Sept 28 -

GSK on Thursday lifted its medium-term growth forecast for its HIV drugs business ViiV, encouraged by strong sales of long-acting injections that aim to replace daily pills for preventing and treating the infection.

The ViiV business, in which Pfizer and Shionogi hold small stakes, is a key element of a push by group CEO Emma Walmsley to improve investor confidence in the strength of GSK's drug development pipeline, which has lagged rivals.

Strong sales of medicines for HIV, the virus that causes AIDS, were one of the drivers behind the company's improved guidance for 2023 earnings, issued in July, alongside continued growth in demand for GSK's shingles vaccine.

The HIV business, the focus of a GSK's capital markets day on Thursday, is now targeting annual rates of sales growth of between 6% and 8%, to reach between 6 billion pounds ($7.31 billion) and 7 billion pounds in 2026, up from "mid-single-digit" percentage growth seen previously.

GSK said its Apretude injection to prevent the viral infection, an alternative to daily pills, continues to gain acceptance among the targeted at-risk population.

A different version of the drug, established brand Cabenuva, has been in use for longer as an anti-HIV treatment.

In the prevention setting, known as pre-exposure prophylaxis, GSK's Apretude competes with Gilead's daily pill, Truvada, and a cheaper generic version sold by Teva as Atripla.

"We have broad reimbursement in the U.S. and uptake has been extremely positive," said ViiV CEO Deborah Waterhouse. Apretude won U.S. approval in late 2021 and in Europe this month.

"We will now talk country-by-country to each of the European nations to see what the situation is from a reimbursement perspective," she added.

The follow-up on the success of Apretude, which is injected every other month, GSK said it is aiming to launch a prevention drug to be given one every four months in 2026, and another one for every six months towards the end of the decade.

The company is facing the step-wise loss of patent protection from 2027 of its best-selling antiviral ingredient dolutegravir, which is in HIV drugs with a combined 1.3 billion pounds in second-quarter sales.

($1 = 0.8203 pounds)

(Reporting by Ludwig Burger; Editing by Anil D'Silva)