Oral and Non-Oral Cholesterol-Lowering Drugs with PCSK9 and Other Biomolecules as Targets: Present Status and Future Prospects.

March 13th, 2025

AQUR

The Future of Cholesterol Management: why oral PCSK9 inhibitors could change everything

Every minute, somewhere in the world, someone suffers a heart attack or stroke. The common culprit? Elevated levels of low-density lipoprotein cholesterol (LDL-C)—more popularly known as “bad cholesterol.”

Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and while the importance of healthy eating and physical activity cannot be overstated, sometimes they aren’t enough. For millions, effective medication becomes the most vital line of defense. And now, in a field long dominated by statins and injections, a new class of drugs is on the horizon—oral PCSK9 inhibitors—bringing hope to patients and physicians alike. Cholesterol gets a bad rap, but it’s not all villainy.

This fat-like substance is essential for life: it stabilizes cell membranes, helps synthesize hormones (like estrogen, testosterone, and cortisol), and is even involved in vitamin D production. But when cholesterol—especially LDL-C—builds up in the blood, it sticks to artery walls, forming plaques that can block blood flow.

This process, called atherosclerosis, is the ticking time bomb behind heart attacks and strokes. That’s why managing cholesterol—especially LDL-C—is a non-negotiable aspect of long-term health

The Traditional Tools: Statins and Beyond

Since the 1980s, statins have been the gold standard in cholesterol-lowering therapy. They work by inhibiting HMG-CoA reductase, an enzyme involved in cholesterol production in the liver. They’re widely prescribed, orally administered, and affordable. But statins aren’t for everyone. Roughly 10% of patients experience side effects, including: muscle pain and weakness (rhabdomyolysis), liver enzyme elevation, increased risk of type 2 diabetes, fatigue and memory fog. For those patients or for those who need more aggressive cholesterol control, other options are needed.

Enter PCSK9: The New Target in Cholesterol Control

In 2003, scientists discovered a new protein called PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9). Its role? Regulating the number of LDL receptors on liver cells—the same receptors responsible for clearing LDL from the bloodstream. Here’s the catch: More PCSK9 = fewer LDL receptors = more LDL-C in your blood. This insight transformed PCSK9 into a superstar target for cholesterol-lowering drug development.

The power of PCSK9 inhibitors, but at a cost

Today, three PCSK9 inhibitors are approved and on the market:

Alirocumab (Praluent)
Evolocumab (Repatha)
Inclisiran (Leqvio)

These drugs are incredibly effective—able to reduce LDL-C by 50–70%. But they all come with two major downsides:

They’re injectable—requiring subcutaneous injections every 2–4 weeks or biannually.
They’re expensive, costing thousands of dollars annually.

For many patients, this makes them impractical despite their effectiveness.

Why Oral PCSK9 Inhibitors Are the Future

Imagine achieving the power of a PCSK9 inhibitor with the convenience of a once-daily pill.

No needles.
No clinic visits.
Lower costs.
Better patient adherence.

That’s the promise of oral PCSK9 inhibitors—and pharmaceutical companies are racing to deliver.

Oral PCSK9 Drugs in Development: Who’s Leading the Race?

Several compounds are in various stages of development, with some already showing powerful results in clinical trials:

🔹 MK-0616 (Merck)

Status: Phase III trials
Effectiveness: Up to 60% LDL-C reduction
Delivery: Daily oral tablet
Fun fact: Called the “molecule of the year” in 2023 for its potential to reshape cholesterol therapy

🔹 AZD0780 (AstraZeneca)

Status: Phase II trials
Key advantage: Demonstrated 78% LDL-C reduction when used with statins
Mechanism: Small molecule that enhances LDL-receptor recycling by inhibiting PCSK9

🔹 NNC0385-0434 (Novo Nordisk)

Status: Completed Phase II trial
Innovation: Uses SNAC technology to survive stomach acid
Limitation: Discontinued for strategic reasons, despite promising results

🔹 CVI-LM001 & DC371739

Origin: Derived from natural plant compounds (e.g., Corydalis ambigua)
Promise: Modulate PCSK9 expression with minimal side effects
Status: Early-phase trials showing significant LDL-C reductions

🔹 AZD8233 (Antisense Therapy)

Status: Discontinued
Challenge: Did not meet efficacy thresholds, highlighting the difficulty of drug delivery to the liver via oral routes

The Science Behind the Pill: How Oral PCSK9 Drugs Work

PCSK9 inhibitors traditionally work by blocking the protein’s interaction with LDL receptors, preventing their degradation. Oral versions aim to do the same, but with small molecules or macrocyclic peptides instead of large injectable antibodies. The biggest challenge? Surviving the stomach and being absorbed effectively—a feat that technologies like macrocyclic design and permeation enhancers are helping solve.

While not nearly as powerful, plant sterols like sitosterol and sitostanol have shown modest cholesterol-lowering effects, especially in children with familial hypercholesterolemia. These natural compounds block cholesterol absorption in the intestine and are being explored for complementary therapies.

The future is promising:

MK-0616 may hit the market as early as 2026
Oral therapies will likely become first-line options for statin-intolerant patients
Prices are expected to fall as competition and innovation increase

Meanwhile, injectable PCSK9 inhibitors are evolving too—offering longer-lasting effects and improved safety profiles. But for most people, a daily pill still feels far more approachable.

Final Thoughts: A Pill That Could Change Lives

The movement toward oral PCSK9 inhibitors reflects more than just scientific innovation—it reflects a shift toward patient-centered care. A treatment only works if people are willing (and able) to take it. If oral PCSK9 inhibitors deliver on their promise, they won’t just change cholesterol numbers. They’ll change lives.

Share this article: