Background 

This study looks at a serious type of bladder cancer called muscle-invasive bladder cancer, or MIBC. These cancers are not all the same—some grow faster and are harder to treat than others. The research team discovered that MIBC can be divided into three main groups, or “subtypes.” These subtypes act like different kinds of diseases, much like certain breast cancers that also fall into distinct groups. 

What the Study Proposes to Address 

Researchers have found that two of the three subtypes of MIBC already respond well to existing treatments. However, the third subtype is much tougher to treat because it resists most current therapies. The good news is that this resistant group of tumors often contains a feature called FGFR3, a biological target that certain drugs can block. These drugs, known as FGFR inhibitors, are already being used in patients. The team wants to figure out the best way to use these inhibitors to fight this difficult subtype of bladder cancer. 

Why This Research Is Important 

If scientists can learn how to make FGFR inhibitors work more effectively, they could create new treatment options for patients whose cancers don’t respond to standard therapies. This would help ensure that people with all three subtypes of MIBC have effective treatment options available. The study could bring researchers one step closer to personalized care—where each patient’s treatment is tailored to the specific type of bladder cancer they have—improving survival and quality of life for more people. 

Final Report Summary 

This study focused on a protein called FGFR3, which is often changed, or mutated, in many bladder cancers. A drug called erdafitinib, recently approved by the FDA, targets this mutation and can help some patients. The researchers wanted to see if drugs like erdafitinib could also help the immune system fight bladder cancer more effectively. Their experiments showed that FGFR3-blocking drugs lower the amount of another protein, CD73, which usually keeps key immune cells called T cells from entering the tumor. Allowing these T cells in could make immunotherapy work better for more patients. 

The team also tested another new drug, vofatamab, to see if it had the same helpful effects in patients with advanced bladder cancer. Working with doctors at MD Anderson, they discovered that vofatamab had little to no effect, either in patients or in lab tests. This finding was disappointing, but it also highlighted an important lesson: new drugs should be carefully studied and compared to similar drugs before being used in large clinical trials. Fortunately, other drugs like erdafitinib are still being tested and may soon give researchers clearer answers and better options for treating bladder cancer. 

None Reported as of August 2025

None Reported as of August 2025

Arlene Siefker-Radtke, MD; MD Anderson Cancer Center
Colin Dinney, MD; MD Anderson Cancer Center
Bogdan Czerniak, MD, PhD; MD Anderson Cancer Center
Woonyoung Choi, PhD; MD Anderson Cancer Center
Trinity Bivalacqua, MD, PhD; University of Pennsylvania
Noah Hahn, MD; Johns Hopkins University
Charles DrakeMD, PhD; Johns Hopkins University