New Targeted Therapy for Platinum-Resistant Ovarian Cancer Under Investigation
At ESGO 2026, the initial results of an early-phase clinical trial of a new drug called TUB-040 in patients with platinum-resistant ovarian cancer were presented. This is what is known as an antibody-drug conjugate (ADC) —a targeted therapy that specifically recognizes cancer cells and delivers a potent cytotoxic agent directly to them.
TUB-040 is an ADC that targets a protein called NaPi2b (sodium-dependent phosphate transport protein 2B). NaPi2b is a transporter that regulates phosphate in tissues such as the lungs and intestines and is found on the cell surface at a higher-than-average rate in high-grade serous ovarian cancer and non-small-cell lung cancer.
What was the study about?
The NAPISTAR 1-01 study is an early Phase 1/2a study primarily designed to evaluate,
how well a new drug is tolerated and
What is the appropriate dosage?
A total of 67 female patients with platinum-resistant high-grade serous ovarian cancer were treated. Many of them had already received multiple lines of therapy—an average of four prior treatments—which often included bevacizumab or PARP inhibitors.
What results were observed?
The results are very promising for an early-stage study:
A confirmed reduction in tumor size was observed in 50% of the patients.
Overall, the disease was at least stabilized in 96% of the patients.
In addition, many of the observed treatment responses were still ongoing at the time of the evaluation, so the final results are still pending.
Side Effects
Overall, the treatment was well tolerated. The most common side effects included nausea, fatigue, and changes in blood test results. Serious side effects were relatively rare. It is also important to note that no serious problems such as pneumonia, nerve damage, or eye problems were observed.
What does this mean for female patients?
The results show that TUB-040 could be a potential new treatment option for patients with platinum-resistant ovarian cancer, especially for those in whom multiple prior treatments have failed.
However, this is still an early Phase 1/2 trial. The drug must therefore be tested in larger studies before a decision can be made on whether it will be used routinely in the future.
Source: Publication (the article is in English)
