First Patient Receives Next-Generation Androgen Biosynthesis Inhibitor for Metastatic Prostate Cancer

The first patient with metastatic prostate cancer has been dosed with the investigational next-generation androgen biosynthesis inhibitor, PRL-02, as part of a phase 1/2a clinical trial (NCT04729114), announced the drug developer, Propella Therapeutics, Inc, in a press release.

PRL-02 formulation of abiraterone decanoate that was designed to be used with hormone therapy to treat prostate tumors without causing adverse liver and drug-drug interaction effects. Multiple studies have already demonstrated the potential of androgens for the treatment of this disease, according to the press release. Now, following a 3 + 3 dose-escalation design, the study of PRL-02 with evaluate its ability to suppress testosterone as a primary end point and its safety and tolerability as a secondary end point.

“PRL-02 may provide improved bioavailability and convenience over the currently available therapies while also providing patients a potentially safer treatment option than the approved androgen biosynthesis inhibitors” said Robert Dreicer, MD professor of medicine and urology at the University of Virginia. “I am personally intrigued by the PRL-02 profile and its potential to be a clinically meaningful new option for the treatment of patients with metastatic prostate cancer.”

Patients with metastatic prostate cancer included in cohort 1 of the study will receive PRL-02 at 180 mg. In cohort 2, the dosing of the agent is escalated to 360 mg, then to 720 mg in cohort 3 and 1260 mg in cohort 4. In all cohorts, PRL-02 is given as a 10 mL vial containing 990 mg of abiraterone decanoate in 5.5 mL of solution. Further, patients treated in the dose-expansion cohort will receive the recommended phase 2 dose of PRL-02 as determined in the phase 1 portion.

According to the study’s protocol, those receiving treatment will remain on the study until their serum testosterone is >1 ng/dL on 2 sequential determinations starting on Day 21 through Day 77, or until they experience unacceptable toxicity, withdraw their consent, at the discretion of the investigator, or following 4 complete cycles of therapy.

The study is actively recruiting patients in treatment sites in Arizona, Indiana, Maryland, Nebraska, New Mexico, and South Carolina. Those eligible are patients with metastatic prostate cancer who have undergone orchiectomy or ongoing gonadotropin-releasing hormone agonist or antagonist therapy for at least 3 months prior to the time of screening and who have an ECOG performance status of 0 or 1, adequate bone marrow reserve, adequate renal and hepatic function, and serum albumin of ≥3 gm/dL and serum potassium of ≥3.5 mEq/L.

Metastatic castration-resistant prostate cancer patients with hepatic metastases or known central nervous system metastases are grounds for exclusion from the study. Patients are also ineligible to enroll if they present with another active neoplastic disease that requires concurrent anti-neoplastic treatment, have undergone major surgery or trauma within 4 weeks of screening for the study or present with visceral metastatic disease or impending fracture due to bone metastases.

In terms of comorbidities and medical history, patients cannot have a history of impaired pituitary or adrenal gland function, need systemic glucocorticoids greater than replacement doses, or of prior myocardial infarction, stroke or transient ischemic attack, or who have an uncontrolled inter-current illness, including but not limited to, ongoing or active infection, New York Heart Association Class 3 or 4 congestive heart failure, uncontrolled hypertension, unstable angina pectoris, uncontrolled cardiac arrhythmia, active interstitial lung disease, poorly controlled diabetes, or psychiatric illness/social situations, or substance abuse.

_Reference:

_{Propella announces first patient dosed in phase 1/2a trial of PRL-02 for treatment of metastatic prostate cancer. News release. Propella Therapeutics, Inc. June 29, 2021. Accessed June 29, 2021. https://bit.ly/3qy4Whs}