Supplementary Figure S2. The effect of covariates, body weight, baseline albumin level, and combination therapy, on tremelimumab exposure metric Cmin1 (PK analysis population)

FIG S1. TMB distribution in samples from HAWK and CONDOR (A) and EAGLE (B).

FIG S2. Kaplan-Meier plot of OS in the durvalumab monotherapy, durvalumab plus tremelimumab and SoC treatment arms in the NLR ≤ 7 subgroup (A) and NLR > 7 subgroup (B) in EAGLE.

Supplementary Data for publication

Supplementary Figure S1. Flow diagram of patients included in the PK analysis, exposure-response analysis, and PD analysis datasets

IntroductionAlthough oncology has seen large scientific and clinical advances over the last decade, it also has one of the lowest success rates for novel agents across therapeutic areas. Adaptive clinical trial design has been a popular option for increasing clinical trial efficiency and the chances of trial success. Seamless clinical trial design are studies in which two or more clinical trial phases are combined into a single study with a pre-specified transition between stages. This integration of phases may enhance efficiency.MethodsTo understand the precedent for the use of seamless designs, this working group was formed to conduct a comprehensive literature search on seamless clinical trials conducted with confirmatory intent in oncology. Trial design features were extracted into a database and analyzed with descriptive statistics.ResultsA literature search identified 68 clinical trials meeting inclusion and exclusion criteria. The most common design feature was a gate on treatment efficacy, where the trial would only proceed to the second stage if sufficient efficacy was observed in the first. The next most common feature was a selection of a dose or treatment regimen. Inferentially and operationally seamless designs were approximately equally represented.DiscussionKey statistical considerations for seamless phase II/III designs include optimizing design choices by evaluating and comparing operating characteristics across design alternatives as well as showing control of overall Type I error rates. Executing the transition between phases should be evaluated for issues related to accrual, drug production, and procedures to maintain trial integrity.ConclusionsWhile there are unique statistical, regulatory, and operational considerations for seamless designs they are also uniquely suited to many development settings. These include, for example, addressing dose selection under FDA's Project Optimus and addressing the growing use of biomarkers and personalized medicine approaches in cancer treatment.

Aim: This study aimed to improve comparative effectiveness estimates and discuss challenges encountered through the application of Bayesian borrowing (BB) methods to augment an external control arm (ECA) constructed from real-world data (RWD) using historical clinical trial data in first-line non-small-cell lung cancer (NSCLC). Materials & methods: An ECA for a randomized controlled trial (RCT) in first-line NSCLC was constructed using ConcertAI Patient360™ to assess chemotherapy with or without cetuximab, in the bevacizumab-inappropriate subpopulation. Cardinality matching was used to match patient characteristics between the treatment arm (cetuximab + chemotherapy) and ECA. Overall survival (OS) was assessed as the primary outcome using Cox proportional hazards (PH). BB was conducted using a static power prior under a Weibull PH parameterization with borrowing weights from 0.0 to 1.0 and augmentation of the ECA from a historical control trial. Results: The constructed ECA yielded a higher overall survival (OS) hazard ratio (HR) (HR = 1.53; 95% CI: 1.21–1.93) than observed in the matched population of the RCT (HR = 0.91; 95% CI: 0.73–1.13). The OS HR decreased through the incorporation of BB (HR = 1.30; 95% CI: 1.08–1.54, borrowing weight = 1.0). BB was applied to augment the RCT control arm via a historical control which improved the precision of the observed HR estimate (1.03; 95% CI: 0.86–1.22, borrowing weight = 1.0), in comparison to the matched population of the RCT alone. Conclusion: In this study, the RWD ECA was unable to successfully replicate the OS estimates from the matched population of the selected RCT. The inability to replicate could be due to unmeasured confounding and variations in time-periods, follow-up and subsequent therapy. Despite these findings, we demonstrate how BB can improve precision of comparative effectiveness estimates, potentially aid as a bias assessment tool and mitigate challenges of traditional methods when appropriate external data sources are available.

