We don't suggest holding your breath, but there may be hope for a genetic EDS cure yet.

GlaxoSmithKline ramped up its investment in rare diseases on Monday with an investment in Italian gene therapy for "bubble boy" disorder, highlighting Big Pharma's growing interest in niche medical conditions.

The genetic disorder, which affects around 350 children worldwide, leaves them without the ability to ward off germs and having to live in a sterile bubble.

Marc Dunoyer, head of Glaxo's rare diseases unit, said the company would target around 200 rare disorders where it saw a good chance of developing and commercializing new medicines.

In the past, rare diseases affecting only hundreds or at most thousands of patients a year, have been largely dismissed by the world's largest drugmakers.

But recently Glaxo and other companies have started to view them as a good way to fatten margins, plug holes in product pipelines and partly offset the impact of generic competition as older mass-market drugs go off patent.

Sanofi-Aventis is placing a biggest bet on the sector with its $18.5 billion bid for U.S. biotech group Genzyme, the world's most successful developer of rare diseases drugs. Genzyme has rejected Sanofi's approach.

Glaxo established its rare diseases unit in February and Pfizer has also made moves to enter the field.

There are 6,000-8,000 rare diseases in the world that, together, affect an estimated 6-8% of the world's population—but Dunoyer said less than 10% of patients were currently being treated.

"Focusing on 200 diseases is a good compromise between the enormity of the task and what we can really address with the team we have in place," Dunoyer told reporters in a conference call.

Prices for drugs to treat rare diseases can be exceptionally high. Genzyme's Gaucher disease treatment Cerezyme, for example, costs more than $200,000 a year. But Dunoyer said Glaxo hoped to make its products available to the maximum number of people worldwide, which would hopefully help bring prices down.

Glaxo has already struck collaborations with unlisted Dutch biotech company Prosensa for a Duchenne muscular dystrophy treatment and is working with Japan's JCR Pharmaceuticals on enzyme deficiency diseases.

It is also working with Isis Pharma Pharmaceuticals on RNA therapeutics for rare and infectious diseases.

The deal with the Italian researchers will give the British drugmaker an exclusive license to an experimental gene therapy for the immune deficiency condition known as ADA-SCID, as well as rights to treatments for six further applications using gene therapy.

Key areas for research include metabolism disorders, like Gaucher and Fabry disease; central nervous system and muscle disorders, such as Huntingdon's and Duchenne muscular dystrophy; immuno-inflammation; and certain rare cancers.

Ben Hirschler • Reuters Health Information © 2010