Sanofi and Regeneron's cholesterol antibody aces phase III trial

Top-line results from the first phase III trial of Sanofi and Regeneron's experimental drug alirocumab (REGN727) suggest the drug could help patients meet cholesterol targets.

When given as a single-agent therapy, alirocumab was able to achieve a significant reduction in low-density lipoprotein (LDL) cholesterol in 47 per cent of patients, three times more than comparator drug Zetia (ezetimibe) from Merck & Co.

Most patients achieved their cholesterol targets on the lowest dose tested (70mg/dL injected every two weeks) in the ODYSSEY MONO study, with the results closely in line with those seen in phase II in terms of both efficacy and safety.

The monoclonal antibody a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor, and the phase III data cements Sanofi and Regeneron's lead in the category over rivals Amgen - whose AMG 145 candidate is in phase III  - Pfizer with RN316 in phase IIb and Roche and Novartis with antibodies in phase II. All the antibodies work by preventing the body from eliminating LDL-C from the bloodstream.

Statin drugs transformed cholesterol-lowering therapy in the 1990s and remain the main weapon in the doctor's arsenal, but "there are still millions of people around the globe who have poorly controlled LDL-C", according to Regeneron's chief scientific officer George Yancopoulos.

Sanofi and Regeneron are currently recruiting around 23,000 patients into a 12-study phase III programme for alirocumab that will also examine the drug's ability to cut cholesterol when given in combination with statins, as well as looking at cardiovascular outcomes.

That programme is expected to take around five years to complete, although the companies hope to bring the antibody to market by late 2015.

The key question for Sanofi and Regeneron is whether alirocumab will be able to carve out a slice of the cholesterol-lowering market given that statins are so widely available and cheap, but a number of analysts think the two companies could have a mega-blockbuster on their hands with sales of $3bn to $6bn a year at peak. Others are less optimistic and suggest that multiple new drugs could end up sharing the market.

Sanofi and Regeneron are quick to point out that there is still a lot of work to be done before alirocumab is ready for market. However, Yancopoulos said:  "It is very gratifying to be able to report the first phase III data for this promising potential new class of lipid-lowering agents."