ASCO GU 2018: TPS383 - ARASENS: A Phase 3 Trial of Darolutamide in Combination with Docetaxel for Men with Metastatic Hormone-sensitive Prostate Cancer

San Francisco, CA (UroToday.com) The addition of either docetaxel or abiraterone acetate plus prednisone to androgen deprivation therapy (ADT) improves overall survival (OS) compared with ADT alone in men with metastatic hormone sensitive prostate cancer (mHSPC). It is hypothesized that other androgen receptor (AR)-targeted therapies could be combined with docetaxel for mHSPC. Darolutamide (ODM-201) is an investigational oral AR antagonist with a unique chemical structure with negligible blood-brain barrier penetration properties, that inhibits tumor growth by binding to AR and AR mutants (eg, W742L and F877L), with high affinity and specificity. In the phase 1/2 ARADES and phase 1 ARAFOR trials, darolutamide demonstrated antitumor activity and was well tolerated in men with metastatic castration-resistant prostate cancer (mCRPC). The ARASENS trial will take the next step and evaluate the addition of darolutamide to standard ADT and docetaxel in men with mHSPC.

Methods:

This is an international, randomized, double-blind, placebo-controlled phase 3 trial (NCT02799602) which is being conducted at over 300 sites in 23 countries. Approximately 1300 men with newly diagnosed mHSPC will be randomized 1:1 to darolutamide (600 mg orally twice daily) or matching placebo. All patients will receive standard ADT + docetaxel (6 cycles). Patients will be stratified by disease extent and alkaline phosphatase level. The trial design is shown in figure 1. Key inclusion criteria include: histologically or cytologically confirmed prostate cancer (PC) patients with documented metastases, who started ADT ± first-generation antiandrogen therapy ≤12 weeks before randomization, with an ECOG performance status 0-1. The primary end-point is OS. Secondary end points include time to mCRPC, initiation of subsequent anticancer therapy, symptomatic skeletal event (SSE)-free survival, time to first SSE, first opioid use, pain progression, and worsening of physical symptoms. The study will assess safety as well. ARASENS  is currently actively enrolling at over 280 sites across 23 countries (Figure 2). 

Figure 1: ARASENS trial design:

Arasens 1

Figure 2 – Participating countries in the ARASENS trial:
Arasens 2


Presented by: Matthew Raymond Smith, MD, PhD

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA