The United States Food and Drug Administration (FDA) has approved AstraZeneca’s Imfinzi (durvalumab) for adult patients diagnosed with limited-stage small cell lung cancer (LS-SCLC) whose disease remains stable following a regimen of concurrent platinum-based chemotherapy and radiotherapy.
The FDA’s decision evidenced by a Priority Review and Breakthrough Therapy Designation, follows encouraging data from the ADRIATIC Phase III trial, highlighted during the American Society of Clinical Oncology’s (ASCO) 2024 Annual Meeting Plenary Session and later published in the New England Journal of Medicine.
Small cell lung cancer (SCLC) is particularly aggressive, with limited-stage SCLC often swiftly advancing after an initial positive response to standard chemotherapy and radiotherapy treatments. Prognosis can be grim, with survival rates of only 15-30% after five years into the diagnosis.
Professor Suresh Senan, from the Amsterdam University Medical Centers, emphasized Imfinzi’s significance, saying, “Durvalumab is the pioneering systemic therapy post-curative-intent chemotherapy and radiotherapy to extend patient survival in this aggressive cancer type — the first such progress in 40 years. The ADRIATIC trial showcased that 57% of patients remained alive three years after starting durvalumab, marking it as a potential game-changer in treatment plans.”
Dave Fredrickson, AstraZeneca’s executive vice president of oncology, noted the breakthrough for patients with LS-SCLC: “This approval enables the initial application of immunotherapy for these patients. The ADRIATIC trial demonstrated a median survival improvement to 22.5 months, surpassing former standards. As the exclusive immunotherapy sanctioned for both limited and extensive-stage SCLC, our commitment to enhancing survival rates is steadfast.”
LiveLung’s founder, Dusty Donaldson, pointed out the significant impact of this breakthrough: “For those with limited-stage small cell lung cancer, known for its recurrence, this treatment is transformative. It’s encouraging that many patients can now access an immunotherapy solution with promising outcome potentials.”
Within the trial, Imfinzi reduced the mortality risk by 27% in comparison to placebo (showing an overall survival hazard ratio of 0.73; 95% CI 0.57-0.93; p=0.0104). Imfinzi’s median OS lingered at 55.9 months against the placebo’s 33.4 months. After three years, 57% of Imfinzi-treated subjects were alive, as opposed to 48% of those on a placebo regimen.
Further, Imfinzi showed a 24% reduced risk for disease progression or mortality (PFS HR 0.76; 95% CI 0.61-0.95; p=0.0161) than placebo. Median PFS extended to 16.6 months for Imfinzi, compared to 9.2 months for placebo, with 46% of patients avoiding disease progression at two years against 34% for those on placebo.
Imfinzi’s safety profile was deemed appropriate and consistent with existing data, with no new safety issues identified.
Securing approval in Switzerland, reflective of the ADRIATIC findings, Imfinzi awaits regulatory assessments for this indication in the EU, Japan, and other global markets.
Leading the charts of cancer mortality in both women and men, lung cancer accounts for a staggering one-fifth of cancer-related fatalities. Approximately 15% of cases fall under small cell lung cancer (SCLC), divided into non-small cell and SCLC classifications.