By Bhanvi Satija and Yadarisa Shabong LONDON (Reuters) -GSK raised its 2025 sales and earnings forecasts on Wednesday as its speciality HIV and cancer medicines posted double digit growth, lifting the British drugmaker's shares. Although U.S. sales of its shingles vaccine Shingrix fell sharply, its shares gained as much as 4.3% to their highest level since May 2024. The stock, which has risen 25% so far in 2025, was up 2.16% at 1040 GMT. GSK's improved outlook comes as CEO Emma Walmsley prepares to hand ...