Clinical trials will start next month on a Vitamin A cream that researchers hope will wipe out wrinkles and restore a youthful look to sun-damaged skin. So far, it has proven itself only on rabbits and mice.
Dr. Thomas Nigra of the Washington (D.C.) Hospital Center said the new cream, called Pelretin, will be tested for six months on 240 patients in three cities and results should be known in about a year.
The tests were organized after Pelretin was tested on rabbits and the rhino mouse, a rodent that is genetically disposed to develop wrinkles early in life. The results of the animal tests, said Nigra, were "dramatic."
The doctor said it may be four years, or more, before Pelretin is available as a prescription compound.
Pelretin, said Nigra, is a "first cousin" to Retin A, a prescription cream that was developed to treat acne but which doctors discovered also is effective against skin wrinkling.
"Pelretin should offer an advantage over Retin A because the early studies suggest it has a similar therapeutic response but with less side effects," he said. "This is really a second generation of cosmetic pharmaceutical."
The side effects of Retin A are not serious but can be irritating, said Nigra. They include a reddening of the skin, scaling and flaking, along with a burning sensation.
The doctor said Pelretin "has been through all of the studies . . . to make sure it is a safe product to be used in human testing."
Both Retin A and Pelretin contain a Vitamin A compound that some researchers claim has been shown in tests to smooth aging, damaged skin.
Other dermatologists, however, claim the creams only give the appearance of smoothing the skin and that the effects are not real.
Nigra said his research with Retin A demonstrates that the compound does remove some wrinkles, giving what he called "excellent" results for 28.5% of patients who use the cream and "good" for 47.6%.
But he said about half of the patients who used the placebo also showed "good" results because "we taught them how to take care of their skin."
Nigra said laboratory tests have shown that Vitamin A compounds do improve skin tone. He said biopsies of skin treated with Retin A show that it has a hormonal effect that causes skin tissue to thicken. This, in turn, causes some wrinkles to smooth out.
The cream works best on very shallow, faint wrinkles, and lightens skin blotches caused by sun damage, Nigra said. He expects Pelretin to have the same effect.
Volunteers for the clinical tests are being accepted at the Washington Hospital Center and at hospitals in Atlanta and San Diego. The study is to start Jan. 8.
Nigra said the patients in the study must be white, between 40 and 70 years of age and have skin that has been moderately to severely damaged from a lifetime of exposure. Other races will be tested later, he said, although dark skins tend not to be easily damaged by the sun.
To test the cream, the patients will be divided into two groups.
Half of the patients will get Pelretin and the other half a cream that contains a placebo, or neutral compound. Which patient gets which cream will be kept secret from both doctor and patient until the test is completed in six months. The effects on the skin of the patients will then be compared.
Nigra said patients will be told to apply the cream once daily, just before bed. He said the Vitamin A compound is known to make the skin very sensitive to sunlight and that all patients will be told to use a sun screen outside.
If the Pelretin tests are successful, Nigra said, Ortho Pharmaceuticals, the New Jersey-based manufacturer of both Retin A and the new cream, will apply to the U.S. Food and Drug Administration for a license to market the product as a skin cream.