Emerging data indicate that SARS-CoV-2-specific CD8⁺ T cells targeting different viral proteins are detectable in up to 70% of convalescent individuals^1,2,3,4,5. However, very little information is currently available about the abundance, phenotype, functional capacity and fate of pre-existing and induced SARS-CoV-2-specific CD8⁺ T cell responses during the natural course of SARS-CoV-2 infection. Here, we define a set of optimal and dominant SARS-CoV-2-specific CD8⁺ T cell epitopes. We also perform a high-resolution ex vivo analysis of pre-existing and induced SARS-CoV-2-specific CD8⁺ T cells, applying peptide-loaded major histocompatibility complex class I (pMHCI) tetramer technology. We observe rapid induction, prolonged contraction and emergence of heterogeneous and functionally competent cross-reactive and induced memory CD8⁺ T cell responses in cross-sectionally analyzed individuals with mild disease following SARS-CoV-2 infection and three individuals longitudinally assessed for their T cells pre- and post-SARS-CoV-2 infection. SARS-CoV-2-specific memory CD8⁺ T cells exhibited functional characteristics comparable to influenza-specific CD8⁺ T cells and were detectable in SARS-CoV-2 convalescent individuals who were seronegative for anti-SARS-CoV-2 antibodies targeting spike (S) and nucleoprotein (N). These results define cross-reactive and induced SARS-CoV-2-specific CD8⁺ T cell responses as potentially important determinants of immune protection in mild SARS-CoV-2 infection.

Background and Aims: Atezolizumab plus bevacizumab (AtezoBev) is the standard of care for first‐line treatment of unresectable HCC. No evidence exists as to its use in routine clinical practice in patients with impaired liver function. Approach and Results: In 216 patients with HCC who were consecutively treated with AtezoBev across 11 tertiary centers, we retrospectively evaluated treatment‐related adverse events (trAEs) graded (G) according to Common Terminology Criteria for Adverse Events v5.0, including in the analysis all patients treated according to label (n = 202, 94%). We also assessed overall survival (OS), progression‐free survival (PFS), overall response (ORR), and disease control rates (DCR) defined by Response Evaluation Criteria in Solid Tumors v1.1. Disease was mostly secondary to viral hepatitis, namely hepatitis C (n = 72; 36%) and hepatitis B infection (n = 35, 17%). Liver function was graded as Child‐Pugh (CP)‐A in 154 patients (76%) and CP‐B in 48 (24%). Any grade trAEs were reported by 143 patients (71%), of which 53 (26%) were G3 and 3 (2%) G4. Compared with CP‐A, patients with CP‐B showed comparable rates of trAEs. Presence and grade of varices at pretreatment esophagogastroduodenoscopy did not correlate with bleeding events. After a median follow‐up of 9.0 months (95% CI, 7.8–10.1), median OS was 14.9 months (95% CI, 13.6–16.3), whereas median PFS was 6.8 months (95% CI, 5.2–8.5). ORR and DCR were respectively 25% and 73%, with no difference across CP classes. Conclusions: This study confirms reproducible safety and efficacy of AtezoBev in routine practice. Patients with CP‐B reported similar tolerability compared with CP‐A, warranting prospective evaluation of AtezoBev in this treatment‐deprived population.

Background and Aims: The heterogeneity of intermediate‐stage hepatocellular carcinoma (HCC) and the widespread use of transarterial chemoembolization (TACE) outside recommended guidelines have encouraged the development of scoring systems that predict patient survival. The aim of this study was to build and validate statistical models that offer individualized patient survival prediction using response to TACE as a variable. Approach and Results: Clinically relevant baseline parameters were collected for 4,621 patients with HCC treated with TACE at 19 centers in 11 countries. In some of the centers, radiological responses (as assessed by modified Response Evaluation Criteria in Solid Tumors [mRECIST]) were also accrued. The data set was divided into a training set, an internal validation set, and two external validation sets. A pre‐TACE model (“Pre‐TACE‐Predict”) and a post‐TACE model (“Post‐TACE‐Predict”) that included response were built. The performance of the models in predicting overall survival (OS) was compared with existing ones. The median OS was 19.9 months. The factors influencing survival were tumor number and size, alpha‐fetoprotein, albumin, bilirubin, vascular invasion, cause, and response as assessed by mRECIST. The proposed models showed superior predictive accuracy compared with existing models (the hepatoma arterial embolization prognostic score and its various modifications) and allowed for patient stratification into four distinct risk categories whose median OS ranged from 7 months to more than 4 years. Conclusions: A TACE‐specific and extensively validated model based on routinely available clinical features and response after first TACE permitted patient‐level prognostication.

Systemic inflammation is a hallmark of cancer, and it has a pivotal role in hepatocellular carcinoma (HCC) development and progression. We conducted a retrospective study including 362 patients receiving immune check-point inhibitors (ICIs) across three continents, evaluating the influence of neutrophiles to lymphocytes ratio (NLR), platelets to lymphocytes ratio (PLR), and prognostic nutritional index (PNI) on overall (OS), progression free survival (PFS), and radiologic responses. In our 362 patients treated with immunotherapy, median OS and PFS were 9 and 3.5 months, respectively. Amongst tested inflammatory biomarkers, patients with NLR ≥ 5 had shorter OS (7.7 vs. 17.6 months, p < 0.0001), PFS (2.1 vs. 3.8 months, p = 0.025), and lower objective response rate (ORR) (12% vs. 22%, p = 0.034); similarly, patients with PLR ≥ 300 reported shorter OS (6.4 vs. 16.5 months, p < 0.0001) and PFS (1.8 vs. 3.7 months, p = 0.0006). NLR emerged as independent prognostic factors for OS in univariate and multivariate analysis (HR 1.95, 95%CI 1.45–2.64, p < 0.001; HR 1.73, 95%CI 1.23–2.42, p = 0.002) and PLR remained an independent prognostic factor for both OS and PFS in multivariate analysis (HR 1.60, 95%CI 1.6–2.40, p = 0.020; HR 1.99, 95%CI 1.11–3.49, p = 0.021). Systemic inflammation measured by NLR and PLR is an independent negative prognostic factor in HCC patients undergoing ICI therapy. Further studies are required to understand the biological mechanisms underlying this association and to investigate the predictive significance of circulating inflammatory biomarkers in HCC patients treated with ICIs.