Imfinzi – sometimes referred to as durvalumab – is what’s called a checkpoint inhibitor which binds onto a tumour cell to stop it tricking the immune system into thinking it is a ‘good’ cell.
The drugs giant said on Friday that the treatment met the second of two primary endpoints in the phase III PACIFIC trial, showing a “statistically-significant” benefit to overall survival in patients with unresectable stage III non-small cell lung cancer (NSCLC) whose disease hadn’t improved after a course of chemotherapy and radiation therapy.
Astra added that there was a “clinically-meaningful improvement” in patients receiving Imfinzi compared to those on the placebo.
The drug met the other primary endpoint of progression free survival (PFS) earlier this year, on which basis it was approved for use in this subset of lung cancer patients in the US.
“Given the aforementioned positive PFS and approval in place already, today's news makes limited difference to the product's potential but does remove the (v low) risk that a failed OS endpoint undermines AZ's position in the indication,” wrote Liberum analyst Roger Franklin in a research note.
“However, it will likely be taken positively given this is early versus the final OS analysis wasn't due until 2019.”
Astra shares opened 0.9% higher at £54.78.