Monolithically integrated 112 Gbps PAM4 optical transmitter and receiver in a 45†nm CMOS-silicon photonics process.

We demonstrate a transmitter and receiver in a silicon photonics platform for O-band optical communication that monolithically incorporates a modulator driver, traveling-wave Mach-Zehnder modulator, control circuitry, photodetector, and transimpedance amplifier (TIA) in the GlobalFoundries Fotonix (45SPCLO) platform. The transmitter and receiver show an open 112 Gbps PAM4 eye at a 4.3 pJ/bit energy efficiency, not including the laser. Extensive use of gain-peaking enables our modulator driver and TIA to achieve the high bandwidths needed in the 45 nm CMOS-silicon photonics process. Our results suggest an alternative to the frequent approach of bump-bonding BiCMOS drivers and TIAs to silicon photonics.

Cellular Localization of Kynurenine 3-Monooxygenase in the Brain: Challenging the Dogma.

Kynurenine 3-monooxygenase (KMO), a key player in the kynurenine pathway (KP) of tryptophan degradation, regulates the synthesis of the neuroactive metabolites 3-hydroxykynurenine (3-HK) and kynurenic acid (KYNA). KMO activity has been implicated in several major brain diseases including Huntington's disease (HD) and schizophrenia. In the brain, KMO is widely believed to be predominantly localized in microglial cells, but verification in vivo has not been provided so far. Here, we examined KP metabolism in the brain after depleting microglial cells pharmacologically with the colony stimulating factor 1 receptor inhibitor PLX5622. Young adult mice were fed PLX5622 for 21 days and were euthanized either on the next day or after receiving normal chow for an additional 21 days. Expression of microglial marker genes was dramatically reduced on day 22 but had fully recovered by day 43. In both groups, PLX5622 treatment failed to affect Kmo expression, KMO activity or tissue levels of 3-HK and KYNA in the brain. In a parallel experiment, PLX5622 treatment also did not reduce KMO activity, 3-HK and KYNA in the brain of R6/2 mice (a model of HD with activated microglia). Finally, using freshly isolated mouse cells ex vivo, we found KMO only in microglia and neurons but not in astrocytes. Taken together, these data unexpectedly revealed that neurons contain a large proportion of functional KMO in the adult mouse brain under both physiological and pathological conditions.

Microglia modulate blood flow, neurovascular coupling, and hypoperfusion via purinergic actions.

Microglia, the main immunocompetent cells of the brain, regulate neuronal function, but their contribution to cerebral blood flow (CBF) regulation has remained elusive. Here, we identify microglia as important modulators of CBF both under physiological conditions and during hypoperfusion. Microglia establish direct, dynamic purinergic contacts with cells in the neurovascular unit that shape CBF in both mice and humans. Surprisingly, the absence of microglia or blockade of microglial P2Y12 receptor (P2Y12R) substantially impairs neurovascular coupling in mice, which is reiterated by chemogenetically induced microglial dysfunction associated with impaired ATP sensitivity. Hypercapnia induces rapid microglial calcium changes, P2Y12R-mediated formation of perivascular phylopodia, and microglial adenosine production, while depletion of microglia reduces brain pH and impairs hypercapnia-induced vasodilation. Microglial actions modulate vascular cyclic GMP levels but are partially independent of nitric oxide. Finally, microglial dysfunction markedly impairs P2Y12R-mediated cerebrovascular adaptation to common carotid artery occlusion resulting in hypoperfusion. Thus, our data reveal a previously unrecognized role for microglia in CBF regulation, with broad implications for common neurological diseases.

Positive Outcomes: Validity, reliability and responsiveness of a novel person-centred outcome measure for people with HIV.

