Effects of Itraconazole and Rifampin on the Pharmacokinetics of Mobocertinib (TAK-788), an Oral Epidermal Growth Factor Receptor Inhibitor, in Healthy Volunteers.

Mobocertinib (TAK-788) is an investigational oral tyrosine kinase inhibitor targeting epidermal growth factor receptor and human epidermal growth factor 2. A phase 1 open-label, 2-period, fixed-sequence, 2-part study (NCT03928327) characterized effects of a strong CYP3A4 inhibitor (itraconazole) and inducer (rifampin) on the pharmacokinetics (PK) of mobocertinib and its active metabolites, AP32960 and AP32914. Healthy volunteers (n = 12 per part) received a single dose of mobocertinib alone (20 mg, part 1; 160 mg, part 2) and with multiple doses of itraconazole 200 mg once daily (part 1) or rifampin 600 mg once daily (part 2). Coadministration of itraconazole with mobocertinib increased the combined molar area under the plasma concentration-time curve from time 0 to infinity (AUC0-∞ ) of mobocertinib, AP32960, and AP32914 by 527% (geometric least-squares mean [LSM] ratio, 6.27; 90% confidence interval [CI], 5.20-7.56). Coadministration of rifampin with mobocertinib decreased the combined molar AUC0-∞ of mobocertinib, AP32960, and AP32914 by 95% (geometric LSM ratio, 0.05; 90%CI, 0.04-0.07). Based on these results, the strong CYP3A inhibitor itraconazole and inducer rifampin significantly influenced the PK of mobocertinib and its active metabolites. Coadministration of mobocertinib with moderate and strong CYP3A inhibitors or inducers is not recommended in ongoing clinical trials.

Single-Dose Pharmacokinetics and Tolerability of the Oral Epidermal Growth Factor Receptor Inhibitor Mobocertinib (TAK-788) in Healthy Volunteers: Low-Fat Meal Effect and Relative Bioavailability of 2 Capsule Products.

Mobocertinib (TAK-788) is a tyrosine kinase inhibitor under investigation for treatment of non-small cell lung cancer with activating EGFR exon 20 insertions. This study examined the safety; tolerability; pharmacokinetics (PK), including food effects; and bioavailability of mobocertinib in healthy volunteers. In part 1, fasted volunteers were randomized to placebo or mobocertinib in single-ascending-dose cohorts (20-160 mg). In part 2, mobocertinib (120/160 mg) was administered on day 1 of periods 1 and 2 under fasted or low-fat meal conditions (2-period, 2-sequence crossover design). In part 3, fasted volunteers received mobocertinib 160 mg in 1 of 2 capsule products on day 1 of periods 1 and 2 with 7-day washout. Safety and PK parameters were assessed. Sixty-nine volunteers were enrolled (mean age, 29 years; 75% male). The most common adverse events (AEs; ≥10% of volunteers) were gastrointestinal AEs (25%-50%) and headache (8%-31%). No serious AEs were reported. A low-fat meal did not affect the PK of mobocertinib or its active metabolites. The geometric mean terminal disposition phase half-life (20 hours) supported once-daily dosing. The 2 capsule products were bioequivalent. These data guided dosing and supported administration of mobocertinib without regard to low-fat meal intake in ongoing and planned clinical studies.

Stem cell challenges in the treatment of neurodegenerative disease.

Neurodegenerative diseases result from the gradual and progressive loss of neural cells and lead to nervous system dysfunction. The rapidly advancing stem cell field is providing attractive alternative options for fighting these diseases. Results have provided proof of principle that cell replacement can work in humans with Parkinson's disease (PD). However, three clinical studies of cell transplantation were published that found no net benefit, while patients in two of the studies developed dyskinesias that persisted despite reductions in treatment. Induced pluripotent stem cells (iPSC) have major potential advantages because patient-specific neuroblasts are suitable for transplantation, avoid immune reactions, and can be produced without the use of human ES cells (hESC). Although iPSCs have not been successfully used in clinical trials for PD, patients with amyotrophic lateral sclerosis (ALS) were treated with autologous stem cells and, though they had some degree of decline one year after treatment, they were still improved compared with the preoperative period or without any drug therapy. In addition, neural stem cells (NSCs), via brain-derived neurotrophic factor (BDNF), have been shown to ameliorate complex behavioral deficits associated with widespread Alzheimer's disease (AD) pathology in a transgenic mouse model of AD. So far, the FDA lists 18 clinical trials treating multiple sclerosis (MS), but most are in preliminary stages. This article serves as an overview of recent studies in stem cell and regenerative approaches to the above chronic neurodegenerative disorders. There are still many obstacles to the use of stem cells as a cure for neurodegenerative disease, especially because we still don't fully understand the true mechanisms of these diseases. However, there is hope in the potential of stem cells to help us learn and understand a great deal more about the mechanisms underlying these devastating neurodegenerative diseases.

