Japan’s Astellas has suffered a fresh setback in its bid to get the go-ahead to sell its once-daily version of the immunosuppressant Prograf in the USA.

The US Food and Drug Administration has only issued an approvable letter for FK506MR (tacrolimus), sold in Europe as Advagraf, for organ rejection in patients receiving liver transplants. This is the second time the agency has asked for more information on the drug, having issued its first approvable letter in January 2007.

Indeed Astellas has been inundated with rejections from the FDA for FK506MR since December 2005 when it submitted a New Drug Application for the use of the treatment in kidney, heart and liver transplant patients. Aside from the approvable letters for the latter indication, the FDA turned down a second bid in March this year to get the green light for kidney transplant patients.

As for the application to get approval of once-daily tacrolimus for organ rejection in heart transplant patients, that was rejected in January last year as well. Now Astellas says it is internally examining the future strategy for the three indications, though the news of the latest approvable letter is a big blow.

The company had been hoping to get the new version of Prograf onto the US market before its patent expired there last month. The original drug brings in $2 billion a year and Astellas was hoping to switch patients onto FK506MR but analysts are not overly worried at the moment about a generic threat to Prograf sales.

The once-daily version has fared better in Europe and Advagraf was launched in its first markets - the UK and Germany – last June for use in kidney and liver transplants.

Mycamine approved in Europe
Staying with Europe and Astellas announced that its antifungal agent Mycamine (micafungin) has been approved by regulators there for the treatment of a variety of Candida infections.

Mycamine will initially be available in the UK and across the European market shortly after. Astellas quoted David Denning of the University of Manchester as saying that the approval “is very good news for patients with life-threatening fungal infections in Europe”. He added that “particularly welcome are the indications for fungal infections in children and babies, often a neglected group in the early drug approval process”.

Mycamine was launched in Japan in 2002 and in the USA three years ago. Astellas said that in these two markets more than 350,000 patients have been treated with the product.