Development of a predictive model of PSA response to a switch from prednisone to dexamethasone in metastatic castrate-resistant prostate cancer patients biochemically progressing on abiraterone.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 88-88
Author(s):  
Reeta Barua ◽  
Cameron Phillips ◽  
Vanessa Sarah Arciero ◽  
Liying Zhang ◽  
Amanda Rahmadian ◽  
...  

88 Background: Abiraterone acetate (AA) is typically administered with prednisone (P) to prevent symptoms of mineralocorticoid excess in patients with metastatic castrate resistant prostate cancer (mCRPC). After biochemical progression on AA + P, there is a sizeable subset of patients who have a renewed PSA response when switched from P to dexamethasone (D). The purpose of this study was to delineate clinical and pathologic factors that are predictive of a PSA response to such a steroid switch. Methods: We performed a retrospective analysis of 87 patients switched from AA+P to AA+D at Sunnybrook Odette Cancer Centre (Toronto, ON, Canada) between December 2012 and September 2018. Information on demographics, disease characteristics, previous treatments and performance status was collected. Response to the P to D switch maneuver was defined as a decrease in PSA by ≥30% within 12 weeks of the intervention (PSA30). Univariate logistic regression analyses were used to create a prediction model for each covariate tested, and R2 was applied for the measure of fit.Using multivariable logistic regression analysis and a backward stepwise selection procedure, we sought to identify patient and/or disease characteristics associated with a PSA30. Results: 38/87 patients (44%) experienced a PSA30. Univariate analysis showed that a favourable ECOG performance status, no prior docetaxel and no prior enzalutamide use were associated with a PSA30. On multivariable logistic regression analysis both favourable ECOG performance status and no prior enzalutamide use remained associated with a PSA30 (Table). Conclusions: A considerable proportionof patients with mCRPC who biochemically progress on AA+P have a renewed PSA response when changed to AA+D.Patients with a favourable ECOG performance status and no prior enzalutamide use are more likely to respond to such a steroid switch. Further prospective studies are needed to validate our findings.[Table: see text]

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15174-e15174
Author(s):  
Bertha E. Sanchez ◽  
Nilesh Gupta ◽  
Meredith Mahan ◽  
Evelyn R Barrack ◽  
Prem-veer Reddy ◽  
...  

e15174 Background: Docetaxel is a tubulin-targeting cytotoxic that remains first-line therapy in metastatic castrate-resistant prostate cancer (mCRPC) patients (pts) even though half of pts are reported to be non-responders. A predictive marker to identify those who will benefit from docetaxel-therapy will assist clinical decision making. High βIII-tubulin (TUBB3) expression has previously been reported to correlate with lack of response to taxanes in other cancers. We evaluated TUBB3 expression as a predictor of docetaxel-resistance in mCRPC. Methods: mCRPC pts treated with at least 3 cycles of docetaxel between 1990 and 2011 were identified retrospectively. TUBB3 immunostaining was performed on archival formalin-fixed, paraffin-embedded tissue. Stain intensity was scored from 0 to 3; 2 and 3 were interpreted as positive. Rates of PSA response were compared between pts with positive (+) and negative (-) TUBB3 expression. Two definitions of PSA response were evaluated (any PSA decline and at least 50% decline). Overall survival (OS) distribution between TUBB3+ and TUBB3- pts was estimated by the Kaplan-Meier method. Results: Of 73 pts, 26 (35%) expressed TUBB3. At diagnosis, the mean age was 65.7 years and the median Gleason score was 8. At the time of docetaxel therapy, the mean age was 71.2 years, the median PSA level was 70.9 (range, 0.2-5253) and 76% had ECOG performance status ≤1. The median number of docetaxel cycles was 7 (range, 3-18). The total dose of docetaxel was not different between groups (p=0.705). The median OS was 19.2 mo. TUBB3 expression was not correlated with any clinical or pathological characteristic (age, Gleason score, stage, ECOG, PSA, LDH, alkaline phosphatase, hemoglobin, visceral disease or chemotherapy before docetaxel). 65% of TUBB3+ pts had any PSA decline compared to 89% of pts with TUBB3- (p=0.0267). 52% of TUBB3+ pts had a PSA decline of ≥ 50% compared to 70% of TUBB3- pts (p=0.0144). Median OS for TUBB3+ pts was 16.8 mo compared to 20.4 mo in TUBB3- pts (p=0.039). Conclusions: High TUBB3 expression was associated with shorter OS and lower PSA response rates in mCRPC pts treated with docetaxel. These findings need to be validated prospectively.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16086-e16086
Author(s):  
T. L. Gillison ◽  
L. J. Appleman ◽  
D. M. Friedland ◽  
T. L. Evans ◽  
P. N. Lara ◽  
...  

