Two of the most closely watched programmes in cardiology walked into the American Heart Association’s Scientific Sessions in Chicago and did not walk out intact. Full results for both trials are now published, the subgroups have been dissected, and the market opens Monday with a cleaner picture of which stocks carry residual risk and which carry a credible remaining case.
Market Snapshot
Cardiology drug stocks dominate the pre-market watchlist. Novartis has said it will discontinue development of pelacarsen for atherosclerotic cardiovascular disease. Novo Nordisk stock dropped as much as 10% on July 31, 2026 after ziltivekimab failed its main goal in the Phase 3 ZEUS trial. Both failures are now fully documented and the full datasets change the valuation calculus for every company in the Lp(a) and inflammation space.
Stocks in Focus
NVS: Pelacarsen reduced Lp(a) levels by 78% in adults with elevated Lp(a) and established cardiovascular disease, yet there was no change in time to nonfatal heart attack, stroke, urgent revascularization, or cardiovascular death. In the subgroup of patients with a baseline Lp(a) of at least 90 mg per deciliter, rates of primary endpoint events were 12.3% in both the pelacarsen and placebo groups. That is the number that closes the escape hatch: analysts had hoped the highest-Lp(a) patients might show a signal. They did not. Novartis will continue investigating pelacarsen for calcific aortic valve stenosis, a narrower and commercially smaller path.
NVO: Over a median follow-up of 33 months, three-point MACE occurred in 17.6% of patients assigned ziltivekimab versus 17.7% assigned placebo, for a hazard ratio of 0.99. Ziltivekimab showed IL-6 pathway inhibition on biomarkers, but that drop did not translate into fewer heart attacks, strokes, or cardiovascular deaths in ZEUS. Novo will continue other cardiovascular studies of ziltivekimab, including ARTEMIS in patients recovering from an acute heart attack, with results expected in the first half of 2027. In heart failure, Novo has said it will close the HERMES trial after a Data Monitoring Committee recommendation to terminate it; ATHENA is completing as planned, with readouts still expected in the first half of 2027. Those trials are now load-bearing for the cardiovascular franchise.
IONS: The full data triggered declines in Novartis and its partner Ionis Pharmaceuticals. Ionis stood to receive tiered royalties in the mid-teens to low-20% range from pelacarsen, along with up to $650 million in milestone payments. Those economics are gone. Watch IONS at the open for the market’s updated read on how much damage the broader pipeline can absorb.
AMGN and LLY: This is where Monday gets interesting. Amgen has said olpasiran reduced Lp(a) by more than 95% in prior studies, a deeper cut than pelacarsen achieved, and OCEAN(a)-Outcomes targets patients with elevated Lp(a). However, pelacarsen was equally ineffective in the high-Lp(a) subgroup as in the overall population, which is a harder result to explain away with potency arguments alone. The pelacarsen failure now means the burden of proof is higher for Lilly’s lepodisiran and Amgen’s olpasiran, with OCEAN(a) now a higher-risk, higher-reward rather than an outright impaired proposition.
Sector Watch
Cardiology biotech faces a credibility event Monday morning. Two mechanisms, Lp(a) lowering via antisense oligonucleotide and IL-6 inhibition, have now each produced a large Phase 3 neutral result. More data is needed to determine whether the miss reflects pelacarsen’s mechanism, trial design, or a challenge to the whole hypothesis that lowering Lp(a) can reduce heart attacks and strokes. Cardiologists presenting the ZEUS findings at AHA stressed that the negative results do not invalidate inflammation’s role in cardiovascular disease. That distinction matters: it keeps Amgen’s and Lilly’s siRNA programmes alive scientifically, but it does not reduce the binary event risk sitting in front of OCEAN(a)-Outcomes.
Catalyst Calendar
- AMGN OCEAN(a)-Outcomes: Amgen’s OCEAN(a)-Outcomes Phase 3 trial is expected to enroll roughly 7,000 patients, but the study remains event-driven and public trial registries point to primary completion in 2028, not December 2026. The next hard catalyst for the entire Lp(a) space is therefore timing clarity, not a guaranteed near-term readout. Full pelacarsen subgroup data, now public, sets the bar analysts and investors will apply.
- NVO HERMES and ARTEMIS: Novo expects ziltivekimab readouts in the first half of 2027 from the ARTEMIS acute heart attack study and the ATHENA heart-failure study. HERMES is being closed after a Data Monitoring Committee recommendation to terminate it.
- IONS earnings and pipeline updates: Watch for management guidance on how the company reweights its portfolio following the loss of pelacarsen milestone economics.
The Cheat Sheet
- Top Market Theme: Lp(a) lowering and IL-6 pathway inhibition have both failed to reduce cardiovascular events in large Phase 3 trials, raising the evidence bar for every remaining programme in the space.
- Stock to Watch: AMGN. Pelacarsen’s subgroup failure removed the most optimistic read-through for olpasiran, but the depth-of-reduction argument and the eventual OCEAN(a) readout make it the pivotal name for the week.
- Sector to Watch: Cardiology biotech. Two simultaneous Phase 3 failures at the AHA’s main conference is a sector-defining event, and Monday’s price action will reset valuations across the board.
- Biggest Risk: The subgroup data showing no signal even in patients with the highest baseline Lp(a) levels is the most bearish new piece of information. If the thesis required deeper cuts, that case is now weaker.
- Biggest Opportunity: NVO on weakness, with cardiovascular readouts still expected in the first half of 2027 and a core GLP-1 franchise that analysts described as largely unaffected by the ZEUS outcome.
- One Thing to Remember: Biomarker reduction and clinical benefit are not the same thing. Both trials proved that point at scale this weekend, and that lesson will reprice every pipeline asset that has not yet shown an outcomes benefit.
