AstraZeneca’s Imfinzi (durvalumab) has become the first immunotherapy to show both significant survival benefit and improved, durable responses in extensive-stage small cell lung cancer (SCLC), after the company announced data from the Phase III CASPIAN trial.

The results showed that the drug significantly improved overall survival (OS) in patients with previously-untreated versions of the disease. It was tested in combination with four cycles of standard-of-care (SoC) chemotherapy (etoposide with either cisplatin or carboplatin), and demonstrated statistically-significant and clinically-meaningful improvement in OS vs. SoC, consisting of up to six cycles of chemotherapy and optional prophylactic cranial irradiation (PCI).

More specifically, the risk of death was reduced by 27% with median OS of 13.0 months for the combination, compared to 10.3 months for SoC. Results also showed a prolonged OS benefit with an estimated 33.9% of patients alive at 18 months following treatment with the combination vs. 24.7% of patients following SoC.

The pharma giant announced that across all efficacy endpoints, benefits were observed in patients including a significantly higher progression-free survival (PFS) rate at 12 months of 17.5% vs. 4.7, as well as a 10.3% increase in confirmed objective response rate (ORR) (67.9% vs. 57.6%), and improved duration of response (DOR) at 12 months (22.7% vs. 6.3%).

José Baselga, executive vice president, Oncology R&D said that the company is “encouraged to see more than a third of small cell lung cancer patients treated with Imfinzi plus chemotherapy alive at the 18-month landmark, which is remarkable given the aggressive nature of the disease.”

He continued to say that “it is also noteworthy that these results may enable physicians to choose Imfinzi in combination with either cisplatin or carboplatin chemotherapy backbones. We look forward to working with regulatory authorities to bring Imfinzi to patients with small cell lung cancer around the world as soon as possible.”

The results were presented at the Presidential Symposium of the IASLC 2019 World Conference on Lung Cancer, hosted by the International Association for the Study of Lung Cancer in Barcelona, Spain.