Harvard neurologist Peter Lansbury argues in the WP that we should end mandatory Phase 3 clinical trials for new pharmaceuticals. Aside from the expense of Phase 3 trials (hundres of millions of dollars) and years of delay he writes that:
There are also scientific reasons to replace Phase 3. The reasoning behind the Phase 3 requirement — that the average efficacy of a drug is relevant to an individual patient — flies in the face of what we now know about drug responsiveness. Very few drugs are effective in all individuals. In fact, most are not effective in large portions of the population, for reasons that we are just beginning to understand.
It’s much easier to get approval for drugs that are marginally effective in, say, half the population than drugs that are very effective in a small fraction of patients. This statistical barrier discourages the pharmaceutical industry from even beginning to attack diseases, such as Parkinson’s, that are likely to have several subtypes, each of which may respond to a different drug. These drugs are the underappreciated casualties of the Phase 3 requirement; they will never be developed because the risk of failure at Phase 3 is simply too great.
Lansbury also recognizes the importance of off-label prescribing and how it flies in the face of FDA power.
Once the FDA has approved a drug based on its effectiveness against one condition, it can be prescribed for any other condition. This practice recognizes that your physician is best equipped to evaluate all the available information and advise whether you could benefit from a particular drug. About 40 to 50 percent of all drug use is for such unapproved, or “off-label,” uses. Some drugs that “failed” in Phase 3 trials for one condition, but were approved for another, are still widely prescribed for the first because physicians agree that the evidence shows they can be effective.
I agree with Lansbury’s analysis and so do a lot of physicians. See my papers Assessing the FDA via the Anomaly of Off-Label Drug Prescriptions and Do Off-Label Drug Practices Argue Against FDA Efficacy Requirements? Testing an Argument by Stuctured Conversations with Experts.