Aardvark reports exploratory HERO and OLE data for ARD-101 in Prader-Willi syndrome

Aardvark Therapeutics reported exploratory efficacy data on October 23, 2026 from its terminated Phase 3 "Hunger Elimination or Reduction Objective" (HERO) trial and its open-label extension (OLE) study in Prader-Willi syndrome (PWS). The HERO trial had randomized 67 of a planned 90 participants before being stopped early, meaning all efficacy results are considered exploratory.¹

On the Hyperphagia Questionnaire for Clinical Trials (HQ-CT), participants saw a modest decline in scores versus placebo by week two of dose escalation on ARD-101.¹ After stopping ARD-101, scores in the treatment group drifted back toward baseline, while the placebo group showed less of a rebound.¹ In the OLE group, patients who crossed over from placebo to ARD-101 saw their HQ-CT scores drop by an average of 6 points.¹ Caregiver and clinician global impression severity scores showed a comparable trend.¹

The company said ARD-101 was generally well tolerated, with most adverse events mild to moderate.¹ One serious cardiac adverse event occurred in a participant on the 800 mg twice-daily dose who was also taking pitolisant, a CYP2D6 substrate, and the FDA agreed the event stemmed from a drug interaction.¹

Aardvark intends to resume ARD-101 dosing in PWS patients at a lower dose than the 800 mg twice-daily level used in HERO and OLE, pending FDA discussions.¹ The FDA lifted the clinical hold on the ARD-101 investigational new drug application, as announced October 22, 2026.¹ The company plans to request an FDA meeting to align on a new Phase 3 design and expects to resume PWS clinical activities in 2027.¹