A tumor is like a stubborn beast that adapts to any poison. The first blow of chemotherapy kills some cells, but the survivors quickly learn to ignore the drug. Head and neck cancer is especially treacherous: in about half of patients, the tumor returns after standard treatment with cisplatin. Cellular aging here is not a dead end but a hidden loophole: cells freeze, like a beast playing dead, and then attack again.
The new treatment plan works in two moves. First, sacituzumab govitecan enters the fray: an antibody with a toxic payload attached. It finds cancer cells by the TROP2 protein on their surface and forces them to age: the cells stop dividing but remain alive. In experiments on head and neck cancer cells, after such treatment, between 35 and 60 percent of cells became aged. Moreover, cells already resistant to cisplatin aged even more readily, because they had more TROP2 protein.
The second move is the senolytic ABT-263. This drug specifically targets aged cells and kills them by blocking the BCL-XL protein, which protects the cell from death. When scientists first treated cells with sacituzumab govitecan and then added ABT-263, between 30 and 60 percent of cells died. Moreover, the death occurred through apoptosis, the programmed self-destruction triggered by the BAX and BAK proteins. If these proteins were disabled, the drug combination stopped working.
Previously, it was unclear why sacituzumab govitecan works poorly in head and neck cancer. Now it is clear: it does not kill cells but merely puts them to sleep, shifting them into senescence. Adding a senolytic prevents them from waking up. This approach could become the basis for clinical trials in patients with tumor recurrence. However, ABT-263 itself is too aggressive for long-term use: it destroys platelets. But safer analogs already exist, such as DT2216, which are undergoing early trials. If they work, the two-step hunt for cancer will become a real treatment strategy.
Sacituzumab govitecan is FDA-approved for metastatic triple-negative breast cancer, but in head and neck cancer trials as a single agent it showed only a modest effect. This work explains why: cells enter senescence and temporarily "fall asleep," then return to dividing. Adding a senolytic prevents them from waking up.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.