AstraZeneca (AZ) has shared “unprecedented” overall survival (OS) results from a late-stage study of Imfinzi (durvalumab) plus Imjudo (tremelimumab) in advanced liver cancer.
The phase 3 HIMALAYA trial has been evaluating a single 300mg priming dose of Imjudo added to Imfinzi 1500mg, followed by Imfinzi every four weeks, in patients with unresectable, advanced hepatocellular carcinoma (HCC) who had not received prior systemic therapy and were not eligible for localised treatment.
The results presented at this year’s European Society for Medical Oncology Congress showed that the combination, known as the STRIDE regimen, reduced the risk of death by 24% compared to sorafenib, a standard-of-care multi-kinase inhibitor, at five years of follow-up.
An estimated 19.6% of patients receiving Imfinzi plus Imjudo were alive at five years versus 9.4% of those in the sorafenib group. Additionally, in a subgroup analysis of patients who achieved disease control, 28.7% of those being treated with STRIDE were alive at five years compared to 12.7% of those in the sorafenib cohort.
AZ added that an exploratory analysis showed that more patients treated with Imfinzi plus Imjudo experienced deep responses leading to longer survival compared to sorafenib, and that safety profile of the regimen was consistent with the known profiles of each medicine.
Almost 900,000 people worldwide are diagnosed with liver cancer every year, with HCC accounting for the majority of cases. More than half of patients are diagnosed with advanced disease, at which point the five-year survival rate is only 7%.
Imfinzi is designed to block the interaction of PD-L1 with the PD-1 and CD80 proteins, countering tumours’ immune-evading tactics and releasing the inhibition of immune responses. Meanwhile, Imjudo blocks the activity of CTLA-4, contributing to T-cell activation, priming the immune response to cancer and fostering cancer cell death.
The combination already holds approvals to treat adults with advanced or unresectable HCC in the US, EU and several other countries.
HIMALAYA lead investigator Lorenza Rimassa, Humanitas University and IRCCS Humanitas Research Hospital, said: “Treatment with [Imfinzi] plus [Imjudo] for patients with advanced liver cancer doubled the OS rate at five years, a significant survival advantage over sorafenib that has also become even more pronounced over time.
“This data reinforces the use of this novel dual immunotherapy regimen and is an important milestone for patients with this devastating disease.”