AZ failure cast further doubts over IL-13 drug asthma class

AstraZeneca's asthma drug tralokinumab has failed in a late-stage trial, running into problems in a class also targeted by Roche.

Tralokinumab failed to meet its primary endpoint of significantly reducing annual asthma exacerbation rate in the late-stage STRATOS 1 trial.

Developed by biologics division MedImmune, tralokinumab is an anti-interleukin-13 (IL-13) human monoclonal antibody.

Chief medical officer Sean Bohen said AZ will now wait for results of the STRATOS 2 trial in the second half of the year.

The STRATOS 1 and STRATOS 2 trials evaluate tralokinumab in reducing the rate of asthma exacerbations in adults and adolescents with severe asthma inadequately controlled on inhaled corticosteroids (ICS) plus long-acting beta2-agonist (LABA).

STRATOS 1 explored the potential to use biomarkers to identify patients with an enhanced response to tralokinumab. STRATOS 2 is designed to validate the biomarker population identified in STRATOS 1.

Tralokinumab has been seen as a risky project after Roche ran into problems with its lebrikizumab, which also blocks IL-13.

In February last year Roche said one late stage asthma trial had succeeded, while another failed.

The Swiss pharma said at the time that it was weighing its options for lebrikizumab but has not made any further announcements.

Last week AZ announced a deal with Pieris Pharmaceuticals to boost its respiratory pipeline with a deal to develop inhaled drugs based around artificial proteins known as anticalins.

The collaboration could provide AZ with a successor to its benralizumab, a IL-5 inhibitor monoclonal antibody that is in late stage development for severe asthma and chronic obstructive pulmonary disease.

AZ hopes for sales of around $2 billion from benralizumab in around four years’ time, but GlaxoSmithKline has already got its rival Nucala (mepolizumab) to market in severe asthma, and  Teva's Cinqair (reslizumab) was approved last year for maintenance of severe asthma.