TRANSFORMER: A Randomized Phase II Study Comparing Bipolar Androgen Therapy Versus Enzalutamide in Asymptomatic Men With Castration-Resistant Metastatic Prostate Cancer

2021 ◽  
pp. JCO.20.02759
Author(s):  
Samuel R. Denmeade ◽  
Hao Wang ◽  
Neeraj Agarwal ◽  
David C. Smith ◽  
Michael T. Schweizer ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Negative Symptoms ◽  
Randomized Study ◽  
Objective Response ◽  
Specific Antigen ◽  
Clinical Activity ◽  
Androgen Therapy ◽  
Androgen Ablation ◽  
Castration Resistant ◽  
Patient Reported

PURPOSE Prostate cancer (PCa) becomes resistant to androgen ablation through adaptive upregulation of the androgen receptor in response to the low-testosterone microenvironment. Bipolar androgen therapy (BAT), defined as rapid cycling between high and low serum testosterone, disrupts this adaptive regulation in castration-resistant PCa (CRPC). METHODS The TRANSFORMER (Testosterone Revival Abolishes Negative Symptoms, Fosters Objective Response and Modulates Enzalutamide Resistance) study is a randomized study comparing monthly BAT (n = 94) with enzalutamide (n = 101). The primary end point was clinical or radiographic progression-free survival (PFS); crossover was permitted at progression. Secondary end points included overall survival (OS), prostate-specific antigen (PSA) and objective response rates, PFS from randomization through crossover (PFS2), safety, and quality of life (QoL). RESULTS The PFS was 5.7 months for both arms (hazard ratio [HR], 1.14; 95% CI, 0.83 to 1.55; P = .42). For BAT, 50% decline in PSA (PSA50) was 28.2% of patients versus 25.3% for enzalutamide. At crossover, PSA50 response occurred in 77.8% of patients crossing to enzalutamide and 23.4% to BAT. The PSA-PFS for enzalutamide increased from 3.8 months after abiraterone to 10.9 months after BAT. The PFS2 for BAT→enzalutamide was 28.2 versus 19.6 months for enzalutamide→BAT (HR, 0.44; 95% CI, 0.22 to 0.88; P = .02). OS was 32.9 months for BAT versus 29.0 months for enzalutamide (HR, 0.95; 95% CI, 0.66 to 1.39; P = .80). OS was 37.1 months for patients crossing from BAT to enzalutamide versus 30.2 months for the opposite sequence (HR, 0.68; 95% CI, 0.36 to 1.28; P = .225). BAT adverse events were primarily grade 1-2. Patient-reported QoL consistently favored BAT. CONCLUSION This randomized trial establishes meaningful clinical activity and safety of BAT and supports additional study to determine its optimal clinical integration. BAT can sensitize CRPC to subsequent antiandrogen therapy. Further study is required to confirm whether sequential therapy with BAT and enzalutamide can improve survival in men with CRPC.

Randomized Phase II Study of Docetaxel and Prednisone With or Without OGX-011 in Patients With Metastatic Castration-Resistant Prostate Cancer

2010 ◽  
Vol 28 (27) ◽  
pp. 4247-4254 ◽  
Author(s):  
Kim N. Chi ◽  
Sebastien J. Hotte ◽  
Evan Y. Yu ◽  
Dongsheng Tu ◽  
Bernhard J. Eigl ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Group Performance ◽  
Performance Status ◽  
Objective Response ◽  
Eastern Cooperative Oncology Group ◽  
Specific Antigen ◽  
Experimental Therapy ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant

