Toxicity of tumor immune checkpoint inhibitors-more attention should be paid

Advances in Immune Checkpoint Inhibitors for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is usually diagnosed in an advanced stage and has become the second deadliest type of cancer worldwide. The systemic treatment of advanced HCC has been a challenge, and for decades was limited to treatment with tyrosine kinase inhibitors (TKIs) until the application of immune checkpoint inhibitors (ICIs) became available. Due to drug resistance and unsatisfactory therapeutic effects of monotherapy with TKIs or ICIs, multi-ICIs, or the combination of ICIs with antiangiogenic drugs has become a novel strategy to treat advanced HCC. Antiangiogenic drugs mostly include TKIs (sorafenib, lenvatinib, regorafenib, cabozantinib and so on) and anti-vascular endothelial growth factor (VEGF), such as bevacizumab. Common ICIs include anti-programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1), including nivolumab, pembrolizumab, durvalumab, and atezolizumab, and anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4), including tremelimumab and ipilimumab. Combination therapies involving antiangiogenic drugs and ICIs or two ICIs may have a synergistic action and have shown greater efficacy in advanced HCC. In this review, we present an overview of the current knowledge and recent clinical developments in ICI-based combination therapies for advanced HCC and we provide an outlook on future prospects.

Immune Checkpoint Inhibitors in Hepatocellular Carcinoma: Current Progresses and Challenges

Hepatocellular carcinoma (HCC) is one of the most common malignant tumor in the world and its incidence is increasing in many countries. In recent years, with the deepening understanding of the immune and pathological mechanisms of HCC, immunotherapy based on the regulation of tumor immune microenvironment has become a new treatment choice for patients with HCC. Immune checkpoint inhibitors (ICIs) targeting programmed death protein-1, programmed death protein-ligand-1, or cytotoxic T-lymphocyte-associated antigen 4 are the most widely used. Instead of general immune-enhancing therapies, ICIs can reactivate anti-tumor immune responses by disrupting co-inhibitory T cell signaling. In this review, the research progress and existing problems of ICIs in the treatment of HCC in recent years are reviewed.

Delivery of gefitinib with an immunostimulatory nanocarrier improves therapeutic efficacy in lung cancer

Background

Combining different cancer treatments represents a promising strategy to improve the therapeutic outcome for lung cancer patients with or without druggable gene alterations.

Methods

We previously developed a polyethylene glycol-based (PEG-based) immunostimulatory nanocarrier (PEG_2k-Fmoc-NLG919) which can efficiently co-deliver an indoleamine 2,3-dioxygenase-1 (IDO1) inhibitor and the chemotherapeutic agent, paclitaxel. This method was found to improve cancer therapy by simultaneously performing immuno- and chemo-therapy. However, whether this nanocarrier could deliver targeted drugs to implement targeted therapy together with immunotherapy remains unclear.

Results

Here, we report that the delivery of the classical tyrosine kinase inhibitor (TKI), gefitinib, with the optimized PEG_5k-Fmoc-NLG919 nanocarrier, increased the sensitivity of lung cancer cells to gefitinib in vitro. Gefitinib was gradually but sufficiently released from the nanocarrier with comparable capacity to inhibit epidermal growth factor receptor (EGFR) activity as using free gefitinib directly. More importantly, treatment with gefitinib-loaded PEG_5k-Fmoc-NLG919 could suppress lung tumor development more efficiently than gefitinib alone in vivo by inducing an immune active microenvironment with more functional CD8⁺ T cells and less regulatory T cell infiltration.

Conclusions

Our study therefore demonstrates that delivery of small molecular targeted drugs with the immunostimulatory nanocarrier is a straightforward strategy for improving antitumor response for lung cancer therapy.

Targeted degradation of immune checkpoint proteins: emerging strategies for cancer immunotherapy

Cancer immunotherapy using immune-checkpoint blockade has displayed promising clinical effects, but prevalent antibody-based inhibitors face multiple challenges such as low response rate, acquired resistance, and adverse effects. The intracellular expression of PD-1/PD-L1 in recycling endosomes and their active trafficking to membrane highlight the importance of depleting rather than interfering with checkpoint proteins. Preclinical investigations on the therapeutic effects of lead compounds that function by degrading immune checkpoint ligands and receptors have reported highly promising results. By harnessing the degradation capabilities of the lysosome, proteasome and autophagosomes, different small molecules and peptides potently induced degradation of checkpoint proteins and enhanced anti-tumor immunity. Both in vitro and in vivo experiments support the therapeutic efficacy of these molecules. Thus, targeted degradation through endo-lysosomal, autophagic, proteasomal, or endoplasmic reticulum-related pathways may provide promising strategies for tackling the challenges in cancer immunotherapy.

Hypoproteinemia being a manifestation of immunotherapy-related liver dysfunction

Immunotherapy has changed the pattern of treatment in cancer. The interaction between programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibits the activation of T cells, and PD-1/PD-L1 inhibitors can increase the immune response to cancer cells by inducing the immune cells, which has become an important clinical method to treat cancer. However, the alteration in the activation of T cells might lead to misidentification between the body's own cells and tumor cells and induce immune-related adverse events (IRAEs), such as pneumonitis, liver dysfunction, rash, colitis, nephritis, and endocrinopathies. And the IRAEs might lead to serious consequences. Studies have reported that PD-1/PD-L1 inhibitor-related hepatotoxicity is one of these adverse events. Most of the studies reported that hepatitis resulting from PD-1 inhibitor was manifested as elevated liver enzymes and bilirubin. Quite a few patients experienced lower degree of hepatotoxicity treated with checkpoint inhibitors, which indicated that it was necessary to focus on immunotherapy-related liver dysfunction. Here, we report a case of immunotherapy-related liver dysfunction with hypoproteinemia as the first manifestation under the treatment of PD-1 inhibitors combined with chemotherapy. This case suggests that hypoproteinemia was one of the manifestations of immunotherapy-related liver dysfunction, which helps us better understand the immunotherapy-related disease.

Challenges and countermeasures of thoracic oncology in the epidemic of COVID-19

Since December, 2019, a 2019 novel coronavirus disease (COVID-19) infected by the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) emerged in Wuhan, Hubei province, and the epidemic situation has continued to spread globally. The epidemic spread of COVID-19 has brought great challenges to the clinical practice of thoracic oncology. Outpatient clinics need to strengthen the differential diagnosis of initial symptoms, pulmonary ground-glass opacity (GGO), consolidation, interstitial and/or interlobular septal thickening, and crazy paving appearance. In the routine of oncology, the differential diagnosis of adverse events from COVID-19 is also significant, including radiation pneumonitis, checkpoint inhibitor pneumonitis (CIP), neutropenic fever, and so on. During the epidemic, indications of transbronchial biopsy (TBB) and CT-guided percutaneous thoracic biopsy are strictly controlled. For patients who are planning to undergo biopsy operation, screening to exclude the possibility of COVID-19 should be carried out. For confirmed or suspected patients, three-level protection should be performed during the operation. Disinfection and isolation measures should be strictly carried out during the operation. At last, more attention to the protection of cancer patients and give priority to the treatment of infected cancer patients.