Allergan, which makes Botox anti-wrinkle injections, has asked the Food and Drug Administration to approve its Lumigan formula to enhance eyelashes for patients 18 and older.
The agency's panel of outside eye and skin specialists voted unanimously that the drug's benefits outweigh its risks.
"I have absolutely no reason to question the efficacy or the effect of Lumigan," said Dr. M. Roy Wilson, chancellor of the University of Denver. "I also want to emphasize that I don't have any concerns about potential side effects on the eyelid."
However, the same panel voted 5-3 with one abstention that Allergan should be required to conduct follow-up studies to address questions about the drug's use among certain patients.
"I'm worried about off-label, nonsupervised use of this medication, and I'm concerned teenagers might use it three or four times a day instead of once," said Dr. Marijean Miller, an ophthalmologist with the Children's National Medical Center in Washington.
Dr. Robert Cykiert, an ophthalmologist at New York University, told CBS' The Early Show that applying Lumigan directly to the eyelashes should be safe and have few side effects.
"Currently the glaucoma drop is put directly into the eye. The new formulation for growing your eyelashes longer will be applied with an applicator to the base of the eyelashes so very little or none of the drug should get into the eye," he said.
Other experts noted that only one African-American patient was included in company trials and said Allergan should be required to show the drug's effectiveness in that population.
Panelists also discussed what types of physicians should be able to prescribe the drug. Allergan would like any licensed physician to be able to write a prescription. However, panelists debated whether younger patients should be able to get the drug only after seeing an eye specialist.
While Allergan is only seeking approval for patients 18 and older, panelists said they expected the drug would be end up being prescribed to younger patients.
The FDA is not required to follow the panel's advice, though it normally does. The agency is expected to make a decision on the drug in mid-2009.
The drug is already marketed to treat eye conditions stemming from glaucoma. In studies for that treatment, researchers first noticed the drug seemed to stimulate eyelash growth.
Irvine, Calif.-based Allergan plans to market the drug under the brand name Latisse, if it is approved as a cosmetic treatment.
"Latisse will offer consumers an FDA-approved product which has been extensively studied in well-controlled clinical trials, is manufactured to pharmaceutical standards, is appropriately labeled for use, and is regulated as a prescription product," Allergan said in a statement.
A study conducted by Allergan showed once-daily application with the formula significantly increased prominence of lashes after four months. The study also met its secondary goals of increasing eyelash length, thickness and darkness.
Allergan has estimated that Latisse could garner more than $500 million in sales annually, however, analysts are more conservative about the product's short-term potential. Cowen & Co. analyst Ken Cacciatore projected in a research note that Latisse would reach $15 million in sales for 2009 and $30 million in 2010.
Shares of Allergan rose $2.12, or 5.8 percent, to close at $38.54.