A strong efficacy result in the first phase III study of Sanofi’s eliglustat shows just what a tough road lies ahead of Protalix Biotherapeutics and Pfizer as they aim to build market share for their recently approved injectable Gaucher’s disease treatment, Elelyso.
The data were eagerly awaited given the potential of eliglustat – which could become the industry’s first-ever orally dosed Gaucher’s drug – to shake up the market. Elelyso probably has the most to lose, being a late entrant into this small market, which could be hit by pricing pressure, as well as the threat of a more conveniently dosed product.
The eliglustat data came from Encore, the first of two phase III registration studies. In the double-blind trial of 40 type 1 Gaucher’s patients, eliglustat achieved a 28% mean reduction in spleen volumes – the primary endpoint – versus a 2% increase for placebo recipients, hitting statistical significance with p<0.0001 and meeting all secondary endpoints, Sanofi said.
Consensus forecasts are for eliglustat to be launched late next year and generate sales of $180m in 2018, and EvaluatePharma calculates a 75% risk-adjusted NPV for the drug of $294m.
This is still a relatively conservative forecast given the current $1.2bn size of the Gaucher’s market. Surprisingly enough, analysts still expect great things from Elelyso, which carries a combined NPV of $1.1bn.
However, expectations will surely be scaled back were eliglustat to enter the market. Sanofi’s two other phase III studies, Encore and Edge, are fully enrolled. Encore, which compares eliglustat versus Cerezyme, is the other trial needed for filing, and is due to report topline data early next year; Edge seeks to reduce dosing from twice to once daily, but is not a registration study.
As well as being dosed orally eliglustat might be able to compete on price, and could find a ready-made market segment in the 15% of patients who develop antibodies to infused Cerezyme.
The rare disease space in general is set for a tougher pricing environment as more products are launched and big pharma takes a closer look at an area that was once the preserve of niche players. Big pharma is likely to find it easier to support lower prices than small companies, and might in any case might find it more difficult to justify very expensive drugs.
This topic was a central theme at FTI Consulting’s recent seminar on rare diseases. Teresa Heggie, a senior vice-president of Shire, said that the cost of rare disease drugs will remain central, and warned that a company “only has one go to get the price right”.
In Gaucher’s pricing has taken a knock with every new product launched. Elelyso was priced at a 25% discount to the first market entrant, Sanofi’s Cerezyme, and a 12% discount to the second, Shire’s Vpriv (Protalix, Pfizer face fight for share after finally winning Gaucher approval, May 2, 2012).
The Protalix/Pfizer drug was launched in the US in May after suffering delays due to manufacturing setbacks, and no doubt these contributed to it being competitively priced. Yesterday Elelyso was approved in Israel, where Protalix retains sole rights.
Owing to regulatory delays, Protalix and Pfizer already missed one golden opportunity to make a dent in the Gaucher’s market when Cerezyme hit a manufacturing snafu at its original developer, Genzyme. The slack was in the event taken up by Shire’s Vpriv, which has itself recently faced US production issues.
With supply of enzyme-replacement therapies set to remain tight the third entrant will need to make the most of its small window of opportunity. Progress of eliglustat will continue to be watched closely.
|Engage||NCT00891202||40 patients, double blind, vs placebo|
|Encore||NCT00943111||160 patients, open label, vs Cerezyme|
|Edge||NCT01074944||171 patients, double blind, once vs twice-daily dosing|
To contact the writer of this story email Jacob Plieth in London at email@example.com