e16086 Background: Docetaxel (D) IV every 21 days, is the only cytotoxic agent that prolongs survival in men with castrate resistant prostate cancer (CRPC). Imatinib (I), a tyrosine kinase inhibitor, modulates PDGFR-ß in tumor vasculature. Based on phase I data from our institution, we hypothesized that D plus I would prolong time to progression (TTP) in patients (pts) with CRPC. Methods: Subjects with CRPC received D 60 mg/m2 IV every 21 days plus I 400 mg PO daily. After 10 pts, the study treatment was modified due to toxicity so that pts received I 400 mg on 10 of 21 days/cycle. The primary endpoint was TTP. Secondary endpoints were rate of PSA response and overall survival (OS). The sample size of 43 pts was designed to provide 90% power to detect an increase in TTP from 5 to 8 months. Results: 43 pts enrolled from 8/05 to 9/08. Age at enrollment ranged from 54–86 years (median 69 years). 14 pts received <1 cycle of D plus I and were unevaluable: 10 had significant toxicity, 4 due to non-treatment related reasons. Primary toxicities were hematologic: 21% G4 neutropenia, 5% G4 anemia, and no G4 thrombocytopenia. Fatigue, nausea, diarrhea, and electrolyte abnormalities were common, but <2 cases each of G3-G4 toxicity occurred. 1 case of G5 non-neutropenic sepsis occurred. 29 pts received >2 cycles of chemotherapy (mean 4.6). 12 pts had PR (41.4%), 9 had SD (31.0%), and 8 had no response (27.6%) by PSA. No objective responses were seen by CT imaging among 10 pts with measurable disease. 3 pts remain on trial. For evaluable pts, overall median TTP was 6.4 months (95% CL: 4.8, 8.4 months) compared with TTP of 5 months seen in previous trials. 23 (79%) pts had PSA progression, 3 pts died before progression, and 3 pts remain on trial. For all evaluable pts who had PR or SD by PSA (N = 21), median TTP was 7.1 months (95% CL: 5.5, 9.1 months). Median OS was 23.1 months (95% CL: 11.61 months, NR), compared with 18.9 months for GC Conclusions: Docetaxel on day 1 plus imatinib 10 days of each 21-day cycle resulted in meaningful improvement in TTP in the subset of pts who showed a response. Toxicity precludes its use in the general population, although its role in select pts with good performance status needs to be explored. [Table: see text]


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 188-188 ◽  
Author(s):  
David Thomson ◽  
Natalie Charnley ◽  
Omi Parikh

