CHICAGO -- Scientists have developed the first medicine proven to reduce the length and severity of the common cold.
Whether this is the long-sought cure is debatable, since it doesn't make the sniffles disappear immediately. Nevertheless, experts say there is little doubt the medicine -- which is still months away from drugstores -- makes people feel better sooner if their cold is caused by a rhinovirus, the most common culprit.
The drug, called pleconaril, makes a runny nose completely clear up a day sooner than usual and begins to ease the symptoms within a day.
Many over-the-counter medicines ease cold symptoms by drying up plugged noses and soothing aches. But this drug is the first to actually make a cold go away faster and to work by attacking the cold virus itself.
The findings were presented Monday by Dr. Frederick Hayden of the University of Virginia at an infectious-disease conference in Chicago sponsored by the American Society for Microbiology. The research was financed by ViroPharma Inc. of Exton, Pa., which is developing the drug.
The company applied in July to the Food and Drug Administration for approval to market the drug. A decision is still months away, perhaps longer.
Safety big concern
Experts say they expect the agency to be unusually cautious, since any medicine to treat a non-lethal infection in healthy people must be extremely safe.
"The safety issues are dramatic," said Dr. Scott Hammer, a virus expert at Columbia University. "They will be looked at very, very carefully."
Nevertheless, Hammer said the drug's benefits appear significant, since a one-day reduction in a viral disease that lasts only a few days is probably the best that can be hoped for.
Hayden said he has seen no significant side effects from pleconaril. Some volunteers have a slight, temporary rise in cholesterol levels, which he said has "no clinical significance."
The company has not said how much it will charge for the medicine, which would sold by prescription under the brand name Picovir, but officials said it is likely to cost as much as antibiotics, which typically are more than $40 for a course of treatment.
The medicine attacks a large group of viruses known as the picornaviruses. Among these is the rhinovirus, the bug that causes about half of all colds.
"It really represents the first effective treatment for a rhinovirus illness," Hayden said.
The medicine stops the virus by fitting into a groove on its surface. This jams the machinery it needs to enter and infect the body's cells.
The latest research is ViroPharma's second attempt to prove that the drug speeds recovery from the common cold. Its earlier study fell short of showing a statistically significant benefit.
In the latest work, conducted a year ago, people who felt colds coming on were randomly assigned to get pleconaril or dummy pills. In all, 2,096 people started in the study within a day of the onset of symptoms.
Testing showed that two-thirds of the volunteers actually had caught a rhinovirus. In these people, runny noses and other symptoms completely went away in an average of six days, compared with seven days in the rhinovirus sufferers getting placeboes.
Volunteers were allowed to take their usual over-the-counter remedies. Nevertheless, those using pleconaril began to feel better than the others within a day of starting treatment. Their symptoms were half gone in three days, compared with four days among those getting dummy pills.
New studies are under way to test the drug in children who have colds as well as in college students to see if it will keep them from catching colds.
Those with fevers were excluded from the study, since their colds are unlikely to result from rhinoviruses.
In general, Hayden said the medicine is likely to be most useful in the spring, summer and fall, when the rhinovirus is the dominant cause of colds. Colds in the late fall and winter are more likely to result from other viruses.
Doctors assume that the sooner people start taking the drug, the better their chances of cutting short their colds. Hayden said pleconaril may work best if people keep a supply at home to use at the first telltale symptoms.
Colds are the single most frequent reason why people go to the doctor. Antibiotics are worthless against colds, though doctors often prescribe them anyway.
An FDA advisory panel is scheduled to review pleconaril next spring. Hayden declined to predict whether it will be approved. However, he said, "I would certainly use it, and I would use it in my family members."
Pleconaril may also work against other kinds of picornaviruses, including ones that causes viral meningitis and middle-ear infections.