By Lisa Seachrist

Washington Editor

WASHINGTON — The FDA said Friday that it has developed a new plan to regulate human cellular and tissue-based products.

Under this most recent Reinventing Government Initiative, the agency will regulate human tissue products such as cord blood, reproductive tissues and modified human cells with an eye to preventing the transmission of infectious disease, preventing contamination of the tissues and ensuring the safety and effectiveness of tissue-based products.

"This new regulatory framework, developed after discussions with industry, academics and professional groups, will allow greater flexibility and innovation in this promising field of medicine," Vice President Al Gore said in a statement.

While human tissues have been used in transplants for decades, research has been accelerating into tissue-derived therapies as varied as skin replacement for burn victims and techniques to use human cells to deliver drugs. The downside to all this activity is that viruses like HIV and hepatitis can be transmitted by these cells.

"The FDA has really looked at these new therapies on a product-by-product basis," said Jill Hartzler Warner, FDA counsel to the director of the center of biologics evaluation and research. "This proposal provides a road map to allow the agency to regulate these products at the right level."

The new rules are a marked departure from the way the agency ordinarily regulates new therapies. Previously, manufacturers were required to file an application with the agency, which would then rule if the therapy was safe and effective. The result was inconsistent levels of regulation.

"We have really seen a patchwork of regulations develop around these products," Warner said. "With these proposed regulations, the agency will address four questions to determine the correct level of regulation."

Warner noted that the agency would address the following questions: Can the transmission of infection be prevented? What processing controls are needed to prevent contamination? How can safety and efficacy be assured? What type of labeling is necessary or permissible?

For example, the agency would not regulate tissues removed from and transplanted into the same person in a single surgical procedure, such as a tendon graft. For most conventional and reproductive tissues that are minimally processed, the agency would require the tissue to be tested for known infectious agents.

For tissues that are stored for use in the same person, a closely related individual or a sexually intimate partner, the agency would recommend, but not require, infectious disease screening as long as the product is expected to provide its conventional function, like stem cell grafting into bone marrow and producing blood cells.

The agency would require full clinical trials and pre-market approval for tissues that are processed to alter their biological or functional characteristics. For example, nerve cells that are genetically engineered to produce dopamine for use in Parkinson's patients would fall under this regulation.

Warner pointed out that under these new guidelines, a company wishing to store cord blood for use in the patient or a closely related relative would not have to gain premarket approval showing that the stem cells in the cord blood can reconstitute hematopoietic potential.

Should those cord blood stem cells be engineered to fight off infection by HIV, then the agency would require proof of safety and efficacy.

"It' s been exciting to work with the agency as they developed a model that makes sense," said Cynthia Fisher, president and CEO at Viacord Inc., in Boston, whose company specializes in banking cord blood. "The agency has with this model provided broader access to these therapies while fully protecting the public health."

Fisher told BioWorld Today that Viacord already exceeds the disease screening requirements set forth in the FDA's plan, but called the proposal "an example of new and innovative thinking at FDA."

"This is a very common sense approach to the use of tissue," Carl Feldbaum, president of the Biotechnology Industry Organization said. "This is an enormously complex field and these regulations make the issues understandable and clear."

The new rules likely will take at least a year to wend their way through the "new regulation" review process. A public hearing is scheduled for March 17. *