With full results reported in heterozygous familial hypercholesterolemia (heFH) for its experimental PCSK9 antibody, Sanofi (NYSE:SNY) and partner Regeneron Pharmaceuticals (NASDAQ:REGN) have now completed a triumvirate of positive phase II data for REGN727, which will go some way to validating this novel approach for lowering ‘bad cholesterol’. Large pivotal trials are now planned for the end of the year.
Good efficacy, even better opportunity
A 77 patient phase II heFH trial, in people on statins with uncontrolled low density lipid cholesterol, revealed those receiving REGN727 showed reductions from baseline LDL-C, or bad cholesterol, of between 28.9%-67.9%, compared with 10.7% of patients on placebo. The drug also demonstrated the ability to drop LDL-C levels to below 100mg/dL in almost 95% of patients, while placebo struggled to achieve that figure in 13% of patients.
The results certainly look impressive and add to positive findings recorded in a much wider patient population of those without heFH but whose high cholesterol levels are not controlled with statins.
This unmet need represents a big opportunity for the company that comes up with a solution for these patients who are potentially at a higher risk of cardiovascular events. Roth Capital estimates that of the 32 million people on medication for high cholesterol, 11 million of those are considered to be uncontrolled on just statins alone, with a further 1.4 million patients either intolerant to or refractory to statin therapy.
First to market
This large addressable population has led analysts to estimate that peak sales of REGN727 could reach $2.5bn. Being first to market would be a big advantage if this approach continues to be validated by more and better positive data.
Competition in the space is not far behind, with the likes of Amgen (NASDAQ:AMGN), with its phase II antibody AMG 145, Pfizer’s (NYSE:PFE) RN316/PF-04950615, Novartis’ (NYSE:NVS) LGT-209 and Alnylam’s (NASDAQ:ALNY) ALN-PCS, an RNAi drug designed to silence the expression of PCSK9.
Worryingly for Regeneron and Sanofi, this compared with 65% mean reduction in REGN727’s phase II study, but as the two studies involved different treatment durations it would be wrong to draw any conclusions at this point. The true difference between the products will emerge when they have both completed large phase III trials.
Given the market opportunity, Amgen is moving fast and investing heavily in the therapy area. The group has initiated six phase II studies enrolling a total of 1,900 patients, in a variety of settings including heFH; hyperlipidaemia; patients who are refractory to statins; and in combination with statins in patients with a risk of heart disease.
A 600-patient trial testing the drug with low-dose statin therapy is due to complete by the end of the year and will be analysed closely to see if AMG 145's clinical advantage is maintained in a larger study.
With some analysts believing that REGN727 may only have a year’s head start at best, Regeneron and Sanofi may have so far managed to maintain pole position in the race to market. But they need to keep up the momentum if they are to claim its multi-billion dollar prize.