In early phase drug development of combination therapy, the primary objective is to preliminarily assess whether there is additive activity from a novel agent when combined with an established monotherapy. Due to potential feasibility issues for conducting a large randomized study, uncontrolled single-arm trials have been the mainstream approach in cancer clinical trials. However, such trials often present significant challenges in deciding whether to proceed to the next phase of development due to the lack of randomization in traditional two-arm trials. A hybrid design, leveraging data from a completed historical clinical study of the monotherapy, offers a valuable option to enhance study efficiency and improve informed decision-making. Compared to traditional single-arm designs, the hybrid design may significantly enhance power by borrowing external information, enabling a more robust assessment of activity. The primary challenge of hybrid design lies in handling information borrowing. We introduce a Bayesian dynamic power prior (DPP) framework with three components of controlling amount of dynamic borrowing. The framework offers flexible study design options with explicit interpretation of borrowing, allowing customization according to specific needs. Furthermore, the posterior distribution in the proposed framework has a closed form, offering significant advantages in computational efficiency. The proposed framework's utility is demonstrated through simulations and a case study.

Immune checkpoint inhibitor (ICI) Kaplan–Meier (KM) curves often show delayed survival benefit followed by long-term survival in a subgroup of patients. Such outcomes can violate the proportional hazards assumption, leading to a loss of statistical power. We aimed to determine common trends in delayed separation to inform future ICI clinical trials. A literature search was performed using Trialtrove® to identify phase III trials of antiprogrammed cell death (ligand)-1 (anti-PD-[L]1) agents in locally advanced/metastatic solid tumors published between January 2010 and September 2021. The frequency of delayed separation of overall survival (OS) and progression-free survival (PFS) KM curves, correlation between duration of delayed separation in OS/PFS KM curves, and correlation between duration of delayed separation in OS/PFS KM curves with corresponding hazard ratios (HRs) were assessed in all-comer and PD-L1 enriched populations. Eighty-five studies with OS/PFS KM curves were identified. Most studies showed delayed separation of OS (> 67.9

Seamless study designs have the potential to accelerate clinical development. The use of innovative seamless designs has been increasing in the oncology area; however, while the concept of seamless designs becomes more popular and accepted, many challenges remain in both the design and conduct of these trials. This may be especially true when seamless designs are used in late phase development supporting regulatory decision-making. The Innovative Design Scientific Working Group (IDSWG) Oncology team conducted a survey to understand the current use of seamless study designs for registration purposes in oncology clinical development. The survey was designed to provide insights into the benefits and to identify the roadblocks. A total of 16 questions were included in the survey that was distributed using the ASA Biopharmaceutical Section and IDSWG email listings from August to September 2022. A total of 51 responses were received, with 39 (76%) respondents indicating that their organizations had seamless oncology studies in planning or implementation for registration purposes. Detailed survey results are presented in the manuscript. Overall, while seamless designs offer advantages in terms of timeline reduction and cost saving, they also present challenges related to additional complexity and the need for efficient surrogate clinical endpoints in oncology drug development.

AbstractPurpose: A novel single-dose regimen of 300 mg tremelimumab in combination with durvalumab [Single Tremelimumab Regular Interval Durvalumab (STRIDE)] has demonstrated a favorable benefit-risk profile in the phase I/II Study 22 (NCT02519348) and phase III HIMALAYA study (NCT03298451). This study evaluated the pharmacokinetics, exposure–response, and exposure–pharmacodynamics relationships of tremelimumab in patients with unresectable hepatocellular carcinoma (uHCC). Patients and Methods: A previous tremelimumab population pharmacokinetic model was validated using data from parts 2 and 3 of Study 22. Exposure–response analyses explored relationships of tremelimumab exposure with efficacy and safety. Pharmacokinetics and pharmacodynamics relationships were evaluated using linear and nonlinear regression models. Results: The observed pharmacokinetics of tremelimumab in uHCC were consistent with predictions; no significant covariates were identified. Tremelimumab exposure was not significantly associated with adverse events, objective response rate, or progression-free survival. Overall survival (OS) was longer for patients with tremelimumab exposure, minimum serum drug concentration (Cmin1) ≥ median versus Cmin1 < median (18.99 months vs. 10.97 months), but this exposure-survival analysis might be confounded with baseline characteristics of albumin level and neutrophil to lymphocyte ratio, which had a significant impact on OS (P = 0.0004 and 0.0001, respectively). The predicted Cmin1 of tremelimumab in STRIDE regimen (12.9 μg/mL) was greater than the estimated concentration of tremelimumab eliciting half-maximal increases (EC50 = 5.24 μg/mL) in CD8+Ki67+ T-cell counts. Conclusions: Our findings support novel insights into tremelimumab pharmacokinetics and exposure–response relationships in HCC and support the clinical utility of the STRIDE regimen in patients with uHCC.

