Erdafitinib Monotherapy or in Combination With Cetrelimab in Muscle-invasive Bladder Cancer Patients With Fibroblast Growth Factor Receptor (FGFR ) Gene Alterations

Inclusion Criteria: 1. Written informed consent stating that he or she understands the purpose of the study and the procedures involved and agrees to participate in the study. 2. Histologically confirmed diagnosis of MIBC (Stage T2-4a N0/N1 M0) obtained via a diagnostic or maximal Transurethral Resection of Bladder Tumor (TURBT) performed no later than 3 months prior to start the screening visit. 3. Pure or predominant (≥50%) urotelial Cancer (UC) histology as determined at the local site. 4. Age ≥ 18 years. 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 6. Decline or ineligible ("unfit") for cisplatin-based chemotherapy 7. Presence of a selected FGFR alteration on analysis of tumour biopsy 8. Adequate organ function 9. No other malignancy 10. Willingness to avoid pregnancy or fathering children Exclusion Criteria: 1. Clinical evidence of N2-N3 tumours or metastatic bladder cancer. 2. Has tumour with any neuroendocrine or small cell component. 3. Patients who are not considered fit for cystectomy or reject cystectomy. 4. Prior FGFR-targeted or an immune checkpoint inhibitor (antiPD1/PDL1 )systemic therapy. 5. Prior systemic therapy, radiation therapy, or surgery for bladder cancer