Friday, April 18, 2014

“Breakthrough Cures”? Reasons for Skepticism

Earlier this week I posted about the current issue of the New England Journal, and mentioned in passing the appearance of antiviral drugs for hepatitis C that are being touted as new miracle cures. My focus in that post—
--was how our so-called free market fails to protect the public interest, so I looked only at the outrageous cost of the hepatitis C drugs and gave a free pass, more or less, to the “cure” claims.

In doing so I overlooked an older and a more recent blog post by our good pal Dr. Roy Poses at Health Care Renewal:

Dr. Poses takes care to show the extraordinarily flimsy evidence on which these new drugs are being ballyhooed. He says a number of things about study design and so on, all of which seem pertinent. But if we try to get a sense of the big picture, all I think we need to know is the natural history of hepatitis C. As Dr. Poses reviews for us, hepatitis C can be a very bad disease leading to liver failure and death. But the total number of folks with the virus who end up with this extreme version of the disease is not that large. A goodly number of people who carry the hepatitis C virus never develop any obvious disease at all. Another good chuck of them develop some liver inflammation, but it never develops into the extreme life-threatening forms.

So before one can get all that excited about a new treatment for hepatitis C, insofar as actual patient-centered outcomes are concerned, we’d need a large-scale follow-up study that showed that people getting the new drugs actually had improved health over the long haul. That would in turn depend on showing that the apparently decent (but hardly perfect) side effect profile of the new drugs is maintained long-term, else the chance of having a bad side effect might be as great as the chance one would have had the bad kind of rapidly-advancing hepatitis C infection with liver damage.

According to Dr. Poses who’s checked out the literature much more carefully than I have, what we know so far is that the new drugs do a pretty good job of clearing the hepatitis C virus from the bloodstreams of patients when followed for a period of up to 24 weeks.

It may well be that a drug that does this good a job of clearing the virus in the short term does an equally good job of saving the patient from long-term, serious consequences of having the virus. Or that may not be the case—we’ve seen many, many instances of initially promising treatments that ultimately fail to pass that test. (This may also be a good time here to remind ourselves of Dr. John Ioannidis’s warning:
--about how it’s a mathematical near-certainty that the first reports about any new drug will give an unduly rosy picture of its effectiveness.)

Now, let’s be fair to the advocates for the new drug. It will take years, to say nothing of tons of money, to do the studies needed to show the real effectiveness of these new hepatitis C drugs. So in the meantime, the data we have so far is probably what’s to be expected at this stage. And so far, the drug is performing more or less as one would expect if indeed it is going to turn out to be a breakthrough drug.

OK, I’ll buy all that. So how about some recognition of the actual limitations of what we know, when this drug is being talked about? Why should supposedly scientifically-aware advocates for the drug feel a need to talk like used car salesmen? (Unless, in fact, their ultimate goal is to sell us a clunker?)

So mea culpa for my earlier post, if I inadvertently added to the hype around these new drugs, instead of joining Dr. Poses in raising the appropriate skeptical concerns. One can hope that the drugs turn out to be what they are hoped to be; and one can also hope that somehow, if that’s the case, people who need them will be able to afford them.

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