A treatment combination of Imjudo (tremelimumab) and Imfinzi (durvalumab) demonstrated improved survival outcomes, including disease control and treatment responses in patients with unresectable (surgically unremovable) hepatocellular carcinoma (liver cancer), according to a presentation at the 2024 ESMO Congress.
The presentation highlighted updated five-year data from the phase 3 HIMALAYA study. These results set new standards in unresectable liver cancer, with one in 5 patients alive at five years, Dr. Lorenza Rimassa said in the presentation.
Rimassa is an associate professor of medical oncology at Humanitas University and head of the Hepatopancreatobiliary Oncology Department at Istituto di Ricovero e Cura a Carattere Scientifico Maugeri Humanitas Research Hospital in Milan, Italy.
“This five-year updated analysis of the HIMALAYA study presents the longest follow-up to date in phase 3 studies for [unresectable liver cancer],” Rimassa said. “[Imjudo plus Imfinzi] sustained an overall survival (OS; time patients live, regardless of disease status) benefit versus [Nexavar (Nexavar)] and demonstrated unprecedented long-term survival benefit at five years, with a five-year survival rate of 19.6% for [Imjudo plus Imfinzi] versus 9.4% for [Nexavar].”
Survival Benefits of Imjudo Plus Imfinzi Versus Nexavar in Unresectable Liver Cancer
A total of 1,171 patients were randomly assigned to three treatment groups. The Imjudo-Imfinzi combination group included 393 patients. There were 389 patients in the Imfinzi monotherapy group and patients 389 patients in the Nexavar group. In the study, 393 patients were treated with the Imjudo-Imfinzi combination and 389 patients received Nexavar.
Patients from the Imjudo-Imfinzi combination group compared with Nexavar sustained an OS benefit. Specifically, the median OS was 16.43 months in the combination group and 13.77 in the Nexavar group. The median follow-up duration was 62.49 versus 59.86 months, respectively.
For patients experiencing disease control, the OS was enhanced, showing rates of 28.7% in the Imjudo-Imfinzi combination group and 12.7% in the Nexavar group at five years and increasing over time. There were 12 patients (3.1%) in the Imjudo-Imfinzi combination group who achieved complete response (disappearance of cancer) versus no patients in the Nexavar group, and 67 patients (17.0%) experienced partial response (tumor shrinkage) versus 20 patients (5.1%), respectively. Stable disease was achieved by 157 (39.9%) in the Imjudo-Imfinzi combination group and 216 patients (55.5%) in the Nexavar group, and 141 patients (35.9%) versus 118 (30.3%), respectively, experienced disease progression.
“More patients treated with [Imjudo-Imfinzi combination] versus Nexavar were still alive, still on study treatment, and fewer received a subsequent therapy at five years,” Rimassa noted.
Patients receiving the Imjudo-Imfinzi combination also experienced deeper tumor responses, including over 50% shrinkage in 34 patients, which was associated with longer overall survival, compared with 12 patients receiving Nexavar. In addition, 80 patients in the Imjudo-Imfinzi combination group versus 114 patients in the Nexavar group experienced minor responses of less than 30% tumor shrinkage; however, this also led to a long-term survival benefit for those receiving Imjudo-Imfinzi combination. In the Imjudo-Imfinzi combination group, there were 168 patients who had no shrinkage or growth versus 169 patients in the Nexavar group.
Safety Outcomes
Rimassa stated that there were no new serious treatment-related side effects after the primary analysis with a data cut-off on Aug. 27, 2023. At the five-year data cut-off of March 1, 2024, 17.5% of patients in the Imjudo-Imfinzi combination group had experienced serious treatment-related side effects, which was the same percentage reported at the primary analysis. Similarly, for the Nexavar group, at the five-year analysis at the data cut-off, there were 9.9% of patients who experienced serious treatment-related side effects versus 9.4% at the primary data cut-off.
There were also 24.8% of patients in the Imjudo-Imfinzi combination group that had serious non-treatment-related side effects at the five-year data cut-off versus 23% at the primary data cut-off, and in the Nexavar group, there were 20.3% of patients experiencing serious non- treatment-related side effects versus 20.3%, respectively.
“Overall survival benefit with [the Imjudo-Imfinzi combination] was enhanced in patients who achieved disease control. Any degree of tumor shrinkage was linked to long-term survival, with those experiencing deep responses showing the greatest benefit. These findings indicate that conventional response measures such as complete response or partial response … may not fully capture the benefits of [the Imjudo-Imfinzi combination],” Rimassa concluded.
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