VK2735 vs Tirzepatide
Comparison of Viking Therapeutics' investigational dual GLP-1/GIP agonist VK2735 with FDA-approved tirzepatide for obesity treatment.
Last updated: January 28, 2026
Dossier labels summarize each dossier's research scope. They do not establish comparative treatment benefit or safety. Read the comparison below in that context.
VK2735
Dossier overview
Tirzepatide
Dossier overview
Overview
VK2735 is Viking Therapeutics’ investigational dual GLP-1/GIP receptor agonist in development for obesity, with both injectable and oral formulations. Tirzepatide (Mounjaro, Zepbound) is Eli Lilly’s approved dual agonist.
Key distinction: Tirzepatide is approved with extensive data; VK2735 is in Phase 2 development but has generated significant interest due to promising early results and oral formulation potential.
Key Facts
| Aspect | VK2735 | Tirzepatide |
|---|---|---|
| Developer | Viking Therapeutics | Eli Lilly |
| Class | GLP-1/GIP dual agonist | GLP-1/GIP dual agonist |
| FDA Status | Investigational (Phase 2) | Approved |
| Formulations | Injectable + Oral | Injectable |
Mechanism Comparison
| Aspect | VK2735 | Tirzepatide |
|---|---|---|
| GLP-1 Receptor | Agonist | Agonist |
| GIP Receptor | Agonist | Agonist |
| Mechanism | Dual activation | Dual activation |
| Half-life | ~6 days | ~5 days |
| Structure | Peptide | Peptide |
How They Work
VK2735:
- Dual agonist activating both GLP-1 and GIP receptors
- Similar mechanism to tirzepatide
- Novel peptide sequence with proprietary modifications
- Oral formulation (VK2735 tablets) also in development
Tirzepatide:
- Dual agonist at GLP-1 and GIP receptors
- GIP component enhances metabolic effects
- Single 39-amino acid peptide
- Well-characterized receptor binding profile
Evidence Quality
VK2735 Research
| Trial Phase | Status | Key Findings |
|---|---|---|
| Phase 1 | Completed | Safety and tolerability established |
| Phase 2 (Injectable) | Completed | ~14.7% weight loss at 13 weeks |
| Phase 2 (Oral) | Ongoing | Early data positive |
| Phase 3 | Not started | Planned |
Current evidence:
- Phase 2 showed rapid weight loss (14.7% at 13 weeks)
- Weight loss curve not yet plateaued at trial end
- Oral formulation showing feasibility
- Limited long-term data
Tirzepatide Research
| Trial Phase | Status | Key Findings |
|---|---|---|
| SURPASS program | Completed | Robust T2D data |
| SURMOUNT program | Completed | Up to 22% weight loss |
| Phase 3 | Extensive | Multiple indications |
| Post-marketing | Ongoing | Real-world evidence growing |
Established evidence:
- Large randomized controlled trials
- Up to 22% weight loss in SURMOUNT-1
- Superior to semaglutide in comparator trials
- 2+ years of post-approval data
Efficacy Comparison
Weight Loss Results
| Metric | VK2735 | Tirzepatide |
|---|---|---|
| Trial duration | 13 weeks (Phase 2) | 72 weeks (Phase 3) |
| Maximum weight loss | ~14.7% at 13 weeks | ~22.5% at 72 weeks |
| Rate of loss | Rapid early loss | Steady progression |
| Plateau reached | No | Yes (by ~72 weeks) |
Important context: Direct comparison is difficult due to different trial durations. VK2735’s 13-week results are promising but cannot be directly compared to tirzepatide’s 72-week outcomes.
Projected Potential
Some analysts project VK2735 could achieve similar or greater weight loss than tirzepatide if the Phase 2 trajectory continues, but this remains speculative until Phase 3 data.
