LONDON - IsoTis BV, of Bilthoven, the Netherlands, has raised US$5 million in a third round of financing that it says will see it through to the middle of next year. The money came from existing shareholders and two venture capital companies: Atlas Ventures GIMV, of Belgium, and 3i plc, of the U.K.

“We are planning an additional round of funding in 1999, and will go for an [initial public offering] early in 2000, with the timing depending on market conditions,“ said Clemens van Blitterswijk, CEO of IsoTis.

The company, founded in 1996, raised $2.5 million in the previous two funding rounds. IsoTis specializes in the development of hard and soft tissue replacements, including bone and skin. It aims to combine expertise in materials science and tissue engineering to produce hybrid implants that offer the best mix of physical and biological properties.

Van Blitterswijk said that with the addition of government and European Community grants, the money would allow the company to build a pilot plant for tissue engineering, and to build production plants for its two biomimetic materials. These facilities will be completed by the middle of 1999. IsoTis also will expand its research teams, paving the way for the first clinical trials of its tissue engineering technology and of metal implants coated with Rainbow, its biomimetic coating.

In November 1997, IsoTis agreed to a collaboration with orthopedic companies Implex Corp., in the U.S., and Stratec Medical AG, in Switzerland, for the development and commercialization of Rainbow, a calcium phosphate coating. The coating is applied at low temperatures, allowing temperature-sensitive compounds to be incorporated, which researchers hope will improve the performance of the prosthesis. “We are focusing on Rainbow as a slow-release system, for example, for antibiotics, or for growth factors to stimulate bone regrowth around the implant,“ van Blitterswijk said.

While IsoTis is aiming to get approval first for Rainbow-coated hip replacements, van Blitterswijk said the coating will be applicable to a range of devices. “There will be advantages to its use on a wide variety of devices, for example, dental implants,“ he said.

When complete, the tissue engineering plant will be able to handle up to 1,000 patients for clinical trials of IsoTis' Osteovitro system. The system involves taking a bone biopsy and multiplying the cells, which are then seeded onto a conventional prosthesis to eventually form a complete coating. In rat trials, the bone growth continues when the hybrid implants are transplanted into the animals. *