Activation of the phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is common in breast cancer. There is preclinical data to support inhibition of the pathway, and phase I to III trials involving inhibitors of the pathway have been or are being conducted in solid tumors and breast cancer. Everolimus, an mTOR inhibitor, is currently approved for the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. In this review, we summarise the efficacy and toxicity findings from the randomised clinical trials, with simplified guidelines on the management of potential adverse effects. Education of healthcare professionals and patients is critical for safety and compliance. While there is some clinical evidence of activity of mTOR inhibition in HR-positive and HER2-positive breast cancers, the benefits may be more pronounced in selected subsets rather than in the overall population. Further development of predictive biomarkers will be useful in the selection of patients who will benefit from inhibition of the PI3K/Akt/mTOR (PAM) pathway.

While immune checkpoint blockade (ICB) has shown promise in patients with hepatocellular carcinoma (HCC), it is associated with modest response rates and immune-related adverse events (irAEs) are common. In this study, we aimed to decipher immune trajectories and mechanisms of response and/or irAEs in patients with HCC receiving anti-programmed cell death 1 (anti-PD-1) therapy. Pre- and on-treatment peripheral blood samples (n = 60) obtained from 32 patients with HCC (Singapore cohort) were analysed by cytometry by time-of-flight and single-cell RNA sequencing, with flow cytometric validation in an independent Korean cohort (n = 29). Mechanistic validation was conducted by bulk RNA sequencing of 20 pre- and on-treatment tumour biopsies and using a murine HCC model treated with different immunotherapeutic combinations. Single-cell analyses identified CXCR3⁺CD8⁺ effector memory T (T_EM) cells and CD11c⁺ antigen-presenting cells (APC) as associated with response (p = 0.0004 and 0.0255, respectively), progression-free survival (p = 0.00079 and 0.0015, respectively), and irAEs (p = 0.0034 and 0.0125, respectively) in anti-PD-1-treated patients with HCC. Type-1 conventional dendritic cells were identified as the specific APC associated with response, while 2 immunosuppressive CD14⁺ myeloid clusters were linked to reduced irAEs. Further analyses of CXCR3⁺CD8⁺ T_EM cells showed cell-cell interactions specific to response vs. irAEs, from which the anti-PD-1 and anti-TNFR2 combination was harnessed to uncouple these effects, resulting in enhanced response without increased irAEs in a murine HCC model. This study identifies early predictors of clinical response to anti-PD-1 ICB in patients with HCC and offers mechanistic insights into the immune trajectories of these immune subsets at the interface between response and toxicity. We also propose a new combination immunotherapy for HCC to enhance response without exacerbating irAEs. NCT03695952. Response rates to immune checkpoint blockade (ICB) treatment in hepatocellular carcinoma (HCC) remain modest and adverse events are common. Herein, we identified early predictors of response and gained an in-depth understanding of the immunological mechanisms behind response and adverse events in patients with HCC treated with ICB. We also proposed a new combination immunotherapy for HCC that enhances response without exacerbating adverse events.

To the Editor,Programmed death-1 (PD-1) checkpoint inhibitors have shown promising results for the treatment of various tumor types, including relapsed and refractory Hodgkin’s lymphoma (HL) [1,2]....

