The August 19 issue of The Medical Letter will include an article on an expensive new drug for treatment of multidrug-resistant tuberculosis that was approved by the FDA for its effectiveness in converting positive sputum to negative. There is no evidence so far that it cures multidrug-resistant tuberculosis or that it saves lives. Is that good enough?
The use of surrogate endpoints in approving new drugs seems to me to have become more contentious over the years. Just knowing that penicillin killed pneumococci was good enough for a few generations of doctors. No one wrote an editorial demanding a placebo-controlled trial with mortality as the endpoint. When a new statin was rolled out every few years, we cautioned against being overly impressed with its ability to lower serum cholesterol levels in the absence of data showing an accompanying reduction in cardiovascular events. So we warned against the use of Lipitor and then against the use of Crestor, until the clinical outcomes data showed that they saved lives, as we might have expected they would.
So what about losing the tubercle bacilli that used to be in your sputum? Wouldn’t that probably be a good thing that could help you live longer? I can’t think that it wouldn’t, but let’s see what the next issue of The Medical Letter has to say about that.