CSL aims to develop stroke therapy

CSL (ASX:CSL), which last week became the world's largest supplier of blood plasma products after its purchase of Aventis Behring, now aims to maximise its return from those products by developing a therapy for stroke.

The therapy takes the form of reconstituted high-density lipoprotein (rHDL), a by-product of the process used to manufacture CSL's intravenous immunoglobulin (IVIG) and other products.

Assoc Prof Russell Basser, who heads CSL's stroke program, told an investor briefing in Sydney yesterday that rHDL was a way to get 'bang for buck' from every litre of plasma produced by the company.

rHDL, he explained, had similar properties to HDL, or so-called 'good' cholesterol. He said the company's researchers had examined several diseases where rHDL might be useful, before deciding to focus on a potentially lucrative therapy for stroke, the death of brain tissue.

That decision was based on the observation that after a stroke, not all the brain cells that are ultimately affected die immediately. A 'penumbra' surrounding the area initially affected dies more slowly, in the hours and days after the initial stroke.

Basser said experiments in rats, conducted in Melbourne and Italy, showed that treatment with rHDL six hours after a stroke produced "very substantial improvement", measured by brain scans and also by observation of the rats' behaviour.

He said other brain-protecting drugs had not shown much benefit: either they showed too little pre-clinical evidence of activity, or their activity was too specific, or they caused adverse side-effects. And the CSL treatment worked in rats up to six hours after a stroke, whereas current treatments needed to be administered within three hours, Basser said.

He said rHDL was stable at room temperature and had a long shelf-life, which meant it could even be stored in ambulances.

"Generally, [one would] use leading-edge biotechnology to block one pathway," Basser said. "Now, the theory is that the best treatment would block multiple pathways. To me, as a clinician, this is a very exciting project."

CSL has established a clinical advisory board to advance the rHDL project, headed by Prof Stephen Davis at Royal Melbourne Hospital, and backed up by leading stroke researchers Mark Fisher in Boston and Alistair Buchan in Calgary.

R&D pipeline

CSL's R&D director, Dr Andrew Cuthbertson, said the company believed rHDL could be a "breakthrough" product.

He said yesterday's briefing was designed to tell investors less about the company's bottom line and more about its product pipeline, which he said would fuel its medium- to long-term growth.

"The investment we make in R&D is strategically aligned with our business," he said. "The money we apply to [R&D] is applied with a commercial rationale."

He said the rHDL program, for example, had the potential to create new, high-margin products from each litre of plasma that CSL processed.