Abiraterone, Enzalutamide, or Apalutamide in Castrate-sensitive Prostate Cancer.

Condition(s) studied

Investigational drug(s) / intervention(s)

Abiraterone acetate: YONSA® (fine particle formulation abiraterone acetate), YONSA® 500 mg (four 125 mg tablets) or 625 mg (five 125 mg tablets) administered orally once daily in combination with methylprednisolone 4 mg administered orally twice daily + physician's choice GnRH agonist/antagonist \[unless the Veteran has had prior bilateral orchiectomy\]. Note that in the first four months the YONSA® dose should not exceed 500 mg administered orally once daily. ZYTIGA® (abiraterone acetate) or generic ZYTIGA 1000 mg (four 250 mg uncoated tablets or two 500 mg film-coasted tablets) administered orally once daily in combination with prednisone 5 mg administered orally once daily + physician's choice GnRH agonist/antagonist \[unless the Veteran has had prior bilateral orchiectomy\].

Apalutamide: Apalutamide (ERLEADA®), 240 mg (four 60 mg tablets) administered orally once daily + physician's choice GnRH agonist/antagonist \[unless the Veteran has had prior bilateral orchiectomy\].

Enzalutamide: Enzalutamide (XTANDI®), 160 mg (four 40 mg capsules) administered orally once daily + physician's choice GnRH agonist/antagonist \[unless the Veteran has had prior bilateral orchiectomy\].

Study summary

The investigators have used national VHA data to demonstrate real-world efficacy of abiraterone and enzalutamide in Veterans with mCRPC. In the real-world that is the VHA, the investigators have successfully estimated g values that accurately predict OS and the use of this metric in other settings should now be explored. In the egalitarian system that is the VHA the treatment of prostate cancer is excellent and uniform across the US. The choices made are clearly personalized, given not all men received all therapies and that younger Veterans were treated more aggressively.

But with survivals that rival those in registration trials that enroll optimally fit individuals usually not encumbered by the co-morbidities that afflict many Veterans, the outcomes are testimony to the fact that for this common malady of older Veterans with whom VA physicians have broad experience the care administered is unsurpassed. Importantly this care at least as regards Veterans with mCRPC demonstrates that given equal access to health care, all men with prostate cancer fare comparably well. As our sophistication in categorizing cancers molecularly has increased this study will look to better examine any emerging differences across study participants.

Eligibility

Primary outcome measure(s)

• Tumor growth rate (g) — 2 years
  Tumor growth rate (g)
• Testosterone levels — 2 years
  Testosterone levels to assess testosterone suppression with androgen deprivation therapy (ADT).

Trial sites (12)