Cardiff Oncology’s investigational PLK1 inhibitor paired with standard-of-care treatment showed a 64% overall response rate (ORR) in the high-dose cohort of a midstage colorectal cancer trial.
The biotech’s share price has risen 58% in the wake of the data drop, up from $2.44 per share at market close yesterday to $3.85 as of 3 p.m. ET today.
The candidate, dubbed onvansertib, is being tested among patients with first-line RAS-mutated metastatic colorectal cancer (mCRC) in a phase 2 study.
The initial results include data from 30 patients randomized to one of three groups: 20 mg of onvansertib plus standard of care, 30 mg of ovansertib and standard treatment, or just standard of care alone, according to a Dec. 10 release (PDF).
The ORR—the trial’s primary endpoint—for patients in the 30-mg onvansertib arm was 64% (7/11), compared to 33% (3/9) for patients in the control group. The ORR for patients receiving 20 mg of onvansertib was 50% (5/10).
For all onvansertib patients, the ORR was 57% (12/21), the San Diego-based biotech said in the release.
Investigators recorded deeper tumor responses among the patients receiving the 30-mg dose compared to those receiving 20 mg, Cardiff added.
Overall, onvansertib combined with standard of care—chemotherapy and bevacizumab—was well tolerated, according to Cardiff. No major or unexpected toxicities were reported.
Cardiff’s KRAS-mutated cancer candidate previously pulled in Pfizer, with the Big Pharma putting up a $15 million equity investment in 2021 to help fund development.
“In addition to the efficacy signal observed, the data demonstrate that onvansertib can safely be combined with the two different chemo backbones that are currently approved as standard of care in the first-line setting, thus providing a key differentiated profile over previous generation PLK1 inhibitors,” Cardiff CEO Mark Erlander, Ph.D., said in the release. A PLK1 inhibitor has yet to make it to market.
In 2021, Amgen became the first company to gain FDA approval for a KRAS treatment, scoring a nod for KRAS G12C inhibitor Lumakras among patients with non-small cell lung cancer and a genetic mutation dubbed KRAS G12C, followed by Mirati Therapeutics' Krazati as a second-line treatment in the same indication.