AstraZeneca has released new high-level data from the final analysis of the Phase III CASPIAN trial, showing that the addition of the anti-CTLA4 antibody tremelimumab to Imfinzi (durvalumab) and standard-of-care (SoC) chemotherapy, did not significantly improve overall survival (OS) in patients with extensive-stage small-cell lung cancer (SCLC).

The results, which the company says will be presented in full at an upcoming medical meeting, come from 805 patients with extensive-stage SCLC who were randomised to receive Imfinzi in combination with etoposide and either carboplatin or cisplatin chemotherapy, or Imfinzi and chemotherapy with the addition of tremelimumab, versus chemotherapy alone.

Last year, however, the study met one of its main goals when Imfinzi plus SoC chemotherapy demonstrated a significant and clinically meaningful improvement in OS, compared to chemotherapy alone at a planned interim analysis. It was just the second experimental arm testing tremelimumab that failed to hit its endpoint.

In addition to this, the safety and tolerability for Imfinzi and tremelimumab were consistent with the known safety profiles of these medicines.

José Baselga, executive vice president, Oncology R&D, said that he is “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.”

He continued, “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.”

Lung cancer is the leading cause of cancer death among both men and women and accounts for about one-fifth of all cancer deaths. It is broadly split into non-small cell lung cancer (NSCLC) and SCLC, with about 15% classified as SCLC; a highly aggressive, fast-growing form of lung cancer that typically recurs and progresses rapidly despite initial response to chemotherapy.