Biological insights from plasma proteomics of non-small cell lung cancer patients treated with immunotherapy.

Introduction: Immune checkpoint inhibitors have made a paradigm shift in the treatment of non-small cell lung cancer (NSCLC). However, clinical response varies widely and robust predictive biomarkers for patient stratification are lacking. Here, we characterize early on-treatment proteomic changes in blood plasma to gain a better understanding of treatment response and resistance. Methods: Pre-treatment (T0) and on-treatment (T1) plasma samples were collected from 225 NSCLC patients receiving PD-1/PD-L1 inhibitor-based regimens. Plasma was profiled using aptamer-based technology to quantify approximately 7000 plasma proteins per sample. Proteins displaying significant fold changes (T1:T0) were analyzed further to identify associations with clinical outcomes using clinical benefit and overall survival as endpoints. Bioinformatic analyses of upregulated proteins were performed to determine potential cell origins and enriched biological processes. Results: The levels of 142 proteins were significantly increased in the plasma of NSCLC patients following ICI-based treatments. Soluble PD-1 exhibited the highest increase, with a positive correlation to tumor PD-L1 status, and, in the ICI monotherapy dataset, an association with improved overall survival. Bioinformatic analysis of the ICI monotherapy dataset revealed a set of 30 upregulated proteins that formed a single, highly interconnected network, including CD8A connected to ten other proteins, suggestive of T cell activation during ICI treatment. Notably, the T cell-related network was detected regardless of clinical benefit. Lastly, circulating proteins of alveolar origin were identified as potential biomarkers of limited clinical benefit, possibly due to a link with cellular stress and lung damage. Conclusions: Our study provides insights into the biological processes activated during ICI-based therapy, highlighting the potential of plasma proteomics to identify mechanisms of therapy resistance and biomarkers for outcome.

Domatinostat favors the immunotherapy response by modulating the tumor immune microenvironment (TIME).

BACKGROUND: The efficacy of PD-(L)1 blockade depends on the composition of the tumor immune microenvironment (TIME) and is generally higher in tumors with pre-existing cytotoxic T cells (CTL) than in those with low CTL numbers. Nonetheless, a significant proportion of patients with pre-existing immunity fail to respond, indicating a therapeutic potential for combining PD-(L)1 blockade with additional immunomodulatory agents in both CTL-high and -low immune phenotypes. Here, we evaluated domatinostat (4SC-202), a class I-selective histone deacetylase (HDAC) inhibitor, for its effect on the TIME and its antitumoral efficacy using syngeneic mouse models with CTL-high or CTL-low tumors. METHODS: Domatinostat was evaluated in PD-1 blockade-insensitive CTL-low (CT26) and CTL-high (C38) syngeneic models alone and in combination with different immune-inhibitory and -stimulatory approaches. Effects on the immunophenotype were assessed via flow cytometry and RNA-seq analyses. The changes in RNA-seq-based immune signatures determined in a murine setting were investigated in patient samples from the first-dose cohort of the SENSITIZE trial (NCT03278665) evaluating domatinostat combined with pembrolizumab in advanced-stage melanoma patients refractory/nonresponding to PD-1 blockade. RESULTS: Domatinostat increased the expression of antigen-presenting machinery (APM) genes and MHC class I and II molecules, along with CTL infiltration, in tumors of both immune phenotypes. In combination with PD-(L)1 blockade, domatinostat augmented antitumor effects substantially above the effects of single-agent therapies, displaying greater benefit in tumors with pre-existing CTLs. In this setting, the combination of domatinostat with agonistic anti-4-1BB or both PD-1 and LAG3 blockade further increased the antitumor efficacy. In CTL-low tumors, domatinostat enhanced the expression of genes known to reinforce immune responses against tumors. Specifically, domatinostat increased the expression of Ifng and genes associated with responses to pembrolizumab and nivolumab. Clinically, these findings were confirmed in patients with advanced melanoma treated with domatinostat for 14 days, who demonstrated elevated expression of APM and MHC genes, the IFNG gene, and the IFN-γ and pembrolizumab response signatures in individual tumor samples. CONCLUSION: In summary, these data suggest a promising potential of domatinostat in combination with immunotherapy to improve the outcome of refractory cancer patients.

Resminostat in patients with relapsed or refractory Hodgkin lymphoma: results of the phase II SAPHIRE study.

This open-label, single-arm phase II study examined efficacy, safety, pharmacokinetics, and biomarkers of histone deacetylase (HDAC) inhibitor resminostat in patients with relapsed or refractory Hodgkin lymphoma. Thirty-seven heavily pretreated patients received 600 (19 patients) or 800 mg (18 patients) oral resminostat daily for the initial 5 days of 14-day treatment cycles. Objective response rate (ORR) (primary) was 34% reaching disease control in 54% patients. Most patients (69%) showed reduced tumor size and reduced [18F]-FDG uptake in target lesions (71%). Median progression-free survival (PFS) was 2.3 months (95%CI [1.3; 3.3]) and median overall survival (OS) was 12.5 months (95%CI [9.6; 18.6]). Patients who responded or stabilized under resminostat had a 10-month longer OS than patients who progressed. Efficacy assessment, pharmacodynamics, and exploratory biomarker results followed plasma levels, showed target engagement and epigenetic modulations. Common drug-related adverse events (AEs) were nausea, vomiting, anemia, thrombocytopenia, and fatigue, mainly grade 1 or 2.

