Pfizer osteoporosis drug gets lukewarm review

* Experimental drug about same as Lilly’s Evista -expert

* Lasofoxifene data left one expert ‘underwhelmed’

* Findings test FDA appetite for ‘me-too’ drugs

CHICAGO, Feb 24 (Reuters) - Pfizer's PFE.N experimental osteoporosis drug lasofoxifene, which is awaiting U.S. regulatory approval, works about as well as currently approved drugs, but not much better, according to a commentary published on Wednesday in the New England Journal of Medicine.

In the current climate of comparative effectiveness research -- where drug companies are being asked to prove their drugs work better than others’ products -- that may not be enough, Dr. Carolyn Becker of Brigham and Women’s Hospital in Boston said.

“Given the plethora of drugs currently available for osteoporosis, studies of new agents should show clear benefits over existing agents,” Becker wrote in the commentary.

She said on that basis, a study of the drug published in the same issue suggests that “lasofoxifene offers no major clinically important benefits over raloxifene for the skeleton, breast, heart, or reproductive tract.”

Raloxifene is made by Eli Lilly and Co LLY.N and sold under the brand name Evista.

Last month, the U.S. Food and Drug Administration asked for additional information from Pfizer Inc PFE.N on the long-delayed lasofoxifene before it would grant U.S. marketing approval. At the time, the company did not say what information the FDA was seeking.

“I think the FDA is starting to say we don’t need 10 drugs that do the same thing unless there is a real advantage in costs, or the way it’s given or the side effect profile or safety. I just don’t see those advantages with this drug,” Becker said in a telephone interview.

Pfizer submitted the current application for lasofoxifene to be used by post-menopausal women with a higher risk of a fracture in December of 2007. An FDA scientific advisory panel voted in September to recommend approval, saying there is a population of post-menopausal women with osteoporosis for whom the drug’s benefits likely outweigh the risks.


In osteoporosis, bones become fragile and porous, increasing the risk of fracture.

Lasofoxifene, which Pfizer hopes to sell under the brand name Fablyn, belongs to the same class of drugs as Evista, known as SERMS or selective estrogen receptor modulators.

In the study published in the New England Journal of Medicine, the drug reduced the risk of both spinal and non-spinal fractures, such as wrist fractures, something Evista does not do.

Becker, an expert in osteoporosis who was asked to review the study by the journal, said the drug “left me underwhelmed.”

“My conclusion after looking at all the data is that it does not offer enough advantages to warrant switching from a drug I’m familiar with,” Becker said.

Pfizer is developing the drug jointly with Ligand Pharmaceuticals Inc LGND.O of San Diego.

If approved, Fablyn would enter a market already crowded with other drugs including Novartis AG's NOVN.VX Reclast, Roche Holding AG's ROG.VX Boniva, Procter & Gamble Co's PG.N Actonel and Merck & Co Inc's MRK.N Fosamax. (Editing by Mohammad Zargham)