The FDA has placed a full clinical hold on Aardvark Therapeutics’ ARD-101 Prader-Willi syndrome program, pausing both the ongoing Phase 3 study and the associated open-label extension. The hold follows a cardiac safety signal observed in healthy volunteers receiving higher doses than those used in other studies. Aardvark said it will unblind trial data to support an FDA review of the combined efficacy and safety dataset and to determine next steps for ARD-101. The company had dosed 68 people in the randomized Phase 3 trial and 19 in an extension before the pause. Separately, the FDA’s hold affects all ARD-101 studies, and earlier actions by Aardvark had already paused related work after the initial voluntary safety pause in March. The timing is critical for funding planning as the company’s cash runway is now extended to mid-2027. Investors reacted sharply to the hold, with Aardvark’s shares falling materially after the FDA action—underscoring the centrality of the company’s most advanced asset to both clinical and financing strategy.