Merck Moves Forward in Bid To Bring First Oral PCSK9 Inhibitor to Market

Merck's oral PCSK9 inhibitor, enlicitide decanoate, demonstrated statistically significant and clinically meaningful reductions in LDL cholesterol in two Phase III trials (CORALreef HeFH and CORALreef AddOn) involving patients with high lipid levels already on statins. BMO Capital Markets estimates this could be a multi-billion dollar opportunity for Merck, expanding the PCSK9 market beyond injectable therapies, with the safety profile appearing consistent with earlier Phase II results. The company is conducting two more late-stage trials, with the Outcomes trial expected to conclude in 2029; if approved, enlicitide decanoate would be the first oral PCSK9 inhibitor.

Analysis

Merck's investigational oral PCSK9 inhibitor, enlicitide decanoate, has demonstrated positive topline results in two Phase III trials, CORALreef HeFH and CORALreef AddOn, achieving statistically significant and clinically meaningful reductions in low-density lipoprotein cholesterol (LDL-C) in patients with hypercholesterolemia already managed with statins. BMO Capital Markets highlighted this development as a potential "multi-billion dollar opportunity," suggesting it could expand the PCSK9 inhibitor market currently dominated by injectable therapies. Importantly, the safety profile appears favorable, with adverse events and serious adverse events balanced across treatment arms, aligning with prior Phase II data and leading BMO to consider the drug "largely de-risked" at this stage. While specific data from these trials were not disclosed, the successful outcomes in meeting primary and key secondary endpoints are significant. The drug's mechanism as an oral PCSK9 inhibitor could offer a convenient alternative to existing treatments. Two further late-stage trials, CORALreef Lipids (expected to conclude later this year) and CORALreef Outcomes (primary completion in November 2029), will provide additional data. If ultimately approved, enlicitide decanoate would be the first oral PCSK9 inhibitor, a notable advancement for Merck's cardiovascular franchise.

Key Decisions for Investors

• The positive Phase III results for enlicitide decanoate significantly bolster Merck's cardiovascular pipeline and present a substantial long-term growth catalyst, justifying a re-evaluation of the company's market position given the potential multi-billion dollar market expansion.
• Investors should closely monitor upcoming milestones, including the release of detailed data from the completed Phase III trials and the topline results from the CORALreef Lipids study expected later this year, to further assess the drug's clinical and commercial viability.
• Given the extended timeline for the CORALreef Outcomes trial (completion in 2029) and pending regulatory approvals, the full market impact is not immediate, but the prospect of a first-in-class oral PCSK9 inhibitor warrants consideration for long-term portfolio allocation, particularly noting the strong positive sentiment (MRK sentiment: 0.8) surrounding this development.