I consult on clinical trials at various drug companies, and I'm broadly sympathetic to Clinical Trial Abundance Project that they talk about.

I think the authors understand that there is no silver bullet here. There is no single obstacle to better drug development--if there were, then one or more drug companies would have discovered it (for more profit) and the rest would have copied.

Of the trials I've been involved in, the most common reasons for not moving faster are:

1. Patient enrollment: For all the common diseases, there are multiple companies testing new drugs, all competing for patients. For rare diseases, the patient population is so small that, again, it is hard to recruit.

2. Molecule development: Many (most?) new drugs being tested are "me-too" drugs that are tweaks of existing, successful drugs. If it cost $100 million to test a new drug, you want to maximize your chances of success, so you are not likely to take risks. Of course, taking more risks also means risking patient lives, so no one is in a hurry to change too quickly.

My particular focus is around the information tech used to analyze the data in the trial. There are a lot of inefficiencies right now, mostly due to primitive, but well-tested, systems. You'd be surprised (or maybe not) at how much clinical trial data gets sent around in random Excel worksheets.