Evidence Strength Comparison
| Factor | VK2735 | Tirzepatide |
|---|---|---|
| Peer-reviewed studies | Few | Extensive |
| Phase 3 trials | None | Multiple completed |
| Total patients studied | ~200 | Thousands |
| Long-term data | None | Available (2+ years) |
| Overall quality | Low (early stage) | High |
Side Effects
VK2735 (Phase 2 Data)
| Side Effect | Incidence | Notes |
|---|---|---|
| Nausea | ~30-40% | Dose-dependent |
| Vomiting | ~15-20% | Common with class |
| Diarrhea | ~10-15% | GI effects expected |
| Constipation | Reported | — |
| Discontinuation rate | ~10% | Due to GI effects |
Tirzepatide (Established Profile)
| Side Effect | Incidence | Notes |
|---|---|---|
| Nausea | 12-33% | Improves with time |
| Diarrhea | 12-21% | Usually transient |
| Vomiting | 5-12% | Dose-related |
| Constipation | 6-12% | Common |
Safety Considerations
VK2735:
- Full safety profile not yet characterized
- Phase 2 GI tolerability similar to class
- Oral formulation safety being evaluated
- Long-term effects unknown
Tirzepatide:
- Well-characterized GI side effect profile
- Rare risks include pancreatitis (class effect)
- Thyroid C-cell tumor warning (precautionary)
- Extensive safety database
Oral Formulation Advantage
VK2735 Oral Development
| Aspect | Status |
|---|---|
| Formulation | Tablet in development |
| Phase | Phase 2 ongoing |
| Early data | Encouraging absorption |
| Potential advantage | No injections needed |
This could be a significant differentiator if VK2735 oral demonstrates:
- Comparable efficacy to injectable
- Acceptable bioavailability
- Manageable GI tolerability
Comparison to oral semaglutide: Oral GLP-1 agonists have lower bioavailability and require fasting; VK2735 oral formulation details pending.
Regulatory Status
| Aspect | VK2735 | Tirzepatide |
|---|---|---|
| FDA Status | Investigational | Approved |
| Phase | Phase 2 | Post-marketing |
| Availability | Clinical trials only | Prescription |
| Projected approval | 2026+ (if successful) | Already approved |
Development Timeline
VK2735 Path to Market (If Successful)
| Milestone | Status/Timeline |
|---|---|
| Phase 2 completion | Completed (2024-2025) |
| Phase 3 initiation | Underway (2025) |
| Phase 3 completion | Expected 2026-2027 |
| FDA submission | Projected 2027+ |
| Potential approval | Projected 2028+ |
Note: Timelines are estimates and subject to change based on trial results and regulatory interactions. Check current clinical trial registries for latest status.
Market Positioning
| Factor | VK2735 | Tirzepatide |
|---|---|---|
| First-mover advantage | No | Yes |
| Oral option | In development | No |
| Differentiation | Efficacy + oral | Established market leader |
| Competition | Entering crowded market | Current standard |
Who Might Consider Each
Tirzepatide (Available Now):
- Patients meeting prescribing criteria
- Type 2 diabetes or chronic weight management
- Those wanting established, approved therapy
- Patients comfortable with weekly injections
VK2735 (Future, If Approved):
- Must await regulatory approval
- May appeal to those preferring oral medication
- Patients who have not responded to current options
- Currently only available via clinical trials
Summary
| Factor | VK2735 | Tirzepatide |
|---|---|---|
| Evidence quality | Low (Phase 2) | High (Phase 3, approved) |
| Weight loss (reported) | ~14.7% (13 weeks) | ~22% (72 weeks) |
| Oral formulation | In development | Not available |
| Availability | Clinical trials only | Prescription |
| Safety profile | Limited data | Well-characterized |
| Market status | Investigational | Approved, available |
Key takeaway: Tirzepatide is an approved, well-studied medication available now. VK2735 shows promising early results and potential oral convenience but remains investigational. The compounds cannot be directly compared until VK2735 completes Phase 3 trials.
This comparison is for educational purposes only. VK2735 is not FDA-approved and only available in clinical trials. Tirzepatide requires a prescription. Consult a healthcare provider for treatment decisions.
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Disclaimer: This comparison is for educational purposes only and does not constitute medical advice. Individual responses to medications vary. Always consult a qualified healthcare provider before making treatment decisions.