OBJECTIVES: Despite successful treatment, people living with HIV experience persisting and burdensome multidimensional problems. We aimed to assess the validity, reliability and responsiveness of Positive Outcomes, a patient-reported outcome measure for use in clinical practice. METHODS: In all, 1392 outpatients in five European countries self-completed Positive Outcomes, PAM-13 (patient empowerment), PROQOL-HIV (quality of life) and FRAIL (frailty) at baseline and 12 months. Analysis assessed: (a) validity (structural, convergent and divergent, discriminant); (b) reliability (internal consistency, test-retest); and (c) responsiveness. RESULTS: An interpretable four-factor structure was identified: 'emotional wellbeing', 'interpersonal and sexual wellbeing', 'socioeconomic wellbeing' and 'physical wellbeing'. Moderate to strong convergent validity was found for three subscales of Positive Outcomes and PROQOL (ρ = -0.481 to -0.618, all p < 0.001). Divergent validity was found for total scores with weak ρ (-0.295, p < 0.001). Discriminant validity was confirmed with worse Positive Outcomes score associated with increasing odds of worse FRAIL group (4.81-fold, p < 0.001) and PAM-13 level (2.28-fold, p < 0.001). Internal consistency for total Positive Outcomes and its factors exceeded the conservative α threshold of 0.6. Test-retest reliability was established: those with stable PAM-13 and FRAIL scores also reported median Positive Outcomes change of 0. Improved PROQOL-HIV score baseline to 12 months was associated with improved Positive Outcomes score (r = -0.44, p < 0.001). CONCLUSIONS: Positive Outcomes face and content validity was previously established, and the remaining validity, reliability and responsiveness properties are now demonstrated. The items within the brief 22-item tool are designed to be actionable by health and social care professionals to facilitate the goal of person-centred care.

Results from Phase I Extension Study Assessing Pexidartinib Treatment in Six Cohorts with Solid Tumors including TGCT, and Abnormal CSF1 Transcripts in TGCT.

PURPOSE: To assess the response to pexidartinib treatment in six cohorts of adult patients with advanced, incurable solid tumors associated with colony-stimulating factor 1 receptor (CSF1R) and/or KIT proto-oncogene receptor tyrosine kinase activity. PATIENTS AND METHODS: From this two-part phase I, multicenter study, pexidartinib, a small-molecule tyrosine kinase inhibitor that targets CSF1R, KIT, and FMS-like tyrosine kinase 3 (FLT3), was evaluated in six adult patient cohorts (part 2, extension) with advanced solid tumors associated with dysregulated CSF1R. Adverse events, pharmacokinetics, and tumor responses were assessed for all patients; patients with tenosynovial giant cell tumor (TGCT) were also evaluated for tumor volume score (TVS) and patient-reported outcomes (PRO). CSF1 transcripts and gene expression were explored in TGCT biopsies. RESULTS: Ninety-one patients were treated: TGCT patients (n = 39) had a median treatment duration of 511 days, while other solid tumor patients (n = 52) had a median treatment duration of 56 days. TGCT patients had response rates of 62% (RECIST 1.1) and 56% (TVS) for the full analysis set. PRO assessments for pain showed improvement in patient symptoms, and 76% (19/25) of TGCT tissue biopsy specimens showed evidence of abnormal CSF1 transcripts. Pexidartinib treatment of TGCT resulted in tumor regression and symptomatic benefit in most patients. Pexidartinib toxicity was manageable over the entire study. CONCLUSIONS: These results offer insight into outcome patterns in cancers whose biology suggests use of a CSF1R inhibitor. Pexidartinib results in tumor regression in TGCT patients, providing prolonged control with an acceptable safety profile.

Recurrent Mutations in Cyclin D3 Confer Clinical Resistance to FLT3 Inhibitors in Acute Myeloid Leukemia.

PURPOSE: Biomarkers of response and resistance to FLT3 tyrosine kinase inhibitors (TKI) are still emerging, and optimal clinical combinations remain unclear. The purpose of this study is to identify co-occurring mutations that influence clinical response to the novel FLT3 inhibitor pexidartinib (PLX3397). EXPERIMENTAL DESIGN: We performed targeted sequencing of pretreatment blasts from 29 patients with FLT3 internal tandem duplication (ITD) mutations treated on the phase I/II trial of pexidartinib in relapsed/refractory FLT3-ITD+ acute myeloid leukemia (AML). We sequenced 37 samples from 29 patients with available material, including 8 responders and 21 non-responders treated at or above the recommended phase II dose of 3,000 mg. RESULTS: Consistent with other studies, we identified mutations in NRAS, TP53, IDH2, and a variety of epigenetic and transcriptional regulators only in non-responders. Among the most frequently mutated genes in non-responders was Cyclin D3 (CCND3). A total of 3 individual mutations in CCND3 (Q276*, S264R, and T283A) were identified in 2 of 21 non-responders (one patient had both Q276* and S264R). No CCND3 mutations were found in pexidartinib responders. Expression of the Q276* and T283A mutations in FLT3-ITD MV4;11 cells conferred resistance to apoptosis, decreased cell-cycle arrest, and increased proliferation in the presence of pexidartinib and other FLT3 inhibitors. Inhibition of CDK4/6 activity in CCND3 mutant MV4;11 cells restored pexidartinib-induced cell-cycle arrest but not apoptosis. CONCLUSIONS: Mutations in CCND3, a gene not commonly mutated in AML, are a novel cause of clinical primary resistance to FLT3 inhibitors in AML and may have sensitivity to CDK4/6 inhibition.

