Aardvark Therapeutics Inc. (NASDAQ:AARD) had a rough Friday. Shares plunged after the biopharmaceutical company unblinded exploratory efficacy data from its terminated Phase 3 HERO trial and open-label extension study, and the headline was essentially: the data are not enough.

The company was evaluating the safety and clinical profile of ARD-101 in patients with Prader-Willi syndrome, a rare genetic disorder whose hallmark is hyperphagia, a condition that causes extreme hunger.

What The Hunger Scores Actually Showed

The HERO trial randomized 67 of 90 planned participants before the company ended the study early. During the second week of dose escalation, participants taking ARD-101 demonstrated a modest reduction in Hyperphagia Questionnaire for Clinical Trials scores versus placebo.

Then there's the rebound. Hunger scores returned near baseline after patients stopped ARD-101, while the placebo cohort showed less rebound. In the open-label extension cohort, participants who switched from placebo to ARD-101 achieved an average six-point reduction in hunger scores. Caregiver and clinician outcome ratings mirrored this trend.

Directionally consistent, in other words, but not definitive. CEO Tien Lee acknowledged as much.

“Though the HERO trial was stopped early and the current partial data are not sufficient to draw definitive conclusions, we believe these exploratory efficacy and safety data are directionally consistent and give us confidence in the continued development of ARD-101 for the treatment of PWS,” said Lee, Founder and CEO of Aardvark.

Safety, A Cardiac Event, And The Path Forward

Patients generally tolerated ARD-101 well, reporting mostly mild to moderate adverse events. The company identified one serious cardiac adverse event at the 800 mg twice-daily dose in a patient concurrently taking pitolisant, which the U.S. Food and Drug Administration attributed to a drug-drug interaction.

Aardvark plans to resume ARD-101 dosing in patients at a dose below 800 mg twice daily. The drugmaker also plans to request an FDA meeting to align its Phase 3 program and advance the therapeutic toward potential regulatory approval.

The Regulatory Rollercoaster

The timing here is worth noting. On Thursday, the FDA lifted the clinical hold on ARD-101. That is normally the kind of news that sends a small biotech stock higher, and it did at the time.

The backstory: in February, Aardvark Therapeutics voluntarily paused its Phase 3 HERO trial due to reversible cardiac observations at higher than target therapeutic doses found during routine safety monitoring. In May, the FDA placed a full clinical hold on ARD-101, applying to all ongoing studies under the IND, including the Phase 3 HERO trial evaluating ARD-101 in patients with hyperphagia linked to Prader-Willi Syndrome, as well as the open-label extension study.

So the hold is gone, but the data that came with the unblinding are not the slam dunk investors might have hoped for. The market's verdict was swift.

AARD Price Action: Aardvark Therapeutics shares were down 56.71% at $1.70 at the time of publication on Friday. The stock is trading at a new 52-week low, according to market data.