188 Background: Abiraterone or enzalutamide are licensed for use post-docetaxel in metastatic castrate resistant prostate cancer (mCRPC). Both target the androgen receptor signalling pathway. There is little information describing their sequential use. Methods: Patients with mCRPC who had failed treatment with docetaxel and abiraterone received enzalutamide as part of an expanded access program. Patients were reviewed four weekly and post-treatment PSA used to determine efficacy. Results: Twenty three patients, median age 76 (range, 65 to 82), performance status of 1 (15/23) or 2 (8/23) with mCRPC (22/23 bone and 4/23 visceral disease) were enrolled. All had received prior docetaxel and abiraterone as well as cabazitaxel (35%), dexamethasone (30%), and stillboestrol (52%). Median biochemical progression free survival (bPFS) was 11.9 weeks. Nine (39%) patients showed sensitivity to enzalutamide, defined as a greater than 50% reduction in PSA. There was a correlation between PSA response to abiraterone and enzalutamide (R=0.45, p=0.03). In 10 out of 23 and 13 out of 23 patients who were sensitive and insensitive to abiraterone, 60% and 23% had a great than 50% reduction in PSA, respectively. There was a trend to improved bPFS in those sensitive to abiraterone (15.7 vs. 11.4 weeks, p=0.40) and in those who showed any PSA response to abiraterone (15.9 vs. 5.3 weeks, p=0.06). Conclusions: Enzalutamide has activity following failure of docetaxel and abiraterone in mCRPC. The effectiveness is more pronounced in those who have responded to abiraterone.


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 177-177
Author(s):  
Hanan Goldberg ◽  
Ally Hoffman ◽  
Teck Sing Woon ◽  
Zachary William Abraham Klaassen ◽  
Thenappan Chandrasekar ◽  
...  

177 Background: PSA produced from prostate cancer (PC) cells escapes proteolytic processing, resulting in a more complexed PSA and a lower %fPSA. Higher %fpsa correlates with lower PC risk. However, the role of fPSA in biochemical recurrence (BCR) after radical prostatectomy (RP) is unknown. Methods: All patients who had BCR after RP and at least one fPSA test, were included. Patients were stratified according to the %fPSA cut-off of 0.15. Multivariable logistic regression analysis was performed to predict covariates associated with a higher %fPSA. Results: A total of 81 men with BCR were found (Table 1). Interestingly, 20% (group 1) vs. 60% (groups 2) become castrate resistant (CRPC), p<0.0001 and the time to reach CRPC state was much shorter in group 2 (33.5 months) vs. group 1 (57.9 months), p=0.05. Additionally, 60% of group 2 patients vs. 32.5% of group 1 patients developed metastasis, p=0.014. Lastly, median survival of 193 months for group 2 patients with no median survival for group 1, Log Rank test p=0.023. Multivariable logistic regression analysis demonstrated that secondary Gleason score of 5 (compared to 3) and %fPSA>0.15 predicted CRPC status (OR 11.63, CI 95% 1.38-97.4, p=0.024, OR 7.99, CI 95% 2-31.95, p=0.003, respectively). Conclusions: %fPSA>0.15 in the setting of BCR confers a more aggressive disease, manifesting in a faster development of CRPC, metastasis and death. Our findings suggest a reversal in the significance of % fPSA values in BCR patients, and should be validated in larger cohorts. [Table: see text]


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. TPS394-TPS394 ◽  
Author(s):  
Chong-xian Pan ◽  
Primo Lara ◽  
Christopher P. Evans ◽  
Mamta Parikh ◽  
Ralph de Vere White ◽  
...  

