Benzinga | Oct 20, 2020 08:34AM EDT

Cardiff Oncology Highlights Presentation Of Efficacy And Biomarker Data From mCRPC Trial Of Onvansertib At 27th Annual Prostate Cancer Foundation (PCF) Scientific Retreat

-- Trial on track to meet prespecified criteria for success on its primary endpoint, with 31% (8/26) disease control rate in evaluable patients in cohorts A and B. Patients eligible for the trial have two consecutive-- Trial on track to meet prespecified criteria for success on its primary endpoint, with 31% (8/26) disease control rate in evaluable patients in cohorts A and B. Patients eligible for the trial have two consecutive rises in PSA levels indicating initial resistance to abiraterone (Zytiga(r))

-- Safety demonstrated across all three dose/dose scheduling cohorts, including cohort C with onvansertib dosed over a longer period of time than cohorts A and B (onvansertib on Days 1 - 14 in a 21-day cycle); 2 of 3 patients treated to-date in cohort C achieved primary efficacy endpoint at 12 weeks

-- Recent collaborative studies with Massachusetts Institute of Technology (MIT) and Decipher Biosciences suggest that prostate cancer patients with the clinically defined basal molecular tumor subtype may be more likely to respond to onvansertib being added to ongoing abiraterone therapy

SAN DIEGO, Oct. 20, 2020 /PRNewswire/ -- Cardiff Oncology, Inc. (Nasdaq: CRDF), a clinical-stage biotechnology company developing drugs to treat cancers with the greatest medical need for new treatment options, including KRAS-mutated colorectal cancer, castration-resistant prostate cancer and leukemia, today announced that new data and analyses related to its ongoing Phase 2 trial of onvansertib in metastatic castration-resistant prostate cancer (mCRPC) patients were featured in an electronic poster at the 27th Annual Prostate Cancer Foundation (PCF) Scientific Retreat. The poster includes efficacy data demonstrating success in achieving the primary endpoint of disease control in patients showing initial resistance to Zytiga(r) (abiraterone); safety across three different dose and dosing schedules, as well as the potential clinical benefit for patients with the basal molecular tumor subtype.

"There is a pressing unmet need for therapies that can address resistance to abiraterone and other androgen receptor signaling inhibitors (ARSi), in mCRPC," said David Einstein, M.D., attending physician at Beth Israel Deaconess Medical Center and principal investigator of the onvansertib Phase 2 trial. "Data presented at the PCF retreat demonstrate the potential of onvansertib to address this need, as we are seeing clinically meaningful rates of disease control, some quite durable, in patients with known mechanisms of ARSi resistance."

Mike Yaffe, M.D., Ph.D., David H. Koch Professor of Science and Professor of Biology and Biological Engineering at MIT, added, "We continue to be excited about the collaboration with Cardiff Oncology and the work we have been conducting to unlock the mechanism of synergy between PLK1 inhibition and abiraterone, which we have previously shown to be independent of AR signaling. We have now identified a specific set of genes related to cell division pathways that can be used to predict which cancer cells will specifically show a synergistic anti-tumor response to treatment with abiraterone in combination with a PLK1 inhibitor. Intriguingly, this set of genes is most correlated with the known molecular basal subtype which suggests that prostate cancer patients with this specific tumor subtype may be more likely to respond to onvansertib-abiraterone combination therapy."

"We are very pleased with the progress and results of the trial to date," said Mark Erlander, Ph.D., chief executive officer of Cardiff Oncology. "In particular, we are encouraged by the identification of a biomarker that could readily select for abiraterone-resistant patients who are most likely to benefit from the addition of onvansertib to their regimen."

Highlights of the PCF Poster Presentation:

Efficacy:

* 8 of 26 (31%) evaluable patients achieved the primary endpoint of disease control (defined by a lack of prostate specific antigen progression) after 12 weeks of treatment

* 14 of 26 (54%) evaluable patients had stable disease (SD) after 12 weeks of treatment

* 8 of 26 (31%) evaluable patients had durable SD (>7 months)

* Of 8 patients harboring AR alterations associated with Zytiga(r) resistance, 3 achieved disease control at 12 weeks, 4 had SD at 12 weeks and 3 had durable SD (>7 months)

Biomarker Analyses:

* Identification of a gene signature (biomarker) associated with onvansertib and abiraterone synergy in prostate cancer cells that is significantly enriched in the basal molecular subtype of prostate cancer patients

Safety:

* The trial's safety lead-in is complete across Arm A (24 mg/m2 onvansertib), Arm B (18 mg/m2 onvansertib) and Arm C (12 mg/m2 onvansertib)

* Data show that the combination of onvansertib and abiraterone (Zytiga(r)) is safe across three different dosing schedules

The poster presented as part of the 27th Annual PCF Scientific Retreat is available on the "Scientific Presentations" section of the Cardiff Oncology website at https://cardiffoncology.com/scientific-presentations/.