Overview

A class action lawsuit has been filed against ESSA Pharma Inc. (“ESSA” or the “Company”) and certain of the Company’s current senior executive officers alleging violations of the federal securities laws.  The Company’s common stock trades in an efficient market on the NASDAQ under the ticker symbol “EPIX.”

The ESSA class action lawsuit is brought on behalf of all persons and entities who purchased or otherwise acquired ESSA securities between December 12, 2023, and October 31, 2024, both dates inclusive (the “Class Period”).  Investors have until March 25, 2025 to seek appointment as lead plaintiff in the ESSA class action lawsuit.

ESSA is a clinical stage pharmaceutical company that focuses on the development of small molecule drugs for the treatment of prostate cancer.  At all relevant times the Company’s lead product candidate was masofaniten (EPI-7386), an investigational, oral, small molecule inhibitor of the androgen receptor, which plays a pivotal role in the development and progression of prostate cancer, especially castration-resistant prostate cancer (“CRPC”).  According to the lawsuit, ESSA was evaluating masofaniten in various clinical trials as a monotherapy and combination therapy for the treatment of prostate cancer.  These trials included, inter alia, EPI7386-CS-010 (the “M-E Combination Study”), a Phase 1/2 study of masofaniten in combination with enzalutamide compared with enzalutamide alone in patients with metastatic CRPC (“mCRPC”).

Phase 1 of the M-E Combination Study was a single-arm dose escalation study of masofaniten in combination with a fixed dose of enzalutamide.  Based on results from the Phase 1 portion of the M-E Combination Study, ESSA purportedly identified a recommended Phase 2 combination dose of masofaniten 600 mg twice daily combined with enzalutamide 160 mg once daily (“QD”).  Phase 2 of the M-E Combination Study compared this recommended combination dose with a 160 mg QD enzalutamide monotherapy, the standard of care for the intended patient population.  The primary endpoint of Phase 2 of the M-E Combination Study was the proportion of patients reaching “PSA90,” which refers to a deep prostate-specific antigen (“PSA”) response with a greater than or equal to 90% decline in PSA.  PSA90 is an important indicator of a patient’s response to prostate cancer treatment.

The ESSA class action lawsuit alleges that Defendants, throughout the Class Period, made materially false and misleading statements regarding the Company’s business, operations, and prospects.  Specifically, Defendants made false and/or misleading statements and/or failed to disclose that: (1) masofaniten in combination with enzalutamide had no clear efficacy benefit over enzalutamide alone; (2) accordingly, masofaniten in combination with enzalutamide was less effective in treating prostate cancer than Defendants had led investors to believe; (3) the M-E Combination Study was unlikely to meet its prespecified Phase 2 primary endpoint; (4) accordingly, Defendants had overstated masofaniten’s clinical, regulatory, and commercial prospects; and (5) as a result, Defendants’ public statements were materially false and misleading at all relevant times.

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If you purchased or otherwise acquired ESSA securities between December 12, 2023, and October 31, 2024, both dates inclusive, and you wish to serve as lead plaintiff in this lawsuit, we encourage you to submit your information to DiCello Levitt LLP via the form on this page. 

You can also contact DiCello Levitt partner Brian O’Mara by calling (888) 287-9005 or at [email protected]. 

The deadline to apply to the Court to serve as lead plaintiff in the ESSA class action lawsuit is March 25, 2025.