A Longitudinal Observation of the Influence of Michigan Sports Concussion Law on Parents' Knowledge and Perception of Sport-Related Concussion.

INTRODUCTION: In 2013, Michigan enacted legislation requiring parents and athletes to receive educational material concerning sport-related concussion (SRC). The aim of this study was to examine trends in concussion knowledge of parents from one community following implementation of Michigan's Sports Concussion Laws (MSCL). METHODS: A convenience sample of parents of students from a suburban school district were surveyed via district email at one year and five years post MSCL implementation. Results were compared to an equivalent 33-item survey obtained prior to the law. Individual questions were compared between the three surveys using Chi-square analysis with statistical significance observed at p < 0.05. RESULTS: A total of 381 responses were obtained from the one-year post-MSCL (1yMSCL) and 178 in the five-year post-MSCL (5yMSCL) survey. Awareness of district policy regarding concussion was significantly higher after implementation of the MSCL (i.e., 77% at 1yMSCL and 71% at 5yMSCL) compared to prior 18% pre-MSCL (p < 0.0001). Respondents to the 5yMSCL survey were also significantly more aware of medical guidelines surrounding "return to play" after SRC compared to 1yMSCL (84.8% v 78.7%, p = 0.01). At 5yMSCL, significantly more respondents agreed that head injuries could cause more brain damage to children than adults (86.5% v 78.7% at 1yMSCL, p = 0.03). Finally, most parents at both survey periods rated the concussion educational material as the most helpful information source regarding SRC. CONCLUSIONS: Based on these results, parental knowledge awareness appears to have increased concerning awareness of medical guidelines for SRC and potential brain damage risks to children after enactment of the MSCL.

Pooled Analysis of PFO Occluder Device Trials in Patients With PFO and Migraine.

BACKGROUND: Although observational studies have shown percutaneous patent foramen ovale (PFO) closure to be a safe means of reducing the frequency and duration of migraine, randomized clinical trials have not met their primary efficacy endpoints. OBJECTIVES: The authors report the results of a pooled analysis of individual participant data from the 2 randomized trials using the Amplatzer PFO Occluder to assess the efficacy and safety of percutaneous device closure as a therapy for episodic migraine with or without aura. METHODS: The authors analyzed individual patient-level data from 2 randomized migraine trials (the PRIMA [Percutaneous Closure of Patent Foramen Ovale in Migraine With Aura] and PREMIUM [Prospective Randomized Investigation to Evaluate Incidence of Headache Reduction in Subjects with Migraine and PFO Using the Amplatzer PFO Occluder Compared to Medical Management] studies). Efficacy endpoints were mean reduction in monthly migraine days, responder rate (defined as ≥50% reduction in monthly migraine attacks), mean reduction in monthly migraine attacks, and percentage of patients who experienced complete cessation of migraine. The safety endpoint was major procedure- and device-related adverse events. RESULTS: Among 337 subjects, 176 were randomized by blocks to device closure and 161 to medical treatment only. At 12-month follow-up, the analysis met 3 of the 4 efficacy endpoints: mean reduction of monthly migraine days (-3.1 days vs. -1.9 days; p = 0.02), mean reduction of monthly migraine attacks (-2.0 vs. -1.4; p = 0.01), and number of subjects who experienced complete cessation of migraine (14 [9%] vs. 1 [0.7%]; p < 0.001). For the safety analysis, 9 procedure-related and 4 device-related adverse events occurred in 245 subjects who eventually received devices. All events were transient and resolved. CONCLUSIONS: This pooled analysis of patient-level data demonstrates that PFO closure was safe and significantly reduced the mean number of monthly migraine days and monthly migraine attacks, and resulted in a greater number of subjects who experienced complete migraine cessation.

