other fields. One classic example is the use of viral load—the amount of virus in a blood sample—to assess a drug’s effect on HIV infection. More recently, the FDA approved two cardiovascular drugs because they dramatically lowered cholesterol in clinical trials, even though the studies were not designed to determine whether the drugs made people healthier.
(The eteplirsen approval was also based on a surrogate endpoint: the amount of an important muscle-protecting protein that patients were able to produce after taking the drug.)
Getting FDA to accept a surrogate endpoint is not as easy as everyone would like: Coetzee of the National MS Society says trying to qualify a surrogate endpoint is “almost as challenging as getting a new drug approved.” For example, Coetzee would like to see the FDA be more flexible to allow brain changes, measured with magnetic resonance imaging, stand in for more conventional measures when studying previously approved MS drugs in children.
In Alzheimer’s, however, the underlying biology remains too mysterious to pinpoint a surrogate. Vradenburg says he’s confident the agency is open to using one “as long as the evidence is there. But the evidence for predictability isn’t there yet.”
TRUMP GIVES NOD TO “RIGHT TO TRY”
A Trump-led FDA could also broaden “right to try” rules that give desperate patients who aren’t enrolled in clinical trials access to drugs that are still experimental. Laws are already on the books in 33 states. In his pharma meeting last week, Trump complained that FDA was denying “terminal” patients such access. But the agency already has a program to approve one-off requests for compassionate use, as it is often called.
Compassionate use protocols might need tweaks, like less paperwork for doctors, says Stanford’s Greely, but FDA is not the bottleneck. Drug companies are not required to provide their experimental drugs outside of clinical trials. (For several stories of people battling for compassionate use access and the many reasons drug makers are reluctant to grant it, see this 2014 CNBC story.)
Handelin of BioPontis, a rare-disease drug developer that uses patient input to steer work, suggests financial encouragement for companies to provide experimental drugs for compassionate use. The Alzheimer’s advocate Vradenburg says the agency needs to get out in front with updated rules, because the day will come—such as with an Alzheimer’s treatment that in early trials stops or reverses the progression of the disease—“when there will be overwhelming demand for ‘right to try.'”
Vradenburg is cautious about the risks. A patient advocate shouldn’t just take “the popular position,” he says.
With more changes coming to the FDA—whatever one might think about them—everyone, including advocates, will in coming months or years likely find themselves reassessing many positions.
Photo of FDA headquarters by This is Bossi via Creative Commons 2.0 license.
