.54 (95% CI: 0.32–0.93) in favour of olaparib and abiraterone in the updated HRR wild type (HRRwt) group (n = 73) and 0.62 (95% CI: 0.23–1.65) in the HRRm group (n = 23). Conclusion: Our results confirm the value of plasma testing for HRRm status when there is insufficient high-quality tissue for multi-gene molecular testing. We show that patients with mCRPC benefit from the combination of olaparib and abiraterone treatment regardless of HRRm status. The combination is currently being further investigated in the Phase III PROpel trial.

2016 ◽  
Vol 34 (22) ◽  
pp. 2636-2643 ◽  
Author(s):  
Cora Sternberg ◽  
Andrew Armstrong ◽  
Roberto Pili ◽  
Siobhan Ng ◽  
Robert Huddart ◽  
...  

Purpose Tasquinimod, a novel oral therapy targeting the tumor microenvironment, significantly improved progression-free survival (PFS) in a randomized, placebo-controlled phase II trial in men with metastatic castration-resistant prostate cancer (mCRPC). This phase III study was conducted to confirm the phase II results and to detect an overall survival (OS) benefit. Patients and Methods Men with chemotherapy-naïve mCRPC and evidence of bone metastases were assigned (2:1) to receive tasquinimod once per day or placebo until progression or toxicity. The primary end point was radiographic PFS (rPFS; time from random assignment to radiologic progression or death) per Prostate Cancer Working Group 2 criteria and RECIST 1.1. The study had 99.9% power to detect an rPFS hazard ratio (HR) of 0.6 with a two-sided alpha error of .05 and 80% power to detect a target HR of 0.8 for OS, the key secondary end point. Results In all, 1,245 patients were randomly assigned to either tasquinimod (n = 832) or placebo (n = 413) between March 2011 and December 2012 at 241 sites in 37 countries. Baseline characteristics were balanced between groups: median age, 71 years; Karnofsky performance status ≥ 90%, 77.3%; and visceral metastases, 21.1%. Estimated median rPFS by central review was 7.0 months (95% CI, 5.8 to 8.2 months) with tasquinimod and 4.4 months (95% CI, 3.5 to 5.5 months) with placebo (HR, 0.64; 95% CI, 0.54 to 0.75; P < .001). Median OS was 21.3 months (95% CI, 19.5 to 23.0 months) with tasquinimod and 24.0 months (95% CI, 21.4 to 26.9 months) with placebo (HR, 1.10; 95% CI, 0.94 to 1.28; P = .25). Grade ≥ 3 adverse events were more frequent with tasquinimod (42.8% v 33.6%), the most common being anemia, fatigue, and cancer pain. Conclusion In chemotherapy-naïve men with mCRPC, tasquinimod significantly improved rPFS compared with placebo. However, no OS benefit was observed.


2019 ◽  
Vol 37 (7_suppl) ◽  
pp. TPS340-TPS340 ◽  
Author(s):  
Noel W. Clarke ◽  
Andrew J. Armstrong ◽  
Antoine Thiery-Vuillemin ◽  
Mototsugu Oya ◽  
Dingwei Ye ◽  
...  

TPS340 Background: A Phase II trial showed olaparib (tablets, 300 mg bid) in combination with abiraterone (1000 mg od plus prednisone/prednisolone 5 mg bid) significantly prolonged radiologic progression-free survival (rPFS) compared with abiraterone alone (median 13.8 vs 8.2 months; hazard ratio 0.65, 95% CI 0.44–0.97, P=0.034) in patients (pts) with mCRPC in the second-line metastatic setting who received prior docetaxel (Clarke et al. Lancet Oncol 2018). Treatment benefits were achieved irrespective of homologous recombination repair (HRR) mutation status, suggesting potential synergy between the two treatments that could impact a broader patient population. PROpel (EudraCT: 2018-002011-10) is the follow-on study to this, and the first Phase III trial to assess a PARP inhibitor in combination with abiraterone as first-line treatment in a genetically unselected mCRPC pt population. Methods: PROpel is a double-blind, placebo-controlled, international, multicenter study of pts randomized (1:1), as for the Phase II trial, to abiraterone (1000 mg od plus prednisone/prednisolone 5 mg bid) plus either olaparib (tablets, 300 mg bid) or placebo. Pts must not have received prior chemotherapy, new hormonal agents or other systemic treatment at mCRPC stage (except docetaxel at metastatic hormone-sensitive prostate cancer stage [mHSPC]). Randomization is stratified according to site of metastases (bone only vs visceral vs other) and docetaxel treatment at mHSPC stage (yes, no). The primary endpoint is investigator-assessed rPFS (RECIST v1.1 [soft tissue] and Prostate Working Cancer Group 3 [PCWG-3 criteria; bone]). Secondary objectives include time to first subsequent therapy or death, time to pain progression, overall survival, and health-related quality of life. Safety and tolerability will also be described. Exploratory endpoints include HRR subgroup analyses to confirm that efficacy is independent of HRR status. Screening across ~200 sites in 20 countries is being conducted to identify a target sample of ~720 pts. Enrollment is expected to begin in October 2018. (Study 8, NCT01972217). Clinical trial information: NCT03732820.


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