Pharmacological Characterization of T-2328, 2-Fluoro-4'-methoxy-3'-[[[(2S,3S)-2-phenyl-3-piperidinyl]amino]methyl]-[1,1'-biphenyl]-4-carbonitrile Dihydrochloride, as a Brain-Penetrating Antagonist of Tachykinin NK1 Receptor

Neurokinin receptors and their implications in various autoimmune diseases

Neurokinin receptors belong to the GPCRs family and are ubiquitously expressed throughout the nervous and immune systems. Neurokinin receptors in coordination with neurokinins playing an important role in many physiological processes, including smooth muscle contraction, secretion, proliferation, and nociception. They also contribute to various disease conditions such as inflammatory bowel disease, rheumatoid arthritis, multiple sclerosis, psoriasis, and cancer. Neurokinin receptors antagonist are potent and highly selective and showing success in treating chemotherapy-induced nausea and vomiting. In this review, discuss the various neurokinin receptor expression on immune cells and their importance in various inflammatory and autoimmune diseases and their therapeutic importance.

•

The Neurokinin receptor is an important regulatory mechanism to control the neuronal and immune systems.

•

Various neurokinin receptors (NK1R, NK2R, and NK3R) are expressed in neurons and cells of the immune system.

•

Substance P (SP) controls the differentiation and function of immune cells.

•

SP-NK1R receptor signaling shows substantial cross-talk between neuronal and immune systems in inflammation and autoimmunity.

Synthesis and Antimalarial Activity of 1,4-Disubstituted Piperidine Derivatives

In order to prepare, at low cost, new compounds active against Plasmodium falciparum, and with a less side-effects, we have designed and synthesized a library of 1,4-disubstituted piperidine derivatives from 4-aminopiperidine derivatives 6. The resulting compound library has been evaluated against chloroquine-sensitive (3D7) and chloroquine-resistant (W2) strains of P. falciparum. The most active molecules—compounds 12d (13.64 nM (3D7)), 13b (4.19 nM (3D7) and 13.30 nM (W2)), and 12a (11.6 nM (W2))—were comparable to chloroquine (22.38 nM (3D7) and 134.12 nM (W2)).

Olanzapine-Based Triple Regimens Versus Neurokinin-1 Receptor Antagonist-Based Triple Regimens in Preventing Chemotherapy-Induced Nausea and Vomiting Associated with Highly Emetogenic Chemotherapy: A Network Meta-Analysis

BACKGROUND

The current antiemetic prophylaxis for patients treated with highly emetogenic chemotherapy (HEC) included the olanzapine-based triplet and neurokinin-1 receptor antagonists (NK-1RAs)-based triplet. However, which one shows better antiemetic effect remained unclear.

MATERIALS AND METHODS

We systematically reviewed 43 trials, involving 16,609 patients with HEC, which compared the following antiemetics at therapeutic dose range for the treatment of chemotherapy-induced nausea and vomiting: olanzapine, aprepitant, casopitant, fosaprepitant, netupitant, and rolapitant. The main outcomes were the proportion of patients who achieved no nausea, complete response (CR), and drug-related adverse events. A Bayesian network meta-analysis was performed.

RESULTS

Olanzapine-based triple regimens showed significantly better no-nausea rate in overall phase and delayed phase than aprepitant-based triplet (odds ratios 3.18, 3.00, respectively), casopitant-based triplet (3.78, 4.12, respectively), fosaprepitant-based triplet (3.08, 4.10, respectively), rolapitant-based triplet (3.45, 3.20, respectively), and conventional duplex regimens (4.66, 4.38, respectively). CRs of olanzapine-based triplet were roughly equal to different NK-1RAs-based triplet but better than the conventional duplet. Moreover, no significant drug-related adverse events were observed in olanzapine-based triple regimens when compared with NK-1RAs-based triple regimens and duplex regimens. Additionally, the costs of olanzapine-based regimens were obviously much lower than the NK-1RA-based regimens.

CONCLUSION

Olanzapine-based triplet stood out in terms of nausea control and drug price but represented no significant difference of CRs in comparison with NK-1RAs-based triplet. Olanzapine-based triple regimens should be an optional antiemetic choice for patients with HEC, especially those suffering from delayed phase nausea.

IMPLICATIONS FOR PRACTICE

According to the results of this study, olanzapine-based triple antiemetic regimens were superior in both overall and delayed-phase nausea control when compared with various neurokinin-1 receptor antagonists-based triple regimens in patients with highly emetogenic chemotherapy (HEC). Olanzapine-based triplet was outstanding in terms of nausea control and drug price. For cancer patients with HEC, especially those suffering from delayed-phase nausea, olanzapine-based triple regimens should be an optional antiemetic choice.