TPS394 Background: Enzalutamide (Enza) and abiraterone (Abi) are commonly used to treat CRPC. Resistance is the most common cause of treatment failure. We discovered that a critical steroidogenic enzyme AKR1C3 was significantly elevated and contributed to intratumoral androgen synthesis in Enza-resistant prostate cancer cells and tumors. Overexpression of AKR1C3 induced androgen receptor variant 7 (AR-V7) expression, while inhibition of AKR1C3 downregulated AR-V7. We then discovered that indomethacin (Indo) inhibited AKR1C3 activation and sensitized resistant CRPC cells to Enza and Abi. One patient accidentally took Indo and achieved biochemical as well as radiological response of his prostate cancer. These findings prompted us to design a clinical trial to test the combination of Indo with Enza for the treatment of CRPC and to study the underlying mechanisms of action and resistance. Methods: This investigator-initiated single-arm Phase Ib/II trial enrolls patients with progressive CRPC after Abi, adequate vital organ function, ECOG performance status 0-2, and serum testosterone < 50 ng/dl. Major exclusion criteria include prior Enza treatment, brain metastasis and history of seizure. In the Phase Ib cohort, patients receive Enza 160 mg po qd and Indo 50 mg po tid to determine toxicity. The Phase II expansion will enroll 26 patients with 21 evaluable patients. This sample size provides 90% power to detect, at the 0.05 level (1-sided), the difference between a PSA response rate of 50% expected with the study treatment and a historical control of 20% with Enza alone. Co-primary endpoints are safety and PSA response of ≥50% decrease. Secondary endpoints include overall response rate as determined by the Prostate Cancer Working Group 2 criteria (PCWG2), progression-free survival and overall survival. Molecular correlative studies are exploratory endpoints. Serum and intratumoral androgen levels, full-length AR, AR-V7 and AKR1C3 will be measured to assess the effect of the combination therapy. To date, 4 patients have been enrolled to the trial (clinicaltrials.gov Identifier No: NCT02935205; this trial is funded by DoD Prostate Cancer Research Program IMPACT award). Clinical trial information: NCT02935205.


2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 81-81
Author(s):  
Michael Rowe ◽  
Ayesha Hidayat ◽  
Stuart Walter ◽  
Adam Pollard ◽  
Timothy Norris ◽  
...  

81 Background: Intermittent hormone manipulation in castrate-sensitive prostate cancer can improve quality of life whilst maintaining comparable disease outcomes with continuous scheduling. Enzalutamide is effective in metastatic castrate-resistant prostate cancer (mCRPC) treatment but can have significant side-effects. We conducted a retrospective analysis of patients treated with intermittent enzalutamide compared with continuous dosing. Methods: Patients prescribed enzalutamide for mCRPC at Royal Cornwall Hospital from September 2011 to February 2018 were included. Data was collected from electronic medical records, selecting patients with at least a 1 month treatment break. Kaplan-Meier analysis of overall survival from enzalutamide start (OS), time to PSA failure (TTF) and total enzalutamide treatment time (TTT) was calculated for intermittent and continuous responders (>50% PSA drop), assigned significance level of 0.05. Results: 243 patients received enzalutamide, 110 (45%) were continuous responders and 29 (12%) had intermittent dosing. All patients treated intermittently had a PSA response prior to first treatment break, which was most commonly for fatigue (60%). 25% were still receiving enzalutamide. Median number of breaks was 1 (range 1-7), time on treatment was 70% and time to first break was 5 months. The intermittent group had significantly improved OS with median not reached, median OS for continuous responders was 19 months (HR 2.39, 95% CI 1.53-3.76, p=0.002). The intermittent group had prolonged TTF (median 13 vs 6 months, p=0.001) and TTT (median 30 vs 10 months, p=0.0003). Conclusions: Intermittent dosing of enzalutamide in these mCRPC patients does not adversely impact OS, increasing time patients remain on treatment. However, this was a small, retrospective, single-centre study; prospective trials are necessary to clarify the role of intermittent enzalutamide.[Table: see text]


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 256-256
Author(s):  
Victoria J. Sinibaldi ◽  
Michal Dadon-Nachum ◽  
Maya Gottfried ◽  
Natalie Maimon ◽  
Zamir Dovrish ◽  
...  

