KH-1 is the first peptide to simultaneously inhibit KRAS G12D and HDAC — two key pancreatic cancer drivers — with nanomolar potency and tumor-shrinking activity in mice.
11.63 nMBinding affinity of KH-1 for KRAS G12D — nanomolar potency against one of cancer's most important and historically 'undruggable' targets
What the researchers found
Researchers discovered KH-1, the first peptide inhibitor that simultaneously targets two critical cancer-driving proteins: KRAS G12D (the most common mutation in pancreatic cancer) and HDAC (histone deacetylase, a downstream effector). KH-1 bound both targets with nanomolar affinity — Kd of 11.63 nM for KRAS G12D and 20.17 nM for HDAC2.
In lab tests, KH-1 inhibited pancreatic cancer cell growth, invasion, and migration, induced cell death (apoptosis), and arrested cells in the G0/G1 phase. In a mouse xenograft model, KH-1 significantly suppressed tumor growth without causing obvious organ toxicity.
Why it matters
KRAS G12D is mutated in ~40% of pancreatic cancers and was long considered 'undruggable.' HDAC is a downstream signal that KRAS uses to promote tumor growth. Hitting both targets with a single peptide molecule could be more effective than targeting either alone, and the lack of organ toxicity in mice is encouraging for a disease that has a 5-year survival rate below 13%.
The numbers in context
KRAS G12D binding: Kd = 11.63 ± 0.71 nM · HDAC2 binding: Kd = 20.17 ± 1.26 nM · Significant tumor growth inhibition in xenograft model · No significant organ toxicity
How the study worked
KH-1 was identified through integrated virtual screening combining pharmacophore screening and molecular docking. Binding affinity was confirmed by microscale thermophoresis (MST) assays. Anti-cancer activity was tested in human pancreatic cancer cell lines measuring proliferation, invasion, migration, apoptosis (flow cytometry), and cell cycle arrest. In vivo efficacy was evaluated in a mouse xenograft tumor model, with organ toxicity assessed.
Who was studied
In vitro human pancreatic cancer cells and in vivo mouse xenograft tumor model
What this study cannot tell us
Mouse xenograft models don't fully recapitulate human pancreatic cancer biology. No human data exists. The peptide's pharmacokinetics (half-life, bioavailability, metabolism) are not discussed. Pancreatic cancer's dense stroma may limit drug penetration in actual patients. Long-term toxicity is not assessed. Comparison to existing KRAS inhibitors or HDAC inhibitors is not provided.
How to read the evidence
This is a preclinical study demonstrating proof-of-concept in cell lines and a mouse xenograft model. While the dual-targeting approach is novel and the nanomolar binding affinity is promising, no human data exists and significant development hurdles remain.
When this study was published
Published in 2026 in the Journal of Medicinal Chemistry, this is cutting-edge work at the forefront of peptide-based cancer drug discovery.
The bigger picture
KRAS has been the holy grail of cancer drug targets — mutated in ~25% of all cancers and historically impossible to drug. Recent breakthroughs with sotorasib and adagrasib (targeting KRAS G12C) opened the door, but G12D mutations (more common in pancreatic cancer) remain harder to target. This peptide approach offers a fundamentally different strategy: using a peptide's larger binding surface to engage KRAS while simultaneously hitting a cooperating target (HDAC), potentially addressing resistance mechanisms that single-target drugs face.
Questions still open
- Can KH-1 be optimized for better pharmacokinetic properties (half-life, oral bioavailability) needed for clinical development?
- How does KH-1's efficacy compare to existing KRAS G12D inhibitors in clinical trials like MRTX1133?
- Would KH-1 be effective against pancreatic cancer's characteristic dense stroma, which often blocks drug penetration?
Common questions
Why is KRAS so important in pancreatic cancer?
Why target both KRAS and HDAC with one molecule?
Read the original research
Discovery of a Novel Dual-Targeting KRASG12D/HDAC Peptide Inhibitor for the Treatment of Pancreatic Cancer.
Journal of medicinal chemistry
Citation
Zhang, Qiaoxuan; Geng, Yifei; Chen, Haitao; Ni, Jiaping; Guan, Lixia; Zhai, Dong Qing; Wang, Yuting; Xu, Shengtao; Niu, Miao-Miao; Zheng, Lufeng; Hu, Weiwei. (2026). Discovery of a Novel Dual-Targeting KRASG12D/HDAC Peptide Inhibitor for the Treatment of Pancreatic Cancer.. Journal of medicinal chemistry. https://doi.org/10.1021/acs.jmedchem.5c02435