Prelude’s PRT13722 Achieves Complete Tumor Regressions and Improved Safety, IND in Mid-2026
Prelude’s PRT13722, a KAT6A degrader, produced complete tumor regressions at well-tolerated doses in HR+/HER2– breast cancer models and synergized with CDK4/6 inhibitors and endocrine therapy. It demonstrated improved hematological safety versus prifetrastat and remains on track to file an IND by mid-2026, Phase 1 initiation set for 2H 2026.
1. Preclinical Efficacy Data
In multiple HR+/HER2– breast cancer CDX and PDX models, PRT13722 delivered durable complete tumor regressions as a monotherapy at well-tolerated dose levels, outperforming dual KAT6A/B inhibitors in depth and breadth of response.
2. Hematological Safety Profile
PRT13722 exhibited an improved preclinical hematological safety profile compared with prifetrastat, suggesting a lower risk of blood cell toxicity and enabling potential combination with standard of care agents.
3. Combination Synergy
The candidate showed synergistic antitumor effects when combined with endocrine therapy, CDK4/6 inhibitors, and PI3Kα inhibitors across both endocrine therapy–sensitive and experienced models, including estrogen receptor-mutant and therapy-resistant cells.
4. Development Timeline
Prelude plans to submit an Investigational New Drug application for PRT13722 by mid-2026 and, pending regulatory clearance, to initiate a Phase 1 clinical trial in the second half of 2026.