AstraZeneca said on Thursday that positive results from the ‘Poseidon’ phase 3 trial showed ‘Imfinzi’, or durvalumab, and tremelimumab, when added to platinum-based chemotherapy, demonstrated a statistically-significant and clinically-meaningful improvement in overall survival and progression-free survival compared to chemotherapy alone in the first-line treatment of patients with stage four metastatic non-small cell lung cancer (NSCLC).
The FTSE 100 pharmaceuticals giant presented the results on Thursday during a Presidential Symposium at the 2021 World Conference on Lung Cancer hosted by the International Association for the Study of Lung Cancer.
It said patients treated with a short course of five cycles of tremelimumab – an anti-CTLA4 antibody – over 16 weeks in addition to Imfinzi and chemotherapy experienced a 23% reduction in the risk of death versus a range of chemotherapy options.
Median overall survival was 14 months, compared to 11.7 months for chemotherapy, and an estimated 33% of patients were alive at two years, versus 22% for chemotherapy.
The treatment combination also reduced the risk of disease progression or death by 28% compared to chemotherapy alone, with a median progression-free survival of 6.2 months versus 4.8 months, respectively.
AstraZeneca said the combination delivered a broadly similar safety profile to the Imfinzi and chemotherapy combination, and did not lead to an increased discontinuation of treatment.
Poseidon also tested the combination of Imfinzi plus chemotherapy, which demonstrated a statistically significant improvement in progression-free survival against chemotherapy alone.
A positive overall survival trend observed for Imfinzi plus chemotherapy did not achieve statistical significance.
“The Poseidon data offer patients further benefit from Imfinzi and are an important validation of our development strategy to explore novel combinations,” said Susan Galbraith, executive vice-president of oncology research and development.
“Adding a short course of tremelimumab to Imfinzi for those patients already receiving chemotherapy, reduced the risk of cancer progressing or death by 28% compared to chemotherapy alone.
“The results also showed the significant survival improvement did not compromise tolerability in the first-line treatment of patients with metastatic non-small cell lung cancer.”
