Cardiff Presents Phase 1 Data Of Onvensertib In Chronic Myelomonocytic Leukemia At ASH 2025

Cardiff Oncology presented Phase 1 investigator‑sponsored data for onvansertib in relapsed/refractory CMML at ASH showing the oral PLK1 inhibitor was generally well tolerated in nine patients and produced preliminary efficacy in ~40% of subjects, including one optimal marrow response at the 9 mg/m2 dose. While the company does not plan further CMML development, management says the results validate single‑agent activity and support its strategic focus on PLK1 inhibition in combination approaches for RAS‑mutated metastatic colorectal cancer and investigator‑led trials in pancreatic cancer, small cell lung cancer and triple‑negative breast cancer. Shares reacted positively, closing at $2.34 (up 10.9%) and trading at $2.35 in after‑hours; the 12‑month trading range is $1.90–$5.64.

Analysis

Cardiff Oncology presented investigator‑sponsored Phase 1 dose‑escalation data for onvansertib (oral PLK1 inhibitor) in relapsed/refractory CMML at ASH on December 8, 2025; the trial enrolled nine patients, reported that monotherapy was relatively well tolerated, and showed preliminary efficacy in ~40% of subjects with one patient achieving an optimal marrow response at the 9 mg/m2 dose level. These results corroborate prior single‑agent signals in small cell lung cancer and validate onvansertib's biological activity across hematologic and solid tumor indications, but the company stated it does not plan further CMML development and will prioritize PLK1 inhibition in combination strategies. Cardiff's strategic focus is on combinations with standard‑of‑care in RAS‑mutated metastatic colorectal cancer and on investigator‑initiated trials in metastatic pancreatic ductal adenocarcinoma, SCLC and triple‑negative breast cancer, which shifts the near‑term value drivers to future combination readouts. The market reacted positively with shares closing $2.34 (up 10.90%) and trading $2.35 afterhours; however, the small nine‑patient sample and early‑stage nature of the data limit statistical confidence, so the stock move appears sentiment‑driven and should be judged against upcoming, larger efficacy and safety datasets and the 12‑month trading range of $1.90–$5.64.

Key Decisions for Investors

• Consider placing CRDF on a monitored watchlist or initiating a small, tactical long position to play validated single‑agent activity while keeping allocation modest given the nine‑patient Phase 1 sample
• Prioritize monitoring readouts from planned combination programs in RAS‑mutated metastatic colorectal cancer and investigator‑initiated trials in pancreatic cancer, SCLC and TNBC as the primary catalysts that would materially de‑risk the program
• Manage risk with position limits or hedges and avoid adding significant exposure until larger controlled cohorts demonstrate reproducible efficacy and acceptable safety, noting the recent 10.9% intraday gain and the 12‑month $1.90–$5.64 trading range