Purpose To determine the clinical activity of OGX-011, an antisense inhibitor of clusterin, in combination with docetaxel/prednisone in patients with metastatic castration-resistant prostate cancer. Patients and Methods Patients were randomly assigned 1:1 to receive docetaxel/prednisone either with (arm A) or without (arm B) OGX-011 640 mg intravenously weekly. The primary end point was the proportion of patients with a prostate-specific antigen (PSA) decline of ≥ 50% from baseline, with the experimental therapy being considered of interest if the proportion of patients with a PSA decline was more than 60%. Secondary end points were objective response rate, progression-free survival (PFS), overall survival (OS), and changes in serum clusterin. Results Eighty-two patients were accrued, 41 to each arm. OGX-011 adverse effects included rigors and fevers. After cycle 1, median serum clusterin decreased by 26% in arm A and increased by 0.9% in arm B (P < .001). PSA declined by ≥ 50% in 58% of patients in arm A and 54% in arm B. Partial response occurred in 19% and 25% of patients in arms A and B, respectively. Median PFS and OS times were 7.3 months (95% CI, 5.3 to 8.8 months) and 23.8 months (95% CI, 16.2 months to not reached), respectively, in arm A and 6.1 months (95% CI, 3.7 to 8.6 months) and 16.9 months (95% CI, 12.8 to 25.8 months), respectively, in arm B. Baseline factors associated with improved OS on exploratory multivariate analysis were an Eastern Cooperative Oncology Group performance status of 0 (hazard ratio [HR], 0.27; 95% CI, 0.14 to 0.51), presence of bone or lymph node metastases only (HR, 0.45; 95% CI, 0.25 to 0.79), and treatment assignment to OGX-011 (HR, 0.50; 95% CI, 0.29 to 0.87). Conclusion Treatment with OGX-011 and docetaxel was well tolerated with evidence of biologic effect and was associated with improved survival. Further evaluation is warranted.

A randomized phase I/II study to examine the contribution of carboplatin to cabazitaxel for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) with and without anaplastic features.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 148-148
Author(s):  
Paul Gettys Corn ◽  
Shi-Ming Tu ◽  
Amado J. Zurita ◽  
John C. Araujo ◽  
Lance C. Pagliaro ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Phase I ◽  
Randomized Study ◽  
Specific Antigen ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Platinum Based Chemotherapy ◽  
Grade 3 ◽  
Carboplatin Auc

148 Background: We recently described “anaplastic” prostate carcinomas (PC), a clinically distinct variant of lethal castration-resistant prostate cancer (CRPC) that share clinical features with small cell carcinomas despite heterogeneous morphology. To test the hypothesis that anaplastic PC are uniquely sensitive to platinum-based chemotherapy, we designed a randomized study of cabazitaxel with or without carboplatin in men with metastatic CRPC (mCRPC) stratified for the presence of at least 1 of 7 previously published anaplastic criteria (Aparicio, Clin Cancer Res 2013;19). Here we report results of the phase I study. Methods: Patients (pts) received intravenous cabazitaxel with carboplatin every 21 days with growth factor support and were imaged every two cycles. A 3+3 sequential dose-escalation design was employed to assess the frequency of dose-limiting toxicity after cycle one and establish a maximal tolerated dose (MTD). Three cohorts were tested: (i) cabazitaxel 20mg/m2 – carboplatin AUC 3, (ii) cabazitaxel 25 mg/m2 – carboplatin AUC 3, and (iii) cabazitaxel 25 mg/m2 - carboplatin AUC 4. Up to 10 cycles were administered in the absence of progression or toxicity. Results: Nine men with mCRPC (five anaplastic) previously treated with docetaxel, received a median of six cycles (2 to 10). All had bone involvement and 6 of 9 had RECIST measurable disease. An MTD was not identified. All pts reported 1 or more adverse event (AE) possibly treatment related (120 Grade 1; 53 Grade 2; 13 Grade 3), most commonly fatigue, anemia, nausea, and diarrhea. Grade 3 AE included anemia (n=2), fatigue (n=1), thrombocytopenia (n=1), hypomagnesemia (n=1), diarrhea (n=1), hypokalemia (n=1), and anorexia (n=1). Prostate-specific antigen declines of more than 70% occurred in 6 of 9 (67%) pts. Two of 6 pts had a partial response, three had stable disease, and one progressed. For pts with elevated bone markers at baseline, 2 of 3 had more than 50% declines in BAP and 4 of 7 had more than 30% declines in urinary N-telopeptide levels. Conclusions: The combination of cabazitaxel and carboplatin is safe and has significant clinical activity. The randomized phase II portion combines cabazitaxel 25 mg/m2 and carboplatin AUC4. Results will be updated at the time of the meeting. Clinical trial information: NCT01505868.

