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PX1 chemists and research educators with hands-on experience in US-based peptide manufacturing, HPLC / mass-spectrometry lot testing, and endotoxin QC. All content is citation-backed and peer-reviewed for accuracy.
PX13-R Results Timeline: What the Trial Data Showed Week by Week
Research Guide
Reviewed By
PX1 QC — Analytical Chemistry Team
Every article is reviewed by PX1's in-house analytical team for accuracy on mechanism, dosing ranges reported in the literature, and lab-handling guidance. We do not publish clinical or medical advice.
Quick answer
Published Phase 2 PX13-R outcomes mapped across 24 and 48 weeks — body weight, hepatic fat, and HbA1c by dose arm, with the caveats that matter.
Key takeaways
- Hepatic fat. Participants with elevated liver fat at baseline showed large reductions, with a substantial proportion reaching normalization thresholds in the higher-dose arms.
- HbA1c. Meaningful reductions across dose arms in the type 2 diabetes cohort.
- Blood pressure and lipids. Directionally favorable changes reported alongside weight reduction.
What "results" means here
Everything below is published clinical trial data, not anecdote. The Phase 2 obesity trial (Jastreboff et al., NEJM 2023) randomized participants to placebo or PX13-R at 1, 4, 8 or 12 mg weekly for 48 weeks with stepped titration.
Body weight by dose arm
| Dose arm | Week 24 (approx.) | Week 48 (approx.) |
|---|---|---|
| Placebo | ~2% | ~2% |
| 1 mg | ~7% | ~9% |
| 4 mg | ~12% | ~17% |
| 8 mg | ~15% | ~21% |
| 12 mg | ~17% | ~24% |
The 12 mg 48-week figure — roughly 24% mean body-weight reduction — was the largest reported for any incretin-class investigational compound at the time of publication, and notably the curves had not plateaued at week 48.
Other reported endpoints
- Hepatic fat. Participants with elevated liver fat at baseline showed large reductions, with a substantial proportion reaching normalization thresholds in the higher-dose arms.
- HbA1c. Meaningful reductions across dose arms in the type 2 diabetes cohort.
- Blood pressure and lipids. Directionally favorable changes reported alongside weight reduction.
Reading the timeline correctly
- Weeks 1–8 are titration, not steady state. Early-phase changes reflect a sub-therapeutic dose ramp.
- The separation between arms widens over time. Dose-response is not visible at week 8 the way it is at week 48.
- The curve was still descending at the study endpoint. Extrapolating beyond 48 weeks from this dataset is speculation.
- Trial conditions included structured lifestyle counseling in all arms, including placebo. That is why placebo is not zero.
Where PX13-R sits versus the rest of the class
PX1-S (GLP-1) and PX12-T (GLP-1/GIP) trials reported smaller mean reductions at their respective top doses. PX13-R's third mechanism — glucagon receptor agonism — is the leading explanation for the additional effect through increased energy expenditure. Compare the pharmacology in PX12-T vs PX1-S and the PX13-R research overview.
Research use only. Not for human consumption. Not intended to diagnose, treat, cure, or prevent any disease.