An eagerly awaited trial of an experimental treatment to prevent the spread of the AIDS virus from pregnant women to their babies has been delayed indefinitely by a drug company's demand that the federal government accept total liability if something goes wrong.
The company, Abbott Laboratories, balked late last month after nearly a year of negotiations over the trial of a product called HIVIG. The nationwide tests, which were to include institutions in Los Angeles, San Diego and San Francisco, could be delayed another year if a new producer must be found. It was initially expected to begin last February.
"I think Abbott just didn't want to do this on the basis that they are not going to make any money on it," Dr. E. Richard Stiehm, a UCLA professor of pediatrics and one of the researchers organizing the nationwide study, charged in an interview Wednesday.
The snag is significant not only because the product holds the promise of reducing the growing problem of pediatric AIDS, but also because it highlights the skittishness of drug and vaccine manufacturers toward testing certain products in humans.
Drug companies, particularly those interested in developing AIDS vaccines, are pressuring the federal government to shield them from liability if their products backfire and end up harming participants in experimental trials.
"Abbott continues to expect that this waiver for product liability will be granted and, once it is, we'll begin to supply the product for clinical trials," said Tracy Lance, a spokeswoman for the Illinois-based company, reading from a company statement.
HIVIG is made from the plasma of otherwise healthy people infected with the human immunodeficiency virus (HIV). The plasma is processed to collect high concentrations of protective antibodies against the virus, while inactivating the virus itself.
Studies of the product, also known as hyperimmune human intravenous immunoglobulin, have suggested it may help reduce the level of virus in an infected person's plasma. No major side effects have been reported in the small studies in adults in which it has been used.
In the trial, which was approved by the U.S. Food and Drug Administration last year, HIVIG would be administered to infected women in their second and third trimesters of pregnancy and during labor and delivery. It would also be given to their babies within 12 hours of birth.
Researchers estimate that about 30% of infants born to infected mothers become infected either during gestation or labor and delivery or immediately after birth. Researchers hope that treatment with HIVIG might cut that rate in half.
"All of the (federal research) institutes and the investigators felt that this was a very important trial," said Dr. Lynne Mofenson, a federal research official at the National Institutes of Health who is helping to organize the study.
If the trial shows that HIVIG works it would provide a justification for immunizing infected mothers with some sort of a vaccine, Stiehm said. Although the mother might not directly benefit, the vaccine would stimulate the development of antibodies and thus protect the baby.
But if the study is derailed and Abbott withdraws from the project, Stiehm said, he fears it will set a dangerous precedent: "I understand there are a number of drug companies dying to get out of the AIDS business."
According to the Abbott spokeswoman, the company is concerned about "a risk, though small" that HIVIG might enhance, rather than reduce, the chance of virus transmission from mother to child. If it did, women in the study might sue Abbott for damages.
Dr. Arthur Ammann, a prominent researcher associated with the Pediatric AIDS Foundation, said he knows of no lawsuit that has succeeded against a drug company over harm caused by a product during research and development.
Ammann said he fears that other drug companies would shy away from testing AIDS drugs aimed at relatively small subgroups of people infected with the AIDS virus, such as pregnant women, simply because they would not see the potential for large, long-term profits.
"One of our major concerns is if this sets a precedent it may sabotage future trials for these groups," Ammann said. About 6,000 infected women become pregnant in the United States every year; about 2,000 infants become infected through their mothers.
Mofenson and Stiehm counter that the risk of enhancement is more theoretical than real and that the study would be cut short if any such trend developed. Furthermore, the risk is detailed in informed consent documents all participants must sign.
While Abbott officials say the government has indemnified drug companies in the past, Mofenson and Stiehm said it would require an act of Congress--something that could take a year to secure and that could cost many lives.
"I had hoped that we would have a trial of a promising therapy up and running by this time, and I'm disappointed that we are not able to start in a timely fashion," said Mofenson, an associate branch chief in the National Institute of Child Health and Human Development.