Amgen adds about $9 billion in value on a Sjögren's drug win, but the release gives no effect size

Amgen said on Tuesday that its experimental drug dazodalibep met the main goal of a late-stage trial in Sjögren's disease, an autoimmune condition with no FDA-approved medicine. The company's release said the OASIZ 301 study showed a "statistically significant and clinically meaningful" improvement in disease activity at week 48 compared with placebo. Reuters, Fierce Biotech and Benzinga all reported the result.

Amgen shares were up 4.2% at $409.74 at 2:54 p.m. ET, from a $393.16 close, according to Nasdaq data.

What the trial measured

OASIZ 301 enrolled about 621 adults with moderate-to-severe systemic disease, meaning the illness goes beyond dryness. Amgen's release lists fatigue, chronic pain, major organ involvement, nerve damage and a higher risk of lymphoma among the disease's serious effects. The primary measure was the change in a standard disease activity score called ESSDAI after 48 weeks. Amgen said improvement showed up as early as week 4 and held through week 48.

On safety, the company listed common colds, urinary tract infections, high blood pressure and infusion reactions as the side effects seen more often on the drug than on placebo, mostly mild to moderate. Dazodalibep is designed to block CD40L, a signal that T cells, B cells and other immune cells use to activate one another, and Amgen specifically reported no imbalance in blood clots or opportunistic infections between the groups.

What the release leaves out

The release gives no numbers for how big the benefit was. There is no score change for either arm, no placebo-adjusted difference and no result for the key secondary endpoints Amgen named, which covered dryness, joint counts, fatigue and the share of patients improving by at least five points. Amgen said full data will come at a medical meeting.

"Met the primary endpoint" says the drug beat placebo by more than chance would explain. It does not say by how much, and that is the figure doctors, payers and investors will price. Until it is published, the 4% move is a bet that the number is good.

The second gap is timing. Amgen is running a second Phase 3 study, OASIZ 303, in patients whose main problem is symptoms such as dryness, fatigue and pain rather than organ involvement. The release says it is expected to complete in the fourth quarter of 2026. A Benzinga headline said an approval filing awaits that data. Today's result covers only the first of the two patient groups Amgen is targeting.

The number behind the move

Nasdaq put Amgen's market value at about $221 billion this afternoon. A gain of $16.58 a share on roughly that base works out to about $9 billion added in a day, for a drug with no disclosed efficacy figure yet. Amgen came to the drug through its acquisition of Horizon Therapeutics, Fierce Biotech noted.

The stock is still about 8% below its 52-week high of $447.03. Amgen is also one of the 30 Dow Jones Industrial Average stocks, and its rise was not enough to lift the Dow, which was down about 0.3% on the afternoon according to our markets board.

For traders, the next dates are the medical meeting where the full OASIZ 301 data appears and the OASIZ 303 readout. See more company moves in Stocks.

Sources: Amgen press release (PR Newswire); Reuters; Fierce Biotech; Benzinga; Nasdaq. Value change calculated by The Company Chronicle from Nasdaq market capitalization and share price data. This is market information, not investment advice.