Combination of Mycobacterium tuberculosis RS ratio and CFU improves the ability of murine efficacy experiments to distinguish between drug treatments

Murine tuberculosis drug efficacy studies have historically monitored bacterial burden based on colony forming units of M. tuberculosis in lung homogenate. In an alternative approach, a recently described molecular pharmacodynamic marker called the RS ratio quantifies drug effect on a fundamental cellular process: ongoing ribosomal RNA synthesis. Here we evaluated the ability of different pharmacodynamic markers to distinguish between treatments in three BALB/c mouse experiments at two institutions. We confirmed that different pharmacodynamic markers measure distinct biological responses. We found that a combination of pharmacodynamic markers distinguishes between treatments better than any single marker. The combination of the RS ratio with colony forming units showed the greatest ability to recapitulate the rank order of regimen treatment-shortening activity, providing proof of concept that simultaneous assessment of pharmacodynamic markers measuring different properties will enhance insight gained from animal models and accelerate development of new combination regimens. These results suggest potential for a new era in which antimicrobial therapies are evaluated not only on culture-based measures of bacterial burden but also on molecular assays that indicate how drugs impact the physiological state of the pathogen.

Pharmacogenetics of quetiapine

(1) Introduction: Quetiapine (QTP) is a dibenzothiazepine derivative, a second generation antipsychotic (AP), which is structurally similar to clozapine. The main indications for use are schizophrenia and depressive disorder. Under manic episodes in bipolar disorder can be used alone or in combination with lithium. The frequency of prescribing QTP is on average 11,987 per 100,000 population, with a positive trend in dynamics: a growth rate of more than 800% within the period 2002 to 2017.(2) Purpose: The review of studies of pharmacogenetic pharmacokinetic and pharmacogenetic pharmacodynamic markers of QTP efficacy and safety.(3) Materials and Methods: A search was carried out for publications of the Science Index, PubMed, Web of Science, Springer databases by keywords and their combinations over the last 10 years. In addition, the review includes earlier publications of historical interest. Despite extensive searches of these commonly used databases and search terms, it cannot be ruled out that some publications may have been missed.(4) Results: The review considers the following pharmacokinetic markers of QTP efficacy and safety: genes are coding isoforms of cytochrome P450 (CYP2D6, CYP2C19, CYP3A4, CYP3A5), P-glycoprotein (ABCB1); pharmacogenetic pharmacodynamic markers of the efficacy and safety of QTP : genes of dopamine receptor isoform (DRD3), dopamine transporter (SCL1A1) and catecholO-methyltransferase (COMT), serotonin receptor isoforms (HTR2C), melanocortin receptor (MC4R), NOTCH protein (NOTCH4), phosphodiesterase 4D (PDE4D), SPoPL protein (SPoPL), multiple EGFlike domain (MEGF10), protocadherin-7 (PCDH7), contactin-associated protein 5 (CNTNAP5) , TRAF2 and NCK-interacting protein kinase (TNIK), spermatogenesis-associated protein 6 (SPATA6L), neurobihin (NBEA), synaptic vesicle protein-2C (SVC2) .(5) Conclusion: Disclosure of pharmacogenetic markers of pharmacokinetics and pharmacodynamics of QTP efficacy and safety in the treatment of patients with schizophrenia and other psychiatric disorders, may provide a key to developing a strategy for its personalized prevention of adverse grug reactions (ADRs) and therapy strategy in real clinical practice.

What is the prospect of indoleamine 2,3-dioxygenase 1 inhibition in cancer? Extrapolation from the past

Indoleamine 2,3-dioxygenase 1 (IDO1), a monomeric heme-containing enzyme, catalyzes the first and rate-limiting step in the kynurenine pathway of tryptophan metabolism, which plays an important role in immunity and neuronal function. Its implication in different pathophysiologic processes including cancer and neurodegenerative diseases has inspired the development of IDO1 inhibitors in the past decades. However, the negative results of the phase III clinical trial of the would-be first-in-class IDO1 inhibitor (epacadostat) in combination with an anti-PD1 antibody (pembrolizumab) in patients with advanced malignant melanoma call for a better understanding of the role of IDO1 inhibition. In this review, the current status of the clinical development of IDO1 inhibitors will be introduced and the key pre-clinical and clinical data of epacadostat will be summarized. Moreover, based on the cautionary notes obtained from the clinical readout of epacadostat, strategies for the identification of reliable predictive biomarkers and pharmacodynamic markers as well as for the selection of the tumor types to be treated with IDO1inhibitors will be discussed.

