The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics (PK), and preliminary antitumor activity of TYRA-300 in cancers with FGFR3 activating gene alterations, including locally advanced/metastatic urothelial carcinoma of the bladder and urinary tract and other advanced solid tumors.

This is a single arm, multi-part, phase 1/2 global trial studying TYRA-300, a novel, potent fibroblast growth factor receptor (FGFR) 3-selective tyrosine kinase inhibitor, in advanced/metastatic urothelial carcinoma of the bladder and urinary tract, that contain activating gene alterations of FGFR3. Phase 1 is a dose-escalation study to evaluate the safety, tolerability, and PK of TYRA-300 to determine the optimal and maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Phase 2 will evaluate the preliminary antitumor activity of TYRA-300 in cancers with FGFR3 activating gene alterations, including locally advanced/metastatic urothelial carcinoma of the bladder and urinary tract and other advanced solid tumors.

Inclusion Criteria:

Phase 1 Part A and Part B

• Men and women 18 years of age or older.
• Eastern Cooperative Oncology Group (ECOG) performance status of ≤1.
• Histologically confirmed advanced solid tumor who have exhausted standard therapeutic options.
• Evaluable (Part A) or measurable (Part B) disease according to RECIST v1.1.
• Histologically confirmed advanced solid tumor with an eligible FGFR3 gene mutation or fusion (Part B).

Phase 2

• Men and women 18 years of age or older.

• ECOG performance status of 0-2 or Karnofsky Performance Scale (KPS) >70.

• At least 1 measurable lesion by RECIST v1.1.

• Histologically confirmed locally advanced/metastatic tumor in one of the following categories:

  • Urothelial carcinoma with an eligible FGFR3 gene mutation or rearrangement who have progressed on a prior FGFR inhibitor and presence of a resistance mutation or other kinase domain mutation.
  • Urothelial carcinoma with an eligible FGFR3 gene mutation or rearrangement who has not received a prior FGFR inhibitor.
  • Any solid tumor with an eligible FGFR3 gene mutation or rearrangement.

Exclusion Criteria (All Phases):

• Has a serum phosphorus level > upper limit of normal (ULN) during screening that remains >ULN despite medical management.
• Any ocular condition likely to increase the risk of eye toxicity.
• History of or current uncontrolled cardiovascular disease.
• Active, symptomatic, or untreated brain metastases.
• Gastrointestinal disorders that will affect oral administration or absorption of TYRA-300.
• Females who are pregnant, breastfeeding, or planning to become pregnant and males who plan to father a child while enrolled in this study.