Amgen Falls 10% After a Rival's Cholesterol Trial Misses Its Goal

Amgen fell 10.1% on Tuesday, closing at $393.17, after a competitor’s late-stage cholesterol trial failed and cast doubt on a drug class Amgen is also pursuing. The selling was heavy. Volume ran at just over three times the stock’s 20-day average, and the drop wiped out $44 from a share price that had ended the prior session above $437.

A trial that lowered the target but not the risk

The trigger came from Novartis. On September 4 the company reported topline results from Lp(a)HORIZON, a Phase III study of an experimental drug called pelacarsen. The trial enrolled 8,323 patients who had elevated lipoprotein(a), an inherited risk factor known as Lp(a), together with established cardiovascular disease. Pelacarsen did lower Lp(a) in those patients. What it did not do was reduce the study’s main measure of harm: the combined rate of cardiovascular death, non-fatal heart attack, non-fatal stroke and urgent coronary procedures, compared with placebo. Pelacarsen is an antisense drug that Novartis licensed from Ionis Pharmaceuticals.

The result carried straight into Amgen because Amgen is chasing the same target. Its drug olpasiran is designed to lower Lp(a) as well, and it is being tested in a late-stage outcomes study called OCEAN(a)-Outcomes. The two treatments are built differently and enrolled different patients, so pelacarsen’s miss does not decide olpasiran’s fate. But it undercut the assumption that lowering Lp(a) reliably lowers the rate of heart attacks and strokes, which is the premise the whole class rests on. BMO Capital cut its rating on Amgen the same session. Novartis shares fell sharply, and Eli Lilly, which is developing its own Lp(a) treatment, slipped as investors marked down the group.

Where Tuesday left the stock

The one-day slide landed on an already-soft stretch. Amgen had drifted down 4.3% over the prior 30 days before Tuesday added the bulk of the damage. The close left the stock 11.5% below its highest point of the past three months, a peak of $444.12, and 21.4% above the range’s low of $323.85. The drop knocked Amgen out of the upper part of its recent range and down into the middle of it, still well clear of the summer floor. For a company this size, a single-session move of that scale is rare.

Volume tells the rest. At just over three times the 20-day pace, Tuesday’s trading confirmed the session was a response to the trial news. The broad market barely moved that day, which pins the decline to the drug class alone. Amgen supplies drugs across cancer, inflammation and heart disease, so a setback in one experimental program still reset how the whole company was valued.

What the olpasiran data will settle

One question now hangs over the stock. It is whether olpasiran, given more time and a different design, produces the outcome pelacarsen could not. That answer rests with the OCEAN(a)-Outcomes trial, and Amgen has not set a public date for its results. Novartis has said it will present the full pelacarsen data at a medical meeting, where cardiologists will examine how completely the drug lowered Lp(a) and why the benefit did not follow. Both events will shape how investors read the class from here. Neither carries a confirmed date yet, and until they arrive the debate over whether Tuesday’s move was an overreaction stays open.

This is a general-market summary for information only — not investment advice, and not a recommendation regarding any security.