Pascal Soriot, the boss of Astra, made headlines earlier this month as rumours emerged he was planning to leave the company to head up Israeli rival Teva.
Speculation sent the company's shares down 4.6 per cent, but Soriot told staff in a memo that rumours were part of "everyday business" and that together he and the company were poised to "achieve something remarkable".
This managed to stifle fears both that Soriot was leaving the company and that news about a critical drug might disappoint.
The findings of a trial for a late-stage lung cancer drug commonly known as Mystic may be revealed at the European Society for Medical Oncology annual meeting in September, which Soriot will attend.
The pharma giant is expected to unveil an 11 per cent drop in second-quarter revenues to $4.9bn on Thursday, the Sunday Times reported.
GSK's Walmsley to boost its pharma division
Emma Walmsley, who succeeded Andrew Witty as GSK's chief executive in April, made her first move to shift the company's focus away from consumer healthcare to double down on its pharmaceuticals division last week with the sale of the Horlicks drinks brand.
Walmsley also announced millions of pounds of additional investment to support the manufacture of respiratory and HIV medicines in the UK. The company's pharma division accounts for more than half of its £27.9bn in annual sales.
An analyst at Morgan Stanley signalled to the Sunday Telegraph that GSK's pharma division is still lagging behind its rivals. Vincent Meunier said he would welcome “a more modern drugs business, more comparable to its peers” at GSK.
Walmsley is expected to elaborate on her plans for overhauling drug research at the company’s first-half results on Wednesday.