Ioannis Karydis

Invariant NKT cells modulate the suppressive activity of IL-10-secreting neutrophils differentiated with serum amyloid A

Neutrophils are the main effector cells during inflammation, but they can also control excessive inflammatory responses by secreting anti-inflammatory cytokines. However, the mechanisms that modulate their plasticity remain unclear. We now show that systemic serum amyloid A 1 (SAA-1) controls the plasticity of neutrophil differentiation. SAA-1 not only induced anti-inflammatory interleukin 10 (IL-10)-secreting neutrophils but also promoted the interaction of invariant natural killer T cells (iNKT cells) with those neutrophils, a process that limited their suppressive activity by diminishing the production of IL-10 and enhancing the production of IL-12. Because SAA-1-producing melanomas promoted differentiation of IL-10-secreting neutrophils, harnessing iNKT cells could be useful therapeutically by decreasing the frequency of immunosuppressive neutrophils and restoring tumor-specific immune responses.

Clinical activity and safety of Pembrolizumab in Ipilimumab pre-treated patients with uveal melanoma

ABSTRACT Background: Untreated metastatic uveal melanoma (UM) carries a grave prognosis. Unlike cutaneous melanoma (CM), there are no established treatments known to significantly improve outcomes for a meaningful proportion of patients. Inhibition of the PD1–PDL1 axis has shown promise in the management of CM and we here report a two center experience of UM patients receiving pembrolizumab. Methods: To assess the efficacy and safety of pembrolizumab, we retrospectively analyzed outcome data of 25 consecutive UM patients participating in the MK3475 expanded access program (EAP) who received pembrolizumab at 2 mg/kg 3 weekly. Tumor assessment was evaluated using RECIST 1.1 and immune-related Response Criteria (irRC) by CT scanning. Toxicity was recorded utilizing Common Terminology Criteria for Adverse Events (“CTCAE”) v4.03. Results: Twenty-five patients were identified receiving a median of six cycles of treatment. Two patients achieved a partial response and six patients stable disease. After a median follow-up of 225 d median progression free survival (PFS) was 91 d and overall survival (OS) was not reached. There was a significant trend for improved outcomes in patients with extrahepatic disease progression as opposed to liver only progression at the outset. Five patients experienced grade 3 or 4 adverse events (AEs); there were no treatment related deaths. Conclusions: Pembrolizumab 2mg/kg q3w is a safe option in UM patients. Disease control rates, particularly in the subgroup of patients without progressive liver disease at the outset are promising; these results merit further investigation in clinical trials possibly incorporating liver targeted treatment modalities.

IDO Induces Expression of a Novel Tryptophan Transporter in Mouse and Human Tumor Cells

IDO is the rate-limiting enzyme in the kynurenine pathway, catabolizing tryptophan to kynurenine. Tryptophan depletion by IDO-expressing tumors is a common mechanism of immune evasion inducing regulatory T cells and inhibiting effector T cells. Because mammalian cells cannot synthesize tryptophan, it remains unclear how IDO+ tumor cells overcome the detrimental effects of local tryptophan depletion. We demonstrate that IDO+ tumor cells express a novel amino acid transporter, which accounts for ∼50% of the tryptophan uptake. The induced transporter is biochemically distinguished from the constitutively expressed tryptophan transporter System L by increased resistance to inhibitors of System L, resistance to inhibition by high concentrations of most amino acids tested, and high substrate specificity for tryptophan. Under conditions of low extracellular tryptophan, expression of this novel transporter significantly increases tryptophan entry into IDO+ tumors relative to tryptophan uptake through the low-affinity System L alone, and further decreases tryptophan levels in the microenvironment. Targeting this additional tryptophan transporter could be a way of pharmacological inhibition of IDO-mediated tumor escape. These findings highlight the ability of IDO-expressing tumor cells to thrive in a tryptophan-depleted microenvironment by expressing a novel, highly tryptophan-specific transporter, which is resistant to inhibition by most other amino acids. The additional transporter allows tumor cells to strike the ideal balance between supply of tryptophan essential for their own proliferation and survival, and depleting the extracellular milieu of tryptophan to inhibit T cell proliferation.

