February 01, 2007
Evaluating Me-Too Drugs for Diabetes
Nearly 20 million people in the U.S. suffer from diabetes -- a 54 percent increase in the past seven years. We're fat, getting fatter, and suffering the consequences. How should the health care system tackle this rising epidemic? Should we launch social programs to combat obesity, like those being tried in West Virginia and Arkansas? Or should we intensify the search for new drugs?
If there is anyone who still harbors doubts about the folly of the latter strategy, a fine review in this week's New England Journal of Medicine by David Nathan of Harvard Medical School will dispel them. He reviews the latest entry into this crowded drug market, Januvia by Merck, which was approved by the Food and Drug Administration last October. Another drug in its class, Galvus from Novartis, could be approved any day. These new drugs represent the first entries from the ninth, I repeat, the ninth class of medicines developed to to reverse the chronically high blood sugar associated with diabetes.
His conclusion about the value of these new drugs appeared right near the top of his review:
In theory, newer classes of antidiabetes medications might be welcome additions to the existing armamentarium; however, those that have been developed recently are generally no more potent, and often less effective in lowering glycemia, than the three oldest classes (insulin, the sulfonylureas, and the biguanides), all of which are more than 50 years old. Moreover, the newer classes are uniformly more expensive and are associated with adverse effects — some that are shared by the older drugs, but others that are new.
The FDA had very little information about Merck's new diabetes drug before approving it. "There was only one published, peer-reviewed, moderately large clinical trial; it included 392 treated patients who were followed for 18 weeks to judge the efficacy and safety of the drug," Nathan wrote. And the results of that paltry trial? The drug "is one of the less effective glycemia-lowering drugs introduced in recent years."
Never underestimate the power of marketing to win a place for this inferior drug in the marketplace. Within two months of its introduction, Merck's new drug had captured 14 percent of the diabetes market, according to business reports. How could that be? "The ability of clinicians to judge the merits of new medications is already limited — most receive their information about them from drug companies' representatives and promotional materials. The dearth of peer-reviewed, published studies on sitagliptin makes it difficult for physicians to weigh the benefits and risks of the medication or to describe them to their patients," Nathan wrote.
His bottom line:
The failure of clinicians and their patients with diabetes to implement currently available interventions aggressively and effectively is, I suspect, the major barrier to good care. This problem will not be fixed by making more medications available. Ensuring the effective and cost-effective use of the medications that have already been established by high-quality clinical trials to control glycemia or prevent diabetes should be a higher priority than flooding the market with ever more medications.
Great post, Merrill. Another consideration--besides post-marketing follow-up--is the emphasis (or de-emphasis) on clinical trials that support the FDA's approval. In a recent PBS interview with von Eschenbach,the interviewer pointed out that clinical trials are often composed of "a large group of people. . .[that are] all within a certain age range, and often the people don't have multiple conditions the way ordinary people do."
To which Eschenbach responded: "Right. And even though there are large numbers of patients sometimes in a clinical trial, it's still really a small subset of people. And drugs can act differently in different patients. Patients are taking other medications in other circumstances. And this is now a great opportunity for us to learn more."
This addresses that fact that "real people" may be taking more than one drug--but it does NOT truly speak to drug-interaction, which, in some instances, can be deadly.
Although I know the answer is still corporate profits, my question is why does the FDA "fast-track" me-too drugs? The harm done to the agency's credibility is tremendous. If the agency--and its "FDA-approved" endorsements--loses whatever integrity it may still possess, lawyers will be eagerly pursuing malpractice claims, relying on the mountains of evidence that the words "FDA-approved" are meaningless and do not RELIEVE doctors from liability. Perhaps only then will the powerful AMA and its members join patients in DEMANDING an oversight agency that places patient welfare above corporate agendas and profits.
Posted by: Melody at February 2, 2007 08:28 AM