Why Is ESSA Pharma (EPIX) Stock Tanking Today - ESSA Pharma (NASDAQ:EPIX)

ESSA Pharma Inc EPIX announced that Johnson & Johnson's JNJ Janssen is suspending enrollment into the Phase 1 study of EPI-7386 with apalutamide or EPI-7386 with abiraterone acetate plus prednisone in metastatic castration-resistant prostate cancer (mCRPC) patients due to operational challenges.
Before suspending enrollment, Janssen treated three mCRPC patients (pre-chemotherapy) with the combination of EPI-7386 and apalutamide or abiraterone acetate plus prednisone for up to four months of therapy.
Related: ESSA Pharma's EPI-7386 Monotherapy / Combo Therapy Show Early Activity Against Prostate Cancer.
In all three patients, the combination of both investigational drug products was safe and well tolerated and yielded sufficient exposures of each drug product, indicative of pharmacological activity.
Initial clinical activity was observed in some patients, with two of three achieving a prostate-specific antigen (PSA) reduction of 90% within 12 weeks.
"We are in discussions with Janssen to supply abiraterone acetate and apalutamide for an ESSA-sponsored combination study and expect to provide more details in the coming months," said David Parkinson, CEO of ESSA.
Price Action: EPIX shares are down 22% at $3.44 on the last check Monday.

ESSA Pharma Shares Tank As Janssen Stops Enrollment In EPI-7386 Combo Prostate Cancer Trials