Amgen (AMGN) is trading lower after the company’s April 30, 2026 first-quarter earnings update put renewed focus on near-term headwinds—even as headline results showed growth. Management flagged that 2026 could see accelerated sales erosion as competition increases, with multiple biosimilars launching globally, reinforcing investor concerns about the pace of declines in mature products.

In Q1 2026, Amgen reported total revenue of about $8.6 billion, up 6% year over year, with non-GAAP EPS of $5.15, and it raised full-year 2026 guidance (revenue and non-GAAP EPS). The market’s focus today is less on the beat/raise and more on the mix: several established franchises are shrinking quickly under competitive pressure, including material declines in Prolia/Xgeva tied to biosimilar dynamics, which heightens sensitivity to any incremental negative development.

Beyond competition-driven erosion, Amgen’s Q1 disclosures also highlighted two notable overhangs: (1) a proposed FDA withdrawal process involving Tavneos and (2) an IRS draft notice of proposed adjustment (NOPA) covering tax years 2016–2018 that the company indicated could be material if sustained. Together, these items can weigh on sentiment because they introduce uncertainty that is not directly resolved by quarterly performance.

Investors will likely watch for updated detail on the trajectory of legacy-brand erosion through Q2 2026, management’s cadence of pipeline readouts and commercialization updates intended to offset LOE declines, and any procedural milestones tied to the Tavneos regulatory process and the IRS matter. With the stock down sharply today, the next catalysts are expected to be follow-on analyst changes, additional company clarifications, and evidence that growth brands can consistently outpace erosion across the portfolio.