Imjudo Combined with Imfinzi Demonstrates Significant Survival Benefit in Chinese Patients from Hong Kong and Taiwan with Unresectable Hepatocellular Carcinoma

Phase III Clinical Study HIMALAYA's Asian Subgroup Data from China, Hong Kong, and Taiwan Show that a Single Priming Dose of Imjudo Combined with Imfinzi Reduces the Risk of Death by 56%

ShanghaiDecember 6, 2022/PR Newswire/ -- 2022 European Society for Medical Oncology Asia Conference/Annual Meeting (ESMOASIA2022) officially announced on December 2 the results of the Phase III clinical study HIMALAYA conducted by AstraZeneca.Imjudo (Generic Name: Tremelimumab)UnitedImfinzi (Generic Name: Durvalumab)Subgroup Analysis Data of First-Line Treatment for Unresectable Liver Cancer in Asia. The published data shows that, compared with sorafenib monotherapy, the addition of a single priming dose of tremelimumab to durvalumab resulted in a median overall survival (mOS) of 29.4 months in the population of Hong Kong and Taiwan, China, which is consistent with the overall data of the Asian subgroup, confirming a statistically significant and clinically meaningful survival benefit.

The combination therapy of durvalumab and tremelimumab with innovative dosing and administration regimens is referred to asSTRIDESolution (Single Tremelimumab Regular Interval Durvalumab）This includes the first dose of only one application of the anti-CTLA-4 monoclonal antibody tremelimumab 300mg in combination with the anti-PD-L1 monoclonal antibody durvalumab 1500mg, followed by durvalumab administered once every four weeks. Based on the results of the Phase III clinical study HIMALAYA, this combination therapy was approved in the United States in October this year for the treatment of adult patients with the most common type of liver cancer—unresectable hepatocellular carcinoma (HCC).

In the study, data from the global population showed that, compared with sorafenib monotherapy, the risk of death was reduced by 22% in patients receiving tremelimumab combined with durvalumab (based on a hazard ratio [HR] of 0.78, 95% confidence interval [CI] 0.66-0.92, p=0.0035). ^[1]. The results published in The New England Journal of Medicine Evidence showed that approximately 31% of patients receiving combination therapy remained alive after three years, with a median overall survival (mOS) of 16.4 months, while only 20% of patients receiving sorafenib monotherapy remained alive during the same follow-up period, with an mOS of 13.8 months.^[2]。

Liver cancer is the third leading cause of cancer death globally and the sixth most common cancer.^[3],[4]In the United States, Europe, and Japan, approximately 80,000 people each year, and in China, about 260,000 people are diagnosed with advanced, unresectable hepatocellular carcinoma.^[5], with a 5-year survival rate of only 7% for late-stage patients.^[6]。

The HIMALAYA study enrolled a total of 1,324 adult patients with unresectable hepatocellular carcinoma, including 479 patients from Asia (excluding Japan) (STRIDE regimen group: 156 cases vs. durvalumab monotherapy group: 167 cases vs. sorafenib control group: 156 cases). In the Asian subgroup of the HIMALAYA study, the risk of death was reduced by 32% in patients receiving the STRIDE regimen (based on a hazard ratio [HR] of 0.68, 95% confidence interval [CI]: 0.52-0.89), with a three-year survival rate of 32.2% and a median overall survival (mOS) of 16.5 months, consistent with global population data. Among the Asian subgroup, a total of 141 patients from Hong Kong and Taiwan were included (STRIDE regimen group: 56 cases vs. durvalumab monotherapy group: 42 cases vs. sorafenib control group: 43 cases), and the risk of death was reduced by 56% in patients receiving the STRIDE regimen (based on an HR of 0.44, 95% CI: 0.26-0.77), with a three-year survival rate of 49.2% and mOS of 29.4 months, which was generally consistent with the data for the entire Asian subgroup. Compared with the global population, a higher proportion of patients in the Asian subgroup had hepatitis B virus (HBV) infections (Asian subgroup: 62% vs. global population: 31%). In the Asian subgroup and the global population, 16% and 27% of patients, respectively, had hepatitis C virus (HCV) infections, while 22% and 42% of patients, respectively, had liver cancer caused by non-viral etiologies.

Moreover, the safety outcomes of the STRIDE regimen group and the durvalumab monotherapy group in the Asian subgroup were consistent with those reported in the global population and previous studies for each drug. Among Asian subgroup patients treated with the STRIDE regimen, 20% experienced treatment-related grade 3 or 4 adverse events (AEs), while 13% of those receiving durvalumab monotherapy experienced these AEs, compared to 31% in the sorafenib-treated Asian subgroup. In the global population, the corresponding rates of these adverse events were 26% (STRIDE regimen group), 13% (durvalumab monotherapy group), and 37% (sorafenib control group).

Professor Fan Jia, academician of the Chinese Academy of Sciences and president of Zhongshan Hospital Affiliated to Fudan University, stated: "The release of the HIMALAYA study data from Hong Kong and Taiwan, China, is undoubtedly good news for patients with unresectable hepatocellular carcinoma in China. First, this analysis is based on patients from Hong Kong and Taiwan, China, who were treated with the STRIDE regimen, making the data highly relevant and significant for patients in mainland China. At the same time, this means that the STRIDE regimen, as a first-line treatment for unresectable hepatocellular carcinoma, has been doubly validated in both the global and Chinese populations, with its efficacy and safety fully confirmed. As the only innovative dual immunotherapy regimen to date [*] that has demonstrated statistically significant and clinically meaningful results, the STRIDE regimen provides a new treatment option for Chinese patients with unresectable hepatocellular carcinoma, contributing to the realization of the great goal outlined in the 'Healthy China 2030' Plan Outline."

AstraZeneca China's General Manager of Oncology, Kevin Chen, stated: "In the past, treatment options for liver cancer patients were limited, and the prognosis was not ideal. The subgroup data results from the HIMALAYA study show that compared to the global population, the overall survival benefit for the population in China, Hong Kong, and Taiwan is more significant, with nearly 50% of patients surviving up to three years, and a more pronounced reduction in the risk of death. This means that Chinese liver cancer patients can benefit more from this treatment regimen, with the potential to achieve long-term survival. At the same time, this further strengthens our commitment to continuous R&D innovation to benefit a broader range of cancer patients beyond those with lung, breast, ovarian, and prostate cancers, as well as our ambition to challenge treatment expectations and change the outcomes for gastrointestinal cancer patients with high unmet needs. We look forward to the early approval of this innovative treatment in China, so it can benefit Chinese patients with unresectable hepatocellular carcinoma as soon as possible."

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[*] As of December 5, 2022