One by one, the dying Americans stood before an impassive panel of doctors and begged for a few more months of life.

"My prayer is to see my only daughter, who's 5 years old, graduate from kindergarten," said Paula Flowers, whose breast cancer had spread to her lungs, bones and eyes.Dying patients and their families who make this pilgrimage to the Food and Drug Administration call medicines breakthroughs even if they don't cure disease. Just the hope of a slightly prolonged life is enough for them to plead for a drug's approval.

It's a stark acknowledgement that drug companies aren't discovering many magic bullets.

"The nature of drug research is changing," said Gerald Mossinghoff, president of the Pharmaceutical Research and Manufacturers Association. "With the progress medical research has made against many front-line, acute diseases, research today increasingly focuses on the toughest, most resistant to cures."

Some of the most eagerly anticipated drugs awaiting FDA approval today appear only modestly effective:

- Riluzole extended the lives of Lou Gehrig's disease patients by only three months, but it's the first drug ever found helpful at all for the fatal neurological disease.

- Gemcydobene prolonged pancreatic cancer survival a median of only six weeks. But 18 percent survived a year, compared with just 2 percent of patients who got standard therapy.

- Taxotere helped advanced breast cancer patients survive a median of 10 months. But some 40 percent of patients responded to it somewhat, more than respond to other drugs.

In December, the FDA approved navelbine, which prolonged survival of certain lung cancer patients a median of two months. It was their first new treatment in 20 years.

"We are now looking at changes in survival that are very modest," acknowledged FDA drug chief Dr. Robert Temple.

But, he said, "it's hard to say three months' more survival is not a value to people who have a terminal illness. Most people given that option would choose to be treated. Who are we to say no?"

"Sometimes healthy people have the arrogant viewpoint that `you are so sick, what are a few months longer?' " agreed Dr. Manfred Karobath of Rhone-Poulenc Rorer, maker of riluzole and taxotere. "They are fighting . . . and you have to respect that."

The key is ensuring patients don't trade quality of life - suffering more side effects - for a little more time, said Dr. Ronald Keeney of the American Academy of Pharmaceutical Physicians. Patients may have to take a drug for two years just to realize an extra two months of life, he said.

"The hope is these drugs will be used in combination, or used in people a bit healthier, so that you will eventually get significantly more impact," added Diane Blum, executive director of Cancer Care Inc.

And the FDA is pushing companies to study drugs in healthier people instead of resting on an approval to treat the worst cases.

But money is at the heart of this movement toward incrementally better drugs, said Keeney. Each drug costs about $350 million to develop, and only seven of every 10 that hit the market recoup their development costs. Just one in 10 will be a blockbuster.

So when a drug that appeared to be a breakthrough in the lab proves only slightly helpful to people, its maker faces the dilemma of whether to proceed or cut its losses, Keeney said.

In the 1980s, companies often avoided that decision by focusing on proven profitable markets, like the battle among Zantac, Tagamet and Pepcid for ulcer sufferers, he said.

Today, that's changed somewhat - 118 drugs are under development for devastating neurological disorders alone, four times the number a decade ago, new data show.

"You can't possibly know what hope and time means," Lou Gehrig's disease sufferer Dolores Simpson told FDA advisers before they agreed riluzole should be approved.