Amgen Stock Slides 12.6% as Novo Nordisk Holds GLP-1 Lead

Amgen's stock has declined 12.6% in the past three months, as investors weigh near-term revenue pressure, patent expirations, obesity-drug competition and uncertainty around future growth drivers, even though its first-quarter results were relatively solid. Meanwhile, Novo Nordisk remains the global market leader in GLP-1 medicines, with a total GLP-1 volume market share of 54.6% across diabetes and obesity care as of 2025-end.

Amgen's revenues rose 6% to $8.62 billion in the first quarter of 2026, driven by growing patient demand for its innovative medicines. Key growth drivers, including Repatha, Evenity, Tezspire, oncology and rare disease drugs, and biosimilar products, generated $5.6 billion in sales in the quarter, up 24% year over year. These products represent almost 70% of Amgen's total product sales. Seventeen of Amgen's products are now annualizing at more than $1 billion in sales, reducing dependence on any single product.

Amgen is developing MariTide, a GIPR/GLP-1 receptor obesity candidate, as a single dose in a convenient autoinjector device with a monthly and possibly less frequent dosing. The company has nine global phase III studies underway with MariTide in obesity and related conditions such as obstructive sleep apnea, cardiovascular disease and heart failure, and three phase III studies in type II diabetes are set to begin in 2026. Beyond MariTide, Amgen sees potential in late-stage programs olpasiran and dazodalibep. In the first quarter of 2026, Amgen's biosimilar products generated sales of $835 million, up 14% year over year, and have delivered more than $14 billion in sales since the first launch in 2018. Phase III studies are evaluating biosimilar versions of Opdivo (ABP 206), Keytruda (ABP 234) and Ocrevus (ABP 692). Patents for Amgen's best-selling drugs Prolia and Xgeva expired in February 2025 in the United States.

Novo Nordisk markets semaglutide drugs under brand names Ozempic and Rybelsus for type II diabetes, and Wegovy for chronic weight management. In 2025, Rybelsus became the first oral therapy approved in the United States to lower the risk of major adverse cardiovascular events in high-risk type 2 diabetes patients. Wegovy's label includes cardiovascular, HFpEF and osteoarthritis indications, while Ozempic remains the only GLP-1 approved to slow kidney disease and reduce cardiovascular death in patients with diabetes. Higher-dose Wegovy injections have been approved in the United States and the EU. In late December, the FDA approved Novo Nordisk's 25 mg oral semaglutide (Wegovy pill) for obesity and cardiovascular disease, subsequently launched in early January. The FDA also approved an oral version of Ozempic for adult type 2 diabetes patients, with a supplemental application for a higher 25 mg tablet under review and a regulatory decision expected by the end of 2026. Novo Nordisk intends to seek regulatory approval for Rybelsus and oral Ozempic in children and adolescents aged 10 to 17 years with type 2 diabetes in the United States and the EU in the second half of 2026.

Novo Nordisk has submitted a regulatory filing seeking approval of CagriSema injection, a follow-up to Wegovy, for obesity. Its mid-stage asset amycretin has shown strong weight-loss efficacy in a phase II study and is slated to enter phase III. In rare disease, the company has secured EU and U.S. approvals for Alhemo to treat hemophilia A and B, and the FDA has granted accelerated approval for Wegovy in treating MASH with fibrosis. Novo Nordisk faces increasing competition from Eli Lilly's tirzepatide medicines, Mounjaro for type 2 diabetes and Zepbound for obesity, as well as the recently approved oral GLP-1 drug orforglipron, marketed as Foundayo. Management expects both sales and operating profit to decline in 2026. Both Novo Nordisk and Eli Lilly have introduced multiple price cuts in response to pressure from the U.S. government to improve patient access to GLP-1 medicines.

The US Section 301 investigation into Germany's pharmaceutical pricing has put the spotlight on how global trade policy can affect large US-based drug companies. Among US pharmaceutical stocks flagged for strong margins and earnings growth are Krystal Biotech, which generates about $417.3 million in revenue from its VYJUVEK gene therapy and has a market cap of US$10.1 billion; Kiniksa Pharmaceuticals International, with about $754.0 million in revenue from ARCALYST and a market cap of US$4.2 billion; and Gilead Sciences, which generates about $29.7 billion in revenue, has a market cap of US$155.8 billion and pays a 2.65% dividend.