FDA staff question usefulness of Sanofi diabetes drugs

(Adds details, comments from FDA reviewers)

By Toni Clarke

May 23 (Reuters) - A preliminary review by the U.S (Other OTC: UBGXF - news) . Food and Drug Administration questioned the usefulness of a combination diabetes drug made by Sanofi SA's and said it was unclear whether one component, lixisenatide, contributed to its benefit.

The French drugmaker is seeking approval for lixisenatide alone and as part of a combination product, iGlarLixi, which Sanofi (LSE: 0O59.L - news) hopes will establish a new paradigm for diabetes therapy by treating patients earlier and more aggressively.

The review comes ahead of a Wednesday meeting of an FDA advisory panel that will discuss lixisenatide and the combination treatment, iGlarLixi, an injection which delivers lixisenatide and Sanofi's drug Lantus in a fixed-dose combination.

The review noted that the lixisenatide component of iGlarLixi is not the dose established as effective for lixisenatide alone, meaning some patients could be exposed to a component that provides no known therapeutic benefit.

On Tuesday, the committee will consider a similar combination treatment made by Novo Nordisk A/S (LSE: 0QIU.L - news) that combines the company's diabetes drugs Victoza and Tresiba. The FDA's preliminary review of that drug raised similar concerns.

Sanofi was given speedier-than-normal review after it bought a priority review voucher from Retrophin Inc (NasdaqGM: RTRX - news) last year for $245 million. Retrophin was granted the voucher as part of an FDA program to spur research into rare pediatric disorders.

Lixisenatide belongs to a class of diabetes treatments called GLP-1 agonists that includes Victoza and Bristol-Myers Squibb Co and AstraZeneca (NYSE: AZN - news) 's Byetta and Bydureon.

The panel will be asked whether there are any safety or efficacy issues that preclude approval of lixisenatide, and they will be asked to vote on whether iGlarLixi should be approved. The FDA is not obliged to follow the recommendation of its advisory panels, but typically does so.

Lixisenatide was approved by regulators in Europe and Japan in 2013 and is sold under the brand name Lyxumia. Sanofi licensed the product from Denmark's Zealand Pharma A/S (LSE: 0NZU.L - news) . Novo Nordisk's drug is sold in Europe as Xultophy.

The reviewer, Dr. Jean-Marc Guettier, director of the FDA's division of metabolism and endocrinology products, said they had "reservations" about Sanofi's conclusion that iGlarLixi offered superior blood sugar control than Lantus alone.

"It (Other OTC: ITGL - news) is unclear whether there is a benefit in the low-dose range that balances the additional safety concerns from adding a second drug," the division said, adding that trial may have created a bias in favor of the combination.

"The treatment difference observed may not reflect the actual treatment difference" they said.

Panelists will be asked to discuss whether use of iGlarLixi should be approved for patients not treated with a basal insulin or a GLP-1, for patients who are inadequately controlled on either drug, or both.

The goal of both companies' products is to combine a GLP-1 and a basal insulin in a single injection instead of two and treat patients with a combination drug early rather than waiting for one drug to wane in effect before moving to another.

An FDA decision on lixisenatide is expected in July and on iGlarLixi in August.

Separately, the Sanofi executive in charge of diabetes and cardiovascular products, Pascale Witz, is leaving the company on June 1 as part of a management shakeup, the company said on Monday.

(Reporting by Toni Clarke in Washington, editing by G Crosse)