Unexpected Stability of a Prodrug to Enzymatic Hydrolysis within a Hydrated HPMC Matrix Tablet.

The uptake of alkaline phosphate present in dissolution medium into a hydrating hydroxypropyl methylcellulose matrix tablet and that its activity was retained therein was demonstrated. This presents a risk to the stability of prodrugs that are substrates of this enzyme such as phosphonooxymethyl derivative prodrugs. It was found that fostemsavir, a phosphonooxymethyl derivative prodrug being developed for the treatment of HIV-1 infection, was unexpectedly resistant to hydrolysis within a hydrated HPMC matrix when subjected to drug release testing in media containing alkaline phosphatase. Studies indicated that this was not due to microenvironmental pH effects, osmolality effects or effective phosphate concentration effects associated with the presence of the prodrug. That the prodrug and not its parent could affect enzyme activity in a concentration dependent manner, and that another phosphate ester prodrug fosphenytoin did not inhibit alkaline phosphatase activity within a hydrated HPMC matrix suggested that the unexpected stability of the HIV-1 therapy prodrug may be associated with the ability of the phosphate group-containing compound itself to inhibit the enzyme at the concentrations it exists at in the hydrated dosage form and so enables the development of the compound in this type of dosage form.

Having permission not to remember: perspectives on interventions for post-traumatic stress disorder in the absence of trauma memory.

Background: It is possible for people to have post-traumatic stress disorder (PTSD) without memory of the trauma event, such as in drug-facilitated sexual assault. However, there is little evidence available on treatment provision for this population. Objective: This study aimed to address this gap by exploring the experiences of people who have had psychological intervention for PTSD without memories (PwM). Method: Interpretative phenomenological analysis was used to explore the lived experience of nine women with PwM, who had sought psychological assessment/therapy. Participants were recruited via social media and completed semi-structured interviews online/via telephone. Results: Identified themes concerned two broad areas: (i) the challenges of having therapy whilst lacking memories and (ii) what was helpful in therapy. Challenges included: delayed help-seeking; having emotional/sensory reactions in the absence of recognisable triggers; experiencing therapy as more applicable to remembered trauma (vs. unremembered); and difficulty discussing and processing unremembered trauma. However, participants also described helpful aspects of therapy including: feeling safe and supported; working with emotional and sensory forms of experience; having scientific explanations for trauma and memory; and having 'permission' from therapists not to remember. Conclusions: Recommendations for clinicians included: being aware that clients with PwM may have more difficulty accessing treatment and perceive it as less applicable to them; focussing on clients' emotions and sensations (not cognitive memories) in therapy; and supporting clients to develop a more self-compassionate understanding of their experiences and lack of memory, thus supporting them to accept that not remembering is 'permitted'. HIGHLIGHTS: • Having therapy for unremembered trauma involves unique challenges, but aspects of therapy can still be helpful.• Suggested 'dos and don'ts' for therapists include recognising the additional barriers to treatment, focussing on emotions (not memories), and normalising memory loss.

Antecedentes: Es posible que las personas tengan un trastorno de estrés postraumático (TEPT) sin recordar el evento traumático, como en una agresión sexual facilitada por drogas. Sin embargo, hay poca evidencia disponible sobre la provisión de tratamiento para esta población.Objetivo: Este estudio tuvo como objetivo abordar esta brecha mediante la exploración de las experiencias de las personas que han tenido una intervención psicológica para TEPT sin recuerdos (PwM en su sigla en inglés).Método: Se usó análisis fenomenológico interpretativo para explorar la experiencia vivida de nueve mujeres con PwM, quienes habían buscado una evaluación/terapia psicológica. Las participantes fueron reclutadas a través de redes sociales y completaron entrevistas semiestructuradas en línea o por teléfono.Resultados: Los temas identificados se referían a dos grandes áreas: (i) los desafíos de tener terapia mientras se carece de memoria; y (ii) lo que fue útil en la terapia. Los desafíos incluyeron: búsqueda de ayuda retardada; tener reacciones emocionales/sensoriales en ausencia de desencadenantes reconocibles; experimentar la terapia como más aplicable al trauma recordado (frente no recordado); y dificultad en discutir y procesar el trauma no recordado. Sin embargo, los participantes tambien describieron aspectos útiles de la terapia incluidos: sentirse seguros y apoyados; trabajar con formas de experiencia emocional y sensorial; tener explicaciones científicas para el trauma y el recuerdo; y tener 'permiso' de los terapeutas para no recordar.Conclusiones: Las recomendaciones para el clínico incluyeron: ser conscientes de que los clientes con PwM pueden tener más dificultades para acceder al tratamiento y percibirlo como menos aplicable a ellos; en la terapia centrarse en las emociones y sensaciones de los clientes (no en los recuerdos cognitivos); y apoyar a los clientes a desarrollar una comprensión más compasiva de sus experiencias y falta de recuerdos, apoyando así que acepten que no recordar está 'permitido'.