Preclinical efficacy studies of a novel nanoparticle-based formulation of paclitaxel that out-performs Abraxane.

PURPOSE: Poly-(gamma-L-glutamylglutamine)-paclitaxel (PGG-PTX) is a novel polymer-based formulation of paclitaxel (PTX) in which the PTX is linked to the polymer via ester bonds. PGG-PTX is of interest because it spontaneously forms very small nanoparticles in plasma. In mouse models, PGG-PTX increased tumor exposure to PTX by 7.7-fold relative to that produced by PTX formulated in Cremophor. In this study, the efficacy of PGG-PTX was compared to that of Abraxane, an established nanoparticular formulation of PTX, in three different tumor models. METHODS: Efficacy was quantified by delay in tumor growth of NCI H460 human lung cancer, 2008 human ovarian cancer and B16 melanoma xenografts growing in athymic mice following administration of equitoxic doses of PGG-PTX and Abraxane administered on either a single dose or every 7 day schedule. Toxicity was assessed by change in total body weight. RESULTS: The efficacy and toxicity of PGG-PTX was shown to increase with dose in the H460 model. PGG-PTX was approximately 1.5-fold less potent than Abraxane. PGG-PTX produced statistically significantly greater inhibition of tumor growth than Abraxane in all three tumor models when mice were given single equitoxic doses of drug. When given every 7 days for 3 doses, PGG-PTX produced greater inhibition of tumor growth while generating much less weight loss in mice bearing H460 tumors. CONCLUSION: PGG-PTX has activity that is superior to that of Abraxane in multiple tumor models. PGG-PTX has the potential to out-perform Abraxane in enhancing the delivery of PTX tumors while at the same time further reducing the toxicity of both single dose and weekly treatment regimens.

Synthesis, characterization, and biological evaluation of poly(L-γ-glutamyl-glutamine)- paclitaxel nanoconjugate.

The purpose of this study was to develop a novel, highly water-soluble poly(L-γ-glutamyl-glutamine)-paclitaxel nanoconjugate (PGG-PTX) that would improve the therapeutic index of paclitaxel (PTX). PGG-PTX is a modification of poly(L-glutamic acid)- paclitaxel conjugate (PGA-PTX) in which an additional glutamic acid has been added to each glutamic side chain in the polymer. PGG-PTX has higher water-solubility and faster dissolution than PGA-PTX. Unlike PGA-PTX, PGG-PTX self-assembles into nanoparticles, whose size remains in the range of 12-15 nm over the concentration range from 25 to 2,000 µg/mL in saline. Its critical micellar concentration in saline was found to be ~25 µg/mL. The potency of PGG-PTX when tested in vitro against the human lung cancer H460 cell line was comparable to other known polymer-PTX conjugates. However, PGG-PTX possesses lower toxicity compared with PGA-PTX in mice. The maximum tolerated dose of PGG-PTX was found to be 350 mg PTX/kg, which is 2.2-fold higher than the maximum tolerated dose of 160 mg PTX/kg reported for the PGA-PTX. This result indicates that PGG-PTX was substantially less toxic in vivo than PGA-PTX.

Embryonic stem cells ameliorate piroxicam-induced colitis in IL10-/- KO mice.

