Q4 2026 ADC Watchlist: Which Catalysts Could Change the Oncology Game?

ADCs offer a compelling prospect: deliver a potent cancer drug to tumors with greater precision, then turn that approach into meaningful patient benefit. Enhertu has shown what that can look like. It improved survival in HER2-positive metastatic breast cancer and has since expanded into earlier treatment settings. It was also the only ADC in the top 10 oncology drugs by sales for 2025 and H1 2026. For bio/pharma investors, the question is which programs have the evidence to follow its path.

ESMO is a major test. TAK's arcotatug tavatecan will present Phase 3 data in advanced gastric and gastroesophageal junction cancer, with a potential Japan filing at stake. Earlier-stage updates from MGNX's MGC026, IDYA's IDE849, and BHVN's BHV-1530 could show whether their efficacy and safety signals warrant further development. ADCs are a prominent theme among the ESMO catalysts we are tracking.

The watchlist extends beyond ESMO. KYNB's FG-3246 interim analysis could sharpen its case in prostate cancer. A Q4 FDA decision will test whether enfortumab vedotin can move into a perioperative bladder cancer regimen with AZN's Imfinzi. For ADCT, Zynlonta combination data and the regulatory path for LOTIS-5 remain important investor questions.

These ten catalysts range from early clinical signals to a Phase 3 readout and an FDA decision. Enhertu illustrates the potential payoff; the coming results will help investors judge which ADC programs are building a credible case of their own.