On Friday, US Federal District Court Judge Henry H. Kennedy Jr. said that the American Academy of Pediatrics and the Elizabeth Glaser Pediatric AIDS (news - web sites) Foundation were sufficiently involved in the case to allow them to appeal the decision even if the FDA declined to do so. The judge noted that the groups have been "directly harmed" by the loss of the rule and that they have "championed this policy from its inception."

Kennedy in October struck down the so-called "pediatric rule," saying the FDA overstepped its authority in issuing it in 1998.

The groups filed their "notice to appeal" on Monday, just hours before the FDA announced it would not join them. Bush administration officials said they will instead pursue legislation in Congress to give the FDA explicit authority to order pediatric drug testing when the agency feels is it warranted.

In a statement issued late Monday, FDA Commissioner Mark McClellan said that "continued litigation is likely to take years, and its outcome is uncertain. The better course now is to work with the committees in Congress and enact new, specific legislation rapidly." The Bush administration did not work to pass a bipartisan bill approved by the Senate Health, Education, Labor and Pensions Committee last fall. That bill died at the end of the Congress.

The two children's health groups, which also support a legislative solution to the problem, said it is nevertheless important to continue the lawsuit.

"Currently three quarters of the drugs prescribed to children haven't been tested for their use," said Kate Carr, president and CEO of the Glaser Foundation. "We will continue to vigorously protect this crucial regulation that is improving the health and well-being of children."

Said Dr. Stephen Edwards, president of the American Academy of Pediatrics: "Each day that passes without the Pediatric Rule puts children senselessly at risk. We must act now, before the rule's absence compromises the health of our next generation."