A Phase 1, Multicenter, Open-label, Dose-escalation Study Evaluating the Safety and Tolerability of Intravenous KK2269 Monotherapy and Combination Therapy With Docetaxel in Adult Participants With Solid Tumors

This is a first-in-human study of KK2269. Part 1 and Part 2 will be conducted as a multicenter, open-label, non-randomized, dose-escalation study. Participants with advanced or metastatic solid tumors for which no standard therapy is available will be enrolled in Part 1. In Part 1, the primary objective is to assess the safety and tolerability of KK2269. In Part 2, only participants with gastric adenocarcinoma, GEJ adenocarcinoma, esophageal adenocarcinoma, or NSCLC who have experienced at least one systemic therapy will be enrolled. In Part 2, the primary objective is to assess the safety and tolerability of KK2269 in combination with docetaxel and to determine the recommended dose(s) and dose interval(s) of KK2269 in combination with docetaxel for subsequent studies. In both Part 1 and Part 2, participants who refuse to undergo standard therapy are also eligible.

Drug: KK2269, Drug: Docetaxel