GSK shares fell 4% to 1,852p in early trading, after the FTSE 100 drugmaker's third-quarter results beat expectations on sales and core earnings.
Sales of £8.9 billion were in line with the consensus forecast, according to Jefferies, which compiled the figures using Visible Alpha data.
Core operating profit of £3.1 billion was 5% ahead, helped by a better gross margin and lower selling and administration costs.
Core earnings per share of 54.6p beat the consensus figure of 50.3p by 9%, with a lower tax rate also helping.
Vaccines let the side down
The weak spot was vaccines, where sales of £2.58 billion missed forecasts of £2.61 billion.
Arexvy, the respiratory syncytial virus (RSV) vaccine, sold £195 million against consensus of £226 million, a miss of 14%.
Shingrix, the shingles jab, brought in £780 million, 6% below expectations.
Specialty medicines, which treat complex or chronic conditions, beat by 1% and general medicines by 3%.
Sales of Exdensur, the new severe asthma treatment, were £27 million, short of the £35 million analysts expected.
Guidance leaves little room
GSK reaffirmed its 2026 guidance, but core earnings per share growth is still expected only in the lower half of its 7% to 9% range.
That is despite royalty income now being expected at the top of its range, at about £900 million, and lower interest charges of £700 million to £750 million, down from £800 million.
Jefferies said consensus sits about 50 basis points below the midpoint of the implied range.
Pipeline delays
There were also timetable slips. The US filing for Bexsero, the meningitis B vaccine, in infants has moved to the first half of 2027 from the second half of 2026.
A China decision on Arexvy for over-60s is now expected in the second half of 2027, rather than the first half.
GSK is also still analysing data from a trial of a four-monthly injectable HIV prevention treatment, after a technical issue with the study, which it said was not about safety or efficacy.
Jefferies rates the shares at "buy" with a price target of 2,500p.