CheckMate 9KD Arm B final analysis: Efficacy and safety of nivolumab plus docetaxel for chemotherapy-naïve metastatic castration-resistant prostate cancer.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 12-12
Author(s):  
Karim Fizazi ◽  
Pablo González Mella ◽  
Daniel Castellano ◽  
Jose Nicolas Minatta ◽  
Arash Rezazadeh ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Response Rate ◽  
Objective Response ◽  
Specific Antigen ◽  
Final Analysis ◽  
Median Number ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Measurable Disease

12 Background: CheckMate 9KD (NCT03338790) is a phase 2 trial of nivolumab (NIVO; anti-PD-1) in combination with rucaparib, docetaxel (DOCE), or enzalutamide for patients with metastatic castration-resistant prostate cancer (mCRPC). DOCE is a standard-of-care chemotherapy for mCRPC that may potentiate antitumor immune responses, thus supporting its use in combination with NIVO, which has shown limited antitumor activity in mCRPC as monotherapy. We report final analysis results for Arm B (NIVO + DOCE) of CheckMate 9KD. Methods: Arm B enrolled patients with chemotherapy-naive mCRPC with ongoing androgen deprivation therapy and ≤ 2 prior novel antiandrogen therapies (NATs; i.e., abiraterone, enzalutamide, etc.). Patients received NIVO 360 mg + DOCE 75 mg/m2 Q3W + prednisone 5 mg BID for ≤ 10 cycles, followed by NIVO 480 mg Q4W until disease progression/unacceptable toxicity (up to 2 years). Coprimary endpoints were objective response rate (ORR) and prostate-specific antigen response rate (PSA-RR; defined as a ≥ 50% PSA reduction). Secondary endpoints included radiographic progression-free survival (rPFS), overall survival (OS), and safety. Results: Of 84 treated patients with a median age of 71 years (range: 53-88), 27% had visceral disease and 54% had measurable disease. The median number of docetaxel cycles was 8; the median number of nivolumab doses was 11. Median follow up was 15.2 months. The table displays the efficacy outcomes, which appear to show comparable ORR in patients receiving versus not receiving prior NAT. There was 1 (2.2%) complete objective response and 17 (37.8%) partial responses in 45 patients with measurable disease. Any-grade treatment-related AEs (TRAEs) occurred in 95.2% of patients, most commonly fatigue (39.3%), diarrhea (35.7%), and alopecia (34.5%). Grade 3-4 TRAEs occurred in 47.6% of patients, most commonly neutropenia (16.7%). TRAEs led to discontinuation in 29.8% of patients. The most common immune-related AEs were GI (35.7%) or skin-related (26.2%). There were 3 treatment-related deaths (1 pneumonitis related to NIVO; 2 pneumonias related to DOCE). Conclusions: NIVO + DOCE has encouraging clinical activity in patients with chemotherapy-naïve mCRPC, regardless of prior NAT, with a safety profile consistent with those of the individual agents. These outcomes support the ongoing phase 3 CheckMate 7DX trial of NIVO + DOCE vs placebo + DOCE for mCRPC (NCT04100018). Clinical trial information: NCT03338790. [Table: see text]

scholarly journals Reinduction of Hormone Sensitivity to Goserelin following Chemotherapy with Vinorelbine in Castration-Resistant Prostate Cancer

2010 ◽  
Vol 10 ◽  
pp. 1814-1817
Author(s):  
Tal Grenader ◽  
Anthony Goldberg
Keyword(s):  
Prostate Cancer ◽  
Specific Antigen ◽  
Serum Levels ◽  
Symptomatic Improvement ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistance ◽  
Luteinizing Hormone Releasing Hormone ◽  
Androgen Ablation ◽  
Castration Resistant ◽  
Cessation Of Treatment

Primary androgen ablation leads to symptomatic improvement and a reduction in prostate-specific antigen (PSA) serum levels in patients with advanced prostate cancer, but all patients eventually become refractory to hormone therapy with progression of the disease and a life expectancy of about a year. We describe a patient who developed castration resistance, was treated with vinorelbine, and continues to be progression free on therapy with luteinizing hormone releasing hormone agonists alone, more than 2.5 years following cessation of treatment with vinorelbine.