Subcutaneous dosing regimens of tocilizumab in children with systemic or polyarticular juvenile idiopathic arthritis

Objectives To determine s.c. tocilizumab (s.c.-TCZ) dosing regimens for systemic JIA (sJIA) and polyarticular JIA (pJIA). Methods In two 52-week phase 1 b trials, s.c.-TCZ (162 mg/dose) was administered to sJIA patients every week or every 2 weeks (every 10 days before interim analysis) and to pJIA patients every 2 weeks or every 3 weeks with body weight ≥30 kg or <30 kg, respectively. Primary end points were pharmacokinetics, pharmacodynamics and safety; efficacy was exploratory. Comparisons were made to data from phase 3 trials with i.v. tocilizumab (i.v.-TCZ) in sJIA and pJIA. Results Study participants were 51 sJIA patients and 52 pJIA patients aged 1–17 years who received s.c.-TCZ. Steady-state minimum TCZ concentration (Ctrough) >5th percentile of that achieved with i.v.-TCZ was achieved by 49 (96%) sJIA and 52 (100%) pJIA patients. In both populations, pharmacodynamic markers of disease were similar between body weight groups. Improvements in Juvenile Arthritis DAS-71 were comparable between s.c.-TCZ and i.v.-TCZ. By week 52, 53% of sJIA patients and 31% of pJIA patients achieved clinical remission on treatment. Safety was consistent with that of i.v.-TCZ except for injection site reactions, reported by 41.2% and 28.8% of sJIA and pJIA patients, respectively. Infections were reported in 78.4% and 69.2% of patients, respectively. Two sJIA patients died; both deaths were considered to be related to TCZ. Conclusion s.c.-TCZ provides exposure and risk/benefit profiles similar to those of i.v.-TCZ. S.c. administration provides an alternative administration route that is more convenient for patients and caregivers and that has potential for in-home use. Trial registration ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904292 and NCT01904279

Exosome markers of LRRK2 kinase inhibition

Hyper-activated LRRK2 is linked to Parkinson’s disease susceptibility and progression. Quantitative measures of LRRK2 inhibition, especially in the brain, maybe critical in the development of successful LRRK2-targeting therapeutics. In this study, two different brain-penetrant and selective LRRK2 small-molecule kinase inhibitors (PFE-360 and MLi2) were orally administered to groups of cynomolgus macaques. Proposed pharmacodynamic markers in exosomes from urine and cerebrospinal fluid (CSF) were compared to established markers in peripheral blood mononuclear cells (PBMCs). LRRK2 kinase inhibition led to reductions in exosome-LRRK2 protein and the LRRK2-substrate pT73-Rab10 in urine, as well as reduced exosome-LRRK2 and autophosphorylated pS1292-LRRK2 protein in CSF. We propose orthogonal markers for LRRK2 inhibition in urine and CSF can be used in combination with blood markers to non-invasively monitor the potency of LRRK2-targeting therapeutics.

Phase I monotherapy dose escalation of RGX-202, a first-in-class oral inhibitor of the SLC6a8/CKB pathway, in patients with advanced gastrointestinal (GI) solid tumors.

3504 Background: About 65% of advanced colorectal cancer (CRC) patients (pts) have creatine kinase B (CKB) expressing tumors. CKB expressing (CKB+) GI cancer cells import creatine via the creatine transporter SLC6a8 and utilize it to generate intracellular ATP. RGX-202, a small molecule inhibitor of SLC6a8, reduces intracellular creatine and ATP levels, leading to apoptosis. RGX-202 treatment triggers complete tumor regressions in multiple CKB+ preclinical models, including KRAS mutant CRC. Methods: RGX-202-001 is a phase I escalation/expansion study of RGX-202 +/- FOLFIRI in pts with advanced GI tumors. The primary safety objective during dose escalation is to identify the maximum tolerated dose (MTD), or the maximum tested dose at which multiple dose-limiting toxicities (DLTs) are not observed. The primary efficacy objective is to estimate the antitumor activity of RGX-202 by RECIST. Results: As of January 31, 2020, 17 pts have been treated in 4 single agent dose escalation cohorts: 600 mg BID (3 pts), 1200 mg BID (4 pts), 2400mg BID (5 pts) and 3600mg BID (5pts) given continuously. No DLTs were observed and an MTD was not reached. Treatment-related adverse events (TRAEs) occurring in > 2 pts are shown in the Table. There were no Grade 4 TRAEs. At the highest dose, 2 of 3 CRC pts had prolonged disease control: a patient with a KRAS G13D mutant cancer had SD for 14 weeks; and a patient with KRAS G12V mutant (MSS) cancer had a confirmed PR ongoing at 30 weeks. Exposure to RGX-202 was greater than dose-proportional and the average AUC0-24 ranged from ~15,700 ng-hr/mL in cohort 1 to 241,097 ng-hr/mL in in Cohort 4. Serum and urine creatine levels, pharmacodynamic markers of SLC6a8 inhibition, correlated with systemic exposure to RGX-202. Conclusions: Among 17 patients treated with single agent therapy, no DLTs occurred; notably, exposures predicted to be sufficient to inhibit human tumor growth from preclinical models were achieved along with concomitant pharmacodynamic effects. These data, along with a durable PR observed in the highest dose cohort, support further development of RGX-202. Consequently, dose escalation in combination with FOLFIRI in patients with advanced GI cancers is underway with plans for expansion in CKB+ CRC pts. Clinical trial information: NCT03597581 . [Table: see text]

