Compared to traditional drugs, specialty drugs tend to be indicated for lower prevalence diseases. Our objective was to compare the potential population health benefits associated with specialty and traditional drugs in the year following product approval.
First, we created a dataset of estimates of incremental quality-adjusted life-year (QALY) gains and incremental life-year (LY) gains for US FDA-approved drugs (1999–2011) compared to standard of care at the time of approval identified from a literature search. Second, we categorized each drug as specialty or traditional. Third, for each drug we identified estimates of US disease prevalence for each pertinent indication. Fourth, in order to conservatively estimate the potential population health gains associated with each new drug in the year following its approval we multiplied the health gain estimate by 10% of the identified prevalence. Fifth, we used Mann–Whitney U tests to compare the population health gains for specialty and traditional drugs.
We identified QALY gain estimates for 101 drugs, including 56 specialty drugs, and LY gain estimates for 50 drugs, including 34 specialty drugs. The median estimated population QALY gain in the year following approval for specialty drugs was 4200 (IQR = 27,000) and for traditional drugs was 694 (IQR = 24,400) (p = 0.245). The median estimated population LY gain in the year following approval for specialty drugs was 7250 (IQR = 39,200) and for traditional drugs was 2500 (IQR = 58,200) (p = 0.752).
Despite often being indicated for diseases of lower prevalence, we found a trend towards specialty drugs offering larger potential population health gains than traditional drugs, particularly when measured in terms of QALYs.