WILMINGTON, Del.—AstraZeneca has presented detailed results from the Phase 3 CASPIAN trial, showing that Imfinzi (durvalumab) significantly improved overall survival (OS) in patients with previously-untreated extensive-stage small cell lung cancer (SCLC). 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.
Imfinzi, in combination with four cycles of standard-of-care (SoC) chemotherapy (etoposide with either cisplatin or carboplatin), demonstrated a statistically significant and clinically meaningful improvement in OS vs. SoC chemotherapy consisting of up to six cycles of chemotherapy and optional prophylactic cranial irradiation (PCI).
The risk of death was reduced by 27%, with a median OS of 13 months for Imfinzi plus chemotherapy, versus 10.3 months for SoC chemotherapy. Results showed an OS benefit with an estimated 33.9% of patients alive at 18 months following treatment with Imfinzi plus chemotherapy, versus 24.7% of patients after SoC chemotherapy.
Benefits were observed across all efficacy endpoints in patients treated with Imfinzi plus chemotherapy, versus SoC chemotherapy. Results showed a higher progression-free survival rate at 12 months (17.5% vs. 4.7%), a 10.3% increase in confirmed objective response rate (67.9% vs. 57.6%), and improved duration of response at 12 months (22.7% vs. 6.3%).
“Patients have had limited treatment options for small cell lung cancer, a devastating disease where the five-year survival rate has been as low as 6%. The significant survival benefit demonstrated with Imfinzi combined with only four cycles of a choice of chemotherapy, compared to a robust control arm, provides evidence and hope of a new treatment option for these patients,” said Luis Paz-Ares, M.D., Ph.D., Chair, Medical Oncology Department at the Hospital Universitario Doce de Octubre in Madrid, and principal investigator in the Phase 3 CASPIAN trial.
SCLC is an aggressive, fast-growing cancer that recurs and progresses rapidly, despite initial response to platinum-based chemotherapy. This is the first study to show efficacy of using a fixed dose of Imfinzi (1500mg) administered every 3 weeks while in combination with chemotherapy for 4 cycles, and then every 4 weeks until disease progression.
The safety and tolerability of Imfinzi in combination with SoC etoposide and platinum-based chemotherapy was consistent with previous trials. Results showed that 61.5% of patients experienced a Grade 3 or 4 adverse event (AE) with Imfinzi plus SoC chemotherapy (all causes), versus 62.4% with SoC chemotherapy. The percentage of patients discontinuing treatment due to AEs was similar between arms (9.4% vs. 9.4%).
“We are 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,” added José Baselga, executive vice president, Oncology R&D, AstraZeneca. “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.”
Imfinzi is already approved in the curative-intent setting of unresectable, Stage III non-small cell lung cancer (NSCLC) after chemoradiotherapy based on the Phase 3 PACIFIC trial. Imfinzi is also being tested following concurrent chemoradiation therapy in limited-stage SCLC in the Phase 3 ADRIATIC trial.
In addition, Imfinzi is being tested as a monotherapy and in combination with tremelimumab, an anti-CTLA-4 monoclonal antibody, as a treatment for patients with NSCLC, SCLC, bladder cancer, head and neck cancer, liver cancer, cervical cancer, biliary tract cancer and other solid tumors.
