Number of patients in trials cited by FDA in approval of 14 HIV/AIDS drugs.

Version 1.1 Jamie Love (with help from Thiru)

September 21, 2000

The following is a breakdown of the average number of patients in clinical trials cited by the FDA in the approval of 14 AIDS drugs. We have broken them down by the three classes of drugs. We have also identified the number of patients in trials that were sponsored or co-sponsored by the US government. The results are summarized as follows:

Nucleoside Analogue Reverse Transcriptase Inhibitors (RT)
Protease Inhibitors (PI)
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI)

         Average number of    Average patients
         patients             no government sponsorship
         referenced in NDA

RT             1,259               409
PI             1,109             1,050
NNRTI          1,310               930

all 14 drugs   1,216               750

In reviewing these numbers, keep in mind that (a) for most of the early
AIDS drugs, clinical trials were eligible for a 50 percent orphan drug
tax credit, and (b), we now have quotes from about 12 organizations that
do clinical trials, and most quote $3 to $5 thousand per patient as the
cost of HIV/AIDS trials.  We also have one report of a $1,000 per
patient trial.  At $5 thousand per patient, the average cost of the
trials, before any government subsidies, would be $6 million (or less
than $4 million if you don't count the trials sponsored or co-sponsored
by the US government).  Also, note that these are only the numbers for
trials cited in the original NDA.  Companies can and usually do conduct
additional trials after a drug is on the market, for a variety of
reasons.   But the pre-NDA trials are of particular interest in terms of
estimated drug development costs, because after the drug is approved
for marketing, it generates its own cash flow.    


            Number of Patients in Clinical trials 
              discussed in FDA NDA approval

Nucleoside Analogue Reverse Transcriptase Inhibitors (RT) 

                 Number of    Number in trials     
                  patients    sponsored/co-sponsored
                  in trial    by government

Zidovudine (AZT)       282          0
Didanosine (ddI)     1,530      1,530
Zalcitabine (ddC)    3,569      3,569
Stavudine (d4T)        822          0
Lamivudine (3TC)       972      don't know
Abacavir               378          0

   For 6 RT drugs:   7,553      5,099

    Average patients per RT:    1,259
    Average patients no-gov       409

Protease Inhibitors (PI)

Saquinavir          1,357         295       
Ritonavir           1,583           0
Indinavir           1,262           0
Nelfinavir            605           0
Amprenavir            736           0

   For 5 PI drugs:  5,543         295
     Average patients per PI: 1,109
     Average patients no-gov 1,050
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI) 

Nevirapine            549        398
Delavirdine         2,452        544
Efavirenz             928        196

For 3 NNRTI drugs:  3,929      1,138

   Average Patients per NNRTI: 1,310
   Average no-gov:               930

See also:

CPT home page IP and health care AIDS drugs