Activated microglia drive demyelination via CSF1R signaling.

Microgliosis is a prominent pathological feature in many neurological diseases including multiple sclerosis (MS), a progressive auto-immune demyelinating disorder. The precise role of microglia, parenchymal central nervous system (CNS) macrophages, during demyelination, and the relative contributions of peripheral macrophages are incompletely understood. Classical markers used to identify microglia do not reliably discriminate between microglia and peripheral macrophages, confounding analyses. Here, we use a genetic fate mapping strategy to identify microglia as predominant responders and key effectors of demyelination in the cuprizone (CUP) model. Colony-stimulating factor 1 (CSF1), also known as macrophage colony-stimulating factor (M-CSF) - a secreted cytokine that regulates microglia development and survival-is upregulated in demyelinated white matter lesions. Depletion of microglia with the CSF1R inhibitor PLX3397 greatly abrogates the demyelination, loss of oligodendrocytes, and reactive astrocytosis that results from CUP treatment. Electron microscopy (EM) and serial block face imaging show myelin sheaths remain intact in CUP treated mice depleted of microglia. However, these CUP-damaged myelin sheaths are lost and robustly phagocytosed upon-repopulation of microglia. Direct injection of CSF1 into CNS white matter induces focal microgliosis and demyelination indicating active CSF1 signaling can promote demyelination. Finally, mice defective in adopting a toxic astrocyte phenotype that is driven by microglia nevertheless demyelinate normally upon CUP treatment implicating microglia rather than astrocytes as the primary drivers of CUP-mediated demyelination. Together, these studies indicate activated microglia are required for and can drive demyelination directly and implicate CSF1 signaling in these events.

Different SARS-CoV-2 haplotypes associate with geographic origin and case fatality rates of COVID-19 patients.

The current pandemic of COVID-19 is caused by the SARS-CoV-2 virus for which many variants at the Single Nucleotide Polymorphism (SNP) level have now been identified. We show here that different allelic variants among 692 SARS-CoV-2 genome sequences display a statistically significant association with geographic origin (p < 0.000001) and COVID-19 case severity (p = 0.016). Geographic variation in itself is associated with both case severity and allelic variation especially in strains from Indian origin (p < 0.000001). Using an new alternative bioinformatics approach we were able to confirm that the presence of the D614G mutation correlates with increased case severity in a sample of 127 sequences from a shared geographic origin in the US (p = 0.018). While leaving open the question on the pathogenesis mechanism involved, this suggests that in specific geographic locales certain genotypes of the virus are more pathogenic than others. We here show that viral genome polymorphisms may have an effect on case severity when other factors are controlled for, but that this effect is swamped out by these other factors when comparing cases across different geographic regions.

Sex- and region-biased depletion of microglia/macrophages attenuates CLN1 disease in mice.

BACKGROUND: The neuronal ceroid lipofuscinoses (CLN diseases) are fatal lysosomal storage diseases causing neurodegeneration in the CNS. We have previously shown that neuroinflammation comprising innate and adaptive immune reactions drives axonal damage and neuron loss in the CNS of palmitoyl protein thioesterase 1-deficient (Ppt1-/-) mice, a model of the infantile form of the diseases (CLN1). Therefore, we here explore whether pharmacological targeting of innate immune cells modifies disease outcome in CLN1 mice. METHODS: We applied treatment with PLX3397 (150 ppm in the chow), a potent inhibitor of the colony stimulating factor-1 receptor (CSF-1R) to target innate immune cells in CLN1 mice. Experimental long-term treatment was non-invasively monitored by longitudinal optical coherence tomography and rotarod analysis, as well as analysis of visual acuity, myoclonic jerks, and survival. Treatment effects regarding neuroinflammation, neural damage, and neurodegeneration were subsequently analyzed by histology and immunohistochemistry. RESULTS: We show that PLX3397 treatment attenuates neuroinflammation in CLN1 mice by depleting pro-inflammatory microglia/macrophages. This leads to a reduction of T lymphocyte recruitment, an amelioration of axon damage and neuron loss in the retinotectal system, as well as reduced thinning of the inner retina and total brain atrophy. Accordingly, long-term treatment with the inhibitor also ameliorates clinical outcomes in CLN1 mice, such as impaired motor coordination, visual acuity, and myoclonic jerks. However, we detected a sex- and region-biased efficacy of CSF-1R inhibition, with male microglia/macrophages showing higher responsiveness toward depletion, especially in the gray matter of the CNS. This results in a better treatment outcome in male Ppt1-/- mice regarding some histopathological and clinical readouts and reflects heterogeneity of innate immune reactions in the diseased CNS. CONCLUSIONS: Our results demonstrate a detrimental impact of innate immune reactions in the CNS of CLN1 mice. These findings provide insights into CLN pathogenesis and may guide in the design of immunomodulatory treatment strategies.

