Pseudoanaphylaxis

Profound hypotension and cardiac arrest after commencement of combined spinal and general anaesthesia in a patient for knee replacement surgery raised the suspicion of anaphylaxis. This seemed to be confirmed when a mast cell tryptase test taken about 90 minutes after the onset of the hypotension was elevated. However, subsequent intradermal skin testing twelve weeks later did not identify a causal drug. Repeat mast cell tryptase at the time showed the same elevation, which led to the correct diagnosis of mastocytosis and a secondary diagnosis that the patient's hypotension and cardiac arrest were the result of her spinal anaesthesia.

If the serum tryptase is elevated during the event but no allergic agent can be identified, a further serum tryptase should be taken several weeks later to exclude a persistent elevation due to mastocytosis.

Affirming Gender Identity of Patients With Serious Mental Illness

Transgender people who experience serious mental illness represent a uniquely vulnerable population. Because of limited research, however, recommendations for treating this population are scarce. In this article, the authors describe the challenge of recognizing gender dysphoria in people with serious mental illness. They then discuss why existing evidence and clinical experience support provision of gender-affirming medical and surgical treatments for transgender people who have serious mental illness and also demonstrate capacity to make informed medical decisions. More research is needed to develop evidence-based treatments and programs for transgender people with serious mental illness.

Voluntary intake and digestibility by sheep of alfalfa ensiled at different moisture concentrations following fertilization with dairy slurry

Dairy slurry is used commonly as an animal-sourced fertilizer in agronomic production. However, residual effects of slurry application on intake and digestibility of alfalfa (Medicago sativa L.) silage from subsequent harvests are not well known. The objective of this study was to determine if moisture concentration of alfalfa silage and timing of dairy slurry application relative to subsequent harvest affected intake and digestibility by sheep. Katahdin crossbred ewes (n = 18; 48 ± 5.3 kg) in mid-gestation were stratified by BW and allocated randomly in each of two periods to one of six treatments arranged in a two × three factorial arrangement. Treatments consisted of recommended (RM; 46.8%) or low (LM; 39.7%) moisture at baling after either no slurry application (NS), slurry application to stubble immediately after removal of the previous cutting (S0), or slurry application 14 d after removal of the previous cutting (S14). Silages were chopped through a commercial straw chopper, packed into plastic trash cans, and then offered to ewes within 4 d of chopping. Period 1 of the intake and digestion study consisted of a 14-d adaptation followed by a 7-d fecal collection period. Period 2 followed period 1 after a 4-d rest and consisted of an 11-d adaptation followed by 7 d of fecal collection. Ewes were housed individually in 1.4 × 4.3-m pens equipped with rubber mat flooring. Feces were swept from the floor twice daily, weighed, and dried at 50 °C. Ewes had ad libitum access to water and were offered chopped silage for a minimum of 10% refusal (DM). Blood samples were collected immediately prior to feeding, and 4 and 8 h after feeding on the day prior to the end of each period. Organic matter intake (g/kg BW) and OM digestibility tended (P < 0.10) to be, and digestible OM intake (g/kg BW) was reduced by slurry application. Lymphocytes (% of total white blood cells) were greater (P < 0.05) from LM vs. RM and from NS vs. S0 and S14. Red blood cell concentrations were greater (P < 0.05) from S14 vs. S0 and from S0 and S14 vs. NS. Serum urea N concentrations did not differ (P > 0.17) across treatments. Therefore, moisture concentration of alfalfa silage within the range used in this study may not affect voluntary intake or digestibility, but slurry application may have an effect on digestible OM intake. Also, moisture concentration of alfalfa silage and time of dairy slurry application may affect specific blood hemograms.

Effect of Renal Impairment on the Pharmacokinetics and Pharmacodynamics of Verinurad, a Selective Uric Acid Reabsorption Inhibitor

BACKGROUND AND OBJECTIVE: Verinurad (RDEA3170) is a high-affinity, selective URAT1 transporter inhibitor in development for treating gout and asymptomatic hyperuricemia. This Phase I, single-dose study investigated the pharmacokinetics, pharmacodynamics, and safety of verinurad in adults with renal impairment and controls with normal renal function.

METHODS

Males aged 18-85 years were enrolled with serum urate (sUA) 4.5-10 mg/dl and creatinine clearance 60- < 90, 30- < 60, 15- < 30, or ≥ 90 ml/min (mild, moderate, severe renal impairment and controls, respectively; n = 7/8). Verinurad 15 mg was administered orally under fasted conditions. Serial plasma/serum and urine samplings were 30 min pre-dose to 72 h post-dose.

RESULTS

Compared to controls, verinurad maximum observed plasma concentration increased by 53, 73, and 128% and area under the concentration-time curve increased by 24, 148, and 130%, in subjects with mild, moderate, and severe renal impairment, respectively; renal clearance decreased by 5, 42, and 79%. Exposures of major verinurad metabolites also increased with increasing renal impairment. Verinurad decreased sUA in all groups, with greater maximal changes in control and mild renal impairment than moderate and severe impairment groups (- 38.3, - 36.9, - 20.5, - 12.6%, respectively). There were no adverse event-related withdrawals or clinically meaningful changes in laboratory values.

