Page 1 - CUA2018 Abstracts - Oncology-Prostate

2018 CUA AbstrACts

Podium Session 1: Prostate Cancer

June 24, 2018; 1030–1130

POD–1.1 Introduction: Nadir testosterone values following initiation of androgen–
PROSPER: A phase 3, randomized, double–blind, placebo– deprivation therapy (ADT) have been shown in several studies to be prog-
controlled study of enzalutamide in men with non–metastatic nostic for outcome, including time to castration–resistant prostate cancer
1
castration–resistant prostate cancer (TTCRPC) and cancer–specific survival (CSS). The biological reasons for
1
5
4
2
3
Fred Saad , Maha Hussain , Karim Fizazi , Per Rathenborg , Neal Shore , this remain unclear. Using cryopreserved serum from the PR.7 trial of inter-
6
7
Eren Demirhan , Katharina Modelska , De Phung , Andrew Krivoshik , Cora mittent vs. continuous ADT, we sought to assess the role of related sex
7
6
Sternberg 8 steroids as prognostic biomarkers in men on ADT for recurrent cancer
1 Centre Hospitalier de l’Université de Montréal, Montreal, QC, Canada; post–radiotherapy.
2 Northwestern University, Chicago, IL, United States; Institut Gustave Methods: Canadian patients in the PR.7 trial randomized to the continuous
3
Roussy, University of Paris Sud, Villejuif, France; Herlev Hospital, Herlev, arm were included. Patients were excluded if they did not receive ADT
4
Denmark; Carolina Urologic Research Center, Myrtle Beach, SC, United (n=3), had <2 years of followup (n=2), received exogenous estrogens or
5
7
States; Pfizer Inc., San Francisco, CA, United States; Astellas Pharma Inc., glucocorticoids (n=5), or samples were unavailable (n=36). Liquid chroma-
6
Northbrook, IL, United States; San Camillo and Forlanini Hospitals, Rome, tography–tandem mass spectrometry (LC–MS/MS) was performed using a
8
Italy validated method to simultaneously analyze 10 steroids: dehydroepiandros-
Study Groups: This study was funded by Astellas Pharma Inc. and Pfizer terone (DHEA), testosterone (T), dihydrotestosterone (DHT), androst–5–
Inc., the co–developers of enzalutamide. Editorial assistance provided by ene–β,17β–diol (5–diol), androstenedione (4–dione), androsterone (AD),
Caitlin Watson of Complete HealthVizion, funded by study sponsors. estrone (E ), estradiol (E ), progesterone, and androstane–3β; 17β–diol
2
1
Introduction: Men with non–metastatic castration–resistant prostate cancer (3βdiol). Descriptive statistics and correlation analyses were performed,
(M0 CRPC) and rapidly rising prostate–specific antigen (PSA) are at high with longitudinal changes categorized as stable, increasing, decreasing, or
risk of developing metastatic (M1) CRPC. Enzalutamide (ENZA) improves mixed. The prognostic value of individual steroid tertiles, as well as E :E ,
1
2
overall survival (OS) and radiographic progression–free survival in men E :T and DHT:T ratios were assessed by Kaplan–Meier analysis and Cox
2
with M1 CRPC. We hypothesized that ENZA will improve metastasis–free proportional hazards adjusted for baseline clinical variables. Outcomes
survival (MFS) in men with M0 CRPC. assessed were TTCRPC, CSS, and overall survival (OS).
Methods: Eligible men with M0 CRPC, PSA doubling time ≤10 months Results: A total of 219 patients were included in the analysis who had a
and PSA ≥2 ng/mL at screening continued androgen–deprivation therapy cryopreserved serum available within two years of randomization, with 104
(ADT) and were randomized 2:1 to ENZA 160 mg or placebo. The primary patients having two subsequent annual samples available for measurement.
endpoint was MFS. Secondary endpoints included time to PSA progression, Values for DHT, T, 4–dione, AD, DHEA, and 5–diol tended to be correlated
time to first use of new antineoplastic therapy, OS, and safety. among samples. Lower DHEA and AD values were significant associated
Results: In 1401 men, ENZA significantly prolonged median MFS (36.6 vs. with older age, as was lower DHEA and DHT values with poorer perfor-
14.7 months; p<0.0001), median time to first use of new antineoplastic mance status. Higher tertiles of E and E were associated with sooner
1
2
therapy (39.6 vs. 17.7 months p<0.0001), and median time to PSA pro- TTCRP (log–rank, p=0.03, p=0.02, respectively). Similar trends were seen
gression (37.2 vs. 3.9 months; p<0.0001]) compared to placebo (Table 1; for 4–dione in predicting TTCRPC (log–rank, p=0.07). Upon adjustment, the
available at https://cua.guide/). In the first interim analysis of OS, there highest tertile of E :T had increased hazard ratios (HR) for CSS (HR 2.36;
2
was a trend in favour of ENZA (hazard ratio [HR] 0.80; p=0.1519). Median 95% confidence interval [CI] 0.90–6.21; p=0.08) and TTCRPC (HR 1.70;
duration of treatment was 18.4 vs. 11.1 months for ENZA vs. placebo. 95% CI 0.90–3.23; p=0.10) relative to the lowest tertile. In an analysis
Adverse events (AEs) were higher with ENZA vs. placebo (any grade: 87% of the subset of patients with longitudinal values, increasing levels of AD
vs. 77%; grade ≥3: 31% vs. 23%; serious: 24% vs. 18%); 10% of patients over time were associated with poorer CSS and OS (log–rank p=0.04 and
discontinued treatment due to AE with with ENZA vs. 8% with placebo. p<0.01, respectively). On adjusted analysis, increasing AD levels had a
Conclusions: In men with M0 CRPC and rapidly rising PSA, ENZA treat- HR for CSS of 3.43 (95% CI 0.63–18.67; p=0.15) and a HR for OS of 4.75
ment resulted in a clinically meaningful and statistically significant 71% (95% CI 1.49–15.17; p<0.01). Limitations include the number of events
reduction in the risk of developing M1 CRPC. AEs were consistent with the for some groups.
established safety profile of ENZA. Conclusions: Increased levels of E , E , and AD during ADT correlated with
1
2
adverse TTCRPC and CSS. Serum sex steroids, including both androgens
and estrogens, may act as prognostic biomarkers in men receiving ADT
POD–1.2 for recurrent prostate cancer. Further investigation is warranted to support
Serum sex steroids as prognostic biomarkers in patients receiving clinical use.
androgen–deprivation therapy for recurrent prostate cancer post– Reference:
radiotherapy: A post–hoc analysis of the PR.7 trial 1. Klotz L, Breau RH, Collins LL, et al. Maximal testosterone suppres-
1
1
2
3
Paul Toren , Azik Hoffman , Keyue Ding , France–Hélène Joncas , Frédéric sion in the management of recurrent and metastatic prostate cancer.
1
1
Pouliot , Yves Fradet , Eric Lévesque , Chantal Guillemette , Laurence Klotz 2 Can Urol Assoc J 2017;11:16–23. https://doi.org/10.5489/cuaj.4303
4
4
1 Department of Surgery, Division of Urology, Université Laval, Quebec City,
QC, Canada; Department of Surgery, Division of Urology, University of
2
Toronto, Toronto, ON, Canada; Canadian Cancer Trials Group, Kingston,
3
ON, Canada; Faculty of Pharmacy, Université Laval, Quebec City, QC,
4
Canada
Study Groups: Study funded by a Prostate Cancer Canada Movember
Discovery Grant.
CUAJ • June 2018 • Volume 12(6Suppl2) S51
© 2018 Canadian Urological Association