Mitigation of helium irradiation-induced brain injury by microglia depletion.

BACKGROUND: Cosmic radiation exposures have been found to elicit cognitive impairments involving a wide-range of underlying neuropathology including elevated oxidative stress, neural stem cell loss, and compromised neuronal architecture. Cognitive impairments have also been associated with sustained microglia activation following low dose exposure to helium ions. Space-relevant charged particles elicit neuroinflammation that persists long-term post-irradiation. Here, we investigated the potential neurocognitive benefits of microglia depletion following low dose whole body exposure to helium ions. METHODS: Adult mice were administered a dietary inhibitor (PLX5622) of colony stimulating factor-1 receptor (CSF1R) to deplete microglia 2 weeks after whole body helium irradiation (4He, 30 cGy, 400 MeV/n). Cohorts of mice maintained on a normal and PLX5622 diet were tested for cognitive function using seven independent behavioral tasks, microglial activation, hippocampal neuronal morphology, spine density, and electrophysiology properties 4-6 weeks later. RESULTS: PLX5622 treatment caused a rapid and near complete elimination of microglia in the brain within 3 days of treatment. Irradiated animals on normal diet exhibited a range of behavioral deficits involving the medial pre-frontal cortex and hippocampus and increased microglial activation. Animals on PLX5622 diet exhibited no radiation-induced cognitive deficits, and expression of resting and activated microglia were almost completely abolished, without any effects on the oligodendrocyte progenitors, throughout the brain. While PLX5622 treatment was found to attenuate radiation-induced increases in post-synaptic density protein 95 (PSD-95) puncta and to preserve mushroom type spine densities, other morphologic features of neurons and electrophysiologic measures of intrinsic excitability were relatively unaffected. CONCLUSIONS: Our data suggest that microglia play a critical role in cosmic radiation-induced cognitive deficits in mice and, that approaches targeting microglial function are poised to provide considerable benefit to the brain exposed to charged particles.

A phase 1/2 study of the oral FLT3 inhibitor pexidartinib in relapsed/refractory FLT3-ITD-mutant acute myeloid leukemia.

FMS-like tyrosine kinase 3 (FLT3) tyrosine kinase inhibitors (TKIs) have activity in acute myeloid leukemia (AML) patients with FLT3 internal tandem duplication (ITD) mutations, but efficacy is limited by resistance-conferring kinase domain mutations. This phase 1/2 study evaluated the safety, tolerability, and efficacy of the oral FLT3 inhibitor PLX3397 (pexidartinib), which has activity against the FLT3 TKI-resistant F691L gatekeeper mutation in relapsed/refractory FLT3-ITD-mutant AML. Ninety patients were treated: 34 in dose escalation (part 1) and 56 in dose expansion (part 2). Doses of 800 to 5000 mg per day in divided doses were tested. No maximally tolerated dose was reached. Plasma inhibitory assay demonstrated that patients dosed with ≥3000 mg had sufficient levels of active drug in their trough plasma samples to achieve 95% inhibition of FLT3 phosphorylation in an FLT3-ITD AML cell line. Based on a plateau in drug exposure, the 3000-mg dose was chosen as the recommended phase 2 dose. The most frequently reported treatment-emergent adverse events were diarrhea (50%), fatigue (47%), and nausea (46%). Based on modified response criteria, the overall response rate to pexidartinib among all patients was 21%. Twenty-three percent of patients treated at ≥2000 mg responded. The overall composite complete response rate for the study was 11%. Six patients were successfully bridged to transplantation. Median overall survival (OS) of patients treated in dose expansion was 112 days (90% confidence interval [CI], 77-150 days), and median OS of responders with complete remission with or without recovery of blood counts was 265 days (90% CI, 170-422 days). This trial was registered at www.clinicaltrials.gov as #NCT01349049.

