Immune System-Activating Drugs in Combination Treatments May Be Next Big Thing for Melanoma

Among solid tumors, the curative potential of immunotherapies has been explored most in melanoma. One reason for this is that melanoma tumors often contain so-called immune infiltrates—patches of T cells, the killer cells of the immune system. It seems that these fighter cells arrive at the ‘battlefield’ to target tumor cells for killing, but instead become ‘frozen,’ unable to attack.  How to activate the tumor-killing potential of T cells has been an area of intense and fruitful research, leading to the development of several immunotherapy drugs. Continue reading…

Gene Expression Data Integration to Squamous Cell Lung Cancer Subtypes Reveals Drug Sensitivity

We analysed RNAseq data of 178 squamous cell lung cancer (SqCC) tumour samples and characterised the features of the different SqCC subtypes to define signature genes and pathway alterations specific to each subtype. Further, we compared the gene-expression features of each molecular subtype to specific time points in models of airway development. We also classified SqCC-derived cell lines and their reported therapeutic vulnerabilities.

Compared with the other three subtypes of cell lines, the secretory-type cell lines were significantly less sensitive to the five most effective drugs (Panobinostat, 17-AAG, Irinotecan, Topotecan and Paclitaxel), possibly because of their low proliferation activity.

The Antimelanoma Activity of the Histone Deacetylase Inhibitor Panobinostat (LBH589) is Mediated by Direct Tumor Cytotoxicity and Increased Tumor Immunogenicity

“Melanoma is the deadliest skin cancer, and its incidence has been increasing faster than any other cancer. Although immunogenic, melanoma is not effectively cleared by host immunity. In this study, we investigate the therapeutic, antimelanoma potential of the histone deacetylase inhibitor (HDACi) panobinostat (LBH589) by assessing both its cytotoxic effects on melanoma cells as well as enhancement of immune recognition of melanoma. Utilizing murine and human melanoma cell lines, we analyzed the effects of LBH589 on proliferation and survival. In addition, we analyzed the expression of several immunologically relevant surface markers and melanoma differentiation antigens, and the ability of LBH589-treated melanoma to activate antigen-specific T cells. Finally, we assessed the in-vivo effects of LBH589 in a mouse melanoma model. Low nanomolar concentrations of LBH589 inhibit the growth of all melanoma cell lines tested, but not normal melanocytes. This inhibition is characterized by increased apoptosis as well as a G1 cell cycle arrest. In addition, LBH589 augments the expression of major histocompatibility complex and costimulatory molecules on melanoma cells leading to an increased ability to activate antigen-specific T cells. Treatment also increases expression of melanoma differentiation antigens. In vivo, LBH589 treatment of melanoma-bearing mice results in a significant increase in survival. However, in immunodeficient mice, the therapeutic effect of LBH589 is lost. Taken together, LBH589 exerts a dual effect upon melanoma cells by affecting not only growth/survival but also by increasing melanoma immunogenicity. These effects provide the framework for future evaluation of this HDAC inhibitor in melanoma treatment.”

A Phase II Study of the Histone Deacetylase Inhibitor Panobinostat (LBH589) in Pretreated Patients with Small-Cell Lung Cancer

“Background: In vitro data suggest that panobinostat (LBH589), a pan-deacetylase inhibitor, may add therapeutic benefit in the treatment of small-cell lung cancer (SCLC) with regression. Methods: This multicenter, nonrandomized phase 2 trial was designed to evaluate antitumor activity of LBH589 in patients with previously treated SCLC. Patients received LBH589 administered intravenously at a dose of 20 mg/mq (days 1-8) every 21 days.”