379 Background: A single priming dose of T (anti-CTLA-4) added to D (anti-PD-L1) in the STRIDE (Single T Regular Interval D) regimen, formerly T300+D, showed encouraging clinical activity and limited toxicity in a phase 2 uHCC study (Study 22, NCT02519348), suggesting single exposure to T is sufficient to improve upon D activity. HIMALAYA (NCT03298451) evaluated the efficacy and safety of STRIDE or D vs sorafenib (S) in uHCC. Methods: HIMALAYA is an open-label, multicenter, phase 3 study, in which pts with uHCC and no prior systemic therapy were initially randomized to STRIDE (T 300 mg plus D 1500 mg [one dose] plus D 1500 mg every 4 weeks [Q4W]), D (1500 mg Q4W), S (400 mg twice daily), or T 75 mg Q4W (4 doses) plus D 1500 mg Q4W (T75+D). Recruitment to T75+D ceased after a planned analysis of Study 22 showed T75+D did not meaningfully differ from D. The primary objective was overall survival (OS) for STRIDE vs S. The secondary objective was OS noninferiority (NI) of D to S (NI margin: 1.08). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR; RECIST v.1.1), duration of response (DoR), and safety. Results: In total, 1171 pts were randomized to STRIDE (N=393), D (N=389), or S (N=389). At data cutoff (DCO), the primary objective was met: OS was significantly improved for STRIDE vs S (hazard ratio [HR], 0.78; 96% confidence interval [CI], 0.65–0.92; p=0.0035; Table). D met the objective of OS NI to S (HR, 0.86; 96% CI, 0.73–1.03). ORRs were higher for STRIDE (20.1%) and D (17.0%) than for S (5.1%). No new safety signals were identified. Grade 3/4 treatment-related adverse events (TRAEs) occurred in 25.8% (STRIDE), 12.9% (D), and 36.9% (S) of pts. Grade 3/4 hepatic TRAEs occurred in 5.9% (STRIDE), 5.2% (D), and 4.5% (S) of pts. No TRAE of esophageal varices hemorrhage occurred. Rates of TRAEs leading to discontinuation were 8.2% (STRIDE), 4.1% (D), and 11.0% (S). Conclusions: HIMALAYA was the first large phase 3 trial with a diverse, representative uHCC population and extensive long-term follow-up to assess both mono- and combination immunotherapy. D was noninferior to S with favorable safety. The combination of a single priming dose of T plus D in STRIDE displayed superior efficacy and a favorable benefit-risk profile vs S. STRIDE is a proposed, novel, first-line standard of care systemic therapy for uHCC. Clinical trial information: NCT03298451. [Table: see text]

BackgroundPatients with advanced biliary tract cancer have a poor prognosis, and first-line standard of care (gemcitabine plus cisplatin) has remained unchanged for more than 10 years. The TOPAZ-1 trial evaluated durvalumab plus chemotherapy for patients with advanced biliary tract cancer.MethodsIn this double-blind, placebo-controlled, phase 3 study, we randomly assigned patients with previously untreated unresectable or metastatic biliary tract cancer or with recurrent disease 1:1 to receive durvalumab or placebo in combination with gemcitabine plus cisplatin for up to eight cycles, followed by durvalumab or placebo monotherapy until disease progression or unacceptable toxicity. The primary objective was to assess overall survival. Secondary end points included progression-free survival, objective response rate, and safety.ResultsOverall, 685 patients were randomly assigned to durvalumab (n=341) or placebo (n=344) with chemotherapy. As of data cutoff, 198 patients (58.1%) in the durvalumab group and 226 patients (65.7%) in the placebo group had died. The hazard ratio for overall survival was 0.80 (95% confidence interval [CI], 0.66 to 0.97; P=0.021). The estimated 24-month overall survival rate was 24.9% (95% CI, 17.9 to 32.5) for durvalumab and 10.4% (95% CI, 4.7 to 18.8) for placebo. The hazard ratio for progression-free survival was 0.75 (95% CI, 0.63 to 0.89; P=0.001). Objective response rates were 26.7% with durvalumab and 18.7% with placebo. The incidences of grade 3 or 4 adverse events were 75.7% and 77.8% with durvalumab and placebo, respectively.ConclusionsDurvalumab plus chemotherapy significantly improved overall survival versus placebo plus chemotherapy and showed improvements versus placebo plus chemotherapy in prespecified secondary end points including progression-free survival and objective response rate. The safety profiles of the two treatment groups were similar. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT03875235.)

