Sir

Your Editorial “A changing drug supply” (Nature 445, 460; 2007) captures some of the realities facing the pharmaceutical industry in the post-blockbuster era. However, tailored drugs with smaller targeted populations are not necessarily cheaper to develop. If this were true, the pharmaceutical industry would have migrated to this model long ago.

Drugs targeted at smaller populations still need to be discovered, validated in pre-clinical models, formulated, and shown to be efficacious and safe in patients — in short, the same requirements as for a potential blockbuster drug. Depending on the disease and a multitude of factors, some clinical trials could potentially be less expensive for a small population, but this is unlikely to be the norm. Going down this path does not guarantee a lack of competition either: as revenue pressures build, more companies will compete for these niche populations. Targeting small populations is not a panacea for the industry illness, just as there are none for human illness.