Eli Lilly and Daiichi Sankyo’s much-touted bloodthinner Effient has been approved by regulators in the USA, though the drug will carry a black box warning.

The U. Food and Drug Administration has approved Effient (prasugrel) to reduce the risk of blood clots from forming in patients who undergo angioplasty to unblock a clogged coronary artery. The approval is based on a trial of 13,608 patients compared the drug to Sanofi-Aventis and Bristol-Myers Squibb's blockbuster Plavix (clopidogrel) in patients with a threatened or an actual heart attack who were about to undergo angioplasty.

Those results showed that the number of patients who had subsequent non-fatal heart attacks was reduced from 9.1% in the Plavix arm to 7% in those who took Effient. However, while the numbers of deaths and strokes were similar with both drugs, patients with a history of stroke were more likely to have another one while taking Effient, the FDA says.

The agency also said that “there was a greater risk of significant, sometimes fatal bleeding seen in patients who took Effient”, hence the black box warning. Additionally, the FDA said that prasugrel should not be used in patients with active pathological bleeding, a history of mini-strokes or stroke, or urgent need for surgery, including coronary artery bypass graft surgery. “Physicians must carefully weigh the potential benefits and risks of Effient as they decide which patients should receive the drug," said John Jenkins, director of the Office of New Drugs, in the FDA’s Center for Drug Evaluation and Research.

Lilly’s chief executive John Lechleiter said that the US approval of Effient, which was approved in Europe in February, “is a major step forward in the treatment of acute coronary syndromes". The green light across the Atlantic will come as a huge relief for both companies, given that the regulatory pathway has been a tricky one.

In February, the FDA’s Cardiovascular and Renal Drugs Advisory Committee voted 9-0 in favour of approval although a row broke out later about the make-up of the panel after it emerged that Sanjay Kaul, a cardiologist at Cedars-Sinai Heart Institute in Los Angeles, who had authored several papers critical of the treatment, was pulled from the committee. This was followed last month by a letter from a scientist, who worked on early clinical studies of prasugrel, and the influential US consumer group Public Citizen which called on regulators to reject the drug “because it is neither safe nor effective”.

The black box warning on Effient is being perceived as a negative by analysts, however, as they believe it will take time for the drug to make inroads in a market dominated by Plavix. Annual sales estimates for prasugrel are now being put at around $500 million, down from forecasts of at least $1 billion not so long ago.

Alimta approved in Europe as maintenance therapy
Lilly received even more good news, this time from European regulators who have expanded approval of Alimta (pemetrexed) to include maintenance treatment of patients with locally advanced or metastatic nonsquamous, non-small-cell lung cancer whose disease has not progressed immediately following platinum-based chemotherapy.

The expanded approval is based on a Phase III trial involving 663 patients with stage IIIB/IV NSCLC whose disease had not progressed after four cycles of chemotherapy. The data showed that patients with certain subtypes of NSCLC who received Alimta plus best supportive care survived for 15.5 months following treatment, compared with 10.3 months for those on best supportive care alone. The news comes less than a week after the FDA granted a similar approval.