Bristol-Myers Squibb’s anti-platelet therapy Plavix (clopidogrel) has become the latest blockbuster to lose patent protection in the US.

A mainstay of heart disease treatment since 1997, Plavix faces immediate generic competition from Cardinal Health.

BMS, who markets Plavix in partnership with Sanofi, has said it will cease promoting the drug immediately following patent expiry.

Used together with aspirin, Plavix is the standard blood-thinning therapy for people who have suffered a heart attack.

The product earned BMS $7.1bn in 2011, a third of the company’s revenue.

BMS has decided not to follow the example of Pfizer, who promoted Lipitor extensively for six months after its US patent expiry, because the usual six-month exclusivity to one generic supplier will not apply.

The reason is that the first authorised supplier of generic clopidogrel, Apotex, forfeited its exclusivity period due to unlicensed sales in 2006.

As a result, seven companies have already received tentative approval to sell generic clopidogrel in the US. Cardinal Health plans a next-day launch. A spokesman for Sun Pharmaceutical Industries said the company would lose no time: “I would not be surprised if there was a stopwatch involved.”

BMS’s 2011 annual report predicted “a rapid, precipitous and material decline in Plavix net sales” following expiry of its US patent.

The company has developed a new blood-thinning drug, Eliquis, in partnership with Pfizer. Its FDA approval for stroke prevention is expected in June.

Boehringer Ingelheim has reduced the UK price of its oral anticoagulant Pradaxa (dabigatran etexilate) by 13%, two weeks after receiving NICE recommendation.

While NICE had judged Pradaxa to be cost-effective for stroke prevention in patients with atrial fibrillation (AF) at £2.52 per day, the new price of £2.20 will increase its appeal to prescribers.

The timing of the price change reflects growing industry awareness that NICE approval is only a step on the way to meeting the value criteria of the NHS.

The final NICE guidance recommended that Pradaxa be considered for the prevention of stroke and systemic embolism in adult patients with non-valvular atrial fibrillation (AF) with one or more risk factors, a potential 900,000 people.

The price drop will help to drive access to the first new oral anticoagulant for stroke prevention in patients with AF in 60 years.

According to a recent BMJ report, drug therapy for stroke prevention in patients with AF is sub-optimal in many cases. Up to 30% receive no treatment, a significant proportion of those treated with warfarin are not well controlled, and treatment with aspirin is not adequate.

There is therefore a large unmet need for effective stroke prevention treatment in these patients, whose risk of stroke may be significantly reduced by Pradaxa.

Duncan Cantor, Boehringer’s Director of Communications, said: “We are committed to working with the NHS to offer the very best value we can. Although NICE deem Pradaxa to be cost effective at £2.52 per day, we believe it is important to make our medicines as affordable as possible in this tough financial climate.

“By lowering the price by 13% to £2.20, the NHS now has every opportunity to make sure this medicine is available to all eligible patients.”