US-based patients with a particular form of lung cancer could now get access to the first targeted therapy for their condition, after the country’s Food and Drug Administration issued accelerated clearance for AstraZeneca’s Tagrisso (formerly AZD9291).

Tagrisso is now the only approved medicine indicated for patients with metastatic non-small cell lung cancer who carry both EGFR and T790M mutations, as detected by an FDA-approved test developed with Roche, who have progressed on or after EGFR tyrosine kinase inhibitor (TKI) therapy.

Almost two-thirds of NSCLC patients who are EGFR mutation-positive and experience disease progression after being treated with an EGFR-TKI develop the T790M resistance mutation, for which there have been limited treatment options to date, AZ said, highlighting the drug’s potential scope.

The FDA’s approval of Tagrisso is based on data from two Phase II trials which showed an overall objective response rate (tumour shrinkage) of 59%, as well as findings from a Phase I study showing an ORR was 51% and median duration of response was 12.4 months.

The most common side effects of Tagrisso are diarrhoea, skin and nail conditions such as dry skin, rash and infection or redness around the fingernails, but the drug may cause serious side effects, including inflammation of the lungs and injury to the heart, the regulator noted.

Continued approval for the drug in this indication, for which it also carries breakthrough and orphan status, may be contingent upon further confirmatory studies.

AZ noted that Tagrisso has been through one of the fastest development programmes, with just two and a half years from start of clinical trials to approval.