JZP898 Intravenous Infusion as Monotherapy and Combination With Pembrolizumab in Adults With Advanced/Metastatic Solid Tumors

Two-part study: Part A Dose Exploration (Parts A1 and A2) and Part B Combination Expansion. Part A Dose Exploration: * Part A1 - a monotherapy dose exploration to determine the monotherapy recommended dose and/or maximum tolerated dose (MTD) (or highest cleared dose level) and safety profile of JZP898. * Part A2 - a combination dose exploration of JZP898 plus pembrolizumab to determine the CombiRD (combination recommended dose for expansion). Part B Combination Expansion: * Part B - combination expansion using a basket design to evaluate clinical antitumor activity and safety profile of JZP898 in combination with pembrolizumab at the CombiRD identified in Part A2.