AstraZeneca’s Imfinzi has been approved in the US as a 1st-line treatment for adult patients with extensive-stage small cell lung cancer (ES-SCLC) in combination with standard-of-care (SoC) chemotherapies, etoposide plus either carboplatin or cisplatin (platinum-etoposide).

The approval by the Food and Drug Administration was based on positive results from the Phase III CASPIAN trial showing Imfinzi in combination with SoC platinum-etoposide demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) versus SoC alone.

“The US approval of Imfinzi brings a new medicine to extensive-stage small cell lung cancer patients in urgent need of new options. Imfinzi is the only immunotherapy to show both a significant survival benefit and improved response rate in combination with chemotherapy for these patients, an important step forward in treating this devastating disease,” says Dave Fredrickson, Executive Vice President, Oncology Business Unit, AstraZeneca.

The Phase III CASPIAN trial

The Phase III CASPIAN trial had two primary endpoints comparing experimental arms to SoC. In the Imfinzi plus SoC arm, the risk of death was reduced by 27% (equal to a hazard ratio of 0.73; 95% CI 0.59-0.91; p=0.0047), with median OS of 13.0 months versus 10.3 months for SoC alone. Results also showed an increased confirmed objective response rate in the Imfinzi plus SoC arm (68% versus 58% for SoC alone). The safety and tolerability for Imfinzi plus SoC was consistent with the known safety profiles of these medicines. The Imfinzi plus SoC data from the CASPIAN trial were published in The Lancet.3

The second experimental arm testing tremelimumab added to Imfinzi and SoC recently completed, but did not meet its primary endpoint. Details will be presented at a forthcoming medical meeting.

The CASPIAN trial used a fixed dose of Imfinzi (1500mg) administered every three weeks for four cycles while in combination with chemotherapy and then every four weeks until disease progression. As part of a broad development programme, Imfinzi is also beingtested following concurrent chemoradiation therapy in patients with limited-stage SCLC in the Phase III ADRIATIC trial with data anticipated in 2021.

Received its first approval in February

Imfinzi received its first approval based on the Phase III CASPIAN trial in Singapore for patients with ES-SCLC in February 2020. Imfinzi in combination with etoposide and either carboplatin or cisplatin is currently under regulatory review for the treatment of ES-SCLC in the 1st-line setting based on the Phase III CASPIAN trial in the EU and Japan.

Photo of Dave Fredrickson: AstraZeneca