Trovagene, Inc. (Nasdaq: TROV), a clinical-stage, Precision Cancer Medicine™ oncology therapeutics company developing drugs that target cell division (mitosis), for the treatment of various cancers including prostate, colorectal and leukemia, today announced new positive data from its Phase 2 trial evaluating onvansertib in combination with Zytiga® (abiraterone acetate - Johnson & Johnson)/prednisone in patients with metastatic Castration-Resistant Prostate Cancer (mCRPC). The data are being presented today at the European Multidisciplinary Congress on Urological Cancers (EMUC) in Vienna, Austria.
"The new data shared today builds upon the encouraging clinical response seen to date when onvansertib is added to treatment in patients who have developed resistance to androgen receptor signaling inhibitor (ARSi), Zytiga®," said Dr. Mark Erlander, Chief Scientific Officer of Trovagene. "Of particular significance are the positive results we are observing in patients who harbor the highly aggressive, resistant variant of the androgen receptor (AR-V7). These patients are resistant to ARS inhibitors including Zytiga® and Xtandi® (enzalutamide - Pfizer) and their therapeutic options are not only limited, but often ineffective. We believe the addition of onvansertib has the potential to deliver transformative benefit to patients with mCRPC by extending the duration of response to treatment with ARS inhibitors."
The newly reported data include efficacy and safety assessments as of the October 28, 2019 data cut-off date for 15 patients that completed 3 months of treatment and were eligible for evaluation of the primary efficacy endpoint of disease control. Response to treatment was evaluated based on a decrease or stabilization in prostate specific antigen (PSA) values (primary endpoint) and confirmed by radiographic scans.
Overall, across both arms (A and B), a 60% response (SD + PR) was observed in patients who were evaluable for efficacy (completed 3 months of treatment); 72% of patients had a decrease in PSA following one cycle of treatment with onvansertib; 6 patients remain on treatment for ≥4 months.
All 5 patients who tested positive for the highly-aggressive, resistant AR-V7 variant had decreases in PSA following one cycle of treatment with onvansertib; the primary efficacy endpoint (SD + PR) was achieved in 3 out of 4 evaluable patients (completing 12 weeks of treatment).
In both arms (A and B) onvansertib in combination with abiraterone was safe and well-tolerated. The most frequent adverse events (AEs) were expected, on-target (based on mechanism of action of onvansertib) hematologic (anemia, neutropenia, thrombocytopenia and white blood cell (WBC) decrease). All hematologic AEs were easily and effectively managed and resolved by delaying or reducing the dose and/or adding growth factor support. No unexpected or off-target AEs have been reported to-date.