What Is NNC0537-1482? The Experimental CNP Peptide Being Studied for Heart Failure

Peptide research is expanding far beyond obesity, muscle growth and metabolic control.

One of the more interesting new areas is cardiovascular disease, particularly heart failure.

A compound now entering human research is NNC0537-1482, an experimental peptide-based analogue of C-type natriuretic peptide, or CNP.

Rather than targeting appetite or glucose control, NNC0537-1482 is designed around a signalling pathway involved in the heart, blood vessels and cardiorenal system.

As of October 2026, Novo Nordisk is running early human studies of the compound in both heart failure and reduced kidney function. (ICHGCP⁠)

What Is NNC0537-1482?

NNC0537-1482 is an investigational CNP analogue developed by Novo Nordisk.

CNP stands for C-type natriuretic peptide.

It is a naturally occurring peptide involved in regulating cardiovascular biology, particularly the structure and function of blood vessels and cardiac tissue.

NNC0537-1482 has been engineered as a longer-acting version suitable for subcutaneous administration.

What Are Natriuretic Peptides?

Natriuretic peptides are a family of naturally occurring signalling molecules.

The best-known members include:

• atrial natriuretic peptide, or ANP
• B-type natriuretic peptide, or BNP
• C-type natriuretic peptide, or CNP

Although they belong to the same family, they have different biological roles.

ANP and BNP are strongly involved in fluid balance, blood pressure and sodium excretion.

CNP has particularly important effects involving:

• blood-vessel biology
• vascular remodelling
• fibrosis
• endothelial function
• cardiac structure

How Does CNP Work?

CNP primarily activates a receptor called natriuretic peptide receptor-B, or NPR-B.

This receptor activates an intracellular signalling molecule called cyclic GMP, or cGMP.

cGMP is involved in several cardiovascular processes including:

• relaxation of blood vessels
• regulation of vascular tone
• suppression of fibrosis
• tissue remodelling
• cellular signalling within the heart

Researchers are interested in whether enhancing this pathway could help protect cardiac tissue in heart failure.

What Is Heart Failure With Preserved Ejection Fraction?

One major target of the current research is heart failure with preserved ejection fraction, commonly abbreviated to HFpEF.

In HFpEF, the heart can still eject a relatively normal percentage of blood with each contraction.

The problem is often that the heart muscle becomes:

• stiff
• poorly compliant
• less able to relax
• less able to fill normally

Patients may experience:

• breathlessness
• fatigue
• reduced exercise tolerance
• fluid retention
• ankle swelling

HFpEF represents a large proportion of modern heart-failure cases.

Why Might CNP Be Useful in HFpEF?

HFpEF is associated with several abnormalities involving:

• vascular stiffness
• cardiac fibrosis
• endothelial dysfunction
• inflammation
• abnormal cardiac remodelling

CNP signalling can influence many of these processes.

Researchers are therefore investigating whether increasing CNP activity could potentially improve the biological environment surrounding the heart and blood vessels.

The UK Health Research Authority describes NNC0537-1482 as a peptide-based CNP analogue being evaluated specifically because CNP signalling may be relevant to cardiovascular structure and function in HFpEF. (Health Research Authority⁠)

Has NNC0537-1482 Been Tested in Humans?

Yes.

A Phase 1b clinical trial began in the UK in October 2025.

The study is randomised, placebo-controlled and double-blinded.

Researchers plan to enrol approximately 36 participants with heart failure.

Participants receive multiple ascending doses of either NNC0537-1482 or placebo. (ICHGCP⁠)

What Is the Current Heart Failure Trial Measuring?

Because this is an early-stage study, the main focus is safety and tolerability.

Researchers are also measuring:

• pharmacokinetics
• blood concentrations of the peptide
• biological markers
• pharmacodynamic responses
• treatment-emergent adverse events

The study is expected to continue into 2027. (ICHGCP⁠)

Why Is Phase 1 Research Important?

Phase 1 research answers basic questions before larger efficacy trials can begin.

Researchers need to determine:

• how much drug reaches the bloodstream
• how long it remains present
• whether exposure increases predictably with dose
• whether blood pressure changes
• whether adverse effects occur
• whether the expected biological pathway is being activated

Only after these questions are answered can larger studies properly test whether the treatment improves clinical outcomes.

Is NNC0537-1482 Also Being Studied in Kidney Disease?

Yes.

A second Phase 1 study began in Germany in 2026.

This study is examining how a single dose of NNC0537-1482 behaves in participants with different degrees of kidney function.

Approximately 54 participants are planned. (EU Clinical Trials⁠)

This is important because kidney function can strongly influence how drugs are processed and eliminated.

Why Are the Heart and Kidneys So Closely Connected?

Heart and kidney function are deeply interconnected.

The kidneys regulate:

• fluid balance
• sodium levels
• blood pressure
• circulating volume

The heart determines how effectively blood reaches the kidneys.

When heart function deteriorates, kidney function can decline.

Likewise, impaired kidney function can worsen fluid retention and cardiovascular strain.

This interaction is often described as the cardiorenal system.

