Imfinzi ( Durvalumab ) has been approved in the US as a 1st-line treatment for adult patients with extensive-stage small cell lung cancer ( ES-SCLC ) in combination with standard-of-care ( SoC ) chemotherapies, Etoposide plus either Carboplatin or Cisplatin ( Platinum-Etoposide ).
The approval by FDA ( Food and Drug Administration ) was based on positive results from the phase III CASPIAN trial showing Durvalumab in combination with SoC Platinum-Etoposide demonstrated a statistically significant and clinically meaningful improvement in overall survival ( OS ) versus SoC alone.
The CASPIAN trial had two primary endpoints comparing experimental arms to SoC.
In the Durvalumab plus SoC arm, the risk of death was reduced by 27% ( equal to a hazard ratio [ HR ] of 0.73; 95% CI 0.59-0.91; p=0.0047 ), with median overall survival of 13.0 months versus 10.3 months for SoC alone.
Results also showed an increased confirmed objective response rate in the Durvalumab plus SoC arm ( 68% versus 58% for SoC alone ).
The safety and tolerability for Durvalumab plus SoC was consistent with the known safety profiles of these medicines.
The second experimental arm testing Tremelimumab added to Durvalumab and SoC recently completed, but did not meet its primary endpoint.
The CASPIAN trial used a fixed dose of Durvalumab ( 1500mg ) administered every three weeks for four cycles while in combination with chemotherapy and then every four weeks until disease progression.
Durvalumab is a human monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, countering the tumour's immune-evading tactics and releasing the inhibition of immune responses.
Lung cancer is the leading cause of cancer death among both men and women and accounts for about one fifth of all cancer deaths.
Lung cancer is broadly split into non-small cell lung cancer ( NSCLC ) and SCLC, with about 15% classified as SCLC.
About two thirds of SCLC patients are diagnosed with ES-SCLC, in which the cancer has spread widely through the lung or to other parts of the body.
Prognosis is particularly poor, as only 6% of all SCLC patients will be alive five years after diagnosis. ( Xagena )
Source: AstraZeneca, 2020