VetCell BioScience Ltd., which has made a name for itself in the animal health industry by using stem cells to treat tendinitis in racehorses, is taking its technology into the human market, with an initial focus on shoulder injuries.

It's hardly a stretch, since there is increasing recognition that horses serve as good translational models for human diseases, particularly in the area of musculoskeletal conditions, said CEO Greg McGarrell, and that's a fact VetCell has been well aware of since the beginning.

"It wasn't an accident," he said. "It wasn't something we stumbled across." The company was founded in 2002 as the first spinout of Royal Veterinary College of London with the near-term goal of commercializing technology involving the use of autologous mesenchymal stem cells to treat tendon injuries in racehorses and other performance horses.

By studying tendon injuries in horses - specifically racehorses, which are apt to suffer tendon damage due to cumulative fatigue - VetCell built an animal health business while "also knowing that we can translate our knowledge up into the human clinical setting," McGarrell told BioWorld Today. "Because of how it's presented, a partial tear to a rotator cuff [in a human shoulder] is almost identical to a flex tendon injury in a horse."

He added that the first human clinical study, to be conducted at Royal National Orthopedic Hospital in London, is imminent and will involve the same procedure as the one used for horses. The treatment involves isolating mesenchymal stem cells from the patient's harvested bone marrow and then growing the cells in a laboratory to the required volume, based on the amount of tissue that needs regenerating in each specific case. Cell processing takes about two to three weeks. Once prepared, the cells are resuspended in the natural supernatant, which contains growth factors to help with tissue regeneration and implantation. That supernatant also carries sodium citrate, which acts as an anti-coagulant for the stem cells until it is dispersed upon implantation.

The therapy then is injected into the core of the lesion. In humans, the process likely will involve "a needle guided into the center of the lesion using ultrasound guidance," McGarrell said.

The market potential for rotator cuff injuries is enormous, affecting an estimated 70 percent of men and women older than 60, and between 2 million and 3 million suffering such injuries in the UK alone. While surgery is available for rotator cuff injuries that involve full tears, VetCell's stem cell treatment would be aimed at treating patients with partial tears.

Designed to regenerate rather than repair tendon cells, VetCell's technology has been effective in racehorses, allowing injured muscles to heal without developing scar tissue and helping prevent further injuries. Following the procedure, patients undergo a controlled rehabilitation program while the tissue starts to regenerate, and VetCell considers that rehabilitation as part of its therapeutic know-how.

Ten percent of the therapy involves the stem cell growth and implantation, with the other 90 percent "coming from knowing how to rehabilitate," McGarrell said. "We have to provide a full service to the health industry."

Depending on its success in treating human shoulder injuries, the company hopes to move into second-generation products and investigate stem cell-based approaches for other conditions caused by damaged tendons or ligaments and joint disorders. But whichever indication it pursues next, VetCell intends to keep using the horse as its translational model.

"If we can figure out how to deal with those [conditions] in horses, we can move up to humans," McGarrell said. "For us, the horse has become the musculoskeletal guinea pig."

VetCell, which has seven full-time employees and relies heavily on collaborations and outsourcing with various laboratories in the U.S., Europe, Australia and South America, received investments of about £800,000 (US$1.5 million) to get the company up and running. McGarrell said he often describes the firm as going "from zero to hero on a shoestring budget" by "keeping the burn rate as low as possible."

The company also generates revenue from its business treating racehorses. During its first four years, VetCell treated about 500 horses, and "we hope to treat at least that number" during 2007 alone, McGarrell said.

But "this is not just your cozy animal health story," he added. As the company moves into the human market, VetCell is looking for additional financing to fund human trials and to support a subsidiary firm that will be responsible for advancing that part of the business.

VetCell is based at the London BioScience Innovation Centre, and is about to set up a U.S. site in North Carolina.