One of the inclusion criteria for the ZEN-3694 stand alone trial is:

"Prior progression on one or more androgen-receptor/androgen-synthesis inhibitor therapies (e.g. abiraterone, enzalutamide, apalutamide, TAK-700 and/or galeterone) by Prostate Cancer Working Group 2 (PCWG2) criteria."

For the ZEN-3694/enzalutamide combo trial, the inclusion criteria include:

"Dose Escalation only: Enzalutamide-naïve patients following prior progression on abiraterone by PCWG2 criteria and within 12 weeks of discontinuing abiraterone

Dose Confirmation Cohort A (DC-A) only: Currently receiving enzalutamide as most recent systemic therapy for mCRPC and have experienced PSA progression by PCWG2 criteria in the absence of radiographic and/or clinical progression. Patients may or may not have experienced prior progression on abiraterone.

Dose Confirmation Cohort B (DC-B) only: Enzalutamide-naïve patients following prior progression on abiraterone by PCWG2 criteria and within 12 weeks of discontinuing abiraterone"

Additional exclusion criteria for the combo trial include:

"Have previously received an investigational BET inhibitor (including previous participation in this study or Study ZEN003694-001)"