Resminostat plus sorafenib as second-line therapy of advanced hepatocellular carcinoma - The SHELTER study.

BACKGROUND & AIMS: No established therapies for patients with hepatocellular carcinoma (HCC) and progression on first-line sorafenib treatment currently exist. This phase I/II trial investigated safety, pharmacokinetics and potential biomarkers of the histone deacetylase inhibitor resminostat and a combination therapy with resminostat and sorafenib. METHODS: Patients with HCC and radiologically confirmed progression on sorafenib were treated in an exploratory, multi-center, open-label, uncontrolled, non-randomized, parallel group phase I/II study. In the combination group (n=38) four dose levels ranged from daily 200 to 600mg resminostat plus 400 to 800mg sorafenib. The monotherapy group (n=19) received 600mg resminostat. RESULTS: 57 patients received treatment. Most common adverse events were gastrointestinal disorders, thrombocytopenia and fatigue. Median maximal histone deacetylase inhibition and highest increase in H4-acetylation matched Tmax of resminostat. Sorafenib or the Child-Pugh score did not affect typical pharmacokinetics characteristics of resminostat. Efficacy assessment as progression-free survival-rate after 6 treatment cycles (12weeks, primary endpoint) was 12.5% for resminostat and 62.5% for resminostat plus sorafenib. Median time to progression and overall survival were 1.8 and 4.1months for resminostat and 6.5 and 8.0months for the combination, respectively. Zinc finger protein 64 (ZFP64) baseline expression in blood cells was found to correlate with overall survival. CONCLUSIONS: The combination of sorafenib and resminostat in HCC patients was safe and showed early signs of efficacy. Sorafenib did not alter the pharmacokinetic profile of resminostat or its histone deacetylase inhibitory activity in vivo. A prognostic and potentially predictive role of ZFP64 for treatment with resminostat should be further investigated in HCC and possibly other cancer indications. LAY SUMMARY: No established therapy for patients with advanced hepatocellular carcinoma and progression under first-line systemic treatment with sorafenib currently exists. Epigenetic modulation by inhibition of histone deacetylases might be able to overcome therapy resistance. This exploratory phase I/II clinical study in patients with radiologically confirmed progression under first-line treatment with sorafenib investigated the histone deacetylases inhibitor resminostat as single agent or in combination with continued application of sorafenib. CLINICAL TRIAL REGISTRATION: The clinical trial has been registered at www.clinicaltrials.gov as NCT00943449.

Thienopyrimidines as ß3-adrenoceptor agonists: hit-to-lead optimization.

Resulting from a vHTS based on a pharmacophore alignment on known ß3-adrenoceptor ligands, an aryloxypropanolamine scaffold comprising a thienopyrimidine moiety was further optimized as a human ß3-AR agonist, yielding a lead compound with an excellent cellular activity of EC(50)=20 pM, selectivity over hß1- and hß2-adrenoceptors and a promising safety profile.

A vHTS approach for the identification of beta-adrenoceptor ligands.

Using a vHTS based on a pharmacophore alignment on known beta3-adrenoceptor ligands, a set of intriguing beta-adrenoceptor ligands was identified, optimization of which resulted in a selective and potent human beta2-AR antagonist.

The peptide-semicarbazone S-2209, a representative of a new class of proteasome inhibitors, induces apoptosis and cell growth arrest in multiple myeloma cells.

Bortezomib is the first approved member of a new class of anti-myeloma agents, the proteasome inhibitors. Further proteasome inhibitors are needed to optimise this promising treatment option. S-2209 [1-[1-{1-[(2,4-Dioxo-imidazolidin-1-ylimino)-methyl]-2-phenyl-ethylcarbamoyl}-2-(1H-indol-3-yl)-ethylcarbamoyl]-2-(1H-indol)] inhibits the chymotryptic activity of the human 20S proteasome (half maximal effective concentration, IC(50) approximately 220 nmol/l) which was determined by a proteasome inhibition assay. A nuclear factor kappaB inhibition assay revealed a half maximal effective concentration (EC(50)) of 0.9 micromol/l. The WST-1 growth assay showed inhibition of cell growth of all tested multiple myeloma (MM) cell lines with an IC(50) between 100 nmol/l and 600 nmol/l. Strong induction of apoptosis was seen in MM cells at nanomolar concentrations (IC(50) approximately 300 nm) as well as in primary myeloma cells. No induction of apoptosis was detected in peripheral blood mononuclear cells from healthy humans. Upregulation of p53, activation of JNK protein, and downregulation of Mcl-1 was revealed. Despite the administration of 15 mg S-2209/kg/d in wistar rats, no toxicity with respect to body weight, hepatic enzymes, creatinine or haemoglobin was seen. Proteasome inhibition in white blood cells isolated from the treated rats was higher in the S-2209 treated animals in comparison with the control animals treated with 0.1 mg/kg/d bortezomib. S-2209 is active in myeloma cells and shows a favourable toxicity profile in first in-vivo studies. S-2209 is a promising agent for further clinical development.