Biotech Starpharma Holdings says it has improved a blockbuster drug that is mainly used to treat colon and colorectal cancer.

Starpharma has conducted a pre-clinical study of the effects of a dendrimer-enhanced nanoparticle version of the drug oxaliplatin on colon cancer.

The results showed that the enhanced drug was better at inhibiting tumours and reducing toxic side-effects than the non-enhanced drug.

Oxaliplatin is sold as Eloxatin by Sanofi and in 2012 generated sales of about $US2 billion (currently around $A2.16 billion).

“These positive results achieved with Starpharma’s dendrimer-enhanced oxaliplatin nanoparticles are the subject of a new patent filing and given the obvious commercial potential, Starpharma now intends to advance dendrimer-enhanced oxaliplatin formulations into development,” the company said in a statement on Wednesday.

Dendrimers are a type of synthetic nanoscale polymer that is highly regular in size and structure and suited to pharmaceutical uses.

Shares in Starpharma gained five cents, or five per cent, to $1.05.