Dataset Information

Efficacy of Testosterone Suppression with Sustained-Release Triptorelin in Advanced Prostate Cancer.

ABSTRACT:

Introduction

Androgen deprivation therapy (ADT) is a mainstay of treatment against advanced prostate cancer (PC). As a treatment goal, suppression of plasma testosterone levels to <50 ng/dl has been established over decades. Evidence is growing though that suppression to even lower levels may add further clinical benefit. Therefore, we undertook a pooled retrospective analysis on the efficacy of 1-, 3-, and 6-month sustained-release (SR) formulations of the gonadotropin-releasing hormone (GnRH) agonist triptorelin to suppress serum testosterone concentrations beyond current standards.

Methods

Data of 920 male patients with PC enrolled in 9 prospective studies using testosterone serum concentrations as primary endpoint were pooled. Patients aged 42-96 years had to be eligible for ADT and to be either naïve to hormonal treatment or have undergone appropriate washout prior to enrolment. Patients were treated with triptorelin SR formulations for 2-12 months. Primary endpoints of this analysis were serum testosterone concentrations under treatment and success rates overall and per formulation, based on a testosterone target threshold of 20 ng/dl.

Results

After 1, 3, 6, 9, and 12 months of treatment, 79%, 92%, 93%, 90%, and 91% of patients reached testosterone levels <20 ng/dl, respectively. For the 1-, 3-, and 6-month formulations success rates ranged from 80-92%, from 83-93%, and from 65-97% with median (interquartile range) serum testosterone values of 2.9 (2.9-6.5), 5.0 (2.9-8.7), and 8.7 (5.8-14.1) ng/dl at study end, respectively.

Conclusion

In the large majority of patients, triptorelin SR formulations suppressed serum testosterone concentrations to even <20 ng/dl. Testosterone should be routinely monitored in PC patients on ADT although further studies on the clinical benefit of very low testosterone levels and the target concentrations are still warranted.

SUBMITTER: Breul J

PROVIDER: S-EPMC5331090 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectiveThe objective of the study is to evaluate whether low nadir testosterone during treatment with triptorelin pamoate, a luteinising hormone-releasing hormone (LHRH) agonist, is associated with improved clinical outcomes in patients with advanced prostate cancer using a retrospective analysis of clinical trial data.Patients and methodsData were pooled from three prospective, 9-12-month Phase III studies of triptorelin monotherapy in patients with advanced prostate cancer (including NCT00751790). The serum testosterone concentration suppression targets evaluated were <0.35 nmol/L (<10 ng/dl), <0.7 nmol/L (<20 ng/dl), <1.7 nmol/L (<50 ng/dl) and ≥1.7 nmol/L. Overall survival (OS) and disease-specific survival (DSS) by testosterone suppression group were assessed by Kaplan-Meier analysis, with log-rank test. The time frame for the primary analysis was Days 1-518 (median OS follow-up 254 days [range, 29-518 days]) and for the sensitivity analyses was Days 1-262. Supplementary analyses combined the ≥0.7- to <1.7-nmol/L and ≥1.7-nmol/L groups.ResultsThe sample size comprised 592 patients (most received triptorelin monotherapy; four reported concomitant androgen receptor-axis-targeted therapy). Nadir testosterones of <0.35, ≥0.35 to <0.7, ≥0.7 to <1.7 and ≥1.7 nmol/L were achieved by 96%, 3.2%, 0.34% and 0.17% of patients, respectively. Better OS with decreasing level of nadir testosterone was observed (p < 0.001) and this persisted after sensitivity/supplemental analyses (all p < 0.001). Differences in DSS with decreasing levels of nadir testosterone were not statistically significant in the primary analysis. Sensitivity/supplemental analysis showed better DSS with decreasing level of nadir testosterone (Days 1-262, p = 0.01; combined groups Days 1-518, p = 0.03; combined groups Days 1-262, p = 0.005).ConclusionLow nadir testosterone achieved during treatment with the LHRH agonist triptorelin was associated with improved OS and DSS in patients with advanced prostate cancer.