Aardvark's HERO trial for ARD-101 in PWS is suspended, completion slips a year
Aardvark kept guiding to a Q3 2026 readout even as its registry record shows the trial suspended and its completion date pushed from March 2026 to March 2027.
Executive Summary
- The registry record for Aardvark's pivotal Prader-Willi Syndrome trial shows a suspension and a year-long push to its completion date, which runs against the sponsor's own repeated near-term readout guidance.
- Aardvark kept telling investors to expect topline data in the third quarter of 2026 in filing after filing, even as the trial's own registry timeline moved a full year later.
- The trial is designed to show whether ARD-101 reduces hyperphagia, the pathological hunger drive that defines Prader-Willi Syndrome, against placebo on a validated caregiver-reported scale.
- No other Phase 3 program in Prader-Willi Syndrome shares ARD-101's target profile, leaving this readout as the only current test of its specific mechanism in the disease even as several small-molecule and peptide programs pursue the same indication through different pathways.
The registry shift
The HERO trial (NCT06828861), a randomized, placebo-controlled Phase 3 study of ARD-101 in 90 patients with Prader-Willi Syndrome, changed status from Recruiting to Suspended on March 19, 2026. Three weeks later, on April 9, 2026, the registry's primary completion date moved from March 1, 2026 to March 1, 2027, a 12-month push. The two changes landed in sequence, with the status change first and the completion-date revision following, rather than the reverse. NCT06828861ARD-101 for Treatment of PWS: The Hunger Elimination or Reduction Objective TrialNCT06828861
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
Guidance that didn't move
Aardvark's second-quarter 2025 disclosure said topline data from the Phase 3 HERO trial "is expected in the third quarter of 2026". That Q3 2026 guidance repeated across at least seven subsequent communications tracked through June 19, 2026, the most recent update before the suspension was reflected in outward guidance. The gap between that guidance and the registry's own revised completion date of March 2027 has not been reconciled in the sponsor's public statements. AardvarkAardvark Therapeutics Reports Second Quarter 2025 Financial Results and Provides Pipeline and ...Aug 13, 2025
The endpoint at stake
The trial's primary endpoint is the change in the Hyperphagia Questionnaire for Clinical Trials (HQ-CT) score, a caregiver-reported measure of the hunger drive that defines the syndrome, in patients randomized to ARD-101 or placebo. Secondary endpoints track caregiver and clinician global-impression-of-severity scores for hyperphagia. The trial enrolled patients in the United States, Canada, the United Kingdom, Australia, and South Korea, and it carries Orphan Drug and Rare Pediatric Disease designations for Prader-Willi Syndrome. NCT06828861ARD-101 for Treatment of PWS: The Hunger Elimination or Reduction Objective TrialNCT06828861
Enrollment held steady
The trial's anticipated enrollment target has not changed, sitting at 90 patients before and after the suspension, which the operational model flags as within its routine band rather than a cut or shortfall. That means the suspension is not paired with an enrollment reduction; whatever triggered the pause did not also shrink the trial's intended size. NCT06828861ARD-101 for Treatment of PWS: The Hunger Elimination or Reduction Objective TrialNCT06828861
The competitive field
Prader-Willi Syndrome hyperphagia has drawn a small-molecule field that includes Soleno Therapeutics' diazoxide choline (NCT05701774, NCT04086810), Harmony Biosciences' pitolisant (NCT07219485), and Radius Pharmaceuticals' cannabidiol (NCT05387798), none of which shares ARD-101's target. No competitor in this field shares ARD-101's specific mechanism, leaving the HERO trial as an isolated test of its own hypothesis rather than one entry in a mechanistically converged race. NCT06828861ARD-101 for Treatment of PWS: The Hunger Elimination or Reduction Objective TrialNCT06828861
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.