TPS373 Background: Esophageal cancer is the eighth most common cancer type and the sixth leading cause of cancer-related death worldwide, and esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer. For patients with locally advanced, unresectable ESCC (AJCC 8th Stage II–IVA), definitive chemoradiotherapy (dCRT) is the current standard of care; however, up to half of patients will experience disease progression within two years of dCRT, and overall survival rates remain suboptimal. The combination of immune checkpoint inhibitors with CRT has demonstrated synergistic antitumor activity in pre-clinical models, and recent clinical data has demonstrated clinical benefit of combined programmed cell death-1 inhibition and preoperative CRT in patients with locally advanced ESCC. KUNLUN (NCT04550260) is a Phase 3, multicenter, global study evaluating the efficacy and safety of durvalumab, a programmed cell death ligand-1 (PD-L1) inhibitor, given concurrently with, and after, dCRT in patients with locally advanced, unresectable ESCC. Methods: Approximately 600 patients will be randomized 2:1 to receive either durvalumab with dCRT (cisplatin plus fluorouracil or cisplatin plus capecitabine, with a total dose of 50–64 Gy radiation), followed by durvalumab for up to approximately 24 months, or placebo with dCRT, followed by placebo for up to approximately 24 months. Eligible patients will have histologically or cytologically confirmed ESCC, and present with locally advanced, unresectable ESCC that is deemed suitable for dCRT. Patients must have an Eastern Cooperative Oncology Group performance status of 0 or 1, and have not received prior anti-cancer treatment. The co-primary endpoint of the study is progression-free survival according to RECIST v1.1 as assessed by blinded independent central review in all randomized patients and in patients with PD-L1-high tumors. Additional endpoints include overall survival and safety. Study enrollment is ongoing. Funding: This study was sponsored by AstraZeneca. References: Hong MH, et al. J Clin Oncol 2019;37(15 suppl). Abs 4027. Clinical trial information: NCT04550260.

PURPOSE This phase I/II study evaluated tremelimumab (anticytotoxic T-lymphocyte–associated antigen-4 monoclonal antibody) and durvalumab (antiprogrammed death ligand-1 monoclonal antibody) as monotherapies and in combination for patients with unresectable hepatocellular carcinoma (HCC), including a novel regimen featuring a single, priming dose of tremelimumab (ClinicalTrials.gov identifier: NCT02519348 ). PATIENTS AND METHODS Patients with HCC who had progressed on, were intolerant to, or refused sorafenib were randomly assigned to receive T300 + D (tremelimumab 300 mg plus durvalumab 1,500 mg [one dose each during the first cycle] followed by durvalumab 1,500 mg once every 4 weeks), durvalumab monotherapy (1,500 mg once every 4 weeks), tremelimumab monotherapy (750 mg once every 4 weeks [seven doses] and then once every 12 weeks), or T75 + D (tremelimumab 75 mg once every 4 weeks plus durvalumab 1,500 mg once every 4 weeks [four doses] followed by durvalumab 1,500 mg once every 4 weeks). Safety was the primary end point. Secondary end points included objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors v1.1 and overall survival; exploratory end points included circulating lymphocyte profiles. RESULTS A total of 332 patients were enrolled (T300 + D, n = 75; durvalumab, n = 104; tremelimumab, n = 69; and T75 + D, n = 84). Tolerability was acceptable across arms, with grade ≥ 3 treatment-related adverse events occurring in 37.8%, 20.8%, 43.5%, and 24.4%, respectively. Confirmed ORRs (95% CI) were 24.0% (14.9 to 35.3), 10.6% (5.4 to 18.1), 7.2% (2.4 to 16.1), and 9.5% (4.2 to 17.9), respectively. An early expansion of CD8+ lymphocytes was associated with response across arms, with highest proliferating CD8+ lymphocyte levels occurring in the T300 + D arm. The median (95% CI) overall survival was 18.7 (10.8 to 27.3), 13.6 (8.7 to 17.6), 15.1 (11.3 to 20.5), and 11.3 (8.4 to 15.0) months in the T300 + D, durvalumab, tremelimumab, and T75 + D arms, respectively. CONCLUSION All regimens were found to be tolerable and clinically active; however, the T300 + D regimen demonstrated the most encouraging benefit-risk profile. The unique pharmacodynamic activity and association with ORR of the T300 + D regimen further support its continued evaluation in HCC.

