Sanofi said its experimental pill for Gaucher disease met its main targets in two late-stage studies, which the French drugmaker will use to bolster its case for regulatory approval.
Eliglustat tartrate could become the first oral treatment for Gaucher disease - a rare genetic disorder affecting some 10,000 patients - and shake up the market for therapies that currently have to be injected bi-weekly.
Eliglustat could generate annual sales of $360 million by 2017, according to ThomsonReuters Pharma forecasts.
Patients with Gaucher disease are deficient in an enzyme that breaks down a certain type of fat, leading to potentially life-threatening organ damage and bone problems.
The first study, presented at a medical congress on Friday, compared eliglustat with a placebo, while the second compared it with Cerezyme, an injectable treatment also sold by Sanofi.
Patients treated with the pill showed a "statistically significant improvement" in the size of their spleen - which typically swells as a result of Gaucher disease - without reporting serious side effects, Sanofi said.
Eliglustat also proved to be as good as Cerezyme at treating the symptoms of the disease, the drugmaker added.
Full data from the second trial will be presented at a medical meeting in the second half of 2013, Sanofi said in a statement.
A third late-stage study is currently testing whether the dosage for eliglustat could be reduced to once from twice daily.
In addition to Cerezyme, which for many years dominated the Gaucher market and was at one point the most expensive drug in the world, costing more than $200,000 a year, current treatments include Shire's Vpriv and Elelyso, sold by Pfizer.