Onvansertib May Elicit Responses in Pancreatic Cancer, Lung Cancer Subsets

Patients with metastatic pancreatic ductal adenocarcinoma responded to treatment with onvansertib in combination with standard of care, as demonstrated in preliminary data from a phase 2 trial.

Preliminary data from another trial in small cell lung cancer (SCLC) also demonstrated a response in patients with relapsed extensive-stage disease who were previously treated with two therapies, according to a press release from Cardiff Oncology, the manufacturer of onvansertib.

In particular, in patients with metastatic pancreatic ductal adenocarcinoma, the objective response rate (the percentage of patients with a partial or complete response to treatment) was 19% from treatment with second-line onvansertib plus standard of care, according to the release. In this trial, standard of care was nanoliposomal irinotecan, leucovorin, and 5-FU.

The median progression-free survival (the time during and after treatment when a patient lives with cancer without the disease progressing) in patients with metastatic pancreatic ductal adenocarcinoma treated with this combination was five months.

Previous studies that evaluated the efficacy of standard-of-care treatments in metastatic pancreatic ductal adenocarcinoma showed an objective response rate of 7.7% and a median progression-free survival of 3.1 months, according to the release.

"We are excited that the data released from these trials, in two challenging cancers with low survival rates, expands the opportunity for onvansertib beyond our lead program in RAS-mutated (metastatic colorectal cancer)," Mark Erlander, chief executive officer of Cardiff Oncology, stated in a press release from the company. "In pancreatic cancer, the strength of the data provides a clear rationale for a first-line trial using onvansertib in combination with (standard of care), which we believe provides the greatest opportunity for a positive impact on patients. In small cell lung cancer, we are encouraged to observe single-agent activity with onvansertib monotherapy in this difficult-to-treat extensive stage refractory setting."

Biomarker Discovery Trial

Researchers are currently conducting a biomarker discovery trial, which is currently enrolling patients with metastatic pancreatic ductal adenocarcinoma, according to the release. Through this, researchers aim to explore the impact of onvansertib give to patients for 10 days. Two patients are enrolled in the study so far.

Although only two patients have been enrolled so far, one patient showed improved results, with a 86% decrease in Ki67, a biomarker which shows how fast the tumor is growing. There was a decrease in CA 19-9 as well, a biomarker doctors use to mark how well the treatment is working for a patient. These findings show that onvansertib may be effective in treating metastatic pancreatic ductal adenocarcinoma.

"Serum carbohydrate antigen 19-9 is the most extensively studied and validated serum biomarker in (pancreatic ductal adenocarcinoma), which provides a clinically meaningful surrogate for response to treatment. We are encouraged by the ability of onvansertib to provide an approximately 30% reduction in this biomarker with only 10 days of monotherapy in a refractory setting," Dr. Fairooz Kabbinavar, chief medical officer of Cardiff Oncology, said in the release.

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