AstraZeneca shares hit by lung cancer drug setback

AstraZeneca shares took a hit after data from a highly anticipated clinical trial suggested a lung cancer drug may not work as well as hoped.

The pharma giant said there had been a number of ‘grade 5 events’ with its trials for datopotamab deruxtecan.

Grade 5 events mean that patients died during the clinical trial and this is likely to raise fears about the safety of the drug. 

The news sent AstraZeneca’s shares down 8 per cent, or 902p, to 10,374p.

The fact that the firm, which is developing the drug alongside Japanese group Daiichi Sankyo, did not announce that the results were ‘clinically meaningful’ was also a blow to investors, who are hoping the treatment will become as successful as AstraZeneca’s other cancer drug Enhertu.

Some analysts have estimated that the drug could generate as much as £14.2billion in sales, with AstraZeneca having already agreed to pay £4.7billion to Daiichi Sankyo for the rights to develop the treatment.

But broker Stifel said that while the adverse side effects could be considered ‘manageable’ by lung cancer specialists, it had expected the company to have learned from previous experience to ‘help and limit such outcomes’.

It added that the absence of any ‘clinically meaningful’ data, as well as patient deaths during the trial, would raise questions about the ‘magnitude of the benefit’ of the drug against existing treatments.

Despite this, Susan Galbraith, AstraZeneca’s head of oncology research, said the results provided ‘compelling evidence’ that the drug could play a role in treating lung cancer.

The firm plans to continue the trial and gather more data on the overall survival of patients using the drug, before publishing the full results.

Datopotamab deruxtecan is an antibody drug conjugate, a method of targeting chemotherapy to make it more effective and reduce its side effects.

Doctors and scientists are trying to move away from the current method of chemo which involves exposing the whole body, killing both cancerous and healthy cells.

In the trial, AstraZeneca said that datopotamab deruxtecan could stall the progression of the disease in patients with advanced lung cancer for longer than the current standard treatment, a chemotherapy drug called docetaxel.