Why E5 Was the Target Nobody Went After

In the first part of her interview with Pharmaceutical Executive, Sandra Coufal, MD, CEO of Toragen, explains why the HPV E5 protein was historically overlooked in favor of E6 and E7, and why that oversight may have cost the field decades of progress.

Coufal notes how the HPV genome contains just eight genes, only three of which are chemically druggable. While prior research focused on E6 and E7 as drivers of viral proliferation, emerging science revealed that E5 plays a distinct and critical role: it enables the virus to hide inside infected cells, shielding them from immune detection. Coufal describes how six E5 proteins link together to form a viral ion channel, a structure known as a Porin, and explains that TGN-S15, Toragen’s lead candidate, directly inhibits the center of that channel.

With more than 20 failed attempts against E6 and one against E7 in preclinical testing alone, Toragen’s E5-targeted approach represents not just a scientific first, but a fundamentally different mechanism of action. This clip sets the foundation for understanding why Toragen believes it has found the target nobody else went after, and why that may prove to be the decisive advantage.