How is the phase 1/2 study of AVZO-103 designed?
AVZO-103-1001 is a dose-escalation and -expansion study enrolling patients at least 18 years of age with histologically or cytologically confirmed locally advanced/metastatic urothelial cancer or other solid tumors.2 Patients need to have an ECOG performance status of 0 or 1, a life expectancy of more than 3 months, and measurable disease per RECIST 1.1 criteria.
Investigators are excluding patients with active central nervous system metastases, although those with asymptomatic and treated brain metastases are eligible if they have radiologically stable metastases for at least 4 weeks prior to the first dose of study treatment and do not require steroids. Those with suspected or confirmed leptomeningeal disease are not eligible, regardless of treatment status. Other key exclusion criteria comprise prior Stevens-Johnson syndrome/toxic epidermal necrolysis; a history of drug-induced interstitial lung disease; a history of any serious cardiovascular condition; infections requiring IV antibiotics, antivirals, or antifungals within 2 weeks prior to first dose; and a history of allogeneic stem cell or solid organ transplant.
During phase 1, investigators are assessing AVZO-103 as a single agent to determine the ADC’s safety and tolerability, determine the maximum tolerated dose, and establish the recommended phase 2 dose. Phase 2 will serve as the trial’s expansion portion, where AVZO-103 will be evaluated for antitumor activity both as a single agent and as part of combination regimens.
The primary end points of phase 1 include safety/tolerability, the incidence of dose-limiting toxicities, and to determine the MTD/RP2D. In phase 2, objective response rate (ORR) will serve as the primary end point. Secondary end points include ORR (phase 1), duration of response (phase 1 and 2), disease control rate (phase 1 and 2), progression-free survival (phase 1 and 2), overall survival (phase 1 and 2), and pharmacokinetics (phase 1).
The study will have an estimated enrollment of 355 patients. After initiating in October 2025, the study has an estimated primary completion date of March 2030.
References
- Avenzo Therapeutics granted fast track designation for AVZO-103, a potential best-in-class Nectin4/TROP2 bispecific antibody-drug conjugate, for the treatment of patients with urothelial cancer previously treated with enfortumab vedotin. News release. Avenzo Therapeutics. November 24, 2025. Accessed November 24, 2025. https://avenzotx.com/press-releases/avenzo-therapeutics-granted-fast-track-designation-for-avzo-103-a-potential-best-in-class-nectin4-trop2-bispecific-antibody-drug-conjugate-for-the-treatment-of-patients-with-urothelial-cancer-previo/
- Study of AVZO-103 as a single agent and in combination therapy in patients with locally advanced or metastatic urothelial cancer or other solid tumors (AVZO-103-1001). ClinicalTrials.gov. Updated November 12, 2025. Accessed November 24, 2025. https://clinicaltrials.gov/study/NCT07193511
- Padcev. Prescribing information. Updated November 2025. Accessed November 24, 2025. https://astellas.us/docs/PADCEV_label.pdf