GSK slides as vaccine weakness, turnaround doubts overshadow Q3 beat

** Shares of GSK GSK.L down 5.5% at 1,817 pence, on track for worst day since April 2025 if losses hold

** GSK beat third-quarter sales and profit expectations, helped by demand for new and specialty medicines

** But vaccines sales fell 2% to £2.58 billion

** Asthma drug Exdensur, which has been on market for just under a year, missed expectations

** Investors remain unconvinced by drugmaker's pipeline expansion plans and a £1.9 billion cost-savings drive announced in July

** GSK reaffirms 2026 guidance

** Stock has fallen about 0.5% YTD