Pharmacodynamic Markers of LRRK2 Inhibition in Biofluids

Hyper-activated LRRK2 is linked to Parkinson’s disease susceptibility and progression. Quantitative measures of LRRK2 inhibition, especially in the brain, may be critical in the clinical development of successful LRRK2-targeting therapeutics. In this study, three different brain-penetrant and selective LRRK2 small-molecule kinase inhibitors (PFE-360, MLi2, and RA283) were orally administered to groups of cynomolgus macaques at different doses. Biofluid markers with proposed pharmacodynamic properties for assessing LRRK2 inhibition were measured from samples of blood, urine, and cerebral-spinal fluid (CSF). LRRK2 kinase inhibition led to consistent reduced pS935-LRRK2 and pRab10 proteins in blood mononuclear cells, reduced exosome LRRK2 protein and di-docosahexaenoyl (22:6) bis (monoacylglycerol) phosphate in urine, and reduced exosome LRRK2 and autophosphorylated pS1292-LRRK2 protein in CSF. Incomplete LRRK2 kinase inhibition reduced LRRK2 protein secretion in exosomes whereas high drug exposures may reduce both exosome and tissue levels of LRRK2 protein. These orthogonal markers for LRRK2 inhibition in urine and CSF can be used in combination with blood markers to non-invasively monitor the potency of LRRK2-targeting therapeutics in the brain and periphery.

ATIM-09. CLINICAL TRIAL IN PROGRESS: A STUDY OF NEOADJUVANT AND ADJUVANT VB-111 FOR TREATMENT OF RECURRENT GBM

BACKGOUND Ofranergene obadenovec (VB-111) is a targeted anti-cancer viral based gene therapy with a dual mechanism: a broad antiangiogenic effect and induction of a tumor directed immune response. Previous study demonstrated a survival benefit for patients with recurrent glioblastoma (rGBM) treated with VB-111 monotherapy that was continued upon progression with combination treatment of VB-111 and bevacizumab. Glioblastoma is an immunologically “cold” microenvironment which fosters immunosuppression and antagonizes anti-tumor immune responses. The role of T-cell infiltration in combating cancer has been increasingly recognized and associated with improved participant outcomes. Based on these observations, this study will assess the hypothesis that neoadjuvant use of VB-111 will lead to a statistically significant increase in tumor infiltrating T lymphocyte (TIL) density within the tumor and enhanced systemic tumor-specific T cell responses. METHODS This is a multicenter, randomized, blinded, placebo-controlled, phase 2 surgical trial to evaluate early immunologic pharmacodynamic parameters for the viral cancer therapy VB-111 in rGBM. 45 participants with rGBM indicated for resection will randomized to one of three treatment arms: Neoadjuvant Arm: intravenous VB-111 prior to resection, and VB-111 every 6 weeks after resection. Adjuvant Arm: placebo prior to resection, and VB-111 every 6 weeks afterwards. The control arm will receive placebo prior to resection followed by standard of care. Upon evidence of contrast-enhancing progression, bevacizumab may be initiated as needed for supportive care and VB-111 will continue until progression is supported at two consecutive time points. Tumor samples will be obtained and archived at the time of surgery, and blood samples will be obtained as pharmacodynamic markers throughout the study to allow DNA sequencing of T cells. The primary endpoint is influence of neoadjuvant VB-111 on TIL density. Other endpoints include safety and tolerability, peripheral T cell response, tumor/microenvironment transcriptomic alteration, and PFS/OS. Study will open for enrolment in 2019.