Aastrom Biosciences Inc., a company focused on the use of autologous cells for regenerative medicine, has announced that the first two patients have been treated in a pivotal clinical trial utilizing the company's tissue repair cells (TRCs) for the treatment of osteonecrosis of the femoral head.

The pivotal trial sponsored by Aastrom is being conducted at Centro Medico Teknon located in Barcelona, Spain. Aastrom initiated patient enrolment and treatment after receiving written approval from the Spanish Drug Agency (AEMPS) and Teknon's Ethics Committee for the company's Investigational Medicinal Product Dossier (IMPD).

"The initiation of this osteonecrosis clinical trial in Spain is an integral step for our overall bone regeneration programme," said George Dunbar, CEO and president of Aastrom. "If successful, the patient data from this pivotal trial will support future registration applications submitted to the regulatory authorities in the EU, as well as to the FDA in the US."

This is Aastrom's first pivotal study evaluating the company's TRC stem cell therapy in patients with osteonecrosis of the femoral head. Initially, ten patients will be accrued into this trial at Teknon and treated by Principal Investigator, Dr Lluis Orozco and Co-Investigators, Dr Robert Soler-Rich and Dr Carles Solano. In general terms, the expected treatment approach will include the removal of the necrotic tissue from the interior of the patient's femoral head (top of the femur), followed by the implantation of TRCs. The expectation is that if the femoral head is strengthened by the re- growth of healthy bone, marrow and vascular tissue, the need for a hip replacement could be delayed or eliminated for patients suffering from this disease.

The primary efficacy endpoint of this trial is to eliminate or delay the progression of osteonecrosis, which will be measured by MRI and X-ray. Patients will be followed for a total of 24 months, post treatment.

"The experience we acquired using the TRC cell product in prior studies of atrophic non-union long bone fractures gave us the confidence to apply the TRC technology to patients with osteonecrosis. We hope to demonstrate significant efficacy over existing therapies," said Dr LluAs Orozco, scientific director, Orthopaedics, of Institut de Terapia Regenerativa Tisular.

The tissues involved in the osteonecrosis disease process include bone, bone marrow and blood vessels (vascular), complicating the development of effective treatments in the past. Aastrom's TRCs, a proprietary mixture of stem and progenitor cells derived from a small sample of the patient's own bone marrow, have been used in separate clinical trials to regenerate all three of these tissues. With this capability, TRCs may offer a novel means to regenerate the tissues lost due to osteonecrosis.

In 2006, Aastrom's proprietary TRCs received an Orphan Drug Designation from the US Food and Drug Administration (FDA) for use in the treatment of osteonecrosis of the femoral head. Aastrom is preparing a protocol for a US pivotal osteonecrosis clinical trial with the FDA.