Genzyme Announces Positive Results from Carticel® Study at Major Sports Medicine Meeting

Findings from Four Year, Multi-Center Clinical Study on Autologous Chondrocyte Implantation Presented, Coincide with New Product Labeling

July 16, 2007 - Genzyme Corporation (Nasdaq: GENZ) announced today findings from the Study of the Treatment of Articular Repair (STAR) which investigated the safety and effectiveness of Carticel® (autologous cultured chondrocytes) in patients who had an inadequate response to a previous knee cartilage repair procedure. This landmark study demonstrated that autologous chondrocyte implantation provided sustained and clinically meaningful improvements in knee function and reductions in knee pain in this patient population with significant limitations and knee pain at baseline. Internationally renowned orthopaedic surgeon, Dr. Brian Cole of Rush-Presbyterian-St. Luke’s Medical Center, presented the data from the STAR study at the American Orthopaedic Society for Sports Medicine (AOSSM) meeting yesterday in Calgary, Canada.

“This was a well done, rigorous study which provided confirmation of our current treatment options for these types of patients,” stated Dr. Cole. “What was particularly compelling is that the study specifically investigated the outcome of patients that were unresponsive to previous surgical treatments. These patients had failed to receive a sustained benefit from another surgery, yet most of them who had a Carticel implant went on to a very good outcome.”

Study Results

The study achieved its endpoints and successfully fulfills Genzyme’s final post-approval commitment to the FDA. Investigators enrolled patients in 29 clinical centers throughout North America in this open label, prospective 4 year study. Carticel is an autologous cell therapy used for the repair of symptomatic cartilage lesions on the thigh bone portion of the knee caused by acute or repetitive trauma in patients who have had an inadequate response to a prior cartilage repair procedure.

The average patient in the study was approximately 35 years old, had a significantly large articular cartilage lesion in their knee and rated their pre-operative knee pain as quite severe (with a median score of 2 on a scale of 1-10 where 0 is the most severe pain and 10 is normal). The patient population experienced significant reductions in knee pain, as well as improvements in function, including recreational and sports activities. Genzyme’s new Carticel labeling, announced on June 25, 2007, incorporates the safety and efficacy data from the STAR study.

“AOSSM provided us with an excellent forum to share the results of the STAR study with leading, national orthopaedic surgeons specializing in sports medicine and cartilage repair,” said Ann Merrifield, president of Genzyme Biosurgery, the division that manufactures and commercializes Carticel. “We were pleased to share the Carticel safety and efficacy data which confirms how the product can truly make a lasting positive impact for patients.”

A Unique Cell Therapy

More than 13,000 patients in the United States have had Carticel implants. Carticel is used by orthopaedic surgeons to treat patients who have clinically significant articular cartilage lesions on the thigh bone part of the knee caused by acute or repetitive trauma that has not responded to a prior cartilage repair procedure. Carticel should only be used in conjunction with debridement, placement of a periosteal flap and rehabilitation. The independent contributions of the autologous cultured chondrocytes and other components of the therapy to outcome are unknown. Carticel employs a unique process to grow a patient’s own cartilage cells for implantation to correct certain types of damage. The treatment starts when an orthopaedic surgeon trained in the use of Carticel provides Genzyme with a biopsy of healthy cartilage taken from a patient’s knee in an arthroscopic procedure. Technicians at Genzyme’s cell culture laboratory in Cambridge, MA, use proprietary methods to grow millions of cells from this biopsy. The cells are then delivered to the hospital, where the surgeon implants them into the patient’s knee defect in a surgical procedure.

Carticel was the first cell therapy to be approved by the FDA. First introduced in March of 1995, Carticel received accelerated approval from the FDA in August of 1997 after the FDA instituted specific cell therapy guidelines. Under accelerated approval, the FDA required Genzyme to conduct confirmatory post-marketing studies.

To learn more about Carticel please visit www.carticel.com.

Cell Therapy Expertise at Genzyme

Genzyme has more than a decade of experience in developing and manufacturing autologous cell therapy products that have been used to treat thousands of patients. Epicel® (cultured epidermal autografts), a cell therapy for treating patients with severe burns, is also manufactured by Genzyme. Together, Carticel and Epicel represent the first such products ever brought to market in the United States, providing Genzyme with superior scientific and commercial expertise in this field.

About Carticel

Carticel is for autologous use and is indicated for the repair of symptomatic, cartilage defects of the femoral condyle (medial, lateral or trochlea), caused by acute or repetitive trauma, in patients who have had an inadequate response to a prior arthroscopic or other surgical repair procedure (e.g., debridement, microfracture, drilling/abrasion arthroplasty, or osteochondral allograft/autograft). Carticel should only be used in conjunction with debridement, placement of a periosteal flap and rehabilitation. The independent contributions of the autologous cultured chondrocytes and other components of the therapy to outcome are unknown. It is not indicated for the treatment of cartilage damage associated with generalized osteoarthritis. It is not recommended for patients whose knee meniscus has been surgically removed unless the patient has undergone surgical reconstruction prior to or concurrent with Carticel implantation.

Pre-existing conditions including meniscal tears, joint instability or malalignment of the joint should be corrected prior to or concurrent with Carticel implantation. It should not be used in patients with a known history of hypersensitivity to gentamicin, other aminoglycosides or materials of bovine origin. Carticel is not routinely tested for transmissible infectious diseases and may transmit disease to the healthcare provider handling Carticel. In addition, it should not be used in patients who have previously had cancer in the bones, cartilage, fat or muscle of the treated limb. Use in children, patients over age 65, or in joints other than the knee has not yet been assessed.

The occurrence of a subsequent surgical procedure, primarily arthroscopy, following Carticel implantation is common. The most common reactions (>5% of patients), derived from the Study of the Treatment of Articular Repair (STAR), include arthrofibrosis/joint adhesions, graft overgrowth, chondromalacia or chondrosis, cartilage injury, graft complication, meniscal lesion, graft delamination, and osteoarthritis.

About Genzyme

One of the world’s leading biotechnology companies, Genzyme is dedicated to making a major positive impact on the lives of people with serious diseases. Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 9,000 employees in locations spanning the globe and 2006 revenues of $3.2 billion. Genzyme has been selected by FORTUNE as one of the “100 Best Companies to Work for” in the United States.

With many established products and services helping patients in nearly 90 countries, Genzyme is a leader in the effort to develop and apply the most advanced technologies in the life sciences. The company’s products and services are focused on rare inherited disorders, kidney disease, orthopedics, cancer, transplant, and diagnostic testing. Genzyme’s commitment to innovation continues today with a substantial development program focused on these fields, as well as immune disease, infectious disease, and other areas of unmet medical need.