AstraZeneca has reported that high-level results from the final analysis of the Phase III CASPIAN trial confirmed a sustained, clinically meaningful overall survival (OS) benefit of its cancer treatment drug Imfinzi.

The trial evaluated the combination of Imfinzi (durvalumab) with a choice of standard-of-care (SoC) chemotherapies in patients with extensive-stage small-cell lung cancer (ES-SCLC).

CASPIAN is a randomised, open-label, multi-centre, global Phase III trial in the first-line treatment of 805 patients with ES-SCLC.

The trial evaluated Imfinzi in combination with etoposide and either carboplatin or cisplatin chemotherapy, or Imfinzi and chemotherapy with the addition of a second immunotherapy, tremelimumab, versus chemotherapy alone.

Imfinzi is a human monoclonal antibody. It binds to PD-L1 and prevents the interaction of PD-L1 with PD-1 and CD80 by countering the tumour’s immune-evading tactics and releasing the inhibition of immune responses.

Tremelimumab is a human monoclonal antibody and is a potential new medicine that targets the activity of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4).

AstraZeneca Oncology R&D executive vice-president José Baselga said: “We are pleased to see the sustained and meaningful survival benefit of Imfinzi for patients with small-cell lung cancer after more than two years median follow up.

“We have already received the first global regulatory approval for Imfinzi with etoposide plus either carboplatin or cisplatin and remain on track for more approvals soon as we provide patients an important new 1st-line treatment option.”

In this analysis, the second experimental arm testing anti-CTLA4 monoclonal antibody tremelimumab added to Imfinzi and SoC failed to meet the primary endpoint of statistically significant OS.

The CASPIAN trial met one primary endpoint for Imfinzi plus SoC (etoposide and either carboplatin or cisplatin chemotherapy) in June last year.

It demonstrated a statistically significant and clinically meaningful improvement in OS versus SoC alone at a planned interim analysis.