The human organic anion transporters OAT1, OAT2, OAT3, OAT4 and URAT1 belong to a family of poly-specific transporters mainly located in kidneys. Selected OATs occur also in liver, placenta, and brain. OATs interact with endogenous metabolic end products such as urate and acidic neutrotransmitter metabolites, as well as with a multitude of widely used drugs, including antibiotics, antihypertensives, antivirals, anti-inflammatory drugs, diuretics and uricosurics. Thereby, OATs play an important role in renal drug elimination and have an impact on pharmacokinetics. In this review we focus on the interaction of human OATs with drugs. We report the affinities of human OATs for drug classes and compare the putative importance of individual OATs for renal drug excretion. The role of OATs as sites of drug-drug interaction and mediators cell toxicity, their gender-dependent regulation in health and diseased states, and the possible impact of single nucleotide polymorphisms are also dealt with.

This single-arm, phase I dose-escalation trial (NCT02983045) evaluated bempega ldesleukin (NKTR-214/BEMPEG), a CD122-preferential IL2 pathway agonist, plus nivolumab in 38 patients with selected immunotherapy-naïve advanced solid tumors (melanoma, renal cell carcinoma, and non-small cell lung cancer). Three dose-limiting toxicities were reported in 2 of 17 patients during dose escalation [hypotension ( n = 1), hyperglycemia ( n = 1), metabolic acidosis ( n = 1)]. The most common treatment-related adverse events (TRAE) were fl u-like symptoms (86.8%), rash (78.9%), fatigue (73.7%), and pruritus (52.6%). Eight patients (21.1%) experienced grade 3/4 TRAEs; there were no treatment-related deaths. Total objective response rate across tumor types and dose cohorts was 59.5% (22/37), with 7 complete responses (18.9%). Cellular and gene expression analysis of longitudinal tumor biopsies revealed increased infi ltration, activation, and cytotoxicity of CD8 + T cells, without regulatory T-cell enhancement. At the recommended phase II dose, BEMPEG 0.006 mg/kg plus nivolumab 360 mg every 3 weeks, the combination was well tolerated and demonstrated encouraging clinical activity irrespective of baseline PD-L1 status. SIGNIFICANCE: These data show that BEMPEG can be successfully combined with a checkpoint inhibitor as dual immunotherapy for a range of advanced solid tumors. Effi cacy was observed regardless of baseline PD-L1 status and baseline levels of tumor-infi ltrating lymphocytes, suggesting therapeutic potential for patients with poor prognostic risk factors for response to PD-1/PD-L1 blockade.

was replaced by the negatively charged aspartate (R466D), glutarate no longer interacted with the mutant. PAH uptake by wild type hOAT1 was stimulated in the presence of chloride, whereas the R466K mutant was chloride-insensitive. Likewise, the uptake of labeled glutarate or ochratoxin A was chloride-dependent in the wild type but not in R466K. Kinetic experiments revealed that chloride did not alter the apparent K m for PAH but influenced V max in wild type OAT1-expressing oocytes. In R466K mutants the apparent K m for PAH was similar to that of the wild type, but V max was not changed by chloride removal. We conclude that Arg 466 influences the binding of glutarate, but not interaction with PAH, and interacts with chloride, which is a major determinant in substrate translocation.

In ion-coupled transport proteins, occupation of selective ion-binding sites is required to trigger conformational changes that lead to substrate translocation. Neurotransmitter transporters, targets of abused and therapeutic drugs, require Na

Background CD137 (4-1BB/TNFRSF9) is a costimulatory receptor belonging to the TNF receptor superfamily. It was originally cloned as an inducible gene from stimulated helper and cytotoxic T cells and has since been shown to also be expressed on natural killer (NK) cells. Agonistic anti-CD137 antibodies have shown potent, often curative antitumour activity in preclinical models. These effects are mainly mediated by cytotoxic T cells and generate long lasting, memory responses. Two human anti-CD137 antibodies, binding to the extracellular domain of CD137, urelumab and utomilumab are currently undergoing clinical testing. Urelumab has shown several single-agent, partial responses, but its use has been hampered by hepatoxicity, whilst utomilumab has shown little or no single agent activity. Methods Bicycles® are a new class of drugs -fully synthetic, constrained bicyclic peptides that combine the attributes of three therapeutic modalities (antibodies, small molecules, and peptides) by delivering high affinity, good PK, and rapid clearance. Their small size (1.5-2 kDa) delivers advantages in tumour penetration, and rapid renal elimination