The standard log‐rank test has been extended by adopting various weight functions. Cancer vaccine or immunotherapy trials have shown a delayed onset of effect for the experimental therapy. This is manifested as a delayed separation of the survival curves. This work proposes new weighted log‐rank tests to account for such delay. The weight function is motivated by the time‐varying hazard ratio between the experimental and the control therapies. We implement a numerical evaluation of the Schoenfeld approximation (NESA) for the mean of the test statistic. The NESA enables us to assess the power and to calculate the sample size for detecting such delayed treatment effect and also for a more general specification of the non‐proportional hazards in a trial. We further show a connection between our proposed test and the weighted Cox regression. Then the average hazard ratio using the same weight is obtained as an estimand of the treatment effect. Extensive simulation studies are conducted to compare the performance of the proposed tests with the standard log‐rank test and to assess their robustness to model mis‐specifications. Our tests outperform the G ρ , γ class in general and have performance close to the optimal test. We demonstrate our methods on two cancer immunotherapy trials.

4087 Background: Study 22, a phase 2 clinical study (NCT02519348) evaluating T (anti-CTLA-4) and D (anti-PD-L1) as monotherapies and in combination indicated the best efficacy-safety profile with a novel combination regimen containing a single, priming dose of T (T300+D). Additionally, an expansion of proliferative CD8+ lymphocytes at Day 15 was observed with T300+D that was associated with improved response. Here, an exploratory molecular analysis of peripheral blood T cell receptors is presented. Methods: Immune-checkpoint inhibitor-naïve pts were randomized to 1 of 2 T+D combinations: T300+D (T 300 mg [1 dose] + D 1500 mg, then D every 4 weeks [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses], then D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W [7 doses] then Q12W). DNA was isolated from PAXgene-preserved whole blood collected at baseline and on Day 29 during the first cycle of Q4W dosing, and then underwent CDR3 sequencing of T-cell receptor β using the immunoSEQ Assay (Adaptive Biotechnologies, Seattle, WA). Associations with objective response rate (ORR) and overall survival (OS) were evaluated. Results: The number of evaluable pts, samples, and overall ORR and OS are provided (Table). Immunosequencing analysis did not reveal significant differences in baseline T-cell clonality across arms. Increased T-cell clonal expansion at Day 29 appeared to be T dose dependent (Table), with no significant difference in the median expansion between the D and T75+D arms. Across all arms, responders had a larger median number of expanded T-cell clones on Day 29 than nonresponders (77.5 vs 40), and this greater expansion trended with longer OS (Table). Further evaluation by arm demonstrated an increase in T-cell clonal expansion in responders vs nonresponders in the T300+D arm. Pts with T-cell expansion above the median in the T300+D and T75+D arms also exhibited longer OS. Both newly expanded and total expanded clones on Day 29 vs Day 1 were associated with improved OS. Conclusions: The observed T dose-dependent increase in T-cell clonal expansion trended with improved ORR and longer OS, with the greatest overall benefit seen with T300+D vs T75+D, D and T. This is consistent with the previously reported observation that T300+D led to the highest median proliferating CD8+ T-cell counts and radiographic response. Further work is needed to differentiate the relative contributions of CD4 and CD8 clonal expansion to increased efficacy. T300+D and D are being evaluated in the phase 3 HIMALAYA study (NCT03298451) in uHCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348. [Table: see text]

