Amgen Falls 10% as Novartis Lp(a) Trial Failure Hits Cholesterol Drug Class

What happened

Amgen shares dropped about 10% on Tuesday after Novartis reported a failed Phase 3 trial for its Lp(a)-lowering therapy, stoking investor fears about the viability of the entire Lp(a) drug class. Amgen's own Lp(a) candidate, olpasiran, is in a pivotal cardiovascular outcomes trial slated to read out in the coming years, and the market is now discounting its success probability. The selloff was broad across developers of Lp(a) therapies, but Amgen was hit hardest among large caps given its significant cardiovascular franchise ambitions. This news compounds existing pressures on Amgen's pipeline, which already faces uncertainty in obesity from MariTide and erosion in legacy products. The stock had been trading around $339, and the decline pushes it closer to the low end of the analyst's range, but still above the attractive entry point of $295.

Implication

The failed Novartis trial introduces new doubt about the billion-dollar-plus opportunity for olpasiran, which had been a key secondary growth driver in Amgen's cardiovascular portfolio. While Amgen's siRNA mechanism differs from Novartis's approach, the market's harsh reaction signals that investors are now pricing a higher probability of class-wide failure, eroding margin of safety. Combined with already identified risks—IRA pricing pressure on ENBREL and Otezla, biosimilar erosion for Prolia/XGEVA, and the binary nature of MariTide—the risk/reward at the current price is unattractive. Long-term holders should monitor upcoming olpasiran data and management commentary for signs of differentiation or de-risking, while potential buyers should wait for a pullback below $295 where the valuation offers a better buffer. This event reinforces the thesis that Amgen's valuation embeds too much pipeline success, and a more conservative stance is warranted.

Thesis delta

The Novartis Lp(a) trial failure incrementally weakens the investment case by adding uncertainty to olpasiran, which was part of the medium-term growth narrative alongside MariTide and Horizon assets. While not a thesis breaker on its own, it reduces the probability-weighted value of the cardiovascular pipeline and supports the existing 'potential sell' rating. The thesis shifts toward a more defensive posture, with the attractive entry point arguably lower given the increased pipeline risk.