Comparison of residual shunt rate and complications across 6 different closure devices for patent foramen ovale.

OBJECTIVES: To compare residual shunt rate and complications associated with six different devices used for PFO closure. BACKGROUND: Transcutaneous PFO closure is an effective treatment for preventing recurrent stroke in patients with a history of cryptogenic stroke. The rate of residual shunt is one metric by which the technical success of PFO closure can be measured. METHODS: Patients who underwent PFO closure at a single center between February 2001 and July 2019 were retrospectively enrolled in the study. Right-to-left shunt at baseline and during follow-up was assessed using transcranial Doppler (TCD) or transthoracic echocardiography (TTE). Periprocedural and device-related complications, including atrial fibrillation, were also assessed. RESULTS: Of 467 PFO closures performed during this period, 320 patients received quantitative assessment of right-to-left shunting both before and after percutaneous closure. The highest effective closure was achieved with the Cardioform device (100%, n = 104), followed by the Amplatzer Cribriform (93%, n = 14), Helex (90%, n = 137), Amplatzer ASO (88%, n = 17), CardioSEAL (86%, n = 14), and Amplatzer PFO (85%, n = 33) devices. The most common significant adverse event was atrial fibrillation, which was more common with the Cardioform device (13%) than the Helex (4%) or the Amplatzer PFO (4%) devices. CONCLUSIONS: The Gore Cardioform Septal Occluder provides more robust closure of a PFO when compared to other devices but its effectiveness is offset by the higher prevalence of transient atrial fibrillation.

Attenuation of neuroinflammation reverses Adriamycin-induced cognitive impairments.

Numerous clinical studies have established the debilitating neurocognitive side effects of chemotherapy in the treatment of breast cancer, often referred as chemobrain. We hypothesize that cognitive impairments are associated with elevated microglial inflammation in the brain. Thus, either elimination of microglia or restoration of microglial function could ameliorate cognitive dysfunction. Using a rodent model of chronic Adriamycin (ADR) treatment, a commonly used breast cancer chemotherapy, we evaluated two strategies to ameliorate chemobrain: 1) microglia depletion using the colony stimulating factor-1 receptor (CSF1R) inhibitor PLX5622 and 2) human induced pluripotent stem cell-derived microglia (iMG)-derived extracellular vesicle (EV) treatment. In strategy 1 mice received ADR once weekly for 4 weeks and were then administered CSF1R inhibitor (PLX5622) starting 72 h post-ADR treatment. ADR-treated animals given a normal diet exhibited significant behavioral deficits and increased microglial activation 4-6 weeks later. PLX5622-treated mice exhibited no ADR-related cognitive deficits and near complete depletion of IBA-1 and CD68+ microglia in the brain. Cytokine and RNA sequencing analysis for inflammation pathways validated these findings. In strategy 2, 1 week after the last ADR treatment, mice received retro-orbital vein injections of iMG-EV (once weekly for 4 weeks) and 1 week later, mice underwent behavior testing. ADR-treated mice receiving EV showed nearly complete restoration of cognitive function and significant reductions in microglial activation as compared to untreated ADR mice. Our data demonstrate that ADR treatment elevates CNS inflammation that is linked to cognitive dysfunction and that attenuation of neuroinflammation reverses the adverse neurocognitive effects of chemotherapy.

Sustained microglial depletion with CSF1R inhibitor impairs parenchymal plaque development in an Alzheimer's disease model.