A phase 2 trial of avelumab in men with aggressive-variant or neuroendocrine prostate cancer.

BACKGROUND: Men with progressive neuroendocrine or aggressive-variant metastatic prostate cancer (NEPC/AVPC) have a poor prognosis and limited treatment options, and immunotherapy has not been tested in such patients. METHODS: We conducted an open label single center phase 2 trial (NCT03179410) of men with progressive NEPC/AVPC either defined by histology or AVPC criteria. Avelumab (10 mg/kg every 2 weeks) was administered until progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR). Secondary endpoints included ORR, radiographic progression-free survival (rPFS), overall survival, and safety. Correlative studies included longitudinal peripheral blood immune phenotyping. The study was limited by the small number of patients enrolled and by the early termination due to COVID-19. RESULTS: A total of 15 men with AVPC/NEPC were enrolled. The median age was 71 (range 51-85 years), and men had received a median of two prior therapies (range 1-3). Median PSA was 54 ng/dl (range 0-393), and 73% of men had liver metastasis. The ORR with avelumab in this setting by iRECIST or RECIST 1.1 was 6.7%, including one patient (6.7%) with a complete remission (CR), 20% with stable disease, and 67% with progressive disease. The patient with the CR had an MSH2 somatic mutation and MSI-high NEPC with central nervous system metastases, and his CR remains durable off all therapy for 2 years. The median rPFS was 1.8 months (95% CI 1.6-3.6 months), and median overall survival was 7.4 months (85% CI 2.8-12.6 months). Safety was consistent with the known profile of avelumab. Phenotyping of peripheral immune subsets suggest enhanced CXCR2-dependent myeloid and T-cell responses in this extraordinary responder. CONCLUSIONS: While the study was terminated early due to slow enrollment at the onset of the COVID-19 pandemic and lower than anticipated objective response rate, PD-L1 inhibition with avelumab monotherapy showed poor efficacy in patients with microsatellite stable NEPC/AVPC. Immune profiling revealed enhanced CXCR2 positive immune cell activation in the one extraordinary responder, suggesting potential mechanisms for further immunotherapy development in this population.

Pharmacodynamic study of radium-223 in men with bone metastatic castration resistant prostate cancer.