256 Background: Standard treatment options for patients (pts) with metastatic castrate-resistant prostate cancer (mCRPC) include docetaxel based chemotherapy, abiraterone, and radium 223. Octogenarian pts (age 80 and older) are often considered to be unfit for chemotherapy. However, recommendations for their management is limited by the paucity of clinical trials data in this population. In countries where abiraterone in the pre-chemotherapy setting has not been approved yet, or for pts who can’t afford it, the CYP 17 inhibitor ketoconazole is used as an alternative advanced hormonal tx. We aimed to study baseline characteristics and outcome of octogenarian versus young (age 60 or younger) pts with mCRPC treated with ketoconazole. Methods: We performed an international multicenter retrospective study of pts with mCRPC, who were treated with ketoconazole at four centers across two different countries. We compared baseline characteristics and outcome of octogenarian versus young pts. The effect of very old age on prostate-specific antigen (PSA) response, progression free survival (PFS), and overall survival (OS), was tested with adjustment of other known confounding risk factors using a chi-square test and partial likelihood test from Cox model. Results: Between 2004 and 2013, 35 octogenarians (median age 83) and 33 young pts with (median age 57) mCRPC were treated with ketoconazole. The groups were balanced regarding the following baseline clinicopathologic characteristics: extent of disease (limited-axial skeleton and/or nodal versus extensive-appendicular skeleton and/or visceral), combined gleason score, pre-treatment risk category (Keizman, Oncologist 2012; based on pre-tx neutrophil to lymphocyte ratio/prostate-specific antigen doubling time, and prior response to ADT), pain intensity, ECOG performance status, alkaline phosphatase level, hemoglobin level, PSA level. In octogenarian versus young pts, PSA response (greater than or equal to 50% decline from baseline) was 40% versus 61% (OR 3.5, p=0.04), median PFS 7 versus 8 months (HR 0.91, p=0.44), and median OS 31 versus 36 months (HR 0.66, p=0.31). Conclusions: In very old vs young mCRPC patients treated with ketoconazole, PSA response was lower. Baseline clinicopathologic characteristics, PFS, and OS were not significantly different between the groups.


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 247-247 ◽  
Author(s):  
Mark Creamer Scholz ◽  
Richard Y. Lam ◽  
Jeffrey S. Turner ◽  
Khang N. Chau ◽  
Lauren K. Becker ◽  
...  

247 Background: Since FDA approval in 2011, abiraterone (Zytiga) has supplanted docetaxel as preferred first-line treatment for metastatic castrate-resistant prostate cancer. In August 2012 enzalutamide (Xtandi) was FDA-approved for the treatment of castrate-resistant prostate cancer after docetaxel (Taxotere). We performed a retrospective chart review at a large medical oncology clinic specializing in prostate cancer to determine the PSA response rates of enzalutamide administered to men who had previously progressed on both abiraterone and docetaxel. This report includes some patients who participated in the Astellas/Medivation-sponsored Early Access Program; however, it represents the author’s independent clinical experience. Methods: Enzalutamide was administered at a dose of 160 mg daily. Patients were subsequently followed with monthly physical examination, PSA and routine blood tests. No hepatotoxicity or seizures occurred. Men were considered evaluable for PSA response if they received enzalutamide for twelve weeks. A PSA decline of 30% from baseline after 12 weeks was defined as a response. A PSA increase of 30% from baseline within 12 weeks was defined as disease progression. Men with neither a 30% increase nor a 30% decline were classified as having stable disease. Results: 66 men were treated and 63 were evaluable for PSA response. Median age was 67. Median baseline PSA was 68.5. All participants had disease that had progressed on abiraterone. 55 men received previous docetaxel. 38 had received previous Provenge. Two men stopped before 12 weeks because of intolerable fatigue. One man died of progressive disease before 12 weeks. After a median follow up of 12.5 weeks, 18(29%) men met criteria for PSA response. 13(21%) men had stable disease and 32(51%) men had PSA progression. Conclusions: Enzalutamide has activity in a heavily pretreated population of men resistant to abiraterone and docetaxel.


2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 245-245
Author(s):  
Johan Chan ◽  
Whee Sze Ong ◽  
Quan Sing Ng ◽  
Chee-Keong Toh ◽  
Tanujaa Rajasekaran ◽  
...  

