Futibatinib in Combination With Durvalumab Prior to Cystectomy for the Treatment of Muscle-Invasive Bladder Cancer Patients Who Are Ineligible for Cisplatin-based Therapy

Inclusion Criteria: * Able to provide signed informed consent * Female or male subjects \>= 18 years old * Bodyweight \>30kg * FGFR1, 2, or 3 overexpression as defined by a score of 3+ or 4+ on ribonucleic acid (RNA) in-situ hybridization (RNAScope assay) * Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 * Histologically confirmed urothelial carcinoma of the bladder * Mixed histologies are permitted if urothelial carcinoma is the predominant histology ( \>= 50%) * Clinical stage T2-T4a, N0, M0 disease by trans urethral removal of bladder tumour (TURBT) and imaging studies (stage II-IIIA per American Joint Committee on Cancer \[AJCC\] 2018) * Refuse or ineligible for cisplatin-based neoadjuvant chemotherapy as defined by any of the following: * ECOG performance status (PS) \> 1 * Creatinine clearance (calculated or measured) \< 60 mL/min as measured by the Cockcroft-Gault formula * Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v 5.0) grade \>= 2 hearing loss * CTCAE v 5.0 grade \>= 2 neuropathy * New York Heart Association (NYHA) class \> II cardiac dysfunction * Treatment with anti-PD-1/PD-L1 therapy for non-muscle invasive bladder cancer (NMIBC) is permitted if it is completed \> 3 months before registration * Eligible for radical cystectomy by the following: * Fit and planned for radical cystectomy according to local guidelines * Archival transurethral resection of bladder tumor (TURBT) tissue submission must be 30 unstained slides. If archival tissue is unavailable, the patient must undergo cystoscopy and biopsy. The tumor sample must contain at least 20% viable tumor * Evidence of post-menopausal status or negative urinary or serum pregnancy test for female premenopausal patients. * Female subjects of childbearing potential and male subjects must be willing to completely abstain or agree to use a highly effective method of contraception (i.e., less than 1% failure rate), from the time of signing informed consent and for the duration of study participation through 90 days following the last dose of study drug. * Hemoglobin \>= 9.0 g/dL * Absolute neutrophil count (ANC) \> 1500 per mm\^3 * Platelet count \>= 100 x 10\^9/L * International normalized ratio (INR) or activated partial thromboplastin time (aPTT) \< 1.5 × upper limit of normal (ULN), unless the patient is receiving anticoagulation therapy provided INR or PTT is within the therapeutic range of the intended anticoagulant therapy * Bilirubin =\< 1.5 x institutional upper limit of normal (ULN) * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) =\< 2.5 x institutional upper limit of normal * Phosphorus ≤ institutional upper limit of normal (ULN) * Measured creatinine clearance (CL) ≥ 30 mL/min or calculated creatinine CL ≥ 30 mL/min by the Cockcroft-Gault formula or by 24-hour urine collection for determination of creatinine clearance * Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up. * Must have a life expectancy of at least 12 weeks Exclusion Criteria: * Women who are pregnant or breastfeeding * Male or female patients of reproductive potential who are not willing to employ effective birth control from screening to 90 days after the last dose of durvalumab monotherapy * Is currently participating in or has participated in a study of an investigational agent or using an investigational device within 4 weeks before the first dose of trial treatment * Has upper tract urothelial carcinoma * Has small-cell carcinoma component on histology * Evidence of measurable nodal or metastatic disease * Concurrent anticancer therapy (e.g., chemotherapy, radiation therapy, surgery, immunotherapy, biologic therapy, hormonal therapy, investigational therapy, intravesical therapy, or tumor embolization) * Received prior systemic chemotherapy for muscle-invasive bladder cancer at any time in the patient's medical history * Has received anti-PD-1/PD-L1 therapy or FGFR inhibitor previously for MIBC, except if used in earlier stage urothelial carcinoma such as non-muscle invasive bladder cancer (NMIBC) and completed \> 3 months prior to registration * Must not have experienced a toxicity that led to permanent discontinuation of prior immunotherapy. * All AEs while receiving prior immunotherapy must have completely resolved or resolved to baseline prior to screening for this study. * Must not have experienced a ≥Grade 3 immune related AE or an immune related neurologic or ocular AE of any grade while receiving prior immunotherapy. NOTE: Patients with endocrine AE of ≤Grade 2 are permitted to enroll if they are stably maintained on appropriate replacement therapy and are asymptomatic. * Must not have required the use of additional immunosuppression other than corticosteroids for the management of an AE, not have experienced recurrence of an AE if re-challenged, and not currently require maintenance doses of \> 10 mg prednisone or equivalent per day. * Underwent major surgery and has not recovered adequately from the intervention's toxicity and/or complications before starting therapy * Has an active second malignancy except for low-risk localized prostate cancer on "watch and wait" * Subjects with a history of malignancy that has been completely treated, with no evidence of active cancer for 2 years before enrollment, or subjects with surgically cured tumors with a low risk of recurrence are allowed to enroll at PI's discretion (e.g. adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease and effectively treated carcinoma in situ without evidence of disease). * Has active cardiac disease, defined as: * Myocardial infarction or unstable angina pectoris within 3 months of the first date of study therapy