* Focus on respiratory and HIV; 30 programmes being stopped
* 1 bln pounds of new cost cuts, but 2020 targets reiterated
* Q2 adjusted EPS 27.2p vs consensus forecast 26.2p (Adds further details and quotes from CEO and analysts)
LONDON, July 26 (Reuters) - GlaxoSmithKline's new chief executive announced plans on Wednesday to narrow the focus of the group's drug research by ditching some non-core medicines to try to improve returns in its core pharmaceuticals business.
Walmsley, who took over in April, said GSK would in future allocate 80 percent of its R&D budget to respiratory and HIV/infectious diseases, along with two other potential areas of oncology and immuno-inflammation.
More than 30 pre-clinical and clinical programmes will be stopped, partnered or divested, and the group is considering options for its rare diseases unit after a strategic review.
It also plans to progressively withdraw support for its struggling diabetes drug Tanzeum and will end a collaboration with Johnson & Johnson over rheumatoid arthritis drug sirukumab, which is close to reaching the market.
"We've been too broadly spread," Walmsley told reporters, adding that the overhaul would not result in a lower R&D budget because GSK had been investing too little in individual experimental drugs in the past.
Spending could also rise as Walmsley and her team go shopping for promising early-stage assets that could be acquired to bolster the pipeline in GSK's priority areas.
The announcement came as Britain's biggest drugmaker reported a 12 percent rise in adjusted earnings per share in sterling terms to 27.2 pence on sales up 12 percent at 7.32 billion pounds ($9.53 billion).
Analysts, on average, had forecast EPS of 26.2 pence and sales of 7.26 billion pounds, according to Thomson Reuters data.
The group reiterated its outlook for 2020, first given in 2015, forecasting sales growth of low-to-mid single digits and adjusted earnings of mid-to-high single digits on a constant currency basis.
For 2017, it now sees EPS growth of 3-5 percent, against 5-7 percent predicted previously, following investment in a "priority review voucher" to accelerate U.S. approval of a new HIV medicine.
Shares in the group fell 1.5 percent by 1200 GMT, with some investors disappointed that Walmsley had not taken the opportunity to increase long-term financial targets.
Given that she announced an extended cost-cutting programme to deliver an additional 1 billion pounds of annual cost savings by 2020, UBS analyst Michael Leuchten said the cautious approach "suggests tougher underlying trends".
Walmsley, who previously headed GSK's consumer health unit after 17 years working for L'Oreal, is known for her focus on benchmarking business performance and she had been expected to set new priorities for pharma R&D.
She also unveiled plans last week for a strategic review and potential divestment of older antibiotics, as well as the sale of two nutritional brands and more than 300 job cuts in Britain.
Revamping GSK's diverse new-drug pipeline is her biggest task, and she wants scientific and commercial teams to work closely together to pick winners. GSK has lagged behind rivals recently in producing multibillion-dollar blockbusters.
Overhauling the R&D machine will take time to deliver results but Walmsley does have a window to make changes as GSK is not expecting its next wave of new drugs until after 2020. It also has no further major patent expiries until 2026.
To some extent GSK is following in the footsteps of its smaller British rival AstraZeneca, which has divested a large number of non-core drug projects recently. Significantly, former AstraZeneca executive Luke Miels, who joins in September, will be a key lieutenant for Walmsley during the shake-up.
GSK benefited once again in the quarter from a weak pound, after last year's Brexit vote, as well as strong demand for HIV medicines and the failure, so far, of generic firms to win U.S. approval for copies of its inhaled lung drug Advair.
But HIV competition is set to increase next year and U.S. generics to Advair, which has generated more than $1 billion in annual sales for GSK since 2001, are likely by mid-2018.
The company extended a commitment to pay its current 80 pence per share annual dividend through 2018.
($1 = 0.7680 pounds) (Additional reporting by Kate Holton, editing by Louise Heavens and Adrian Croft)