AstraZeneca’s share price plunged after the drugmaker reported a major setback in trials of a new lung cancer treatment.
Shares in the FTSE 100 company fell by 16% to its lowest level in almost five months after the firm announced the results from the study, known as Mystic.
Testing of its immunotherapy drug, known as durvalumab but also by the brand name Imfinzi, combined with tremelimumab, showed it was no more effective at shrinking tumours in patients with advanced lung cancer than chemotherapy.
Lung cancer is the world’s biggest cancer killer in both men and women – accounting for a third of fatalities.
Current treatments remain reliant on chemotherapy alongside targeted radiation therapy.
Image: Pharmaceutical giant AstraZeneca said drug sales fell by 11% in the first half of 2017
Announcing the full results of the trial, taking place across 26 countries, the firm’s chief medical officer Sean Bohen said while the initial results were “disappointing”, the firm would continue to assess whether the treatment prolonged overall survival.
The news came as the company reported that total revenue fell 11% to $10.45bn (£7.95bn) in the first half of this year, with product sales also down by 11% to $9.78bn (£7.44bn) in the same period.
The firm saw a 37% increase in operating profit to $1.8bn (£1.4bn).
The pharmaceutical giant also announced it had agreed a multi-billion-dollar deal to develop and commercialise another cancer drug, Lynparza, with rival Merck.
Merck will pay AstraZeneca up to $8.5bn (£6.5bn) under the deal.
AstraZeneca chief executive Pascal Soriot described the move as an “exciting step” with “a company that shares our passion for science to deliver new medicines for cancer patients”.
Merck chief executive Kenneth C Frazier added: “We look forward to working with AstraZeneca to create greater value for patients and shareholders than if both companies worked independently.”