AstraZeneca’s (AZ) Imfinzi (durvalumab) has received approval from the US Food and Drug Administration (FDA) for treating adults with limited-stage small cell lung cancer (SCLC) whose disease has not progressed after concurrent platinum-based chemotherapy and radiation therapy. This marks a significant milestone in addressing an aggressive cancer type with limited treatment options.
Key Highlights:
- Targeted Condition:
- SCLC is a highly aggressive form of lung cancer, accounting for 15% of all lung cancer diagnoses.
- Limited-stage SCLC (LS-SCLC): Found in approximately 30% of SCLC patients, it is confined to one lung or side of the chest but carries a poor prognosis despite standard treatment.
- Mechanism of Action:
- Imfinzi blocks PD-L1 interaction with PD-1 and CD80 proteins, enhancing the immune system’s ability to detect and fight cancer cells.
- Existing Approvals:
- Imfinzi is already approved for extensive-stage SCLC (ES-SCLC), a more advanced form of the disease where cancer has spread beyond the initial lung.
- ADRIATIC Trial Results:
- Overall Survival (OS):
- Imfinzi reduced the risk of death by 27%.
- Median OS: 55.9 months (Imfinzi) vs. 33.4 months (placebo).
- At three years, 57% of Imfinzi-treated patients were alive compared to 48% with placebo.
- Progression-Free Survival (PFS):
- Imfinzi reduced the risk of disease progression or death by 24%.
- Median PFS: 16.6 months (Imfinzi) vs. 9.2 months (placebo).
- At two years, 46% of Imfinzi patients had not experienced progression, compared to 34% with placebo.
- Overall Survival (OS):
Implications:
The FDA approval positions Imfinzi as a transformative option for LS-SCLC patients, extending survival and delaying disease progression in a population with urgent unmet needs. This decision highlights the growing impact of immunotherapy in improving outcomes for cancers previously considered difficult to treat.