Research identifies MDA-9 protein as potential drug target to overcome treatment resistance in head and neck cancer

Aug 6, 2026

A collaborative study from Virginia Commonwealth University identifies the scaffold protein MDA-9/Syntenin as a key driver of head and neck squamous cell carcinoma (HNSCC) and a mediator of therapy resistance. Researchers demonstrated that an experimental small-molecule inhibitor, IVMT-Rx-4, selectively blocks MDA-9/Syntenin to eradicate cancer stem cells and suppress the stemness marker BMI1. In preclinical models, IVMT-Rx-4 reversed cisplatin resistance and restricted tumor growth with no observed toxicity.

MDA-9 protein targeting

▪The scaffold protein MDA-9/Syntenin, which was first cloned by Paul B. Fisher and his team, organizes molecular partners to influence tumor-cell migration, invasion, angiogenesis, and immune suppression.
▪Collaborative research from Virginia Commonwealth University departments identified the multifunctional scaffold protein MDA-9/Syntenin as a significant driver of head and neck squamous cell carcinoma and a mediator of drug resistance.

IVMT-Rx-4 inhibitor mechanism

▪The small-molecule inhibitor IVMT-Rx-4, developed by InVaMet Therapeutics, selectively blocks the function of MDA-9/Syntenin by interfering with its interactions with partner proteins essential for oncogenic functions.
▪IVMT-Rx-4 is an intermediate synthesis product of the drug PDZ1i, demonstrating improved water solubility, lower cellular efflux, and enhanced sensitivity compared to unmodified PDZ1i.

Cancer stem cell eradication

▪The research team demonstrated that MDA-9/Syntenin maintains cancer stem cell function in head and neck squamous cell carcinoma, and that IVMT-Rx-4 can effectively target and eradicate these stem cells.
▪IVMT-Rx-4 suppresses the transcription factor BMI1, which serves as a functional cancer stem cell marker in head and neck squamous cell carcinoma cells.

Chemotherapy resistance reversal

▪Combining the experimental inhibitor IVMT-Rx-4 with standard chemotherapy produced a more pronounced anticancer effect in preclinical models than either treatment approach alone.
▪Experimental evidence suggests that IVMT-Rx-4 can reverse chemotherapy resistance in head and neck squamous cell carcinoma cells, specifically blocking increases in cisplatin-resistant stem cells.

Preclinical safety profile

▪Laboratory models generated without the MDA-9/Syntenin protein showed no overt physiological defects or toxicity, displaying increased resistance to metastatic spread.
▪In preclinical cancer models of head and neck squamous cell carcinoma, IVMT-Rx-4 restricted tumor growth and metastasis with no observed toxicity, leaving some models completely tumor-free.