* GSK's dominance of lung drug market no longer guaranteed
* Pricing pressure jeopardises profitability of newer drugs
* American Thoracic Society meeting crucial for GSK
* Could lead to heightened interest in inhaler Trelegy
By Ben Hirschler
LONDON, May 18 (Reuters) - GlaxoSmithKline is putting more marketing muscle behind its new lung drugs and is looking for a sales boost as top respiratory experts gather to analyse clinical trials data at a meeting in San Diego this weekend.
The British drugmaker has dominated the lung drug market for decades, but its pre-eminence is no longer guaranteed, given declining sales of the ageing Advair inhaler, which could soon face generic competition in the United States.
The market is also seeing intensified pricing pressure, raising doubts over the long-term profitability of newer drugs.
That makes this year's meeting of the American Thoracic Society (ATS) from May 18 to 23 a critical venue for GSK.
Luke Miels, GSK's head of pharmaceuticals, told Reuters the good sales trajectory seen in the first quarter with its novel three-in-one inhaler Trelegy and the injectable Nucala had continued since March, with ATS offering further upside.
A recent expanded U.S. label for Trelegy, to include chronic obstructive pulmonary disease (COPD) patients who need long-term therapy, means GSK can aim its product at millions more patients. Doctors will be presented with clinical data from a pivotal study in this patient group at ATS.
The so-called IMPACT study showed GSK's once-daily Trelegy was superior to other approaches at reducing severe attacks and improving lung function.
"I think the IMPACT data is going to generate lot of interest and out of that we will see a heightened interest in Trelegy," Miels said.
Still, pricing pressure in respiratory medicine remains a black cloud, especially with U.S. generic Advair looming.
Although Advair copycats failed to launch in 2017 as U.S. regulators knocked back applications, they are very possible this year, with Mylan due to hear next month whether the U.S. Food and Drug Administration will approve its version.
The price squeeze in the U.S. inhaler market is proving more severe than GSK had anticipated at the start of the year, particularly in the ICS/LABA area, which includes Advair. Another class known as LAMA medicine is faring better.
Since Trelegy includes all three products in a single inhaler, it is potentially caught in the cross-fire.
GSK has priced Trelegy at a 20 percent discount to its components and the company has not reduced the price since its launch, but Miels acknowledged this might change once Advair generics arrive.
"We are not experiencing direct pressure on Trelegy at this point in time. I think it's reasonable to think there will be some pressure with the introduction of Advair generics but we're confident we can manage that," he said.
Outside the United States, which is likely to account for around 60 percent of sales, Trelegy has already launched in Britain and is now being rolled out in Germany and Canada.
Consensus analyst forecasts compiled by Thomson Reuters don't predict it becoming a $1 billion-a-year blockbuster before 2023 but Miels said such estimates looked conservative.
"We are more confident," he said. "Time will tell but I hope that over time the analysts will move their numbers up."
Miels, who was hired by new CEO Emma Walmsley last year from AstraZeneca, has redeployed resources to focus on such priority products and nearly all of GSK's more than 2,000 respiratory reps in the United States are now selling Trelegy and Nucala, plus two other relatively new lung drugs Breo and Anoro.
That leaves only a small contract team working on Advair.
GSK will also present long-term data on Nucala - a new kind of biotech drug for severe asthma - at ATS. The medicine has enjoyed a head-start over rivals but now faces competition from AstraZeneca's Fasenra.
Reporting by Ben Hirschler; Editing by Susan Fenton