WASHINGTON _ In early October, researchers at theUniversity of California at San Francisco (UCSF) will forthe first time transplant bone marrow from a baboon intoa human patient with advanced AIDS, despite concernsthat it could result in the transmission of baboon-to-human diseases.

Species-to-species transmission of disease is a seriouspublic health concern for officials from the Centers forDisease Control and Prevention (CDC) who are mindfulthat diseases such as AIDS and the Ebola virus aresuspected to have jumped to humans from non-humanprimates. They aired those concerns at a public hearinglast month called by the FDA to examine the possiblepublic health risks of xenotransplantation.

BioWorld Today learned late Tuesday that the transplantwas given the go-ahead on July 27, less than two weeksfollowing that hearing, after the FDA resolved severaloutstanding questions about the highly experimentalinvestigation.

The FDA removed a "hold" from the investigational newdrug (IND) application held by University of Pittsburghresearcher Suzanne Ildstad and UCSF professor StevenDeeks if certain conditions are met. Neither of theresearchers returned phone calls placed by BioWorldToday for interviews.

One of those conditions centers on the researchersmaking a good faith effort to search for a baboon that isfree of foamy virus, an especially virulent disease that isfatal in most baboons. Foamy virus is a retrovirus of thesub-family spumavirinae, found in primates and othermammals. It is so named because of lace-like changesproduced in monkey kidney cells.

In addition, the FDA asked for more assurances that stepswould be taken to protect the health care workers andother patients from possible contamination.

If Ildstad and Deeks supply the agency with adequatescientific documentation on issues such as validation ofthe diagnostic tests performed to screen baboons as donorcandidates, requests to perform additional transplants willbe considered, an FDA official told BioWorld Today.

"The FDA and CDC must take more global views ofxenotransplantation than investigators who are focusingon only one patient," said Michael Egan, senior vicepresident of Diacrin Inc., of Charlestown, Mass. Egan lastyear shepherded through the FDA the biotech company'sapplication to use porcine cells in patients withAlzheimer's disease.

The conditions placed on researchers are consistent withFDA efforts to reach a consensus on how to regulate thegrowing field of xenotransplantation. FDA officials havemade it clear that they wish to enter into a dialogue on thefuture of xenotransplantation with the academiccommunity and the growing number of biotech firms thatare using animal organs and tissues to develop newtherapeutic approaches.

The FDA plans to issue guidelines on xenotransplantationnext January. (See BioWorld Today, July 17, 1995, p. 1.)The agency is expected to require that researchersdocument a number of key steps in xenotransplantationincluding screening of animals for disease, informedconsent that permits extensive follow-up, post-surgicalsurveillance and a national registry of xenografts.

The FDA's approval of the baboon-to-human experimentis another sign that the FDA is "looking favorably on thefield of xenotransplantation," said John Logan, vicepresident for research and development at Nextran, basedin Princeton, N.J. Nextran is a partnership between DNXCorp., of Raritan, N.J., and Baxter Healthcare Corp., asubsidiary of Baxter International Inc. in Deerfield, Ill.

"The agency made an informed decision," said Logan."While there has been a lot of FDA bashing recently, theagency asked the right questions of the investigators,convened a panel of noted experts in the field, looked attheir pluses and minuses in a public meeting and finallymade their decision based on a clinical protocol."

Several requests from biotech companies to developproducts involving xenotransplantation have beenapproved by the FDA. In addition to Diacrin's use ofporcine fetal cells in patients with Parkinson's disease,Nextran earlier this month won FDA approval to testtransplanting livers from genetically altered pigs intohumans until suitable human organs become available.(See BioWorld Today, July 28, 1995, p. 1.)

Researchers at UCSF now are reviewing candidates forthe transplant, said Alice Trinkl, a hospital spokeswoman.

She dismissed the conclusion that the recipient would beSan Francisco AIDS activist Jeff Getty, whose family hadmade an emotional appeal before an FDA advisorycommittee to approve the protocol. (See BioWorldToday, July 17, 1995, p. 1.)

"Getty is a top candidate but details about the recipientand the protocol will be announced just prior to surgery,"Trinkl said. n

-- Michele Robinson Washington Editor

(c) 1997 American Health Consultants. All rights reserved.