Starpharma takes stake in start-up Dimerix

In one of the more intriguing examples of technological cross-pollination, Melbourne dendrimer-drug developer Starpharma Holdings (ASX:SPL, USOTC:SPHRY) announced today it has become a foundation shareholder in a new Perth-based biotech, Dimerix Bioscience.

Starpharma has taken a 30 per cent equity stake in Dimerix, a drug-development company specialising in G-protein coupled receptors (GPCRs), a class of molecules that regulate a multitude of signalling pathways in eukaryotic cells.

Dimerix was established to commercialise technology developed by researchers at the Western Australian Institute for Medical Research (WAIMR) who, according to Starpharma CEO John Raff, are considered to be at the leading edge of GPCR research internationally.

The WAIMR team is investigating how proteins bind simultaneously to multiple G-protein coupled receptors, to activate specific signalling pathways within cells.

Starpharma's interest in Dimerix stems from the fact that its dendrimers - giant, elaborately branched synthetic molecules, are similar in size to the proteins that activate GPCR pathways, and can be tailored to interact with the receptors in the same way as the native protein ligands.

Raff said that the native proteins have multiple functional domains that interact with specific combinations of G-protein coupled receptors. The proteins draw the receptors together on the surface of the cell, in combinations that selectively activate specific signalling pathways.

The process, called receptor coupling, explains the polyvalent activity of many new drugs. "We will synthesis dendrimers of different sizes, and with different spatial arrangements of their functional groups, so they will bind to multiple GPCRs, like the native ligands," Raff said.

"More than 25 per cent of all modern drugs target GPCRs. Dendrimers offer a more direct way of getting effective binding - it's a bigger challenge to effect coupling with small molecules.

"It's a very hot area for research, and we thought we'd get in there and help Dimerix get established so they can interact with pharma companies - we've been told by a number of groups that they really are the leaders in this area.

"It's also a way of drawing Big Pharma into the area. If we can demonstrate that our dendrimers are efficient drugs for GBCR targets, it improves our own prospects.

Raff said StarPharma already has one joint research project with Dimerix, in the oncology-drug area.

He said the collaboration was another example of Starpharma's strategy of partnering with developers of world-leading technologies complementing its own, simultaneously leveraging Starpharma's unique nano-drugs and strong IP position.

Starpharma had successfully applied the model to establish its Michigan-based investee Dendritic NanoTechnologies (DNT), in which it holds 33 per cent equity. After just three years, the partnership was recognised as a leader in the field of nanotechnology, for a total investment of just AUD$4 million on Starpharma's part.

The Dow Chemical Company had recently validated DNT's leadership in nanotechnology by transferring ownership of its portfolio of 196 dendrimer patents and associated royalty streams to DNT, in exchange for taking 30 per cent equity in the company.