Rezubio’s RZ-520 IND clearance and Acepodia’s ACE-723 IND clearance together expand early clinical activity across respiratory and liver cancer programs. Both updates include readiness to dose in Phase I settings, with regulatory signals from both the FDA and China’s NMPA for Rezubio. While these are early-stage steps, IND clearances are typically the gatekeeper event that determines whether preclinical promise can translate into human pharmacology and safety. For target-driven drug classes such as ADCs and novel respiratory therapies, Phase I dosing will be the first major checkpoint. The launches also underline how companies continue to pursue parallel development pathways between the US and China, potentially accelerating follow-on studies if tolerability profiles allow.