Mylan stood by its earnings forecasts for fiscal 2007 yesterday, despite the approval of another generic rival to Johnson & Johnson’s Duragesic pain-relieving patch in the US market that sparked a 13% drop in its share price.

The US Food and Drug Administration (FDA) gave a green light to another copycat version of Duragesic (fentanyl) developed by the US subsidiary of Greek company Lavipharm SA, although the latter said it has not yet decided when to launch its product.

Mylan said earlier in the day that expects earnings per share to be in the region of $1.35-$1.55 in fiscal 2007, ending March next year, a little higher than analysts polled by First Call/Thomson Financial who are expecting $1.32. But in an embarrassing moment for the company, it also said in the statement that it did not expect any generic competitors to reach the market in the fiscal year, just hours before the FDA cleared the Lavipharm product.

In a statement, Lavipharm said it would give more details of its launch plans for the product, which will compete in a market estimated to be worth around $1 billion in 2005, at the end of August. The company also markets a nitroglycerin patch product for angina.

Lavipharm also said this is the first time that a pharmaceutical product developed by a company of Greek origin has been approved by the FDA.

Mylan was the first company to win approval of a copycat version of Duragesic (fentanyl) in the USA, after a long and troublesome registration in which the license for its product was approved, and then revoked after J&J won a six-month patent extension for Duragesic, in 2004. But it was re-approved in February 2005 and has been a driver of Mylan’s sales growth at a time when the US generics market as a whole has been tackling increased competition and pricing pressure.

Analysts estimate that the product accounts for around a fifth of Mylan’s total revenues, bringing in around $70 million in the second quarter of this year.

Mylan may have battled with J&J to bring its transdermal fentanyl to market in the USA, but the two now find themselves in partnership as they try to block further approvals of Duragesic generics. Both companies have filed Citizen’s Petitions with the FDA requesting that additional entrants in to the marketplace should have to conduct clinical trials of their products in order to gain approval.

At the heart of the petitions is whether the overlay adhesives used in rival fentanyl patch products alter the amount of fentanyl delivered across the skin.