Polyfluorinated groups in medicinal chemistry

Introduction of novel and diverse functional groups in drug discovery is always seen with hesitancy until good activity and low toxicity characteristics are proven. The introduction of fluorine in drug-like compounds is now a well-accepted strategy in medicinal chemistry. However, polyfluoroalkyl groups, with the exception of trifluoromethyl substituents, are not well explored yet. Our aim is to show to the readers how polyfluorinated groups can be beneficial to the properties of pharmaceutically active compounds by highlighting the structure–activity relationship (SAR) studies that led to the selection of polyfluorinated moieties as key structural features. Despite the fact that the use of higher polyfluoroalkyl/aryl moieties is still in its infancy, we believe that they will soon acquire the same importance of their lower parents.

Treatment with the NK1 antagonist emend reduces blood brain barrier dysfunction and edema formation in an experimental model of brain tumors

The neuropeptide substance P (SP) has been implicated in the disruption of the blood-brain barrier (BBB) and development of cerebral edema in acute brain injury. Cerebral edema accumulates rapidly around brain tumors and has been linked to several tumor-associated deficits. Currently, the standard treatment for peritumoral edema is the corticosteroid dexamethasone, prolonged use of which is associated with a number of deleterious side effects. As SP is reported to increase in many cancer types, this study examined whether SP plays a role in the genesis of brain peritumoral edema. A-375 human melanoma cells were injected into the right striatum of male Balb/c nude mice to induce brain tumor growth, with culture medium injected in animals serving as controls. At 2, 3 or 4 weeks following tumor cell inoculation, non-treated animals were perfusion fixed for immunohistochemical detection of Albumin, SP and NK1 receptor. A further subgroup of animals was treated with a daily injection of the NK1 antagonist Emend (3 mg/kg), dexamethasone (8 mg/kg) or saline vehicle at 3 weeks post-inoculation. Animals were sacrificed a week later to determine BBB permeability using Evan's Blue and brain water content. Non-treated animals demonstrated a significant increase in albumin, SP and NK1 receptor immunoreactivity in the peritumoral area as well as increased perivascular staining in the surrounding brain tissue. Brain water content and BBB permeability was significantly increased in tumor-inoculated animals when compared to controls (p<0.05). Treatment with Emend and dexamethasone reduced BBB permeability and brain water content when compared to vehicle-treated tumor-inoculated mice. The increase in peritumoral staining for both SP and the NK1 receptor, coupled with the reduction in brain water content and BBB permeability seen following treatment with the NK1 antagonist Emend, suggests that SP plays a role in the genesis of peritumoral edema, and thus warrants further investigation as a potential anti-edematous treatment.

Aprepitant for management of severe pruritus related to biological cancer treatments: a pilot study

BACKGROUND

Itch is a common side-effect of treatment with anti-EGFR antibodies and tyrosine-kinase inhibitors. We designed a pilot single-centre study to assess the effects of aprepitant-a neurokinin receptor inhibitor-for management of severe pruritus induced by biological drugs.

METHODS

In this single-group, prospective study, we consecutively enrolled 45 outpatients with metastatic solid tumours treated with biological drugs at the Campus Bio-Medico Hospital of Rome, Rome, Italy, between September, 2010, and November, 2011. We classified patients into two groups: a refactory group, for patients with pruritis refractory to standard treatment, or a naive group, for patients who had not been previously treated for pruritis. Aprepitant (125 mg on day 1; 80 mg on day 3; 80 mg on day 5) was given to patients in the refractory group after at least 1 week of standard systemic treatment. In the naive group, aprepitant was given in the same schedule as the refractory group, after first onset of severe pruritus. Intensity of itch was evaluated by Visual Analogue Scale (VAS) score. The primary endpoint was change in median VAS score. This trial is registered with ClinicalTrials.gov, number NCT01683552.

FINDINGS

Median VAS in the refractory group was 8·00 (95% CI 7·93-8·57) at baseline and 1·00 (0·00-2·00) after 1 week of treatment with aprepitant (p<0·0001). In the naive group, VAS score was 8·00 (7·43-8·37) at baseline and 0·00 (0·06-1·08) after 1 week of treatment (p<0·0001). 41 (91%) patients responded to aprepitant (ie, had a >50% reduction in intensity of pruritis) and pruritus recurred in only six (13%) patients. No adverse events related to aprepitant occurred.

INTERPRETATION

Aprepitant decreases severe pruritus induced by biological treatments; it is an old drug, widely available, and therefore easy to add to the armamentarium of supportive treatment. Although to our knowledge no other studies of the anti-itch activity of aprepitant are planned, the results of our trial warrant confirmation in phase 2 and 3 trials.

FUNDING

None.

Targeting classical but not neurogenic inflammation reduces peritumoral oedema in secondary brain tumours

Dexamethasone, the standard treatment for peritumoral brain oedema, inhibits classical inflammation. Neurogenic inflammation, which acts via substance P (SP), has been implicated in vasogenic oedema in animal models of CNS injury. SP is elevated within and outside CNS tumours. This study investigated the efficacy of NK1 receptor antagonists, which block SP, compared with dexamethasone treatment, in a rat model of tumorigenesis. Dexamethasone reverted normal brain water content and reduced Evans blue and albumin extravasation, while NK1 antagonists did not ameliorate oedema formation. We conclude that classical inflammation rather than neurogenic inflammation drives peritumoral oedema in this brain tumour model.