FDA Approves AstraZeneca’s Imfinzi for Limited-Stage Small Cell Lung Cancer

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The FDA has approved AstraZeneca’s Imfinzi (durvalumab) to treat adults with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed after platinum-based chemotherapy and radiation therapy. According to the company, the approval was based on positive results from the Phase III ADRIATIC trial and was supported by Priority Review status and Breakthrough Therapy Designation. Additionally, this marks the first systemic immunotherapy available for LS-SCLC.¹

“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. The ADRIATIC trial showed 57 percent 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,” said Suresh Senan, PhD, professor, clinical experimental radiotherapy, Amsterdam University Medical Centers, The Netherlands, international coordinating investigator in the trial, in a press release.

The randomized, double-blind, placebo-controlled, multi-center global ADRIATIC trial evaluated Imfinzi monotherapy and the combination of Imfinzi plus Imjudo (tremelimumab) versus placebo. The trial included 730 patients with LS-SCLC whose disease had not progressed following concurrent chemotherapy.

Patients were randomly assigned to receive a 1500 mg fixed dose of Imfinzi with or without Imjudo 75 mg every four weeks for up to four doses/cycles each, followed by Imfinzi every four weeks for up to 24 months. The primary endpoints of the study were progression-free survival and overall survival (OS), while key secondary endpoints included OS and PFS for Imfinzi plus Imjudo versus placebo, safety, and quality of life measures. A total of 164 centers in 19 countries across North and South America, Europe, and Asia participated in the trial.

Results found that Imfinzi reduced the risk of death by 27% and achieved a median OS of 55.9 months versus 33.4 months with placebo. An estimated 57% of patients treated with Imfinzi were alive at three years compared to 48% for placebo. Additionally, the treatment reduced the risk of disease progression or death by 24% versus placebo. The safety profile for Imfinzi was found to be consistent with its known profile, was generally manageable, and no new safety signals were identified.¹

“This approval for Imfinzi marks a breakthrough for patients with limited-stage small cell lung cancer, allowing them to receive immunotherapy for the first time. The ADRIATIC trial showed an improvement in median overall survival of 22.5 months, setting a new benchmark. Imfinzi is now the only immunotherapy approved for both limited- and extensive-stage small cell lung cancer, underscoring our commitment to improving survival rates,” said Dave Fredrickson, EVP, oncology business unit, AstraZeneca, in the press release.

According to Yale Medicine, SCLC accounts for 15% of all lung cancers in the United States, making it much less common than non-small cell lung cancer. An estimated 60% of all SCLC cases have already metastasized to other areas in the body by the time it is diagnosed. When SCLC metastasizes, the cancer can cause symptoms that are not typically associated with lung cancer, including bone pain, seizures, confusion, and paralysis.²

"This new treatment option is a game changer for patients with limited-stage small cell lung cancer, a disease known for its high rate of recurrence. Historically, more often than not, clinical trials to identify new treatment options for this type of cancer have failed to show benefit. We are therefore so excited that many more people will now have the opportunity to access this immunotherapy treatment that holds the potential to significantly improve outcomes,” said Dusty Donald, founder, executive director, LiveLung, in the press release.

References

1. Imfinzi approved in the US as first and only immunotherapy regimen for patients with limited-stage small cell lung cancer. Imfinzi. December 5, 2024. Accessed December 5, 2024. https://www.astrazeneca.com/media-centre/press-releases/2024/imfinzi-approved-in-us-for-limited-stage-sclc.html

2. Small Cell Lung Cancer. Yale Medicine. Accessed December 5, 2024. https://www.yalemedicine.org/conditions/small-cell-lung-cancer#:~:text=SCLC%20accounts%20for%20about%2015,the%20time%20it%20is%20diagnosed.