What should I do if I become drug-resistant after taking Erdafitinib?

If drug resistance occurs after taking Erdafitinib (Erdafitinib), patients should communicate and consult with their doctor in a timely manner. Since each person’s constitution is different and their response to drug resistance is also different, the doctor may conduct a series of examinations and evaluations to determine whether drug resistance is really occurring, rather than other reasons leading to reduced efficacy. If resistance does develop, doctors may consider modifying the treatment plan. This may include switching to other targeted drugs, using different chemotherapy drugs or immunotherapy.

The inverse correlation between FGFR expression and tumor immunogenicity may explain the adverse response to ICIs in luminal-papillary urothelial carcinoma (UC). One study showed that high expression of FGFR3 was closely associated with a T cell-exhausted microenvironment and reduced interferon-γ-responsive genes in UTUC. In experimental models, the combination of erdafitinib and anti-PD-1 drugs appears to overcome ICI resistance by enhancing anti-tumor immunity compared with erdafitinib alone. Study results showed the combination was well tolerated, with an ORR of 17% in 15 participants. Preliminary results from the phase II study showed an ORR of 68% in patients who received the combination and 33% in patients who received erdafitinib alone.

The original version of erdafitinib has not yet been launched in China, so it cannot be covered by medical insurance. The original version of erdafitinib currently sold in Hong Kong may cost more than 20,000 yuan per box of specifications 4mg*14 tablets (the price may fluctuate due to exchange rates). Cheaper erdafitinib generic drugs produced by other pharmaceutical factories are also sold overseas. The pharmaceutical ingredients are basically the same as those of the original drug. For example, the price of 4mg*60 tablets produced by a Bangladeshi pharmaceutical factory may be more than 3,000 yuan per box (the price may fluctuate due to exchange rates).