Imfinzi + tremelimumab demonstrated unprecedented survival in 1st-line unresectable liver cancer with 31% of patients alive at three years.- AstraZeneca

This novel dose and schedule of Imfinzi and tremelimumab, an anti-CTLA4 antibody, is called the STRIDE regimen (Single Tremelimumab Regular Interval Durvalumab). Results from the trial will be presented on 21 January at the 2022 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium.

Patients treated with the STRIDE regimen experienced a 22% reduction in the risk of death versus sorafenib (based on a hazard ratio [HR] of 0.78, 96.02% confidence interval [CI] 0.65-0.93; p=0.0035). Median OS was 16.4 months versus 13.8 for sorafenib. An estimated 31% of patients were still alive at three years versus 20% for sorafenib. Results also showed an increase in objective response rate (ORR) with the STRIDE regimen versus sorafenib (20.1% vs. 5.1%). Median duration of response (DoR) was 22.3 months with the STRIDE regimen versus 18.4 with sorafenib.

The addition of tremelimumab to Imfinzi did not increase severe liver toxicity, and no bleeding risk was observed. HIMALAYA also tested Imfinzi monotherapy, which demonstrated non-inferior OS to sorafenib (HR 0.86; 95.67% CI 0.73-1.03; non-inferiority margin 1.08) with a median OS of 16.6 months versus 13.8, and an improved tolerability profile versus sorafenib.

The safety profiles of the STRIDE regimen and for Imfinzi alone were consistent with the known profiles of each medicine, and no new safety signals were identified. Grade 3 or 4 treatment-related adverse events (AEs) were experienced by 25.8% of patients treated with the STRIDE regimen and by 12.9% of patients treated with Imfinzi alone, versus 36.9% of patients on sorafenib. Incidence of Grade 3 or 4 treatment-related hepatic events were low across treatment arms (5.9% for the STRIDE regimen and 5.2% for Imfinzi, versus 4.5% for sorafenib). Treatment-related AEs led to treatment discontinuation in 8.2% of patients treated with the STRIDE regimen and 4.1% of patients treated with Imfinzi alone, versus 11% for sorafenib.