6511 Background: In NSCLC, bTMB assessed from circulating tumor DNA shows promise as a predictive survival biomarker for immunotherapy, but its value in R/M HNSCC is uncertain. We evaluated bTMB as a predictor of survival in R/M HNSCC. Methods: EAGLE (NCT02369874) was a randomized, open-label, phase 3 trial evaluating D (anti-PD-L1), or D+T (anti-CTLA-4), vs CT in R/M HNSCC. Patients (pts) with disease progression after platinum-based CT were randomized (1:1:1) to D (10 mg/kg intravenous [IV] every 2 weeks [Q2W]), D (20 mg/kg IV Q4W) + T (1 mg/kg IV Q4W for up to 4 doses, followed by D at 10 mg/kg Q2W) or CT. bTMB was assessed in pretreatment plasma samples using the Guardant Health OMNI platform. Association of somatic loss of function mutations with OS was assessed. Results: 736 intent-to-treat pts were randomized; 247 were evaluable for bTMB (BEP). bTMB expression was not linked to HPV status, PD-L1 status, age, gender, tumor location, or ECOG PS. Smoking and progression within 6 months on multi-modality CT in localized disease trended with higher bTMB. OS and PFS HRs were significantly improved for D or D+T vs CT in pts with high bTMB (≥16 mut/Mb) vs low (<16 mut/Mb; Table). The benefit of D or D+T vs CT in pts with high bTMB generally improved with increasing cutoff. 74 pts (27 D, 20 D+T, 27 CT pts) were bTMB high. 18-month OS rates were higher for D+T (22%; 95% CI 7%–42%) and D (33%; 95% CI 17%–51%) vs CT (0%; 95% CI 0%–0%) in pts with high bTMB. Pts with mutations in KMT2D, a HNSCC tumor suppressor gene, showed improved OS for D+T vs CT (HR 0.39; 95% CI 0.18–0.85). A trend of improved OS for D+T vs CT (HR 0.19; 95% CI 0.03–1.03) was also seen in pts with ATM mutations. Conclusions: This is the first retrospective analysis of a phase 3 trial to show bTMB may be predictive of outcomes for checkpoint inhibitors in R/M HNSCC. In pts with high bTMB, D or D+T improved OS hazards by at least 60%, vs CT at cutoffs ≥16 mut/Mb. Validation of bTMB as a predictive biomarker is ongoing. Clinical trial information: NCT02369874 . [Table: see text]

4508 Background: The combination of dual immune checkpoint inhibitors (ICI) T (anti–CTLA-4) and D (anti–PD-L1) showed tolerability with a promising objective response rate (ORR) in the initial cohort of this study (NCT02519348). Subsequent evaluation of pts with solid tumors treated with increasing doses of T suggested priming with a higher dose of T may induce a stronger immune response and enhance anti-tumor activity. Thus, the randomized expansion cohorts comprised 4 arms evaluating T and D as monotherapies and 2 T+D regimens, including a novel T+D regimen featuring a single, priming dose of T. Methods: ICI-naïve pts with aHCC who progressed on, were intolerant to, or refused sorafenib were randomized to one of two T+D combinations: T300+D (T 300 mg + D 1500 mg 1 dose followed by D Q4 weekly [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses] followed by D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W). Safety was the primary endpoint. ORR by blinded, independent central review using RECIST v1.1, duration of response (DoR), circulating lymphocytes, and overall survival (OS) were assessed. Results: At data cut-off (09/02/2019), 332 pts were enrolled. Median follow-ups were 11.7 months (mo) for T300+D, 14.6 (T75+D), 8.9 (D), and 15.8 (T). Treatment-related adverse event (trAE) incidences are shown (Table); no deaths were attributed to trAEs for T300+D or T. The T300+D arm had the highest confirmed ORR (DoR not reached [NR]) and longest OS (Table). A unique proliferative T cell profile was identified for pts in the T300+D arm, suggesting additive biologic activity for the combination, and showed pts with an OR exhibited high cytotoxic (CD8) counts. Conclusions: The encouraging clinical activity and tolerable safety profile suggest T300+D provides the best benefit-risk profile as opposed to T75+D or monotherapies. The unique pharmacodynamic activity of the T300+D regimen further supports its use in aHCC. T300+D and D are being evaluated in the ongoing phase III HIMALAYA study (NCT03298451) in first-line HCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348 . [Table: see text]

