AstraZeneca's new anti-clotting drug and 'megabrand' Exanta has been approved across 14 European countries, but problems with UK and Ireland authorisation means its launch will be delayed in these countries.

Exanta (ximelgatran) is expected to receive its first launch in the coming months following its first European approval from reference member state France in December last year. The drug is tipped to become one of AstraZeneca's biggest brands, analysts predicting peak sales anywhere between £1.3 billion and £3 billion.

AstraZeneca stressed that the UK and Ireland's regulators' concerns were not over safety or efficacy but the timing and dosing of the drug in its first indication - prevention of blood clots following major orthopaedic surgery.

The treatment regime approved by France and 14 other EU countries involves an initial injectable formulation four to eight hours after completion of surgery followed by oral Exanta 24mg twice daily, up to 11 days.

AstraZeneca says this approach "reflects changing trends in clinical practice across Europe", but a spokesman added that variations remain in practices from country to country, and that the UK and Ireland were not in complete agreement with this regime.

Exanta is the first oral treatment for thrombosis in 60 years, and is the first in a new class of direct thrombin inhibitors. AstraZeneca hopes the more convenient oral formulation of Exanta, will make it popular with healthcare professionals and patients. Standard treatment heparin can only be given under medical supervision in hospital, while newer low molecular weight heparins such as Aventis' Clexane/Lovenox do not have to be administered in hospital but are only available as injections.

More than half of patients undergoing major hip or knee surgery can develop a blood clot, and AstraZeneca claims "no treatment regime to date has successfully balanced efficacy and bleeding risk with oral dosing," something it says Exanta offers.

The initial indication for orthopaedic surgery is seen as a "proof of concept" approval for the drug, with the company setting its sights on competing with established treatment warfarin for stroke prevention in patients with atrial fibrillation and thetreatment of venous thromboembolism.

Applications for these indications have been filed in Europe and the US, where the drug missed out on a fast track priority review. Analysts say one reason for the standard review is the FDA desire to examine data on raised liver enzymes in some patients, a side-effect which caused some concerns in development, but is not widely considered to be a major issue.

Exanta has several advantages over warfarin, including standard doses of Exanta rather than individualised doses and none of the dietary restrictions necessary for patients taking the older drug.

Related Articles:

Exanta ready for launch across Europe

Wednesday, January 07, 2004

pharmafocus@pharmafile.co.uk