Amgen (AMGN) Fell 5% on a Drug That Isn’t Even Its Own. Here’s the Lp(a) Bet Now in Question.

Amgen's stock dipped 5% following Novartis' announcement that its Lp(a)-lowering drug, pelacarsen, had failed to reduce a composite cardiovascular event measure in a Phase 3 trial. This news had a ripple effect, as Amgen's own siRNA drug, olpasiran, relies on a similar biological premise. Although olpasiran has demonstrated a 95% reduction in Lp(a) in Phase 2 trials, the Lp(a)HORIZON trial provided no evidence that deeper Lp(a) lowering would translate to clinical benefit.

The failure of pelacarsen to reduce the composite of cardiovascular events has cast doubt on the entire hypothesis that lowering Lp(a), a genetic cardiovascular risk factor, directly cuts cardiovascular events. While Amgen's diversified portfolio, including MariTide in obesity, Repatha in cholesterol, and Tezspire in asthma, helps mitigate the impact of individual failures, the olpasiran stock selloff still stands at 5% after hours.