BACKGROUND: Radium-223 is a targeted alpha-particle therapy that improves survival in men with metastatic castration resistant prostate cancer (mCRPC), particularly in men with elevated serum levels of bone alkaline phosphatase (B-ALP). We hypothesized that osteomimicry, a form of epithelial plasticity leading to an osteoblastic phenotype, may contribute to intralesional deposition of radium-223 and subsequent irradiation of the tumor microenvironment. METHODS: We conducted a pharmacodynamic study (NCT02204943) of radium-223 in men with bone mCRPC. Prior to and three and six months after radium-223 treatment initiation, we collected CTCs and metastatic biopsies for phenotypic characterization and CTC genomic analysis. The primary objective was to describe the impact of radium-223 on the prevalence of CTC B-ALP over time. We measured radium-223 decay products in tumor and surrounding normal bone during treatment. We validated genomic findings in a separate independent study of men with bone metastatic mCRPC (n = 45) and publicly accessible data of metastatic CRPC tissues. RESULTS: We enrolled 20 men with symptomatic bone predominant mCRPC and treated with radium-223. We observed greater radium-223 radioactivity levels in metastatic bone tumor containing biopsies compared with adjacent normal bone. We found evidence of persistent Cellsearch CTCs and B-ALP (+) CTCs in the majority of men over time during radium-223 therapy despite serum B-ALP normalization. We identified genomic gains in osteoblast mimicry genes including gains of ALPL, osteopontin, SPARC, OB-cadherin and loss of RUNX2, and validated genomic alterations or increased expression at the DNA and RNA level in an independent cohort of 45 men with bone-metastatic CRPC and in 150 metastatic biopsies from men with mCRPC. CONCLUSIONS: Osteomimicry may contribute in part to the uptake of radium-223 within bone metastases and may thereby enhance the therapeutic benefit of this bone targeting radiotherapy.

Determination of 2-Hydroxypyridine-1-Oxide (HOPO) at sub-ppm levels using derivitization and gas chromatography with mass spectrometry detection (GCMS).

This work describes the development and validation of an analytical method to determine residual trace levels of 2-Hydroxypyridine-1-Oxide (HOPO) in an active pharmaceutical ingredient (API). A method was required to be specific and sensitive enough to determine sub-ppm levels of this reagent. The approach taken to use a derivitization step overcame two of the primary challenges associated with the analysis of HOPO. Firstly, HOPO can tautomerize and the derivitization step provides a single stable entity to monitor, and secondly, the reaction enhances the volatility of the analyte to facilitate the use of gas chromatography. Mass spectrometry detection provides both suitable specificity and sensitivity. This paper describes the method development and optimisation of the derivitization step, the chromatographic conditions and mass spectrometry detection, together with a summary of the validation of the method. The method has been demonstrated to be robust and suitable to determine HOPO levels in commercially manufactured API materials.

Cigarette smoke-induced Ca2+ release leads to cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction.

Chronic obstructive pulmonary disease affects 64 million people and is currently the fourth leading cause of death worldwide. Chronic obstructive pulmonary disease includes both emphysema and chronic bronchitis, and in the case of chronic bronchitis represents an inflammatory response of the airways that is associated with mucus hypersecretion and obstruction of small airways. Recently, it has emerged that exposure to cigarette smoke (CS) leads to an inhibition of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel, causing airway surface liquid dehydration, which may play a role in the development of chronic bronchitis. CS rapidly clears CFTR from the plasma membrane and causes it to be deposited into aggresome-like compartments. However, little is known about the mechanism(s) responsible for the internalization of CFTR following CS exposure. Our studies revealed that CS triggered a rise in cytoplasmic Ca(2+) that may have emanated from lysosomes. Furthermore, chelation of cytoplasmic Ca(2+), but not inhibition of protein kinases/phosphatases, prevented CS-induced CFTR internalization. The macrolide antibiotic bafilomycin A1 inhibited CS-induced Ca(2+) release and prevented CFTR clearance from the plasma membrane, further linking cytoplasmic Ca(2+) and CFTR internalization. We hypothesize that CS-induced Ca(2+) release prevents normal sorting/degradation of CFTR and causes internalized CFTR to reroute to aggresomes. Our data provide mechanistic insight into the potentially deleterious effects of CS on airway epithelia and outline a hitherto unrecognized signaling event triggered by CS that may affect the long term transition of the lung into a hyper-inflammatory/dehydrated environment.

Nonantibiotic macrolides prevent human neutrophil elastase-induced mucus stasis and airway surface liquid volume depletion.

