It genuinely takes a massive amount of labor using mostly highly paid professionals like doctors, nurses, and research scientists. Even before any trials start, the support materials for a premarketing application for a drug are usually in the thousands of pages and include clinical trial protocols that describe minutiae like how blood samples will be drawn so data is comparable between hospitals. Then you have to find participating hospitals, PIs, and patients which means lots of negotiation and patient screenings and TV/radio/web advertising. Then you have to manufacture the drugs in small to medium quantities. Then you have to actually run the trials which means paying a lot of people and most if not all of their medical care related to the clinical trial.
Phase I trials, for example, are usually carried out under constant medical supervision and push the dosage as high as they can until 50% of the cohort will no longer tolerate it. That alone is usually thousands or tens of thousands per day per patient.
By the time you get to phase III where you have hundreds to thousands of patients, you're shelling out up to $1k per patient for the incentive and $100-1k per checkup for the length of the trial. A 1k person phase III can easily cost tens of millions in labor just to administer the drug and collect samples once a month for a year. Data provenance and normalization is important so a not insignificant chunk of this time is largely unavoidable paperwork.
And getting FDA approval is not the finish line. It's just the start of the roll-out. Now employ teams of reps to get the drug covered by every commercial insurance company and all Medicare/Medicaid parties so that patients have access to this life-saving treatment, get policies and authorization forms and billing codes created and implemented. Do outreach to make sure doctors and patients even know that a drug has been approved and how it compares to existing options.
Phase I trials, for example, are usually carried out under constant medical supervision and push the dosage as high as they can until 50% of the cohort will no longer tolerate it. That alone is usually thousands or tens of thousands per day per patient.
By the time you get to phase III where you have hundreds to thousands of patients, you're shelling out up to $1k per patient for the incentive and $100-1k per checkup for the length of the trial. A 1k person phase III can easily cost tens of millions in labor just to administer the drug and collect samples once a month for a year. Data provenance and normalization is important so a not insignificant chunk of this time is largely unavoidable paperwork.