Abstract: PD37-01
Sources of Funding: This study was funded by an unrestricted grant from Ferring Labs to the CURC.

Introduction

Intermittent androgen deprivation therapy (IADT) is widely used for the treatment of men with prostate cancer. However, the optimal duration of ADT induction is unknown. Duration of IADT induction varies from 3 to 12 months in phase 2 and 3 studies, but different periods of induction have never been compared prospectively. This is the first report of a randomized CURC trial comparing the effect of 4 months vs 10 months of degarelix induction on the length of the off treatment interval in men with biochemical failure. _x000D_ Purpose: To assess the effect of 4 months vs. 10 months of degarelix therapy on the length of the off treatment interval in men receiving IADT for biochemical recurrence after definitive local therapy_x000D_

Methods

This was a prospective, open label, multicentre randomized trial. 101 patients were enrolled, and 91 were randomized. Eligible patients had biochemical recurrence after definitive local therapy with surgery or radiation, a rising PSA > 5.0, and no evidence of bone metastases. Patients were stratified for PSA < or > 10, and Gleason score <= or > 7. Patients were randomly allocated to 4 or 10 months of degarelix (240 mg loading dose, then 80 mg/mo). The primary end point was the time until PSA reached 5.0 during the off treatment interval. Secondary endpoints included the effect of 4 vs 10 months of induction ADT on PSA nadir, time to CRPC, testosterone recovery, BMD loss, and side effects.

Results

The median age was 75, and median PSA was 12. There was no difference between the 2 groups in median age, PSA, BMI, racial distribution, Gleason score, T stage, ECOG, smoking history, or baseline testosterone. _x000D_ The median time off treatment was 22.8 months. There was no difference between 4 and 10 months of ADT induction in the median off treatment interval (p=0.38) (Fig 1). PSA nadir < 0.1, but not baseline PSA predicted for a more prolonged off treatment duration. There was no difference in time to testosterone recovery between the groups (median 7.2 months). _x000D_

Conclusions

There was no difference in the duration of the off treatment interval between the 4 and 10 month degarelix groups. This study suggests that a shorter course of ADT induction offers comparable benefit with respect to the duration of the off treatment interval in men with PSA failure and may reduce the side effects and costs of ADT. _x000D_ _x000D_

Funding

This study was funded by an unrestricted grant from Ferring Labs to the CURC.