Raimund Kuelzer

The bradykinin B1 receptor antagonist BI113823 reverses inflammatory hyperalgesia by desensitization of peripheral and spinal neurons.

Bradykinin is a neuropeptide released after tissue damage which plays an important role in inflammatory pain. The up‐regulation of the bradykinin B1 receptor in response to inflammation makes it an attractive target for drug development. Aim was to investigate if the selective B1 receptor antagonist BI113823 reduces inflammation‐induced mechanical hyperalgesia and if the effect is mediated via peripheral and/or spinal B1 receptor antagonism.

The somatostatin receptor 4 agonist J-2156 reduces mechanosensitivity of peripheral nerve afferents and spinal neurons in an inflammatory pain model

Somatostatin (SST) is a peptide hormone that regulates the endocrine system and affects neurotransmission via interaction with G protein-coupled SST receptors and inhibition of the release of different hormones. The aim of this study was to investigate whether the analgesic properties of the selective SSTR4 agonist J-2156 are mediated via peripheral and/or spinal receptors. Effect on mechanical hyperalgesia in the Complete Freund׳s Adjuvant (CFA) model was measured after intraperitoneal application of J-2156. Electrophysiological neuronal recordings were conducted 24 h after injection of CFA or vehicle into the paw of Wistar rats. Mechanosensitivity of peripheral afferents of the saphenous nerve as well as of spinal wide dynamic range (WDR) and nociceptive-specific (NS) neurons were measured after systemic or spinal application of J-2156. In CFA animals J-2156 dose dependently reduced hyperalgesia in behavioral studies. The minimal effective dose was 0.1 mg/kg. Mechanosensitivity of peripheral afferents and spinal neurons was significantly reduced by J-2156. NS neurons were dose dependently inhibited by J-2156 while in WDR neurons only the highest concentration of 100 µM had an effect. In sham controls, J-2156 had no effect on neuronal activity. We demonstrated that J-2156 dose-dependently reduces peripheral and spinal neuronal excitability in the CFA rat model without affecting physiological pain transmission. Given the high concentration of the compound required to inhibit spinal neurons, it is unlikely that the behavioral effect seen in CFA model is mediated centrally. Overall these data demonstrated that the analgesic effect of J-2156 is mediated mainly via peripheral SST4 receptors.

Pharmacokinetics of Nintedanib in Subjects With Hepatic Impairment

Nintedanib is an intracellular inhibitor of tyrosine kinases used in the treatment of non–small cell lung cancer and idiopathic pulmonary fibrosis (IPF). This phase 1 open‐label study investigated the influence of mild and moderate hepatic impairment on the pharmacokinetics (PK), safety, and tolerability of nintedanib following oral administration of a single 100‐mg dose. Subjects with hepatic impairment classified as Child‐Pugh A (mild hepatic impairment) or Child‐Pugh B (moderate hepatic impairment) were eligible. The control group comprised healthy matched subjects. Primary end points were Cmax and AUC0–∞ of nintedanib. Thirty‐three subjects received nintedanib (8 in each of the Child‐Pugh A and Child‐Pugh B groups and 17 controls). The shape of the plasma concentration–time curve for nintedanib was similar between Child‐Pugh A or B and healthy subjects. Nintedanib exposure was ∼2‐fold higher in Child‐Pugh A subjects and ∼8‐fold higher in Child‐Pugh B subjects than in healthy subjects. Adverse events were reported in 3 Child‐Pugh B subjects (37.5%), no Child‐Pugh A subjects, and 3 healthy subjects (17.6%). In conclusion, exposure to nintedanib was higher in Child‐Pugh A and B subjects than in matched healthy subjects. A single dose of nintedanib 100 mg had an acceptable safety and tolerability profile in subjects with hepatic impairment. Results of this dedicated phase 1 study are in line with exploratory investigations into the PK of nintedanib in patients with advanced solid tumors or IPF and hepatic impairment.