By Monica Heger
In 1983, US lawmakers passed the Orphan Drug Act to encourage pharmaceutical companies to pursue treatments for largely ignored diseases affecting small populations. And for the next 15 years or so, the number of rare diseases given orphan drug status hovered between about 40 and 80 per year. But over the last decade, that number began steadily increasing, and last year the US Food and Drug Administration (FDA) granted a record 192 designations.
“There’s been a substantial upsurge of interest in orphan drugs and rare disorders,” says James Cloyd, director of the Center for Orphan Drug Research at the University of Minnesota–Twin Cities College of Pharmacy. According to Cloyd, reasons for this jump include a push from federal regulators and patient advocacy groups to target rare diseases, new genomic technologies that allows researchers to subtype diseases into rare niches, and the death of the blockbuster model of drug development
Developing orphan drugs “makes a lot of business sense if you don’t have a blockbuster,” says Syamala Ariyanchira, an independent Malaysia-based pharmaceutical consultant who estimates that the orphan drug market will exceed $80 billion this year. Yet despite all of the new designations from the FDA — which give drug developers extended market exclusivity, tax breaks on clinical trials and a waiver of some application fees — the regulatory agency approved only 14 new orphan drugs in 2010, a number on par with the average across the past two decades.
Part of the explanation is that orphan designation is relatively simple, requiring only that a company show scientific rationale that its experimental drug will treat a specific rare disease, whereas drug approval still requires lengthy clinical trials. Thus, Ian Phillips, director of the Center for Rare Disease Therapies at the Keck Graduate Institute in Claremont, California, predicts the uptick in current designations will translate into new marketed therapies in about six to nine years.
Although the increase in designations is a welcome advance, there are still fewer than 400 approved orphan drugs and around 7,000 rare diseases still without any available treatments, notes Sharon Terry, president and chief executive of Genetic Alliance, a Washington, DC–based advocacy group. “I’m not sure that’s a success story,” she says.