Score One for the FDA as Rest of World Finally Yanks Thelin

January 3rd, 2011. By Hunter West

Time to give credit where credit is due. And this time, the US Food and Drug Administration (FDA) got it right. 

Recently it was announced, in a joint statement by Health Canada and Pfizer Canada, that Thelin (sitaxsentan) was being taken off the market in Canada, as well as every country in which it had been sold, due to risk for potentially fatal liver damage. 

Never heard of Thelin? There’s a reason for that. Thelin is not available in the US. Never was. That’s because the FDA refused to approve the drug designed to treat pulmonary hypertension. In the view of the FDA, the benefits did not outweigh the risks. 

In a bid to win FDA approval for marketing Thelin in this country, Pfizer Inc. launched a series of clinical trials. However, those trials have been abandoned following the deaths of three trial participants. 

According to a report in the Globe and Mail, Canada’s national newspaper, liver damage was a known complication of Thelin. However, in announcing that it was abandoning further clinical trials, Pfizer noted that it had discovered a  “new potentially life-threatening idiosyncratic risk” of liver injury among patients that is difficult to predict or guard against. 

Thus, there will be no further clinical trials, and Thelin will be coming off the market in Australia, Europe and Canada where it had been previously approved. Given the known risks associated with Thelin, Canadians are wondering how Thelin ever won Health Canada approval in the first place. 

The FDA has been maligned, chastised, ridiculed and kicked to the curb over the appearance of lax oversight both in the approval, and ongoing supervision of drugs and medical devices. And to be sure, much of that criticism is warranted. 

However, on this occasion the FDA stuck to its guns and has been vindicated. There can be little doubt the FDA was feeling the pressure, given that Thelin was already on the market elsewhere in the world with no apparent adverse effects (Pfizer Canada estimates the usage for Thelin in Canada was very small, about 100 patients—with no deaths or adverse reactions reported). 

While the FDA came off smelling like a rose on this one, there are still problems and many questions remain… 

Why is the FDA not fully-funded by the Feds, thereby giving it a complete, autonomous and arms-length relationship with the drug companies, rather than deriving a portion of its funding from the very industry it is intended to police? 

Why does the FDA not have the power to unilaterally make decisions with regard to drugs—including their wholesale removal from the market—without consent from the manufacturer? At present the FDA has the power only to urge a manufacturer to off a product from the market, and such announcements are usually made in tandem with the drug maker. 

But while the FDA has sole discretion over the approval process, once that happens the relationship changes. If the FDA holds all the cards going in, the agency has fewer as the game goes on. 

That leaves the balance of power with the drug manufacturers, who are in this game primarily to make money. They know that the toughest sell is with the FDA going in. Once a drug is approved, it’s a lot harder to get rid of it. The FDA can study a drug to death and offer a position. However that position is hardly binding. 

The FDA still needs a massive infusion of cash and a complete overhaul of its mandate, in order to give it more teeth. 

That said, what teeth it has was brought to bear over Thelin. While other countries gave Thelin the nod, the FDA stood firm and refused to budge until it had better information in its hands from clinical trials. Without that information, its position was that Thelin was too great a risk. 

The FDA was proven right.

Tags: FDA, Pfizer, Thelin

This was posted on Monday, January 3rd, 2011 at 10:34 am and is filed under Drugs/Medical . Feel free to respond, or trackback. Read our comments policy.