The biomarker fell but the disease did not: how one failure repriced three companies that did not run the trial

Executive summary

• What happened. On Friday 4 September, after the US market closed, Novartis announced that its Phase 3 Trial Lp(a)HORIZON had missed its primary endpoint. The drug, pelacarsen, lowered lipoprotein(a) — but the company said through its head of development that this “did not translate into a reduction in cardiovascular risk in the overall study population”.
• Why this matters beyond Novartis. The market was not pricing one drug but an entire mechanism. Two companies that did not run the trial — Amgen and Eli Lilly — declined because they are developing drugs targeting the same biomarker. Amgen’s trial will not complete before March 2028, and Lilly’s before March 2029; neither has announced a single result yet.
• The clean measurement enabled by the calendar. US markets were closed on Monday 7 September for Labor Day, while the Zurich exchange was open. Zurich therefore priced the pelacarsen news alone, with no other news alongside it: a close at −3.18%. Every larger figure relates to a different drug announced on Tuesday.
• The key finding. When New York opened on Tuesday, the Opening Cross was ranked precisely by ownership of the science that failed: Novartis −12.53%, followed by Ionis −10.22%, then Amgen −6.48%, then Eli Lilly −0.97%. By the close, that order had reversed: 7.84 percentage points returned to Ionis, while a further 3.60 points came out of Amgen. The open priced ownership; the close priced positions.
• The control, and its limits. The biotechnology indices XBI closed at −1.15% and IBB at −2.17%. Novartis and Amgen moved five to twelve times more than the sector, and that dispersion carries the meaning. Ionis and Eli Lilly, meanwhile, ended around the sector move itself — itself part of the result: Ionis’s idiosyncratic loss was almost entirely erased.