AstraZeneca’s Imfinzi (durvalumab) in combination with Imjudo (tremelimumab) plus platinum-based chemotherapy has been approved in the US for the treatment of adult patients with Stage IV (metastatic) non-small cell lung cancer (NSCLC).
The approval by the Food and Drug Administration (FDA) was based on the results from the POSEIDON Phase III trial. Patients treated with a limited course of five cycles of the anti-CTLA-4 antibody Imjudo added to Imfinzi plus four cycles of platinum-based chemotherapy experienced a 23% reduction in the risk of death versus a range of chemotherapy options (based on a hazard ratio [HR] of 0.77; 95% CI 0.65-0.92; p=0.00304). An estimated 33% of patients were alive at two years versus 22% for chemotherapy. This treatment combination also reduced the risk of disease progression or death by 28% compared to chemotherapy alone (HR 0.72; 95% CI 0.60-0.86; p=0.00031).
Updated results from the POSEIDON Phase III trial after approximately four years of follow-up presented at the European Society of Medical Oncology (ESMO) Congress 2022 and published in the Journal of Clinical Oncology demonstrated sustained survival benefit, improving overall survival (OS) by 25% compared to chemotherapy alone (HR 0.75; 95% CI 0.63-0.88). An estimated 25% of patients treated with the combination were alive at three years versus 13.6% for those treated with chemotherapy alone. The safety profile for Imjudo plus Imfinzi and chemotherapy was consistent with the known profiles of each medicine, and no new safety signals were identified.
In the US, lung cancer is the second most commonly diagnosed cancer, with more than 236,000 patients expected to be diagnosed in 2022. For patients with metastatic NSCLC, prognosis is particularly poor, as only approximately 8% will live beyond five years after diagnosis.
Melissa Johnson, MD, director of Lung Cancer Research, Sarah Cannon Research Institute at Tennessee Oncology in Nashville, Tennessee, and a lead investigator in the POSEIDON Phase III trial, said: “Metastatic non-small cell lung cancer remains a significant treatment challenge because many patients’ tumours do not respond well to standard therapies, including checkpoint inhibitors. The approval of this dual immunotherapy regimen with chemotherapy introduces a new, generally well-tolerated treatment option for patients with this devastating disease and gives them the chance to benefit from the long-term survival advantage seen with CTLA-4 inhibition.”
Dave Fredrickson, executive vice president, Oncology Business Unit, AstraZeneca, said: “This approval underscores the importance of delivering novel treatment combinations that extend survival in metastatic non-small cell lung cancer, a complex setting where many patients still face a dismal prognosis. This marks the second indication for Imjudo added to Imfinzi in just a few weeks following its approval in unresectable liver cancer, reinforcing the benefits of this new medicine and our commitment to improving patient outcomes in cancer settings with continued unmet need.”
Regulatory applications are also currently under review in Europe, Japan and several other countries for this indication based on the POSEIDON results.
Imfinzi is the only approved immunotherapy and the global standard of care in the curative-intent setting of unresectable, Stage III NSCLC in patients whose disease has not progressed after chemoradiation therapy based on the PACIFIC Phase III trial. Imfinzi is also approved in the US, the EU, Japan, China and many other countries around the world for the treatment of extensive-stage small cell lung cancer (ES-SCLC) based on the CASPIAN Phase III trial. Imfinzi is approved in the US and several other countries in combination with chemotherapy for the treatment of locally advanced or metastatic biliary tract cancer based on the TOPAZ-1 Phase III trial, and it is approved with Imjudo in the US for the treatment of unresectable hepatocellular carcinoma based on the HIMALAYA Phase III trial.