KEYNOTE-046 (Part B): Effects of ADXS-PSA in combination with pembrolizumab on survival in metastatic, castration-resistant prostate cancer patients with or without prior exposure to docetaxel.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 126-126 ◽  
Author(s):  
Mark N. Stein ◽  
Lawrence Fong ◽  
Anthony E. Mega ◽  
Elaine Tat Lam ◽  
John W. Heyburn ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Trial ◽  
Phase 1 ◽  
Specific Antigen ◽  
Prior Exposure ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Clinical Trial Information

126 Background: ADXS-PSA, an attenuated Listeria monocytogenes-based immunotherapy targeting prostate-specific antigen (PSA), is currently being evaluated in combination with pembrolizumab as a treatment for progressive metastatic castration-resistant prostate cancer (mCRPC) in the phase 1/2 KEYNOTE-046 trial (Part B). Methods: A total of 37 patients received 1x109 CFU + 200 mg pembro IV every 3 wks, for up to 2 yrs or until progression/toxicity. Results: At entry, patients were ~70 yrs with median a Gleason score of 9, and bone predominant disease (70%). MSI-High was negative in 36 pts who were able to be tested. Eighteen (48.6%) patients had received prior docetaxel, 15 pts of whom (83.3%) had also received 1-2 next generation hormonal agents (NGHAs). Nineteen (51.3%) had not received prior docetaxel and 16 of these pts (84.2%) had received 1-2 NGHAs. Overall, 16 out of 37 pts (43%) had a decreased PSA post-BL with 6/37 (16%) pts achieving a confirmed PSA reduction ≥50% from baseline. The median OS (months) for the whole group (37 pts) was 33.6 m (95% CI, range 15.4-33.6 months). The mOS for pts with and without prior exposure to docetaxel was 16 m (5.9 -33.6) and NR at 30 months of follow-up (15.4-NR), respectively. Prolonged survival was observed in pts regardless of prior therapies, microsatellite stable (MSS) status or PSA delta <50% or ≥50%. Conclusions: Results with ADXS-PSA in combination with pembrolizumab in mCRPC, with or without prior docetaxel, show promising clinical activity to be further assessed in randomized studies. Clinical trial information: NCT02325557.

scholarly journals End Points and Outcomes in Castration-Resistant Prostate Cancer: From Clinical Trials to Clinical Practice

2011 ◽  
Vol 29 (27) ◽  
pp. 3695-3704 ◽  
Author(s):  
Howard I. Scher ◽  
Michael J. Morris ◽  
Ethan Basch ◽  
Glenn Heller
Keyword(s):  
Prostate Cancer ◽  
Clinical Trials ◽  
Specific Antigen ◽  
Disease Status ◽  
Castration Resistant Prostate Cancer ◽  
End Points ◽  
New Therapeutic Approaches ◽  
Castration Resistant ◽  
Patient Reported ◽  
Early Phase Clinical Trials

New therapeutic approaches for castration-resistant prostate cancer (CRPC) introduce new treatment dilemmas: how best to sequence these options to maximally benefit patients, what tests to perform before and after treatment to assess disease status, and how to interpret the test results and use them to guide treatment. New and specific end points for different classes of drugs are needed to provide the information to guide these treatment decisions. In 2008, the Prostate Cancer Working Group 2 consensus criteria for early-phase clinical trials redefined clinical trial end points as first, to control, relieve, or eliminate disease manifestations present when treatment is started and second, to prevent or delay future disease manifestations. Disease manifestations include prostate-specific antigen (PSA), soft-tissue disease (nodes and/or viscera), bone disease (most common site of spread), and symptoms. Recent US Food and Drug Administration (FDA) approvals for CRPC therapies have been based on the prevent/delay end points that reflect unequivocal benefit to a patient: prolongation of life or reduction in skeletal-related events (SREs). For the practicing oncologist, the control/relieve/eliminate outcomes should serve primarily to inform the decision of whether to continue therapy. In this review, we consider individual end points such as PSA, imaging, and patient-reported outcomes in the context of the control/relieve/eliminate and prevent/delay framework. We address the time-to-event end points of metastasis prevention, SRE, time to progression, and overall survival in the context of regulatory approvals. We also discuss circulating tumor cells measured with the CellSearch assay, recently cleared by the FDA for monitoring CRPC.

scholarly journals Phase II Trial of Bevacizumab, Thalidomide, Docetaxel, and Prednisone in Patients With Metastatic Castration-Resistant Prostate Cancer

2010 ◽  
Vol 28 (12) ◽  
pp. 2070-2076 ◽  
Author(s):  
Yang-Min Ning ◽  
James L. Gulley ◽  
Philip M. Arlen ◽  
Sukyung Woo ◽  
Seth M. Steinberg ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Overall Survival ◽  
Combination Therapy ◽  
Phase Ii ◽  
Specific Antigen ◽  
Clinical Activity ◽  
Castration Resistant Prostate Cancer ◽  
Time To Progression ◽  
Castration Resistant ◽  
Phase Ii Studies

