Durvalumab and tremelimumab, with or without lenvatinib, combined with transarterial chemoembolisation in participants with embolisation-eligible hepatocellular carcinoma (EMERALD-3): a global, randomised, open-label, sponsor-blinded, phase 3 study.
BACKGROUND: Transarterial chemoembolisation (TACE), a standard treatment for embolisation-eligible hepatocellular carcinoma (HCC), induces tumour immune responses. Single tremelimumab regular interval durvalumab (STRIDE) is a standard treatment in advanced HCC. In this phase 3 trial, we assessed the efficacy and safety of STRIDE, with or without lenvatinib, plus TACE, in participants with embolisation-eligible HCC. METHODS: EMERALD-3 is a phase 3, randomised, open-label, sponsor-blinded study, conducted at 177 medical sites in 21 countries. Eligible participants were 18 years or older (aged ≥21 years in Egypt or Singapore) at screening and had confirmed HCC (by imaging or histopathologically from biopsy specimen, surgery, or both) not amenable to curative surgery, curative ablation, or transplantation but amenable to TACE. Participants had Child-Pugh class A liver function, an Eastern Cooperative Oncology Group performance status of 0-1, and at least one measurable target intrahepatic lesion per modified Response Evaluation Criteria in Solid Tumours. Participants were randomly allocated in a 1:1:1 ratio to receive STRIDE plus lenvatinib plus TACE, STRIDE plus TACE, or TACE until each group reached its preplanned enrolment target of 175 participants. After the STRIDE plus TACE group reached its enrolment target, randomisation was adjusted to continue in a 1:1 ratio between the STRIDE plus lenvatinib plus TACE group and TACE group until approximately 275 participants were enrolled in each of these two groups. Randomisation used a centrally assigned interactive response technology system, stratified by region, baseline tumour burden, and previous palliative embolisation. In the STRIDE plus lenvatinib plus TACE group, on the first day, participants were given 300 mg tremelimumab intravenously, followed by 1500 mg durvalumab plus oral lenvatinib (8 mg for <60 kg bodyweight or 12 mg for ≥60 kg bodyweight); participants then received 1500 mg durvalumab every 4 weeks plus once-daily lenvatinib for up to 36 cycles. In the STRIDE plus TACE group, participants were given 300 mg tremelimumab and 1500 mg durvalumab intravenously on the first day, followed by 1500 mg durvalumab every 4 weeks. The technique and number of TACE procedures were at the investigators' discretion, with the first procedure administered at least 7 days after the first dose of durvalumab in the two investigation treatment groups and within 7 days of random allocation in the TACE group. The primary endpoint was progression-free survival for STRIDE plus lenvatinib plus TACE versus TACE. Key secondary endpoints were overall survival for STRIDE plus lenvatinib plus TACE versus TACE and progression-free survival and overall survival for STRIDE plus TACE versus TACE. This study was registered with ClinicalTrials.gov (NCT05301842), with enrolment completed. FINDINGS: From March 28, 2022, to Nov 20, 2024, 1124 participants were screened. The full analysis set comprised 760 participants, who were randomly allocated to STRIDE plus lenvatinib plus TACE (n=293), STRIDE plus TACE (n=175), or TACE (n=292). 633 (83%) participants were male and 127 (17%) were female; 548 (72%) were Asian. At the first data cutoff (Sept 2, 2025); the overall median follow-up for progression-free survival was 10·0 months (IQR 4·6-17·2); median follow-up for progression-free survival was 11·0 months (IQR 4·8-18·4) for STRIDE plus lenvatinib plus TACE and 8·3 months (4·1-15·5) for TACE. Median progression-free survival was 13·0 months (95% CI 12·2-16·7) for STRIDE plus lenvatinib plus TACE versus 9·8 months (8·0-11·4) for TACE (HR 0·70 [95% CI 0·57-0·86]; p=0·0007). At the second data cutoff (Feb 23, 2026) and a median follow-up for overall survival of 24·6 months (IQR 16·5-31·5) for STRIDE plus lenvatinib plus TACE and 22·9 months (14·9-30·2) for TACE, median overall survival was 39·5 months (95% CI 34·1-not reached) for STRIDE plus lenvatinib plus TACE and 34·7 months (28·8-not reached) for TACE (HR 0·84 [95% CI 0·65-1·09]; p=0·18). At this data cutoff, median progression-free survival was 12·9 months (95% CI 10·2-15·9) for STRIDE plus TACE and 8·1 months (6·5-10·2) for the first 175 participants randomised to TACE (HR 0·71 [95% CI 0·56-0·91]), with median follow-up of 10·3 months (IQR 4·6-23·7) for STRIDE plus TACE and 7·7 months (3·0-18·5) for the first 175 participants randomly allocated to TACE. The most common adverse events of maximum grade 3 or 4 were hypertension (34 [12%] of 287) for STRIDE plus lenvatinib plus TACE, post-embolisation syndrome and anaemia (ten [6%] of 175 each) for STRIDE plus TACE, and post-embolisation (17 [6%] of 290) for TACE. 184 (64%) participants receiving STRIDE plus lenvatinib plus TACE, 89 (51%) receiving STRIDE plus TACE, and 68 (23%) receiving TACE had serious adverse events. Treatment-related adverse events with an outcome of death during the treatment-emergent period occurred in seven (2%) of 287 participants who received STRIDE plus lenvatinib plus TACE (two for myocarditis; and one each for hepatic failure, haemophagocytic lymphohistiocytosis, septic shock, cardiac failure, and unknown cause), none of 175 participants who received STRIDE plus TACE, and two (1%) of 290 participants who received TACE (one each for acute myocardial infarction and unknown cause). INTERPRETATION: STRIDE plus lenvatinib plus TACE showed a statistically significant progression-free survival improvement versus TACE. These findings support a STRIDE-based regimen as a potential new treatment option for people with embolisation-eligible HCC; additional follow-up is being conducted for final analysis of overall survival across treatment groups. FUNDING: AstraZeneca.