The approval was based on phase 3 trial results which showed a 27% reduction in the risk of death versus placebo.
RT’s Three Key Takeaways:
- FDA approval granted for LS-SCLC treatment: AstraZeneca’s Imfinzi (durvalumab) received FDA approval for treating adults with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed after concurrent platinum-based chemotherapy and radiation therapy.
- Phase 3 trial shows improved survival rates: Results from the ADRIATIC phase 3 trial demonstrated a 27% reduction in the risk of death with Imfinzi compared to placebo, with a median overall survival of 55.9 months versus 33.4 months and 57% of patients alive at three years.
- Approval addresses unmet need in LS-SCLC: Imfinzi is the first systemic therapy to improve survival in this setting in decades, providing a new option for patients with this aggressive form of lung cancer.
AstraZeneca’s Imfinzi (durvalumab) has been approved in the United States for the treatment of adult patients with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy.
The approval was granted by the Food and Drug Administration (FDA) after securing Priority Review and Breakthrough Therapy Designation. It was based on results from the ADRIATIC phase 3 trial which were presented during the Plenary Session of the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting and subsequently published in the New England Journal of Medicine.
SCLC is a highly aggressive form of lung cancer.1 LS-SCLC typically recurs and progresses rapidly, despite initial response to standard-of-care chemotherapy and radiotherapy. The prognosis for LS-SCLC is particularly poor, as only 15-30% of patients will be alive five years after diagnosis.
“Durvalumab is the first and only systemic treatment following curative-intent, platinum-based chemoradiotherapy to show improved survival for patients with this aggressive form of lung cancer. This finding represents the first advance for this disease in four decades,” says Suresh Senan, PhD, professor of clinical experimental radiotherapy at the Amsterdam University Medical Centers, The Netherlands, and international coordinating investigator in the trial, in a release. “The ADRIATIC trial showed 57% of patients were still alive at three years after being treated with durvalumab, which underscores the practice-changing potential of this medicine in this setting.”
Phase 3 Trial Results
In the trial, Imfinzi reduced the risk of death by 27% versus placebo. Estimated median overall survival was 55.9 months for Imfinzi versus 33.4 months for placebo. An estimated 57% of patients treated with Imfinzi were alive at three years compared to 48% for placebo.
Imfinzi also reduced the risk of disease progression or death by 24% versus placebo. Median progression-free survival was 16.6 months for Imfinzi versus 9.2 months for placebo. An estimated 46% of patients treated with Imfinzi had not experienced disease progression at two years compared to 34% for placebo.
The safety profile for Imfinzi was generally manageable and consistent with the known profile of this medicine. No new safety signals were observed.
Imfinzi is also approved in Switzerland in this setting based on the ADRIATIC results. Regulatory applications are currently under review in the EU, Japan, and several other countries in this indication.
