CXCR4 inhibition in human pancreatic and colorectal cancers induces an integrated immune response.

Inhibition of the chemokine receptor CXCR4 in combination with blockade of the PD-1/PD-L1 T cell checkpoint induces T cell infiltration and anticancer responses in murine and human pancreatic cancer. Here we elucidate the mechanism by which CXCR4 inhibition affects the tumor immune microenvironment. In human immune cell-based chemotaxis assays, we find that CXCL12-stimulated CXCR4 inhibits the directed migration mediated by CXCR1, CXCR3, CXCR5, CXCR6, and CCR2, respectively, chemokine receptors expressed by all of the immune cell types that participate in an integrated immune response. Inhibiting CXCR4 in an experimental cancer medicine study by 1-wk continuous infusion of the small-molecule inhibitor AMD3100 (plerixafor) induces an integrated immune response that is detected by transcriptional analysis of paired biopsies of metastases from patients with microsatellite stable colorectal and pancreatic cancer. This integrated immune response occurs in three other examples of immune-mediated damage to noninfected tissues: Rejecting renal allografts, melanomas clinically responding to anti-PD1 antibody therapy, and microsatellite instable colorectal cancers. Thus, signaling by CXCR4 causes immune suppression in human pancreatic ductal adenocarcinoma and colorectal cancer by impairing the function of the chemokine receptors that mediate the intratumoral accumulation of immune cells.

Phase I clinical trial repurposing all-trans retinoic acid as a stromal targeting agent for pancreatic cancer.

Pre-clinical models have shown that targeting pancreatic stellate cells with all-trans-retinoic-acid (ATRA) reprograms pancreatic stroma to suppress pancreatic ductal adenocarcinoma (PDAC) growth. Here, in a phase Ib, dose escalation and expansion, trial for patients with advanced, unresectable PDAC (n = 27), ATRA is re-purposed as a stromal-targeting agent in combination with gemcitabine-nab-paclitaxel chemotherapy using a two-step adaptive continual re-assessment method trial design. The maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D, primary outcome) is the FDA/EMEA approved dose of gemcitabine-nab-paclitaxel along-with ATRA (45 mg/m2 orally, days 1-15/cycle). Dose limiting toxicity (DLT) is grade 4 thrombocytopenia (n = 2). Secondary outcomes show no detriment to ATRA pharmacokinetics.. Median overall survival for RP2D treated evaluable population, is 11.7 months (95%CI 8.6-15.7 m, n = 15, locally advanced (2) and metastatic (13)). Exploratory pharmacodynamics studies including changes in diffusion-weighted (DW)-MRI measured apparent diffusion coefficient after one cycle, and, modulation of cycle-specific serum pentraxin 3 levels over various cycles indicate stromal modulation. Baseline stromal-specific retinoid transport protein (FABP5, CRABP2) expression may be predicitve of response. Re-purposing ATRA as a stromal-targeting agent with gemcitabine-nab-paclitaxel is safe and tolerable. This combination will be evaluated in a phase II randomized controlled trial for locally advanced PDAC. Clinical trial numbers: EudraCT: 2015-002662-23; NCT03307148. Trial acronym: STARPAC.

SPR detection of cardiac troponin T for acute myocardial infarction.

A surface plasmon resonance (SPR) sensor developed for the rapid, sensitive and specific detection of cardiac troponin T (cTnT) in serum samples is reported in this work. An extensive optimisation of assay parameters was conducted to achieve optimal detection strategy. Both direct and sandwich immunoassay formats were investigated and optimised. The response obtained was enhanced further by the use of gold nanoparticles (AuNPs) conjugated to the anti-cTnT detection antibody. A regeneration method was developed to enable the reuse of the SPR sensor for multiple sample application. The SPR immunosensor showed good reproducibility for cTnT detection in the concentration range of 25-1000 ng mL(-1) and 5-400 ng mL(-1) for the direct and sandwich assays in buffer, respectively. The linear regression analysis was performed and R(2) value was found as 0.99 for both assays. In order to optimise the sensor for serum analysis, nonspecific binding of serum proteins was reduced through the use of additives in the dilution buffer. To achieve greater sensitivity, the performance of the cTnT immunosensor sandwich assay in human serum was evaluated using non-modified and AuNP modified detector antibodies. A detection limit (LOD) for the immunosensor in 50% serum was assessed as 5 ng mL(-1) cTnT for the standard sandwich assay and 0.5 ng mL(-1) cTnT when using AuNP conjugated detector antibodies with a linear dynamic range of 0.5-40 ng mL(-1). The dissociation constant was found as 3.28 × 10(-9) M using Langmuir binding model which indicates high affinity between cTnT and its antibody. The proposed SPR immunosensor has a promising potential to be developed for point-of-care testing for the early diagnosis of acute myocardial infarction (AMI). This method can also be used for the rapid detection of biomarkers in central nervous system diseases.

Recommendations on biomarker bioanalytical method validation by GCC.

The 5th GCC in Barcelona (Spain) and 6th GCC in San Antonio (TX, USA) events provided a unique opportunity for CRO leaders to openly share opinions and perspectives, and to agree upon recommendations on biomarker bioanalytical method validation.

Recommendations on bioanalytical method stability implications of co-administered and co-formulated drugs by Global CRO Council for Bioanalysis (GCC).

An open letter written by the Global CRO Council for Bioanalysis (GCC) describing the GCC survey results on stability data from co-administered and co-formulated drugs was sent to multiple regulatory authorities on 14 December 2011. This letter and further discussions at different GCC meetings led to subsequent recommendations on this topic of widespread interest within the bioanalytical community over the past 2 years.

Conference report: the 3rd Global CRO Council for Bioanalysis at the International Reid Bioanalytical Forum.

The 3rd Global CRO Council Closed Forum was held on the 3rd and 4th July 2011 in Guildford, United Kingdom, in conjunction with the 19th International Reid Bioanalytical Forum. In attendance were 21 senior-level representatives from 19 CROs on behalf of nine European countries and, for many of the attendees, this occasion was the first time that they had participated in a GCC meeting. Therefore, this closed forum was an opportunity to increase awareness of the aim of the GCC and how it works, share information about bioanalytical regulations and audit findings from different agencies, their policies and procedures and also to discuss some topics of interest and aim to develop ideas and provide recommendations for bioanalytical practices at future GCC meetings in Europe.

Systemic availability of the active metabolite hydroxy-fasudil after administration of fasudil to different sites of the human gastrointestinal tract.

This study evaluated the gastrointestinal absorption of fasudil, a novel Rho kinase inhibitor for the treatment of stable angina, at different sites using remote-controlled capsules and assessed the feasibility of developing an extended-release formulation. Ten healthy male volunteers were enrolled, and 8 subjects completed this single-dose, open-label, randomized, 5-way crossover study. Forty milligrams of fasudil HCl was administered as solution to the distal ileum and ascending colon, as powder to the ascending colon, and orally as an immediate-release tablet and solution. All treatments were well-tolerated and no serious adverse events were observed. The mean systemic availabilities of M3 relative to the oral solution were 1.04 (distal ileum, solution), 1.14 (ascending colon, solution), 1.27 (ascending colon, powder) and 1.04 (oral tablet), indicating similar systemic availability of M3 after administration of fasudil HCl to different gastrointestinal sites. The results suggest that development of a once-a-day extended-release formulation for fasudil HCl should be readily achievable.