A peptide influencing vascular and cGMP signalling could therefore potentially affect both systems.

What Does Pharmacokinetics Mean?

Pharmacokinetics describes what the body does to a drug.

Researchers measure:

• absorption
• maximum blood concentration
• distribution
• metabolism
• elimination
• half-life

For NNC0537-1482, understanding these characteristics is essential because naturally occurring CNP has a relatively short duration of action.

The engineered analogue needs to maintain useful biological exposure for much longer.

Is NNC0537-1482 Similar to Cenderitide?

They share some biological territory, but they are different compounds.

Cenderitide is an older designer natriuretic peptide engineered to activate both GC-A and GC-B signalling.

It has already undergone several early human heart-failure studies.

A 2026 cardiovascular review described cenderitide as a dual-receptor designer peptide capable of increasing cGMP and influencing renal and cardiac physiology. (Springer⁠)

NNC0537-1482 is a newer CNP analogue being developed separately by Novo Nordisk.

What Can Earlier Designer Peptide Research Tell Us?

Earlier compounds such as cenderitide provide useful proof that natriuretic-peptide signalling can be manipulated pharmacologically.

In early human studies, cenderitide increased cGMP activity while producing relatively modest effects on blood pressure.

But evidence from one peptide cannot automatically be transferred to another.

NNC0537-1482 has its own:

• molecular structure
• receptor activity
• pharmacokinetics
• dose-response relationship
• safety profile

That is why dedicated human trials are necessary.

Could CNP Cause Low Blood Pressure?

Potentially.

Natriuretic-peptide pathways can influence vascular tone.

Excessive activation could theoretically contribute to:

• dizziness
• hypotension
• changes in renal perfusion

Monitoring blood pressure and cardiovascular responses is therefore an important part of early development.

This is one reason Phase 1 studies increase doses gradually rather than immediately testing large exposures.

Is NNC0537-1482 a Peptide?

Yes.

It is a peptide-based CNP analogue.

That makes it a genuine example of modern therapeutic peptide engineering.

Rather than targeting a metabolic hormone receptor, it attempts to reproduce and extend a naturally occurring cardiovascular signalling peptide.

Is NNC0537-1482 Approved?

No.

NNC0537-1482 remains an early-stage investigational compound.

The current studies are Phase 1.

There is currently no evidence establishing that it:

• improves heart-failure symptoms
• reduces hospitalisations
• improves survival
• improves exercise capacity
• prevents cardiac remodelling

Those questions would require substantially larger later-stage trials.

Why Is This Research Important?

Heart failure remains a major cause of illness and hospitalisation worldwide.

Although treatment has improved considerably, HFpEF remains biologically complex and difficult to treat.

Researchers are therefore looking beyond conventional pathways and investigating:

• inflammation
• fibrosis
• metabolism
• vascular dysfunction
• natriuretic peptide signalling

NNC0537-1482 represents the last of these approaches.

Why Is CNP Different From GLP-1 Peptides?

The underlying biology is completely different.

GLP-1 peptides primarily influence:

• appetite
• insulin
• glucose
• gastrointestinal signalling

CNP-based peptides primarily influence:

• vascular signalling
• cardiac remodelling
• fibrosis
• cGMP pathways

This illustrates just how broad modern peptide therapeutics have become.

Could CNP Research Extend Beyond Heart Failure?

Potentially.

CNP signalling is involved in several tissues.

Its biology has already attracted attention in:

• cardiovascular disease
• skeletal growth
• vascular dysfunction
• fibrosis

Navepegritide, which we have already covered, uses the CNP pathway for achondroplasia.

NNC0537-1482 explores essentially the same biological family from a completely different therapeutic direction: heart failure.

What Still Needs to Be Answered?

Almost everything relating to clinical effectiveness remains unknown.

Researchers need to establish:

• safe dose ranges
• human half-life
• optimal dosing frequency
• effects on blood pressure
• effects on kidney function
• changes in cardiac biomarkers
• whether fibrosis is affected
• whether exercise capacity improves
• whether symptoms improve
• whether hospitalisations can eventually be reduced

These questions will require years of further research.

The Bottom Line

NNC0537-1482 is an experimental C-type natriuretic peptide analogue being developed by Novo Nordisk for cardiovascular disease.

A randomised Phase 1b study is currently recruiting participants with heart failure in the UK, with researchers investigating safety, pharmacokinetics and biological effects. (ICHGCP⁠)

A second Phase 1 programme is evaluating how kidney function affects the pharmacokinetics of the peptide. (EU Clinical Trials⁠)

There are currently no late-stage efficacy results.

But the programme is scientifically interesting because it represents a completely different direction for therapeutic peptides.

Rather than controlling appetite, stimulating muscle pathways or altering glucose metabolism, NNC0537-1482 is attempting to manipulate CNP and cGMP signalling within the cardiovascular system.

For researchers following the expansion of peptide medicine into heart and kidney disease, NNC0537-1482 is an early-stage compound worth watching.

This article is for research and educational purposes only. NNC0537-1482 remains investigational and is not presented as an approved or established treatment.