The primary objective of this work is to determine the repairing potential of murine embryonic stem cells (ES) in murine model of Crohn's disease (CD). Colitis, induced in IL10-/- KO mice using piroxicam, was associated with the increased levels of IL-12. Enhanced yellow fluorescent protein (EYFP) marked murine ES cells (R1/129) and control non-fluorescent ES cells were subjected to in vitro differentiation into intestinal epithelial cells. IL 10-/- KO mice were injected with pre-differentiated ES-YFP cells and sacrificed after 2 and 3 months. Histopathological analysis of intestines demonstrated a progressive improvement in colitis (from grade-4 to grade-1 and -0) and decreased levels of IL-12 cytokine following transplantation. Fluorescent and confocal microscopy demonstrated presence of ES-EYFP cells in the colon, small intestine, liver, and thymus tissues but none in the spleen and bone marrow. The EYFP signal was not detected in sham (non-transplanted mice with induced colitis) and control IL10-/- KO mice. Engraftment, detected at 3 months post-transplant, correlated with markedly improved grading in colon histology (grade-1 or -0) and weight gain, as well as with decreased rectal prolapses. In vitro pre-differentiated ES cells migrated and homed exclusively into the colon, small intestine, and the liver, engrafted for long term, reduced inflammation and tissue damage, and restored immune balance. These findings suggest that pre-differentiated ES cells may become alternative source of stem cell therapy for CD with dual functions i.e. regenerating damaged epithelium and restoring immune imbalance occurring in this disease.

A regulatory role of Wnt signaling pathway in the hematopoietic differentiation of murine embryonic stem cells.

One of the most important issues in stem cell research is to understand the regulatory mechanisms responsible for their differentiation. An extensive understanding of mechanism underlying the process of differentiation is crucial in order to prompt stem cells to perform a particular function after differentiation. To elucidate the molecular mechanisms responsible for the hematopoietic differentiation of embryonic stem cells (ESCs), we investigated murine ES cells for the presence of hematopoietic lineage markers as well as Wnt signaling pathway during treatments with different cytokines alone or in combination with another. Here we report that Wnt/beta-catenin signaling is down-regulated in hematopoietic differentiation of murine ES cells. We also found that differentiation induced by the interleukin-3, interleukin-6, and erythropoietin combinations resulted in high expression of CD3e, CD11b, CD45R/B220, Ly-6G, and TER-119 in differentiated ES cells. A high expression of beta-catenin was observed in two undifferentiated ES cell lines. Gene and protein expression analysis revealed that the members downstream of Wnt in this signaling pathway including beta-catenin, GSK-3beta, Axin, and TCF4 were significantly down-regulated as ES cells differentiated into hematopoietic progenitors. Our results show that the Wnt/beta-catenin signaling pathway plays a role in the hematopoietic differentiation of murine ESCs and also may support beta-catenin as a crucial factor in the maintenance of ES cells in their undifferentiated state.

A role for biliverdin IXalpha in dorsal axis development of Xenopus laevis embryos.

The determinants of Xenopus laevis embryos that act before their first cell division are mandatory for the formation of mRNas required to establish the dorsal axis. Although their chemical identities are unknown, a number of their properties have long been recognized. One of the determinants is present in the cytoplasm and is sensitive to UV light. Thus, exposing stage 1 embryos to either standard 254-nm or, as shown here, to 366-nm UV light during the 0.3-0.4 time fraction of their first cycle inactivates the cytoplasmic determinant. As a consequence, both types of irradiated embryos fail to express dorsal markers, e.g., goosecoid and chordin, without affecting formation of ventral markers, e.g., Vent-1. The developmental outcome is dorsal axis-deficient morphology. We report here that biliverdin IXalpha, a normal constituent of cytoplasmic yolk platelets, is photo-transformed by irradiation with either 254- or 366-nm UV light and that the transformation triggers the dorsal axis deficiency. When the 254- or 366-nm UV-irradiated embryos, fated to dorsal axis deficiency, are incubated solely with microM amounts of biliverdin, they recover and form the axis. In contrast, incubation with either in vitro photo-transformed biliverdin or biliverdin IXalpha dimethyl ester does not induce recovery. The results define an approach to produce dorsal axis-deficient embryos by photo-transforming its biliverdin by irradiation with 366-nm UV light and identify an unsuspected role for biliverdin IXalpha in X. laevis embryogenesis.