A new 'cosmeceutical' to boost eyelash growth - from the maker of Botox - could take a bite out of the mascara market

US drugmaker Allergan, the California-based company that makes antiwrinkle treatment Botox, has developed a new cosmetic drug that makes eyelashes grow longer, thicker and darker.

On 4 June the company announced it would file for US Food and Drug Administration approval for the drug before the end of September - confirming speculation it would make an eyelash-boosting drug based on bimatoprost, the active ingredient its glaucoma drug Lumigan.

Increased eyelash growth is one of the commonest side-effects of Lumigan, which in 2001 was approved in the US as a glaucoma treatment to reduce pressure inside the eye in the US. Botox’s cosmetic effects were discovered in a similar way, when doctors giving the injection to relieve muscle spasms and treat crossed eyes noticed that wrinkles around the eyes were also reduced.

The company has now reformulated bimatoprost to be applied directly to the base of the eyelashes - and recently completed clinical trials have confirmed produces significant eyelash growth, Allergan says. When taken as a glaucoma formulation, the drugs side effects include eye redness and darkening of the eyelid and eye colour due to increased pigmentation. The darkened eye colour is likely to be permanent. Allergan declined to comment on the incidence of side effects triggered by the eyelash formulation during clinical trials.

The company says it has been in discussions with the FDA over the drug throughout its development, and expects the regulator’s decision on the drug’s approval in 2009. The company says it is also assessing demand for the product outside the US, and plans to seek approvals accordingly.

Bimatoprost is a synthetic member of the prostaglandin family, a group of signalling molecules produced naturally by the body and all based on a five-membered ring bearing two side chains. Allergan claims it holds patents in the US and abroad that give it exclusive rights to make prostaglandin-based eyelash treatments, and in November 2007 sued several companies it claimed were infringing its patent. Later that month, the FDA sent US marshals to seize 12,862 tubes of Age Intervention Eyelash, a product sold by California-based Jan Marini Skin Research that was found to contain bimatoprost.

Allergan estimates it will make about $1.4 billion (?0.72 billion) from sales of Botox during 2008, and predicts sales of its eyelash drug could exceed $500 million in annual sales, based on the estimate that the global mascara market is worth $3.7 billion each year.

Following the Allergan announcement, New York-based Goldman Sachs analyst James Kelly concluded that FDA approval was likely for the drug even though it will be marketed as a cosmetic. ’We are less concerned about FDA conservatism, given the history of the product in the eye,’ he said. Kelly forecast the product would launch in 2009, with sales peaking at $500 million.

James Mitchell Crow