Introduction: Development of immune-related adverse events (irAEs) has been associated with enhanced efficacy with the use of immune checkpoint inhibitors (ICIs). It remains unknown whether such an association exists in advanced hepatocellular carcinoma (aHCC). This study aims to evaluate the association between irAEs and ICI efficacy in patients with aHCC. Methods: We performed a retrospective cohort study on patients with aHCC who received at least one dose of an ICI between May 2015 and November 2019 at the National Cancer Centre Singapore. The primary study objectives were to compare the overall survival (OS) and progression-free survival (PFS) between patients with and without irAEs. Complementary multivariable landmark analyses were performed at the 6-week and 12-week landmarks. Data cutoff was December 31, 2020. Results: One hundred and sixty-eight patients were included. Median age was 69 years, 85.7% were male, 57.7% had hepatitis B infection, 60.7% had ECOG 0, and 78.0% had Child-Pugh A liver cirrhosis. 82.7% received ICI monotherapy, while 17.3% received ICI in combination. Development and severity of irAE were correlated with survival. The median PFS for grade ≥3 irAE versus grades 1–2 irAE versus no irAE was 8.5 versus 3.6 versus 1.3 mths (p < 0.001). The median OS for grade ≥3 irAE versus grades 1–2 irAE versus no irAE was 26.9 versus 14.0 versus 4.6 mths (p < 0.001). Patients with ≥2 irAEs had a significantly longer OS on multivariable analysis (adjusted hazard ratio [aHR]0.35, p < 0.001). The presence of grade ≥3 irAEs was associated with a significantly longer OS on the multivariable analysis at the 6-week landmark (aHR0.34, p = 0.030) and 12-week landmark (aHR0.28, p = 0.011). The use of systemic corticosteroids in patients with irAE was associated with a trend toward a longer OS (20.7 vs. 14.3 mths, p = 0.064). Conclusion: Our study suggests that the presence of all-grade irAEs may be a potential prognostic biomarker in patients with aHCC treated with ICI. Patients with more severe irAEs and multisystem involvement have better prognosis. The prompt use of systemic corticosteroids to treat patients with irAEs is key to ensure the best long-term outcomes for these patients.

Introduction: Sorafenib was historically the standard of care for advanced hepatocellular carcinoma (aHCC) until it was superseded by the combination of atezolizumab and bevacizumab. Thereafter, several novel first-line combination therapies have demonstrated favorable outcomes. The efficacies of these treatments in relation to current and previous standards of care are unknown, necessitating an overarching evaluation. Methods: A systematic literature search was conducted on PubMed, EMBASE, Scopus, and the Cochrane Controlled Register of Trials for phase III randomized controlled trials investigating first-line systemic therapies for aHCC. Kaplan-Meier curves for overall survival (OS) and progression-free survival (PFS) were graphically reconstructed to retrieve individual patient-level data. Derived hazard ratios (HRs) for each study were pooled in a random-effects network meta-analysis (NMA). NMAs were also conducted using study-level HRs for various subgroups, according to viral etiology, Barcelona Clinic Liver Cancer (BCLC) staging, alpha-fetoprotein (AFP) levels, macrovascular invasion, and extrahepatic spread. Treatment strategies were ranked using p scores. Results: Among 4,321 articles identified, 12 trials and 9,589 patients were included for analysis. Only two therapies showed OS benefit over sorafenib: combined anti-programmed-death and anti-VEGF pathway inhibitor monoclonal antibodies (Anti-PD-(L)1/VEGF Ab), including atezolizumab-bevacizumab and sintilimab-bevacizumab biosimilar (HR = 0.63, 95% CI = 0.53–0.76) and tremelimumab-durvalumab (HR = 0.78, 95% CI = 0.66–0.92). Anti-PD-(L)1/VEGF Ab showed OS benefit over all other therapies except tremelimumab-durvalumab. Low heterogeneity (I2 = 0%) and inconsistency (Cochran’s Q = 0.52, p = 0.773) was observed. p scores for OS ranked Anti-PD-(L)1/VEGF Ab as the best treatment in all subgroups, except hepatitis B where atezolizumab-cabozantinib ranked highest for both OS and PFS, as well as nonviral HCC and AFP ≥400 μg/L where tremelimumab-durvalumab ranked highest for OS. Conclusion: This NMA supports Anti-PD-(L)1/VEGF Ab as the first-line therapy for aHCC and demonstrates a comparable benefit for tremelimumab-durvalumab which also extends to certain subgroups. Results of the subgroup analysis may guide treatment according to baseline characteristics, while pending further studies.

Immune checkpoint inhibitors (ICIs) have demonstrated promising results in a variety of advanced cancer types. The phenomenon of hyperprogressive disease (HPD) has only been documented in recent years, however, there have been no reports of HPD in hepatocellular carcinoma. We present a case series of six patients with advanced hepatocellular carcinoma treated with ICIs who demonstrated rapid radiological progression, this was confirmed by comparing tumor growth rates before and during treatment with HPD defined as tumor growth rateratio ≥2. Although ICIs have demonstrated profound efficacy in advanced cancer, they might also be responsible for HPD in a small subset of patients. The ability to predict treatment response to ICI is thus of importance in protecting patients from the deleterious effects of HPD.