A cure for the common cold used to be in the "Mission: Impossible" file, along with cold fusion, perpetual motion and a Rose Bowl invitation for the University of Connecticut football team. Pasadena may still be a distant dream, but anti-cold-virus medication is actually on the horizon.
Defeating the common cold is nothing to sneeze at. More than 200 distinct viruses cause colds, according to Linda Lambert, influenza and related respiratory disease program officer at the National Institute of Allergy and Infectious Diseases.
"It's hard to imagine right now that you could have one drug or one vaccine that could prevent infection by such a diverse group of viruses," she said. But at least one drug that offers partial coverage could make it to the drugstore before long. And several others look promising.
Pleconaril - trade name Picovir - takes aim at picornaviruses, a virus family that accounts for about half of all colds and includes rhinoviruses. In study data released last month, the use of pleconaril reduced the severity of cold symptoms and knocked a day off the length of colds. Unable to reproduce on their own, cold viruses typically hijack nose and throat membrane cells in order to create more copies of themselves. Pleconaril disrupts this process. It is being jointly developed by ViroPharma Inc. of Exton, Pa., and Aventis Pharmaceuticals of Bridgewater, N.J. It is the only such cold drug undergoing federal Food and Drug Administration scrutiny. There is no way to know if or when the FDA will approve it.
Another anti-cold drug in development is labeled AG7088 by Agouron Pharmaceuticals of La Jolla, Calif., a subsidiary of Pfizer Inc. AG7088 is a protease inhibitor that interferes with the replication mechanism of cold-causing rhinoviruses. Agouron began a large human trial of AG7088 a little over two years ago, but the medication is not yet up for FDA approval.
One drug that showed promise in a study published in 1999 was Tremacamra, a recombinant molecule that blocked the cellular receptors in the nose where most cold viruses "dock" in order to cause their misery. Patients who used it got fewer and less-severe colds. But Boehringer Ingelheim Pharmaceuticals Inc., with its United States headquarters in Ridgefield, said that it shelved Tremacamra more than a year ago in favor of other projects.
"There were business reasons to change directions," said Sheila Burke, manager of public relations and communications at the firm. She could not elaborate on the thinking behind the decision.
Lambert, of the National Institute of Allergy and Infectious Diseases, said her agency is supporting other anti-common cold research, including attempts to create a human antibody nasal spray that would block the infection process in the nose. One small firm plans to use recombinant technology to grow the human antibodies in plants.
For most people, colds are a nuisance, so why invest heavily in a cure?
Lambert said that research into cold viruses can provide insight into other, more serious infections. Lambert also observed that while most colds are mild and clear up by themselves, colds also can trigger more serious complications like middle ear infections, worsened asthma and even pneumonia.
Even simple colds have a big financial impact because Americans suffer so many - 1 billion - each year. In 1996, federal data show that colds caused 45 million days of restricted activity, undoubtedly many of these employee sick days. Colds also caused 22 million lost school days that year. "There is a huge economic burden to common colds," Lambert said.Copyright © 2014, Los Angeles Times