Infigratinib Before Surgery for the Treatment of Upper Tract Urothelial Cancer

Inclusion Criteria: * Have low grade UTUC undergoing nephroureterectomy or ureterectomy, or high grade UTUC and not eligible for cis-platin neoadjuvant chemotherapy either due to medical comorbidities (e.g., cardiac dysfunction, hearing loss, glomerular filtration rate \[GFR\] \< 50), or based on \< 49% risk prediction of non-organ confined disease by clinical nomogram * Have adequate biopsy tissue available for mutational analysis, as determined by the study pathologist, prior to enrollment. Any biopsy of index UTUC tissue available within 6 weeks of enrollment may be used * Calculated or measured creatinine clearance \>= 30 mL/min * Have an Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 * Are able to read and/or understand the details of the study and provide written evidence of informed consent as approved by Institutional Review Board (IRB)/Independent Ethics Committee (IEC) * Have recovered from AEs of previous systemic anti-cancer therapies to baseline or grade 1, except for alopecia * Are able to swallow and retain oral medication * Are willing and able to comply with scheduled visits, treatment plan and laboratory tests * If a woman of childbearing potential (WOCBP), must have a negative pregnancy test within 7 days of the first dose of study drug. A woman is not of childbearing potential if she has undergone surgical sterilization (total hysterectomy, or bilateral tubal ligation or bilateral oophorectomy at least 6 weeks before taking study drug)…