245 Background: The presence of AR-V7 in metastatic castrate resistant prostate cancer (mCRPC) men has been associated with worse outcome in men initiated on 2nd generation androgen receptor signalling inhibitors (ARSI) in the Caucasian population. A multinational study was conducted to investigate this in the Asian population. Methods: mCRPC patients were recruited prospectively across 5 countries. Blood samples were collected and processed from patients with progressive disease immediately before the initiation of a new treatment and at progression. AR-V7 detection were performed using 3 methods: CTC enrichment followed by automated immunofluorescent staining (Clearbridge [CB]), CTC enrichment followed by reverse-transcription PCR analysis (IBN), and the AdnaTest Prostate Cancer(Adna) platform for CTC analysis and detection. Only blood samples collected in Singapore underwent all 3 methods of detecting AR-V7. Comparison of AR-V7 prevalence using the 3 detection methods were done on patients with the AdnaTest platform as gold standard. We examined associations between AR-V7 status and PSA response rates, PSA progression free survival and overall survival(OS). Results: 102 patients were recruited. 72 patients had ARSi while 30 patients had chemotherapy. 66 patients were included for the comparison of AR-V7 detection methods. AR-V7 prevalence rate was 14.3% (95% CI 4.8-30.3), 21.6% (95% CI 12.9-32.7) and 33.7% (95% CI 24.6-43.8) based on Adna, CB and IBN respectively. Concordance between Adna and CB was 75% while Adna and IBN was 68%. AR-V7- patients had a trend towards higher PSA response, lower risk of PSA progression as compared to AR-V7+ patients. AR-V7- patients had a significantly lower risk of death as compared to AR-V7+ patients detected by Adna and IBN platforms but not the CB platform. The association between ARV7 status and outcomes did not vary when compared across treatment groups. Conclusions: AR-V7 positivity in Asian mCRPC patients is consistent with the data reported in Western populations with lower PSA response rates, PSA progression free survival and OS. This data suggest that ARV7 is more likely a prognostic than a predictive biomarker. Clinical trial information: 2015/2797.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 77-77
Author(s):  
Eric Zhuang ◽  
Edward M. Uchio ◽  
Michael B. Lilly ◽  
John P. Fruehauf

77 Background: Lycopene, the carotenoid responsible for the red colors seen in tomatoes, grapefruit, and other foods, has demonstrated synergism with docetaxel in prostate cancer cell culture and tumor xenograft models. This phase II study investigated the clinical activity and safety profile of docetaxel plus lycopene in advanced castrate resistant prostate cancer. Methods: Eligible patients had histologically confirmed adenocarcinoma of the prostate, two rising pre-study prostate specific antigen (PSA) values ≥ 1 ng/ml, and no prior treatment with any chemotherapy, biological therapy, or investigational drug. All patients initially received docetaxel 75mg/m2 every 21 days in combination with lycopene 30 mg orally once daily. The primary endpoint was PSA response rate, defined as the proportion of subjects achieving a ≥ 50% reduction in PSA at any point after starting therapy. Secondary endpoints included median time to PSA progression, duration of response (DOR), and overall survival (OS). Results: Fourteen patients were screened, and thirteen patients were initiated on protocol therapy. Median age was 77 years (range 55-90). Twelve patients (92%) had bone metastases. Four patients (30%) had bone and visceral metastases. The PSA response rate was 76.9% [95% confidence interval (CI), 46.2-94.9], comprising of ten PSA responses. Two patients had a best response of stable disease, yielding a disease control rate of 92% [95% CI, 57.2-98.2]. Median time to PSA progression was 8 months [95% CI, 3.5-8.7]. Median duration of response was 7.3 months [95% CI, 4.8-13.2]. On 5-year follow-up, median overall survival was 35.1 months [95% CI, 25.7-57.7]. The most frequently reported ( > 15%) non-hematologic adverse events included diarrhea, nausea, vomiting, peripheral neuropathy, weight loss, fatigue, onycholysis, and alopecia. One patient (7%) experienced febrile neutropenia. No patients experienced grade 3 or above anemia. Conclusions: The combination of docetaxel with lycopene led to improved PSA response rate and tolerability in patients with advanced castrate resistant prostate cancer. Docetaxel plus lycopene merits further research in this patient population. Clinical trial information: NCT01882985.


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