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.

scholarly journals A phase II single-arm study of pembrolizumab with enzalutamide in men with metastatic castration-resistant prostate cancer progressing on enzalutamide alone

2020 ◽  
Vol 8 (2) ◽  
pp. e000642 ◽  
Author(s):  
Julie N Graff ◽  
Tomasz M Beer ◽  
Joshi J Alumkal ◽  
Rachel E Slottke ◽  
William L Redmond ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Dna Repair ◽  
Phase Ii ◽  
Checkpoint Inhibitors ◽  
Objective Response ◽  
Specific Antigen ◽  
Subsequent Treatment ◽  
Castration Resistant Prostate Cancer ◽  
Entire Cohort ◽  
Castration Resistant

BackgroundCheckpoint inhibitors can induce profound anticancer responses, but programmed cell death protein-1 (PD-1) inhibition monotherapy has shown minimal activity in prostate cancer. A published report showed that men with prostate cancer who were resistant to the second-generation androgen receptor inhibitor enzalutamide had increased programmed death-ligand 1 (PD-L1) expression on circulating antigen-presenting cells. We hypothesized that the addition of PD-1 inhibition in these patients could induce a meaningful cancer response.MethodsWe evaluated enzalutamide plus the PD-1 inhibitor pembrolizumab in a single-arm phase II study of 28 men with metastatic castration-resistant prostate cancer (mprogressing on enzalutamide alone. Pembrolizumab 200 mg intravenous was given every 3 weeks for four doses with enzalutamide. The primary endpoint was prostate-specific antigen (PSA) decline of ≥50%. Secondary endpoints were objective response, PSA progression-free survival (PFS), time to subsequent treatment, and time to death. Baseline tumor biopsies were obtained when feasible, and samples were sequenced and evaluated for the expression of PD-L1, microsatellite instability (MSI), mutational and neoepitope burdens.ResultsFive (18%) of 28 patients had a PSA decline of ≥50%. Three (25%) of 12 patients with measurable disease at baseline achieved an objective response. Of the five responders, two continue with PSA and radiographic response after 39.3 and 37.8 months. For the entire cohort, median follow-up was 37 months, and median PSA PFS time was 3.8 months (95% CI: 2.8 to 9.9 months). Time to subsequent treatment was 7.21 months (95% CI: 5.1 to 11.1 months). Median overall survival for all patients was 21.9 months (95% CI: 14.7 to 28 .4 months), versus 41.7 months (95% CI: 22.16 to not reached (NR)) in the responders. Of the three responders with baseline biopsies, one had MSI high disease with mutations consistent with DNA-repair defects. None had detectable PD-L1 expression.ConclusionsPembrolizumab has activity in mCRPC when added to enzalutamide. Responses were deep and durable and did not require tumor PD-L1 expression or DNA-repair defects.Trial registration numberclinicaltrials.gov (NCT02312557).

Clinical activity of abiraterone acetate in patients with castration-resistant prostate cancer who received prior ketoconazole therapy.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 99-99 ◽  
Author(s):  
Bo Zhao ◽  
Jorge A. Garcia ◽  
Timothy D. Gilligan ◽  
Brian I. Rini ◽  
Robert Dreicer
Keyword(s):  
Prostate Cancer ◽  
Specific Antigen ◽  
Underlying Mechanism ◽  
Abiraterone Acetate ◽  
Clinical Activity ◽  
Drug Discontinuation ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Psa Response ◽  
Psa Progression