NY-ESO-1 specific antibody and cellular responses in melanoma patients primed with NY-ESO-1 protein in ISCOMATRIX and boosted with recombinant NY-ESO-1 fowlpox virus.

Vaccination strategies based on repeated injections of NY‐ESO‐1 protein formulated in ISCOMATRIX particles (NY‐ESO‐1 ISCOMATRIX) have shown to elicit combined NY‐ESO‐1 specific antibody and T cell responses. However, it remains unclear whether heterologous prime‐boost strategies based on the combination with NY‐ESO‐1 ISCOMATRIX with different NY‐ESO‐1 boosting reagents could be used to increase NY‐ESO‐1 CD8+ or CD4+ T cell responses. To address this question, we carried out a randomized clinical trial in 39 high‐risk, resected melanoma patients vaccinated with NY‐ESO‐1 ISCOMATRIX, and then boosted with repeated injections of either recombinant fowlpox virus encoding full length NY‐ESO‐1 (rF‐NY‐ESO‐1) (Arm A) or NY‐ESO‐1 ISCOMATRIX alone (Arm B). We have comprehensively analyzed NY‐ESO‐1 specific T cells and B cells response in all patients before and after vaccination for a total of seven time points per patient. NY‐ESO‐1 ISCOMATRIX alone elicited a strong NY‐ESO‐1 specific CD4+ T cell and antibody response, which was maintained by both regiments at similar levels. However, CD8+ T cell responses were significantly boosted in 3 out of 18 patients in Arm A after the first rF‐NY‐ESO‐1 injection and such responses were maintained until the end of the trial, while no patients in Arm B showed similar CD8+ T cell responses. In addition, our results clearly identified immunodominant regions in the NY‐ESO‐1 protein: NY‐ESO‐179–102 and NY‐ESO‐1115–138 for CD4+ T cells and NY‐ESO‐185–108 for CD8+ T cells in a large proportion of vaccinated patients. These regions of NY‐ESO‐1 protein should be considered in future clinical trials as immunodominant epitopes.

Infliximab for IPILIMUMAB-Related Colitis-Letter.

Ipilimumab, an anticytotoxic T-lymphocyte–associated protein (CTLA)-4 antibody, was approved in 2011 by the FDA for the treatment of advanced melanoma ([1, 2][1]). Our study aimed to evaluate the impact of immunosuppressants used for the treatment of immune-related adverse events (irAE) on outcome

Targeted Next-Generation Sequencing of Plasma DNA from Cancer Patients: Factors Influencing Consistency with Tumour DNA and Prospective Investigation of Its Utility for Diagnosis

Use of circulating tumour DNA (ctDNA) as a liquid biopsy has been proposed for potential identification and monitoring of solid tumours. We investigate a next-generation sequencing approach for mutation detection in ctDNA in two related studies using a targeted panel. The first study was retrospective, using blood samples taken from melanoma patients at diverse timepoints before or after treatment, aiming to evaluate correlation between mutations identified in biopsy and ctDNA, and to acquire a first impression of influencing factors. We found good concordance between ctDNA and tumour mutations of melanoma patients when blood samples were collected within one year of biopsy or before treatment. In contrast, when ctDNA was sequenced after targeted treatment in melanoma, mutations were no longer found in 9 out of 10 patients, suggesting the method might be useful for detecting treatment response. Building on these findings, we focused the second study on ctDNA obtained before biopsy in lung patients, i.e. when a tentative diagnosis of lung cancer had been made, but no treatment had started. The main objective of this prospective study was to evaluate use of ctDNA in diagnosis, investigating the concordance of biopsy and ctDNA-derived mutation detection. Here we also found positive correlation between diagnostic lung biopsy results and pre-biopsy ctDNA sequencing, providing support for using ctDNA as a cost-effective, non-invasive solution when the tumour is inaccessible or when biopsy poses significant risk to the patient.

Percutaneous hepatic perfusion with melphalan in uveal melanoma: A safe and effective treatment modality in an orphan disease

Metastatic uveal melanoma (UM) carries a poor prognosis; liver is the most frequent and often solitary site of recurrence. Available systemic treatments have not improved outcomes. Melphalan percutaneous hepatic perfusion (M‐PHP) allows selective intrahepatic delivery of high dose cytotoxic chemotherapy.