What Is VK2735? The Dual GIP/GLP-1 Agonist Being Developed in Oral and Injectable Forms

The next generation of obesity medicines is increasingly focused not just on which receptors are targeted, but also on how treatments are delivered and maintained over time.

VK2735 is one of the more interesting examples.

It is an investigational dual GIP and GLP-1 receptor agonist being developed by Viking Therapeutics in both:

• once-weekly injectable form
• once-daily oral tablet form

As of October 2026, both formulations have progressed into Phase 3 development, making VK2735 one of the most advanced next-generation metabolic peptide programmes currently in clinical research. (Viking Therapeutics InvestorRoom⁠)

What Is VK2735?

VK2735 is an experimental molecule designed to activate two important metabolic hormone receptors:

• GIP
• GLP-1

These are the same two receptor systems targeted by tirzepatide.

The aim is to combine complementary effects involving appetite, glucose regulation, insulin signalling and body weight.

What makes VK2735 particularly unusual is that Viking is developing the same active compound in both injectable and oral forms. (Viking Therapeutics⁠)

What Is GLP-1?

GLP-1, or glucagon-like peptide-1, is a naturally occurring hormone released after eating.

It helps regulate:

• appetite
• satiety
• insulin secretion
• blood glucose
• gastric emptying

GLP-1 receptor agonists have become one of the most important classes of modern metabolic medicines.

What Is GIP?

GIP stands for glucose-dependent insulinotropic polypeptide.

Like GLP-1, it is released in response to food.

GIP influences:

• insulin secretion
• glucose handling
• energy storage
• fat-tissue biology

Researchers discovered that activating GIP and GLP-1 together can produce stronger metabolic effects than targeting GLP-1 alone in some settings.

This led to the development of dual agonists.

How Does VK2735 Work?

VK2735 is designed to activate both the GLP-1 receptor and GIP receptor.

The precise balance of activity at each receptor is important.

Rather than simply combining two separate drugs, a dual agonist incorporates both activities into a single molecular structure.

The goal is to produce complementary metabolic effects through one treatment.

How Is VK2735 Different From Tirzepatide?

Mechanistically, the two are similar because both target:

• GIP
• GLP-1

But they are different molecules with different pharmacological properties.

VK2735 has its own:

• receptor activity profile
• pharmacokinetics
• dosing schedule
• molecular structure
• clinical development programme

Perhaps the biggest practical difference is Viking’s plan to develop both oral and injectable versions of the same active compound.

That could potentially allow patients to move between formulations depending on their treatment stage.

What Did the Injectable Studies Show?

Subcutaneous VK2735 has already produced substantial weight-loss signals in earlier clinical studies.

Viking has now moved the injectable formulation into the VANQUISH Phase 3 programme.

VANQUISH-1 has enrolled approximately 4,500 adults with obesity or overweight without type 2 diabetes.

VANQUISH-2 has enrolled approximately 1,000 adults with obesity or overweight and type 2 diabetes.

Participants are receiving weekly doses of:

• 7.5 mg
• 12.5 mg
• 17.5 mg
• or placebo

for 78 weeks. (Viking Therapeutics InvestorRoom⁠)

What Is Particularly Interesting About the Maintenance Research?

This may ultimately become one of VK2735’s most distinctive features.

Obesity is a chronic condition.

Producing weight loss is only one part of treatment.

Maintaining that loss over years can be just as important.

Viking has therefore begun investigating whether people can initially use weekly VK2735 and later transition to less frequent maintenance dosing.

What Did the Maintenance Study Show?

In September 2026, Viking reported results from a maintenance-dosing study.

Participants initially received weekly subcutaneous VK2735.

Researchers then investigated less frequent maintenance schedules.

Viking reported that participants switching to every-other-week dosing maintained up to 97% of their previous weight reduction during the studied maintenance period.

Participants switching to monthly injections maintained up to approximately 90%.

The company also reported placebo-adjusted weight loss of around 22% at week 33 in participants receiving weekly 17.5 mg dosing before maintenance transitions. (Viking Therapeutics InvestorRoom⁠)

These results are preliminary company-reported findings rather than final Phase 3 outcomes.

But they raise an important question:

Could obesity treatment eventually involve an intensive weight-loss phase followed by less frequent maintenance treatment?

Could VK2735 Eventually Be Taken Monthly?

Potentially.

The maintenance programme specifically includes investigation of:

• monthly injections
• every-other-week injections
• oral maintenance dosing

The concept remains experimental.

Longer and larger trials are needed before researchers can determine whether monthly treatment reliably maintains weight reduction over extended periods.

What About Oral VK2735?

This is where the programme becomes particularly interesting.

Viking has developed an oral tablet formulation of VK2735.

In the Phase 2 VENTURE-Oral study, once-daily oral treatment for 13 weeks produced progressive average weight reductions of up to approximately 12.2% from baseline. (Viking Therapeutics InvestorRoom⁠)

Researchers reported no clear weight-loss plateau during the 13-week study.

How Significant Is 12.2% in 13 Weeks?

It is an impressive early signal.

But several cautions are important.

The study lasted only 13 weeks.

Longer treatment does not necessarily mean weight loss will continue at the same rate.

Phase 2 studies are also much smaller than Phase 3 trials.

