Key Highlights

● Biohaven soared to around $14.55 after the FDA accepted its resubmitted rare disease drug application.

● Aardvark jumped to about $4.73 after hours when the FDA lifted a clinical hold.

● Lucid Diagnostics rose after Medicare began paying $1,938.01 per EsoGuard test.

● Lycia Therapeutics priced an upsized IPO at $18.00 a share, raising about $317.5 million.

In biotech, a single regulatory letter can be worth more than a quarter's earnings. Thursday proved the point.

Shares of Biohaven (NYSE:BHVN) soared on Thursday, October 22, trading around $14.55 in the early afternoon, according to market data, after the Food and Drug Administration accepted its resubmitted application for a rare disease drug. After the closing bell, Aardvark Therapeutics (NASDAQ:AARD) jumped in after-hours trading when the agency lifted a clinical hold on its lead program.

The moves came as the health care sector climbed to a record high, even as the broader S&P 500 fell 93.74 points to 7,663.43.

Biohaven gets a second chance

Biohaven said the FDA accepted its new drug application resubmission for Vyglxia, also known as troriluzole, in spinocerebellar ataxia. The agency treated the filing as a complete response to the complete response letter it issued on November 4, 2025, according to a Biohaven filing.

The FDA set a target decision date in the first quarter of 2027, without naming a specific day. It also plans to convene its Peripheral and Central Nervous System Advisory Committee, with a meeting date to come "in the near term," the company said.

The resubmission included "new positive supportive analyses," according to the company's filing. The stock was even higher earlier in the day, with premarket and morning gains larger than its afternoon level, according to market snapshots.

Aardvark's hold is lifted

Aardvark announced at 4:05 p.m. ET that the FDA had lifted the clinical hold on ARD-101, its experimental treatment for hyperphagia, the extreme hunger linked to Prader-Willi syndrome. The shares rose to about $4.73 in after-hours trading.

The company paused dosing on February 27, 2026, after observing reversible ECG changes, and the FDA hold followed in May. A follow-up study in healthy volunteers showed no cardiac events at the tested doses, the company said.

"We are pleased that the FDA has lifted the clinical hold on ARD-101," founder and chief executive Tien Lee said. The company has scheduled a webcast for 8:00 a.m. ET on Friday, October 23, to discuss exploratory data.

A Medicare milestone

Lucid Diagnostics (NASDAQ:LUCD) also jumped after hours on reimbursement news rather than an FDA ruling. The company said it has begun receiving Medicare payments for its EsoGuard test at $1,938.01 per test and closed a $15.0 million private placement. "Medicare is now paying for EsoGuard," chairman and chief executive Lishan Aklog said.

The other side of the ledger

Not all of Thursday's biotech news was welcome. Moderna (NASDAQ:MRNA) sank after Phase 3 melanoma vaccine data with partner Merck (NYSE:MRK) reportedly leaked ahead of its scheduled presentation, and was the worst performer in the S&P 500. Avalo Therapeutics plunged on a read-through from rival AbbVie's skin disease data, while MoonLake Immunotherapeutics rallied on the same news.

Korro Bio surged after releasing preclinical data for KRRO-111 in alpha-1 antitrypsin deficiency.

New supply is also arriving. Lycia Therapeutics priced an upsized initial public offering of 17,640,000 shares at $18.00 each, raising about $317.5 million. It is set to begin trading on Friday.

Friday's Biotech Calendar

Aardvark's Friday webcast will be the next event for that stock. Biohaven investors will watch for the FDA advisory committee date. Moderna and Merck present full melanoma data at the ESMO conference in Madrid on Saturday, and Lycia's market debut on Friday will offer a read on appetite for new biotech issues.