* FDA review of Glaxo/Theravance drug backs efficacy
* FDA notes some inconsistencies in safety data
* Analysts believe review broadly positive (Adds analyst comments, stock prices)
By Toni Clarke
WASHINGTON, Sept 6 A U.S. Food and Drug Administration review of GlaxoSmithKline Plc and Theravance Inc's experimental drug to treat chronic obstructive pulmonary disease bodes well for approval, analysts said on Friday.
The review, posted on the FDA's website, comes ahead of a meeting next Tuesday of outside medical experts who will discuss the drug and recommend whether the agency should approve it. The FDA is not required to follow the advice of its expert panels but typically does so.
The report, written by FDA reviewer Dr Jennifer Rodriguez Pippins, notes that the drug appears to work at the dose proposed by the company, but that the safety database, while large, is "not entirely conclusive, particularly in regards to cardiovascular safety." The database lists the side effects reported in clinical trials.
Overall, she said, the cardiovascular safety profile was unremarkable and the number of major heart-related problems was fairly low, but imbalances were found when subsets of data were examined, particularly in nonfatal heart attacks.
"Whether these imbalances and discrepancies constitute a safety signal when taken in the context of the complete development program will be a topic for further discussion," she said.
The drug, Anoro, is an inhaled combination of vilanterol, a long-acting beta-agonist that is designed to open the airways, and umeclidinium, a long-acting muscarinic receptor antagonist, which works to improve lung function.
Analysts expect the drug to generate sales of more than $2 billion a year by 2018 according to the average estimate of six analysts polled by Thomson Reuters. A decision is expected by Dec. 18.
Chronic obstructive pulmonary disease, or COPD, is the third-leading cause of death in the United States, according to federal data. It is a condition often associated with smoking that can include emphysema, chronic bronchitis, or both.
Investment analysts interpreted the FDA staff review positively.
James Gordon, an analyst at J.P. Morgan, said in a research note that while he expects a good deal of discussion around the cardiovascular safety data, "we don't expect the data on this question to be a barrier to approval, as the FDA on balance seems comfortable."
An imbalance in the number of nonfatal heart attacks was seen in some shorter trials testing for efficacy but not in the longer-term safety trial, which the FDA said was "reassuring."
Graham Parry, an analyst at Merrill Lynch, said in a research report that investors had been concerned that the companies may not have selected the right once-daily dose, and that the FDA might request twice-daily dosing trials.
However, he said, "FDA appears to back GSK's dose selection including Anoro's once-daily dosing."
In May, the FDA approved another drug for COPD made by the two companies called Breo. Breo is an inhaled combination of vilanterol and the corticosteroid fluticasone furoate, which reduces inflammation. That drug is expected to generate $1.9 billion by 2018.
Theravance plans to split into two publicly traded companies, separating the respiratory drugs it is developing with Glaxo from its other operations.
After the split, the company holding the respiratory drugs will be called Royalty Management Co. The second company, to be called Theravance Biopharma, will focus on developing drugs for rare diseases.
The move has fueled speculation that Glaxo, which owns 27 percent of Theravance, may eventually buy Theravance's most lucrative products.
Theravance shares were up 2.8 percent at $37.75 on the Nasdaq on Friday morning, while GlaxoSmithKline shares were down 0.2 percent at 1,650.00 pence in London. (Editing by Gerald E. McCormick, Grant McCool and Matthew Lewis)