Amgen's cholesterol-lowering drug Repatha (evolocumab) continues to generate significant revenue growth while facing mounting safety questions that could reshape its market position. The company's ongoing HEROIC study is evaluating whether the PCSK9 inhibitor can reduce major cardiovascular events such as heart attack and stroke when combined with standard care in patients with atherosclerotic cardiovascular disease.
Clinical Efficacy Under Scrutiny
The FOURIER trial, which enrolled 27,564 patients, demonstrated a 15% relative risk reduction in the composite endpoint of cardiovascular death, myocardial infarction, stroke, or coronary revascularization. These results led to Repatha's expanded FDA indication and established its role in high-risk cardiovascular populations.
However, a 2022 reanalysis published in BMJ Open has cast doubt on the trial's mortality data integrity. The reanalysis revealed a 41.4% inconsistency rate in cause-of-death reporting between the Clinical Study Report and original findings, suggesting a potential 28% higher relative risk of cardiac deaths in the evolocumab group. While Amgen defended the trial's rigor, citing access to comprehensive adjudication data, the controversy has raised questions about Repatha's safety profile.
Recent data from the FOURIER-OLE study provide some reassurance, showing no cognitive decline in patients achieving LDL-C levels as low as 34 mg/dL during a 5.1-year follow-up period, addressing concerns about neurocognitive risks associated with very low cholesterol levels.
Strong Commercial Performance Despite Challenges
Repatha has demonstrated remarkable commercial resilience despite its high price tag exceeding $14,000 annually. By 2025, Amgen reported a 31% year-over-year sales increase to $696 million, driven by 36% volume growth. This growth reflects improved payer coverage, strategic rebates, and growing recognition of Repatha's role in lipid management.
The drug generated approximately $1.6 billion in global sales for Amgen in 2023, holding about 60% of the U.S. PCSK9 market share. The broader PCSK9 inhibitor market reached an estimated $4.5 billion in 2023 and is expanding at a compound annual growth rate of 12% from 2024 to 2030.
Competitive Landscape Intensifies
Repatha faces increasing competition in the evolving PCSK9 inhibitor market. Its primary rival, Praluent from Regeneron and Sanofi, offers similar efficacy but potentially lower net prices due to aggressive rebates. Novartis' Leqvio (inclisiran), a siRNA therapy requiring biannual dosing, has emerged as a disruptive force with its convenience and cost-effectiveness, particularly capturing market share in Europe.
Biosimilars pose a growing long-term threat, with Samsung Bioepis advancing a biosimilar to evolocumab that could potentially enter the market post-2029 when Repatha's core patents expire. Other competitors include oral agents like Merck's Zetia (ezetimibe) and novel therapies such as Esperion's bempedoic acid.
Pipeline Innovation and Future Prospects
Amgen is positioning itself for future growth through pipeline innovation. The company's olpasiran, an investigational siRNA targeting lipoprotein(a), demonstrated over 90% Lp(a) reduction in Phase 2 trials and is now advancing to Phase 3. This represents a significant opportunity to address unmet needs in lipid disorders, particularly Lp(a)-related hyperlipidemia where treatment options remain limited.
The outcome of the HEROIC study could provide additional evidence to support Repatha's cardiovascular benefits and potentially justify price premiums while maintaining market share. However, the company must navigate ongoing safety concerns while competing against next-generation therapies including oral PCSK9 inhibitors and gene-editing approaches.
Market Outlook and Investment Implications
Repatha's global sales are projected to grow at a 10% compound annual growth rate through 2027, driven by expanding indications and market penetration, before facing biosimilar competition. U.S. net prices are expected to stabilize at $3,500 annually through 2026, then decline to $3,000 by 2030 due to patent expirations and market forces.
The growing prevalence of cardiovascular disease and unmet need for lipid-lowering therapies present compelling long-term opportunities, with Asia-Pacific markets offering 15-20% higher growth rates than mature markets. However, stakeholders must prepare for price pressures from biosimilars, regulatory reforms including the Inflation Reduction Act, and intensifying competition from innovative delivery mechanisms and treatment approaches.
