Surrogate sore point
If you had osteoporosis, chances are you’d be happy if offered a drug known to increase bone density. But astute readers would be even happier to take a drug that had been shown not only to make bones denser, but decrease fracture rates.
This distinction between surrogate endpoints such as bone density, and clinically relevant endpoints such as fracture risk, is hardly new, and it was twenty years ago that the FDA shifted the barrier for osteoporosis drugs to reflect the difference.
Right now, diabetes drugs are in the spotlight after reports that while patients on rosiglitazone (Avandia) may have good glycaemic control, it may come with an increased risk of myocardial infarction.
An FDA subcommittee met on 30th July to discuss the cardiac risks associated with rosiglitazone, and voted to recommend that the drug stay on the market but with warning labels and extensive education. In Australia, the Therapeutic Goods Administration has said stronger warnings will be included in the product information for the drug but the exact wording hasn’t yet been determined.
But according to an article by the FDA committee’s chairman in this week’s NEJM, we need a total rethink about the regulation of diabetes drugs.
Endocrinologist Clifford Rosen says it’s not surprising that glycaemic control has been the centerpiece of treatments for type 2 diabetes for many years, with several drugs shown to reduce glycosylated haemoglobin being approved.
“However, change in the glycated hemoglobin level is a relatively poor surrogate for cardiovascular outcomes in type 2 diabetes, accounting for only 5 – 15% of the variation in ischemic risk”, writes Rosen, who urges a “regulatory sea change” on diabetes drugs.
Without one, five years down the track we’ll be in the same position of having a new wonder drug designed to treat a devastating chronic disease but that does more good than harm, he says.
While testing new drugs using real clinical measures such as cardiac events rather than surrogates such as blood tests is costly, in the long run it will save time, money and probably lives.
NEJM 2007 Online 8 August.
This distinction between surrogate endpoints such as bone density, and clinically relevant endpoints such as fracture risk, is hardly new, and it was twenty years ago that the FDA shifted the barrier for osteoporosis drugs to reflect the difference.
Right now, diabetes drugs are in the spotlight after reports that while patients on rosiglitazone (Avandia) may have good glycaemic control, it may come with an increased risk of myocardial infarction.
An FDA subcommittee met on 30th July to discuss the cardiac risks associated with rosiglitazone, and voted to recommend that the drug stay on the market but with warning labels and extensive education. In Australia, the Therapeutic Goods Administration has said stronger warnings will be included in the product information for the drug but the exact wording hasn’t yet been determined.
But according to an article by the FDA committee’s chairman in this week’s NEJM, we need a total rethink about the regulation of diabetes drugs.
Endocrinologist Clifford Rosen says it’s not surprising that glycaemic control has been the centerpiece of treatments for type 2 diabetes for many years, with several drugs shown to reduce glycosylated haemoglobin being approved.
“However, change in the glycated hemoglobin level is a relatively poor surrogate for cardiovascular outcomes in type 2 diabetes, accounting for only 5 – 15% of the variation in ischemic risk”, writes Rosen, who urges a “regulatory sea change” on diabetes drugs.
Without one, five years down the track we’ll be in the same position of having a new wonder drug designed to treat a devastating chronic disease but that does more good than harm, he says.
While testing new drugs using real clinical measures such as cardiac events rather than surrogates such as blood tests is costly, in the long run it will save time, money and probably lives.
NEJM 2007 Online 8 August.
posted by ozdocblog at 8:46 PM
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