Each year, approximately one million people in the U.S. and five million people worldwide suffer a heart attack. Many suffer considerable heart muscle injury that greatly impairs the ability of the heart to adequately pump blood to the body. Eventually, this deterioration of heart function can lead to congestive heart failure, which affects five million people in the U.S. at a cost to society in the tens of billions of dollars.

The companies will attempt to develop a treatment that minimizes the deterioration of heart function after a heart attack by using MSCs, which can be isolated from the bone marrow of adult donors. The potential benefit from stem cell therapy is that the effect of fully functional cells incorporated into the diseased tissue would result in better treatment than mechanical or pharmaceutical agents. It has been demonstrated that MSCs have the ability to engraft and differentiate into mature, specialized cell types such as those found in muscle or blood vessels.

One of the most promising characteristics of MSCs is that they do not generate the rejection response typically associated with organ transplantation, which requires a life-long regimen of immuno-suppressive drugs. This enables Osiris to produce enough MSCs from one healthy bone marrow donor to treat hundreds of patients.

Osiris is the exclusive owner of broad intellectual property rights to MSC technology and is developing multiple therapeutic applications. Animal research performed by Osiris has shown that MSCs delivered after a heart attack resulted in a significantly better functioning heart several weeks later as compared to control animals that suffered the same injury. Human clinical trials designed to demonstrate safety are scheduled to start this year in the United States.

Boston Scientific and Osiris are developing both intravenous infusion and direct injection methods of treatment. Boston Scientific has developed a specialized injection catheter designed to allow the safe and effective injection of the cells to the affected area of the heart. The alliance calls for Osiris to manufacture the MSCs and Boston Scientific to sell both the cells and the injection catheters globally.

"The development of adult stem cells for the treatment of cardiovascular disease is in its early stages, but it holds long-term promise as a potential new therapy," said Jim Tobin, President and Chief Executive Officer of Boston Scientific. "It represents a ground-breaking approach because it is a biological therapy, rather than a mechanical or pharmaceutical one. This alliance is an example of our ongoing commitment to advancing the most innovative solutions to the most challenging medical problems."

"This adds strong credibility for the use of our adult mesenchymal stem cells to treat cardiovascular disease," said Bill Pursley, President and Chief Executive Officer of Osiris. "Boston Scientific has made a substantial investment to assist our efforts, both financially and through R&D collaboration, to potentially bring therapeutic products to millions of heart patients worldwide. We're looking forward to working with such a dynamic company."

Boston Scientific Corporation is a worldwide developer, manufacturer and marketer of medical devices. The Company's products are used in a broad range of interventional medical specialties.

Osiris Therapeutics, Inc. is the leader in adult stem cell therapy for tissue regeneration, using its proprietary mesenchymal stem cell and universal MSC technologies. These "off-the-shelf" MSCs from unrelated donors are isolated from bone marrow and are used in recipients without immune suppression, representing a viable business strategy for the commercialization of stem cell therapies. The Company's current focus includes the use of universal MSCs for bone marrow transplantation support in hematological malignancies, cardiac repair after acute myocardial infarction or congestive heart failure, and regeneration of meniscus after meniscectomy.

This press release contains forward-looking statements with respect to Boston Scientific. Boston Scientific wishes to caution the reader of this press release that actual results may differ from those discussed in the forward-looking statements and may be adversely affected by, among other things, risks associated with new product development and introduction, clinical trials, regulatory approvals, base research, the Company's overall business strategy, and other factors described in the Company's filings with the Securities and Exchange Commission.