Biotech Values

[drbio45]

BUY OR SELL-Placenta vs bone marrow in battle to save limbs

http://www.forexyard.com/en/news/BUY-OR-SELL-Placenta-vs-bone-marrow-in-battle-to-save-limbs-2011-03-10T181915Z

Thursday March 10, 2011 03:19:18 PM GMT
BUYSELL/STEMCELL-CLI (RPT)* CLI results in 160,000 U.S. amputations a year
* Potential U.S. market worth over $2 bln
* Different approaches, different therapies
By Anand Basu and Shravya Jain
BANGALORE, March 10 (Reuters) - Two stem cell research firms are going head-to-head in the race to develop a first treatment for critical limb ischemia (CLI), where severely blocked arteries cut the flow of blood to hands and legs.
CLI afflicts about 1 million Americans and results in 160,000 amputations each year.
The battle pits Aastrom Biosciences against Pluristem Therapeutics , and focuses on two different approaches to find a treatment in a market potentially worth more than $2 billion a year, according to Vical .
There are currently no drugs approved by the U.S. Food and Drug Administration (FDA) for CLI, and companies including Vical and Sanofi-Aventis have seen experimental medicines fail late-stage trials.




Ann Arbor, Michigan-based Aastrom has been the leading candidate to produce a breakthrough, but is struggling with a late-stage trial design and doubts over the efficacy of its approach.

The autologous therapy it favours processes stem cells from a patient's bone marrow and injects them into the affected limb.

Israel-based Pluristem, instead, processes stem cells from donors' placenta -- an allogeneic therapy better suited for treating CLI, according to several researchers and analysts.

It plans to start a mid-stage trial this year.

"I believe the Pluristem approach is much better than Aastrom's," said National Securities Analyst Jason Kolbert.

"There's a wealth of anecdotal information that suggests young (placental) cells are more potent and vibrant than autologous cells from older patients with co-morbidities."

Some researchers favour using younger cells from placenta, as cells from bone marrow are less potent and can lose their ability to form new blood vessels with ageing.

"Stem cells derived from bone marrow will not be young, as the average age of CLI patients is around 65-70," said Dr. Amish Raval, Assistant Professor at the University of Wisconsin School of Medicine and Public Health. He is principal investigator in clinical trials at the university testing autologous cells.

Aastrom CEO Tim Mayleben, however, says that although the cells are taken from elderly patients, they are processed for 12 days and produce a potent product, proven in clinical studies.

"I don't think there's any data in the scientific literature to suggest patient's bone marrow is older and thus not as potent, but certainly it's talked about in scientific circles," he told Reuters.


IN THE BANK

Also, the processed cells produced by Pluristem's approach are off-the-shelf and ready-to use, while it can take two weeks to process stem cells taken from a patient's bone marrow.

"Unlike autologous cells, you can sort and bank allogeneic cells," said Michael Murphy, clinical director of the stem cell center at Indiana University School Of Medicine.

Cells are also more easily available using donated placentas rather than bone marrow.

"Allogeneic cells offer more promise for utility in clinical application as they can be collected, expanded, banked and are immediately ready for administration, which is critical for CLI treatment," said Murphy at Indiana University.

Murphy, who has previously worked for Aastrom, is principal investigator of a late-stage trial using autologous therapy for CLI, sponsored by privately owned U.S. orthopaedics group Biomet Biologics, and an early-stage trial using allogeneic therapy, sponsored by Medistem .

There are benefits from the autologous approach, however, with a very low risk of immune rejection since cells come from the patient.

"Autologous will have better safety data and is likely to have less long-term clinical monitoring and low or zero worry about tumours and any immune rejection," said Scimitar Equity analyst Henry McCusker.

Aastrom's Mayleben agrees.

"Cells derived from bone marrow are incredibly safe and very efficacious. We've treated 400 patients with our autologous cell therapies and we have never experienced any immune rejection," he said.

"I think it's a little early to compare and contrast different approaches. At the end of the day, what really matter is, does it work?" (Reporting by Anand Basu and Shravya Jain in Bangalore, Editing by Ian Geoghegan)


--------------------------------------------------------------------------------