The real test will be whether the results remain strong across hundreds or thousands of participants over much longer periods.

Has Oral VK2735 Reached Phase 3?

Yes.

On 14 October 2026, Viking announced the start of the SUNRISE Phase 3 programme for oral VK2735.

Two trials are planned:

SUNRISE-1 — adults with obesity or overweight without type 2 diabetes.

SUNRISE-2 — adults with obesity or overweight and type 2 diabetes.

Each study plans to enrol approximately 560 participants.

Participants will receive daily doses of:

• 27.5 mg
• 35 mg
• 55 mg
• or placebo

for 68 weeks. (Viking Therapeutics InvestorRoom⁠)

Why Is an Oral Version Important?

Injectable therapies have transformed obesity treatment.

But injections are not necessarily the preferred option for everyone.

An effective oral dual agonist could potentially offer:

• easier administration
• greater convenience
• less resistance to starting treatment
• more flexibility for long-term therapy
• easier maintenance strategies

This could be particularly important if obesity treatment increasingly becomes a long-term or lifelong intervention.

Is Oral VK2735 Still a Peptide?

VK2735 is designed around peptide hormone receptor pharmacology, but oral peptide development is technically challenging because peptides are normally broken down in the digestive tract.

The development of oral versions therefore requires specialised formulation strategies.

Exactly how oral VK2735 achieves sufficient systemic exposure is part of the drug’s proprietary pharmaceutical design.

What Were the Side Effects in the Oral Study?

Gastrointestinal effects were the most commonly reported adverse events.

These were consistent with what is commonly seen with incretin-based therapies.

Viking reported that approximately 98% of drug-related adverse events were mild or moderate.

GI effects generally appeared earlier in treatment and tended to decrease with continued dosing. (Viking Therapeutics InvestorRoom⁠)

Larger Phase 3 trials will provide a much clearer assessment of tolerability.

Why Are Researchers Interested in Switching Between Oral and Injectable Treatment?

This could eventually become one of the most practical aspects of VK2735.

A patient might theoretically use:

weekly injections during active weight reduction

followed by

an oral or less-frequent maintenance regimen

once a target weight is reached.

Viking has explicitly designed its development programme around this concept of induction and maintenance. (Viking Therapeutics InvestorRoom⁠)

That would represent a different treatment model from simply using the same dose indefinitely.

How Does VK2735 Compare With Retatrutide?

The receptor profiles are different.

VK2735 targets:

• GIP
• GLP-1

Retatrutide targets:

• GIP
• GLP-1
• glucagon

Retatrutide therefore adds glucagon receptor activity.

That does not automatically make it superior.

Different receptor balances can produce different effects on:

• appetite
• glucose
• metabolic rate
• fat metabolism
• tolerability

Direct clinical comparisons would be needed.

How Does VK2735 Compare With Survodutide?

Again, the second receptor differs.

VK2735 targets:

GIP + GLP-1

Survodutide targets:

glucagon + GLP-1

Both represent attempts to improve on single-receptor GLP-1 therapy, but through different biological pathways.

Is VK2735 Approved?

No.

VK2735 remains investigational.

Neither the oral nor injectable formulation has been approved for routine clinical use.

Both still need to complete Phase 3 development and regulatory review.

What Still Needs to Be Answered?

The Phase 3 programmes should help establish:

• long-term weight-loss effectiveness
• comparative effectiveness between doses
• gastrointestinal tolerability
• effects in people with type 2 diabetes
• long-term safety
• cardiovascular effects
• whether weight loss plateaus
• whether oral treatment performs similarly to injections
• whether reduced-frequency maintenance dosing works long term

These questions will determine whether VK2735 becomes genuinely competitive with established metabolic therapies.

Why Is VK2735 Particularly Interesting?

There are now many experimental incretin drugs.

VK2735 stands out because Viking is attempting to build an entire treatment strategy around one molecule.

That strategy potentially includes:

weekly injectable induction

daily oral treatment

every-other-week maintenance

and possibly

monthly maintenance injections

Rather than viewing obesity treatment as one fixed dose delivered forever, this approach treats weight management as different phases requiring different dosing strategies.

That could become an increasingly important concept in metabolic medicine.

The Bottom Line

VK2735 is an investigational dual GIP/GLP-1 receptor agonist being developed in both oral and injectable forms.

The injectable programme is already in Phase 3, with approximately 5,500 participants enrolled across the VANQUISH trials. (Viking Therapeutics InvestorRoom⁠)

The oral formulation produced average weight reductions of up to approximately 12.2% after 13 weeks in Phase 2 research and entered its own Phase 3 SUNRISE programme in October 2026. (Viking Therapeutics InvestorRoom⁠)

Perhaps most interestingly, researchers are also investigating whether people can move from weekly treatment to oral, fortnightly or even monthly maintenance regimens.

VK2735 therefore represents more than another dual incretin agonist.

It represents an attempt to create a flexible weight-loss and long-term maintenance platform around the same molecule.

Whether that strategy succeeds will depend on the Phase 3 results.

But for researchers following the next generation of metabolic peptides, VK2735 is one of the most important programmes to watch.

This article is for research and educational purposes only. VK2735 remains investigational and is not presented as an approved or established treatment.