Many risk genes for the development of Alzheimer's disease (AD) are exclusively or highly expressed in myeloid cells. Microglia are dependent on colony-stimulating factor 1 receptor (CSF1R) signaling for their survival. We designed and synthesized a highly selective brain-penetrant CSF1R inhibitor (PLX5622) allowing for extended and specific microglial elimination, preceding and during pathology development. We find that in the 5xFAD mouse model of AD, plaques fail to form in the parenchymal space following microglial depletion, except in areas containing surviving microglia. Instead, Aß deposits in cortical blood vessels reminiscent of cerebral amyloid angiopathy. Altered gene expression in the 5xFAD hippocampus is also reversed by the absence of microglia. Transcriptional analyses of the residual plaque-forming microglia show they exhibit a disease-associated microglia profile. Collectively, we describe the structure, formulation, and efficacy of PLX5622, which allows for sustained microglial depletion and identify roles of microglia in initiating plaque pathogenesis.

Phase Ib study of the combination of pexidartinib (PLX3397), a CSF-1R inhibitor, and paclitaxel in patients with advanced solid tumors.

PURPOSE: To evaluate the safety, recommended phase II dose (RP2D) and efficacy of pexidartinib, a colony stimulating factor receptor 1 (CSF-1R) inhibitor, in combination with weekly paclitaxel in patients with advanced solid tumors. PATIENTS AND METHODS: In part 1 of this phase Ib study, 24 patients with advanced solid tumors received escalating doses of pexidartinib with weekly paclitaxel (80 mg/m2). Pexidartinib was administered at 600 mg/day in cohort 1. For subsequent cohorts, the dose was increased by ⩽50% using a standard 3+3 design. In part 2, 30 patients with metastatic solid tumors were enrolled to examine safety, tolerability and efficacy of the RP2D. Pharmacokinetics and biomarkers were also assessed. RESULTS: A total of 51 patients reported ≥1 adverse event(s) (AEs) that were at least possibly related to either study drug. Grade 3-4 AEs, including anemia (26%), neutropenia (22%), lymphopenia (19%), fatigue (15%), and hypertension (11%), were recorded in 38 patients (70%). In part 1, no maximum tolerated dose was achieved and 1600 mg/day was determined to be the RP2D. Of 38 patients evaluable for efficacy, 1 (3%) had complete response, 5 (13%) partial response, 13 (34%) stable disease, and 17 (45%) progressive disease. No drug-drug interactions were found. Plasma CSF-1 levels increased 1.6- to 53-fold, and CD14dim/CD16+ monocyte levels decreased by 57-100%. CONCLUSIONS: The combination of pexidartinib and paclitaxel was generally well tolerated. RP2D for pexidartinib was 1600 mg/day. Pexidartinib blocked CSF-1R signaling, indicating potential for mitigating macrophage tumor infiltration.

Significance of Coronary Artery Calcium Found on Non-Electrocardiogram-Gated Computed Tomography During Preoperative Evaluation for Liver Transplant.

Guidelines to evaluate patients for coronary artery disease (CAD) during preoperative evaluation for orthotopic liver transplantation (OLT) are conflicting. Cardiac catheterization is not without risk in patients with end-stage liver disease. No study to date has looked at the utility of non-electrocardiogram-gated chest computed tomography (CT) in the preliver transplant population. Our hypothesis was that coronary artery calcium scores (CACSs) from chest CT scans ordered during the liver transplant workup can identify patients who would benefit from invasive angiography. Nine hundred and fifty-three patients who underwent coronary angiography as part of their OLT workup were considered. Charts were randomly selected and reviewed for the presence of a chest CT performed before coronary angiography during the OLT workup. Agatston and Weston scores were calculated. CACS results were compared with coronary angiography findings. Nine of 54 patients were found to have obstructive CAD by angiography. Receiver-operating characteristic analysis demonstrated that an Agatston score of 251 and a Weston score of 6 maximized sensitivity and specificity for detection of obstructive coronary disease. An Agatston score <4 or Weston score <2 excluded the presence of obstructive CAD; using these thresholds, 13 patients (24%) or 15 patients (28%), respectively, could have theoretically avoided catheterization without missing significant CAD. In conclusion, our data identify the strength of CACS in ruling out coronary disease in patients being evaluated for OLT. Calcium scoring from non-electrocardiogram-gated CT studies may be integrated into preoperative algorithms to rule out obstructive CAD and help avoid invasive angiography in this high-risk population.