Stenting is growing in popularity as a means of keeping arteries narrowed by atherosclerotic plaques from closing completely, precipitating a heart attack or other major cardiovascular event. The device functions as a scaffold, supporting the walls of the affected artery and preventing closure.
So-called 'bare' stents have been used for more than 20 years, but while effective they have limitations, notably that the artery tissue can in time grow through their mesh structure and re-close the vessel. The solution is to coat the stent with a drug that can prevent this tissue growth, and this requires a drug-carrying coating.
Stenting has tended to be more popular in the US than in Europe, but this has changed with the launch of the first drug-coated products from Johnson & Johnson (Cypher) and Guidant (Achieve).
Market research has suggested that the market for drug-coated stents could be worth as much as $5 billion (€4.1bn) in 2005, a remarkable growth considering sales were non-existent until the end of 2001 in the US and 2002 in Europe.
The two polymers covered by the license agreement are PolyActive and OctoDEX, which OctoPlus is already developing in preclinical studies to make controlled release formulations for the pharmaceutical industry.
Biodegradable polymers have the ability to be combined with one or more drugs and applied to a medical device, yet are naturally degraded by the body over time.
PolyActive is a multiblock polymeric system based on two well-known polymers used for the controlled release of proteins and hydrophobic small molecule drugs. In particular, PolyActive has been used in thousands of patients as part of two FDA approved products.
It has an existing Drug Master File lodged with the US Food and Drug Administration, which means that the testing required for incorporating it into drug products has already been completed.
Meanwhile, OctoDEX is a delivery system for the controlled release of proteins and large particles such as liposomes and antigens and is based on cross-linked dextran microspheres. OctoPlus recently reported successful completion of Phase I studies for a sustained release formulation of human growth hormone based on OctoDEX.
Giving a tantalising view of what the company hopes to explore with the polymers, Bruce Barclay, president and chief operating officer of SurModics, noted that in time it may be possible to use them to make fully dissolvable medical devices for local drug delivery.
He added that the polymers expand the types of molecules that SurModics can work with, as they are suitable for delivering proteins and other large molecule therapeutic agents.
Meanwhile, last month, Occam International, another Dutch company, licensed a drug delivery technology for use in cardiovascular stents to Xtent.