*

Q2 core EPS 43.4 pence vs forecast 38.9 pence

*

Raises 2024 core EPS forecast for second time this year

*

Strong cancer, HIV drug sales offset slower vaccines

growth

(Adds detail on RSV vaccine in paragraphs 3 to 5)

By Yadarisa Shabong and Maggie Fick

July 31 (Reuters) - British drugmaker GSK raised

its annual earnings and sales forecasts on Wednesday after

beating second-quarter expectations on strong sales of its

cancer and HIV treatments.

CEO Emma Walmsley's bet on infectious disease drugs and

vaccines, including new blockbuster respiratory syncytial virus

(RSV) vaccine Arexvy, has been paying off as GSK faces a

combination of patent expiries and declining revenue from

current best-sellers by the end of this decade.

But sales of Arexvy, which launched in the U.S. last year

and took two-thirds of the market in a blow to Pfizer's ( PFE )

rival jab, came in below market expectations at 62 million

pounds ($80 million), versus forecasts for 70 million pounds.

A U.S. public health agency's decision last month to narrow

the recommended age for use of RSV vaccines and delay the

recommendation for adults under 60 unnerved GSK investors, who

had hoped for a larger market for Arexvy this winter. Shares

fell 6% the day after that decision was announced.

Citing the U.S. agency's decision, GSK cut its forecast for

2024 vaccine sales. It now expects that business to grow by a

low to mid-single digit percentage, from an earlier expectation

of high single-digit to low double-digit percentage growth.

However, improved sales of cancer, HIV and other

speciality medicines are expected to more than offset the lower

vaccine sales growth, the company said.

GSK reported second-quarter core earnings per share (EPS) of

43.4 pence on sales of 7.88 billion pounds, beating analysts'

average forecasts of 38.9 pence and 7.51 billion pounds

respectively, according to a company-compiled consensus.

It now expects 2024 core EPS to increase between 10% and

12%, from an earlier forecast of 8% to 10% growth. This is the

second time this year it has raised its 2024 profit forecast.

Sales for the year are forecast to rise between 7% and 9%,

from a previous range of 5% to 7% growth.

($1 = 0.7790 pounds)