August 31, 2012

Most good ideas don’t work

Since newspapers almost exclusively cover positive results in medical research, it’s easy to have an unrealistically optimistic view of progress.  Most weeks, there are multiple stories about some new compound or extract that kills cancer cells in the lab, but we don’t learn what happens later.  And no, these treatments aren’t suppressed by evil multinational drug companies, who are actually in desperate need of new things to sell us.  As a partial corrective, here are some relatively recent research findings that make it less likely we’ll soon get new treatments for important diseases.

Alzheimer’s:  trials of two antibodies against amyloid plaques, which had shown promise in mice, failed to  show benefits in patients (one was robustly null, the other was borderline and the company hasn’t quite given up hope).  Inhibiting one of the enzymes that makes amyloid has also failed.

Heart disease:  Raising ‘good’ HDL cholesterol was a big hope, but three separate approaches to treatment have so far failed to provide any convincing benefit in clinical trials, and genetic studies suggest that although HDL is associated with lower risk, it may not actually be responsible for the reduction.

 Diabetes:  drugs to reduce insulin resistance through a new target called PPAR were going to be the new revoluation.  Troglitazone and rosiglitazone (Avandia) got into use but turned out not to actually reduce complications of diabetes, several others didn’t make it past clinical trials.  An even more promising approach was to inhibit one of the transporter proteins in the kidney, and dump all the excess glucose in urine. It didn’t work either.

One piece of good news as balance: a very promising new antibiotic for tuberculosis has succeeded in a phase II trial of drug-resistant TB.  The trial looked at how fast patients became non-contagious, and the new antibiotic got more patients to that state, faster.  The next step, just about to start, is a longer trial to see if patients are actually cured — it could still fail, of course.

 

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »