Key Highlights

● Aardvark traded around $4.73 after the bell on October 22, an after-hours price.

● The FDA lifted the clinical hold on ARD-101 for Prader-Willi syndrome.

● Dosing stopped on February 27, 2026, after reversible ECG changes.

● A webcast is scheduled for Friday at 8:00 AM ET.

Shares of Aardvark Therapeutics (NASDAQ:AARD) surged in after-hours trading on Thursday, October 22, 2026, after the company said the US Food and Drug Administration had lifted a clinical hold on its experimental drug ARD-101. The move came after the regular session closed, putting the small biotech among the notable after-hours gainers on the Nasdaq Composite.

The stock traded around $4.73 after the bell. Aardvark is a micro-cap company with a market value of roughly $85 million. After-hours prices are not closing prices, and Friday's regular session will show whether the gain holds.

What the FDA decided

Aardvark announced at 4:05 PM ET that the FDA had lifted the clinical hold on ARD-101, which the company is developing to treat hyperphagia in Prader-Willi syndrome.

Prader-Willi syndrome is a rare genetic disorder. One of its hallmark features is hyperphagia, an intense and persistent hunger that can be extremely difficult for patients and families to manage. That makes progress on new treatment approaches closely watched by patients, doctors and investors alike.

"We are pleased that the FDA has lifted the clinical hold on ARD-101," Founder and Chief Executive Tien Lee, M.D., said.

How the hold came about

The program had been on pause for months. Aardvark stopped dosing on February 27, 2026, after it observed reversible ECG changes, which are changes in the electrical activity of the heart. The FDA's clinical hold followed in May.

To address the issue, the company ran a follow-up study in healthy volunteers that monitored ECG readings. That study showed no cardiac events at doses of 200 milligrams and 400 milligrams taken twice a day, according to the company.

The lifting of the hold means Aardvark can move forward with clinical development of the drug. A hold is one of the more serious setbacks a development-stage biotech can face, and its removal clears a significant uncertainty for a company of Aardvark's size.

Webcast on Friday morning

Aardvark has scheduled a webcast for Friday, October 23, at 8:00 AM ET, before the market opens. The company plans to discuss exploratory data from its HERO study and the related open-label extension, or OLE. Investors will be listening for detail on how the drug performed and on the timeline for resuming dosing.

The regular-session backdrop

Thursday's regular session was a split one. Technology and chip stocks were hammered after Meta Platforms (NASDAQ:META) reported heavy AI spending and negative free cash flow, and Lam Research (NASDAQ:LRCX) warned of supply constraints. The Nasdaq Composite fell 694.00 points to 26,008.86, its steepest drop since June 5, and lost about $1 trillion in market value, according to market data.

Health care fared far better. The S&P 500 health care sector hit a record high, even though Moderna (NASDAQ:MRNA) slid after late-stage melanoma vaccine data appeared before its scheduled presentation. About two of every three S&P 500 stocks rose, according to market reports, and the Russell 2000 edged up 3.01 points to 2,784.03.

Small biotech stocks were active throughout the day. Biohaven (NYSE:BHVN) jumped after the FDA accepted its resubmitted application for a drug in spinocerebellar ataxia, while Korro Bio (NASDAQ:KRRO) rose on preclinical data.

Aardvark Details Its Path Back to Dosing

Friday's 8:00 AM ET webcast is the immediate focus, along with any update on when Aardvark expects to resume dosing in Prader-Willi patients. The regular session will be the first full test of the after-hours rally. As with many micro-cap biotech stocks, the shares may remain volatile as investors digest the details.