A large phase III study called the CHIPRO trial, presented at the 2026 ASCO Annual Meeting, looked at whether adding a targeted therapy called chiauranib to standard weekly chemotherapy (paclitaxel) could help people with platinum-resistant or platinum-refractory ovarian cancer.
These are cancers that have either stopped responding to platinum chemotherapy or returned after it, and can be especially difficult to treat.
What the CHIPRO trial looked at
In this study, patients were randomly assigned to receive either chiauranib plus weekly paclitaxel or placebo plus weekly paclitaxel. Treatment continued until the cancer got worse or side effects became too difficult to manage.
Many patients in the study had already received multiple prior treatments, including PARP inhibitors and other targeted therapies, making this a population with very limited remaining options.
A meaningful delay in cancer growth
The main goal of the study was to measure how long patients lived without their cancer growing or spreading, called progression-free survival, or PFS.
Patients who received the combination of chiauranib plus paclitaxel went about 4.6 months before their cancer worsened, compared with about 2.7 months for chemotherapy alone. This means the combination nearly doubled the time patients lived without their cancer getting worse and reduced the risk of progression or death by 57%.
More tumors shrunk with the combination
The study also looked at how many patients had their tumors shrink.
About 32% of patients who received the combination saw their tumors shrink, compared with about 14% who received chemotherapy alone. In addition, most patients in the combination group had at least some reduction in tumor size.
This suggests the combination helped more people experience a visible response to treatment.
Overall survival was similar between groups
At the time of this analysis, overall survival was about the same in both groups, around 12 months.
This means that while the combination helped slow cancer growth, it has not yet been shown to help patients live longer overall. Researchers will continue to follow patients to see if this changes over time.
Why these results matter
Platinum-resistant ovarian cancer is an area where treatment options are limited, and new approaches are urgently needed.
This study is important because it was a large, well-designed phase III trial and included many patients who had already been treated with several lines of therapy. The results suggest that adding chiauranib may offer a meaningful way to better control disease in this setting.
How chiauranib works
Chiauranib is a targeted therapy that works in several ways. It helps block cancer cell growth and division, reduces the formation of blood vessels that tumors need to grow, and may also affect the tumor’s surrounding environment, including immune activity.
By working on multiple pathways at once, it may help overcome some of the resistance seen in hard-to-treat cancers.
What about side effects?
Side effects were common in both groups, but more frequent in the combination arm.
Most side effects involved low blood counts, such as neutropenia (low white blood cells) and anemia (low red blood cells). These can increase the risk of infection, fatigue, and may require dose delays or adjustments. Serious side effects were also more common with the combination, so careful monitoring is important during treatment.
Key takeaway
The CHIPRO trial shows that adding chiauranib to weekly paclitaxel may help slow cancer growth and increase tumor shrinkage in people with platinum-resistant ovarian cancer. While it has not yet been shown to help patients live longer overall, these results offer a promising step forward in an area where new treatment options are urgently needed.
Want a summary of ASCO 2026 ovarian cancer highlights? Here’s an overview of key takeaways from this year’s event.