Mucus clearance is an important component of the lung's innate defense system. A failure of this system brought on by mucus dehydration is common to both cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). Mucus clearance rates are regulated by the volume of airway surface liquid (ASL) and by ciliary beat frequency (CBF). Chronic treatment with macrolide antibiotics is known to be beneficial to both CF and COPD patients. However, chronic macrolide usage may induce bacterial resistance. We have developed a novel macrolide, 2'-desoxy-9-(S)-erythromycylamine (GS-459755), that has significantly diminished antibiotic activity against Staphylococcus aureus, Streptococcus pneumonia, Moraxella catarrhalis, and Haemophilus influenzae. Since neutrophilia frequently occurs in chronic lung disease and human neutrophil elastase (HNE) induces mucus stasis by activating the epithelial sodium channel (ENaC), we tested the ability of GS-459755 to protect against HNE-induced mucus stasis. GS-459755 had no effect on HNE activity. However, GS-459755 pretreatment protected against HNE-induced ASL volume depletion in human bronchial epithelial cells (HBECs). The effect of GS-459755 on ASL volume was dose dependent (IC50 ~3.9 µM) and comparable to the antibacterial macrolide azithromycin (IC50 ~2.4 µM). Macrolides had no significant effect on CBF or on transepithelial water permeability. However, the amiloride-sensitive transepithelial voltage, a marker of ENaC activity, was diminished by macrolide pretreatment. We conclude that GS-459755 may limit HNE-induced activation of ENaC and may be useful for the treatment of mucus dehydration in CF and COPD without inducing bacterial resistance.

Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration.

Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.

TGFbeta3 and loading increases osteocyte survival in human cancellous bone cultured ex vivo.

The goal of this study was to assess the effect of the addition of TGFbeta(3), alone or in combination with loading, on the survival of osteocytes in 3D human explant cancellous bone during long-term culture in an ex vivo loading bioreactor. Human cancellous bone explants were cultured for up to 14 days with or without TGFbeta(3) (15 ng ml(-1)) and with or without loading (300 cycles, at 1 Hz, producing 4000 microstrain). Bone core response was visualized using undecalcified histology with morphological methods after embedding with Technovit 9100 New resin. Histological examination revealed normal gross level bone structure with or without the application of load or the addition of TGFbeta(3). The viability of the osteocytes within the bone was assessed by lactate dehydrogenase (LDH) activity. We demonstrate that this ex vivo loading bioreactor is able to maintain a high percentage (over 50%) of viable osteocytes throughout the bone explants after 14 days in ex vivo culture. Further to this, the combination of daily loading and TGFbeta(3) administration produced superior osteocyte survival at the core centres when compared to loading or TGFbeta alone.

Oxidative DNA damage in osteoarthritic porcine articular cartilage.

Osteoarthritis (OA) is associated with increased levels of reactive oxygen species. This study investigated if increased oxidative DNA damage accumulates in OA articular cartilage compared with non-OA articular cartilage from pigs with spontaneous OA. Additionally, the ability of nitric oxide (NO) or peroxynitrite (ONOO(-)) induced DNA damage in non-OA chondrocytes to undergo endogenous repair was investigated. Porcine femoral condyles were graded for the stage of OA, macroscopically by the Collins Scale, and histologically by the modified Mankin Grade. Levels of DNA damage were determined in non-OA and OA cartilage, using the comet assay. For calibration, DNA damage was measured by exposing non-OA chondrocytes to 0-12 Gray (Gy) of X-ray irradiation. Non-OA articular chondrocytes were treated with 0-500 microM of NO donors (NOC-18 or SIN-1), and DNA damage assessed after treatment and 5 days recovery. A significant increase (P < 0.01) in oxidative DNA damage occurred in OA chondrocytes in joints with Mankin Grades 3 or greater, compared to non-OA chondrocytes. The percentage of nuclei containing DNA damage increased significantly (P < 0.001) from early to late grades of OA. An increase of approximately 0.65-1.7 breaks/1,000 kb of DNA occurred in OA, compared to non-OA nuclei. NOC-18 or SIN-1 caused significant DNA damage (P < 0.001) in non-OA chondrocytes that did not undergo full endogenous repair after 5 days (P < 0.05). Our data suggest significant levels of oxidative DNA damage occur in OA chondrocytes that accumulates with OA progression. Additionally, DNA damage induced by NO and ONOO(-) in non-OA chondrocytes does not undergo full endogenous repair.