BackgroundSurvival outcomes are poor for patients with metastatic urothelial carcinoma who receive standard, first-line, platinum-based chemotherapy. We assessed the overall survival of patients who received durvalumab (a PD-L1 inhibitor), with or without tremelimumab (a CTLA-4 inhibitor), as a first-line treatment for metastatic urothelial carcinoma.MethodsDANUBE is an open-label, randomised, controlled, phase 3 trial in patients with untreated, unresectable, locally advanced or metastatic urothelial carcinoma, conducted at 224 academic research centres, hospitals, and oncology clinics in 23 countries. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0 or 1. We randomly assigned patients (1:1:1) to receive durvalumab monotherapy (1500 mg) administered intravenously every 4 weeks; durvalumab (1500 mg) plus tremelimumab (75 mg) administered intravenously every 4 weeks for up to four doses, followed by durvalumab maintenance (1500 mg) every 4 weeks; or standard-of-care chemotherapy (gemcitabine plus cisplatin or gemcitabine plus carboplatin, depending on cisplatin eligibility) administered intravenously for up to six cycles. Randomisation was done through an interactive voice–web response system, with stratification by cisplatin eligibility, PD-L1 status, and presence or absence of liver metastases, lung metastases, or both. The coprimary endpoints were overall survival compared between the durvalumab monotherapy versus chemotherapy groups in the population of patients with high PD-L1 expression (the high PD-L1 population) and between the durvalumab plus tremelimumab versus chemotherapy groups in the intention-to-treat population (all randomly assigned patients). The study has completed enrolment and the final analysis of overall survival is reported. The trial is registered with ClinicalTrials.gov, NCT02516241, and the EU Clinical Trials Register, EudraCT number 2015-001633-24.FindingsBetween Nov 24, 2015, and March 21, 2017, we randomly assigned 1032 patients to receive durvalumab (n=346), durvalumab plus tremelimumab (n=342), or chemotherapy (n=344). At data cutoff (Jan 27, 2020), median follow-up for survival was 41·2 months (IQR 37·9–43·2) for all patients. In the high PD-L1 population, median overall survival was 14·4 months (95% CI 10·4–17·3) in the durvalumab monotherapy group (n=209) versus 12·1 months (10·4–15·0) in the chemotherapy group (n=207; hazard ratio 0·89, 95% CI 0·71–1·11; p=0·30). In the intention-to-treat population, median overall survival was 15·1 months (13·1–18·0) in the durvalumab plus tremelimumab group versus 12·1 months (10·9–14·0) in the chemotherapy group (0·85, 95% CI 0·72–1·02; p=0·075). In the safety population, grade 3 or 4 treatment-related adverse events occurred in 47 (14%) of 345 patients in the durvalumab group, 93 (27%) of 340 patients in the durvalumab plus tremelimumab group, and in 188 (60%) of 313 patients in the chemotherapy group. The most common grade 3 or 4 treatment-related adverse event was increased lipase in the durvalumab group (seven [2%] of 345 patients) and in the durvalumab plus tremelimumab group (16 [5%] of 340 patients), and neutropenia in the chemotherapy group (66 [21%] of 313 patients). Serious treatment-related adverse events occurred in 30 (9%) of 345 patients in the durvalumab group, 78 (23%) of 340 patients in the durvalumab plus tremelimumab group, and 50 (16%) of 313 patients in the chemotherapy group. Deaths due to study drug toxicity were reported in two (1%) patients in the durvalumab group (acute hepatic failure and hepatitis), two (1%) patients in the durvalumab plus tremelimumab group (septic shock and pneumonitis), and one (<1%) patient in the chemotherapy group (acute kidney injury).InterpretationThis study did not meet either of its coprimary endpoints. Further research to identify the patients with previously untreated metastatic urothelial carcinoma who benefit from treatment with immune checkpoint inhibitors, either alone or in combination regimens, is warranted.FundingAstraZeneca.