99 Background: Studies have shown activity of Abiraterone acetate (AA) in patients (pts) with castration-resistant prostate cancer (CRPC) who have received prior ketoconazole. Prostate-specific antigen (PSA) response to AA in relation to previous PSA response to ketoconazole was investigated. Methods: A retrospective analysis was conducted to determine the clinical activity of AA in men with CRPC who have received prior ketoconazole therapy at our institution. Time to PSA progression (PSA TTP) was defined by PCWG2 criteria, a PSA reduction of 50% or more was considered as PSA response. Results: Thirty four pts were identified. Nineteen pts (56%) had previous PSA responses on ketoconazole, with a median PSA TTP of 11 months (95% confidence interval [CI] 6.8-19.9). Subsequently, 11 of 34 (33%) of pts achieved a PSA response on AA, with a median PSA TTP of 6 months (95% CI 4.9-9.5). Among the 19 pts having a PSA response on ketoconazole, only four (21%) pts subsequently had PSA response to AA. Two of these pts had transient PSA response with PSA TTP less than 3 months on kKetoconazole, one patient discontinued Ketoconazole due to side effects, one patient had intermittent non-castrate testosterone levels. In contrast, 7 of 15 (46.7%) pts without prior PSA response to ketoconazole subsequently achieved PSA response on AA (p=0.11). Of note, PSA reduction of less than 50% on AA was observed in 9 of 34 pts (26%), which was associated with a longer median PSA TTP compared to pts who had PSA-progressive disease (5.9 months [95% CI 3.5-7.3] vs.1.5 months [95% CI 1.0-3.5], p=0.028). Five of these nine patients had a prior PSA response to ketoconazole but required drug discontinuation for reasons other than disease progression. Conclusions: PSA response to prior ketoconazole therapy is associated with lower PSA response rate to subsequent AA. The observation suggests that there is a biologically distinct subset of patients who are ketoconazole-resistant but abiraterone-sensitive, the underlying mechanism needs to be further investigated.

Association of co-occurring gene alterations and clinical activity of rucaparib in patients with BRCA1 or BRCA2 mutated (BRCA+) metastatic castration-resistant prostate cancer (mCRPC).

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 80-80
Author(s):  
Wassim Abida ◽  
Akash Patnaik ◽  
David Campbell ◽  
Jeremy David Shapiro ◽  
Alan Haruo Bryce ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Response Rate ◽  
Objective Response ◽  
Specific Antigen ◽  
Response Rates ◽  
Clinical Activity ◽  
Plasma Samples ◽  
Tp53 Mutations ◽  
Measurable Disease ◽  
Psa Response

80 Background: The poly(ADP-ribose) polymerase (PARP) inhibitor rucaparib was granted accelerated approval by the US Food and Drug Administration for patients with BRCA+ mCRPC based on results from the phase 2 TRITON2 study (NCT02952534). The TP53 tumor suppressor gene is among the most frequently mutated genes in human cancers, including mCRPC, and alterations in TP53, PTEN, and RB1 are associated with poor prognosis in patients with prostate cancer and other tumor types. We present data on co-occurring alterations in patients with BRCA+ mCRPC treated with rucaparib in TRITON2. Methods: Patients had progressed on 1–2 lines of androgen receptor-directed therapy and 1 taxane-based chemotherapy and were treated with rucaparib 600 mg BID. Tissue and/or cell-free DNA extracted from plasma samples were profiled comprehensively for genomic alterations using Foundation Medicine, Inc., next-generation sequencing assays. Objective response rate (ORR) was assessed per modified Response Evaluation Criteria in Solid Tumors and Prostate Cancer Working Group 3 criteria by independent radiologic review of patients with measurable disease. Prostate-specific antigen (PSA) response rate (≥50% decrease from baseline) was assessed in all patients. Results: Tissue and/or plasma samples were available for 114/115 patients with BRCA+ mCRPC (visit cutoff date: Dec. 23, 2019). Among patients with BRCA+ mCRPC who had samples available for comprehensive genomic profiling, 36.8% (42/114) had a co-occurring alteration in TP53. Deleterious alterations in PTEN were observed in 34.2% (39/114) of patients, 44% (17/39) of which were homozygous deletions of PTEN. RB1 loss was observed in 12.3% (14/114) of patients and was seen more frequently in patients with measurable disease (18.0%, 11/61) than in patients with non-measurable disease (5.7%, 3/53). Although patients with and without TP53 mutations had generally similar baseline demographics and disease characteristics, visceral disease was more prevalent in patients with TP53 mutations (54.8%; 23/42) than in those without them (29.2%; 21/72). Similar ORR and PSA response rates were seen in patients with BRCA+ mCRPC with or without TP53 mutation, with a non-significant trend towards lower response rates in patients with co-occurring TP53 alterations. Conclusions: Results from TRITON2 showed antitumor activity for rucaparib in patients with BRCA+ mCRPC associated with or without co-occurring alterations in TP53. Demographics and additional efficacy analyses in genomic subgroups with co-occurring alterations in TP53, PTEN, and RB1 will be reported. Clinical trial information: NCT02952534. [Table: see text]

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