This year's run in drug stocks gained vigor from new treatments for heart attacks and strokes. Maybe some of those stocks are losing wind.

At this past weekend's congress of the European Society of Cardiology, in Munich, good results came out on drugs from Amgen, Arrowhead Pharmaceuticals, and Crispr Therapeutics. Their shares are all lower this week.

Amgen said that its big-selling cholesterol cutter shot, Repatha, reduced deaths by 20% in a study of 12,000 patients at high risk of having their first heart attack or stroke. The stock is down 1% from Friday's close, to a Tuesday afternoon price of $432.50.

Repatha brought Amgen sales of $3 billion last year, as doctors prescribed it to patients with high levels of the artery-scarring LDL cholesterol. The drug inhibits a natural protein known as PCSK9, which keeps the liver from clearing LDL from the blood. Doctors might prescribe Repatha more widely, thanks to the new evidence of its preventive power.

Arrowhead stock is down a steeper 6% since Friday, to $83, despite showing impressive data from a Phase 3 trial of its Plozasiran, which silences a gene that raises blood levels of triglycerides.

Besides harming arteries, high triglycerides can hospitalize people by bringing on excruciatingly painful inflammations of the pancreas. Among patients with chronically high levels of those fatty particles, Arrowhead's gene-silencer cut triglycerides by 80%, and reduced acute pancreatitis attacks by a similar proportion.

Even if Arrowhead can get approval from the U.S. Food and Drug Administration by mid-2027, as it hopes, it will be playing catch-up to rival Ionis Pharmaceuticals. In June 2026, the FDA approved Ionis' Tryngolza gene-silencer for patients with severely high triglycerides. The two companies each say there will be plenty of room for the products, because the roughly one million Americans with the condition are underserved.

One other biotech company whose good news failed to lift its stock was Crispr Therapeutics. The company is one of the half-dozen start-ups that came public to commercialize the Crispr gene-editing technologies, which can permanently change our cells' DNA templates to correct harmful genes.

Crispr stock is down 7% in the last two days to $56.75, even after showing Saturday's conference attendees the excellent one-year results among 15 patients who had edits of their ANGPTL3-producing gene, which regulates blood levels of LDL cholesterol and triglycerides.

The patients' one-year declines in those troublemaking blood fats were even deeper than those measured 30 and 60 days after the one-time infusions of Crispr's CTX310. After a year, LDL and triglycerides fell about 50% in the patients who had received the biggest infusions of Crispr's treatment.

While the gene-editor's triglyceride reduction wasn't as deep as that shown by Ionis, Arrowhead, or the Regeneron Pharmaceuticals drug Evkeeza, the Crispr treatment cuts LDL better than those drugs. In a Monday note, H.C. Wainwright analyst Mitchell Kapoor says he'll be watching to see how competitive CTX310's triglyceride cutting proves to be.