CONCLUSION

Exposures of verinurad and metabolites increased with decreasing renal function. Consistent with the renal-dependent mechanism of action of verinurad, increasing severity of renal impairment was associated with decreased sUA lowering. Verinurad safety assessments were similar regardless of renal impairment. Continued investigation of verinurad is warranted in patients with gout and renal impairment. CLINICALTRIALS.

GOV IDENTIFIER

NCT02219516.

Oral Plasma Kallikrein Inhibitor for Prophylaxis in Hereditary Angioedema

BACKGROUND

Hereditary angioedema is a life-threatening illness caused by mutations in the gene encoding C1 inhibitor (also called C1 esterase inhibitor) that lead to overactivation of the kallikrein-bradykinin cascade. BCX7353 is a potent oral small-molecule inhibitor of plasma kallikrein with a pharmacokinetic and pharmacodynamic profile that may help prevent angioedema attacks.

METHODS

In this international, three-part, dose-ranging, placebo-controlled trial, we evaluated four doses of BCX7353 (62.5 mg, 125 mg, 250 mg, and 350 mg once daily) for the prevention of angioedema attacks over a 28-day period. Patients with type I or II hereditary angioedema with a history of at least two angioedema attacks per month were randomly assigned to BCX7353 or placebo. The primary efficacy end point was the number of confirmed angioedema attacks. Key secondary end points included angioedema attacks according to anatomical location and quality of life.

RESULTS

A total of 77 patients underwent randomization, 75 received BCX7353 or placebo, and 72 completed the trial. The rate of confirmed angioedema attacks was significantly lower among patients who received BCX7353 at daily doses of 125 mg or more than among those who received placebo, with a 73.8% difference at 125 mg (P<0.001). Significant benefits with respect to quality-of-life scores were observed in the 125-mg and 250-mg dose groups (P<0.05). Gastrointestinal adverse events, predominantly of grade 1, were the most commonly reported adverse events, particularly in the two highest BCX7353 dose groups.

CONCLUSIONS

Once-daily oral administration of BCX7353 at a dose of 125 mg or more resulted in a significantly lower rate of attacks of hereditary angioedema than placebo. Mild gastrointestinal symptoms were the principal side effect. (Funded by BioCryst Pharmaceuticals; APeX-1 ClinicalTrials.gov number, NCT02870972 .).

Efficacy and safety of 6 or 8 weeks of simeprevir, daclatasvir, sofosbuvir for HCV genotype 1 infection

The phase 2, open-label ACCORDION (ClinicalTrials.gov: NCT02349048) study investigated the efficacy, safety and pharmacokinetics of a 6- or 8-week regimen of simeprevir, daclatasvir and sofosbuvir in treatment-naïve patients with chronic hepatitis C virus (HCV) genotype (GT) 1 infection and either early-stage fibrosis or compensated cirrhosis. Patients were assigned to treatment groups according to their fibrosis stage. Early-stage fibrosis: simeprevir 150 mg, daclatasvir 60 mg, sofosbuvir 400 mg once daily for 6 weeks; compensated cirrhosis: same regimen for 8 weeks. The primary endpoint was sustained virologic response 12 weeks after the end of treatment (SVR12). Safety, tolerability and pharmacokinetics of simeprevir, daclatasvir and sofosbuvir were investigated. Sixty-eight patients were treated (6-week group: n = 59; 8-week group: n = 9). SVR12 was achieved by 86.4% (51/59) of patients with early-stage fibrosis and by 100% (9/9) of patients with cirrhosis. The main reason for not achieving SVR12 in the 6-week group was viral relapse (11.9%; 7/59). One patient had on-treatment failure due to an early withdrawal (lost to follow-up due to incarceration). One patient with SVR12 in the 6-week group had a late viral relapse at post-treatment week 24. No clinically significant drug-drug interactions were observed. Adverse events were reported in 63.2% of patients (43/68) and were mainly grade 1/2. None of these led to treatment discontinuation. The 3 direct-acting antiviral regimens of simeprevir, daclatasvir and sofosbuvir were safe and well tolerated in treatment-naïve, HCV GT1-infected patients with early-stage fibrosis or compensated cirrhosis.

Effects of rotating antibiotic and ionophore feed additives on volatile fatty acid production, potential for methane production, and microbial populations of steers consuming a moderate-forage diet

Ionophores and antibiotics have been shown to decrease ruminal methanogenesis both in vitro and in vivo but have shown little evidence toward a sustainable means of mitigation. Feed additive rotation was proposed and investigated for methane, VFA, and microbial population response. In the present study, cannulated steers ( = 12) were fed a moderate-forage basal diet in a Calan gate facility for 13 wk. In addition to the basal diet, steers were randomly assigned to 1 of 6 treatments: 1) control, no additive; 2) bambermycin, 20 mg bambermycin/d; 3) monensin, 200 mg monensin/d; 4) the basal diet + weekly rotation of bambermycin and monensin treatments (B7M); 5) the basal diet + rotation of bambermycin and monensin treatments every 14 d (B14M); and 6) the basal diet + rotation of bambermycin and monensin treatments every 21 d (B21M). Steers were blocked by weight in a randomized complete block design where the week was the repeated measure. Rumen fluid was collected weekly for analysis ( = 13), and results were normalized according to individual OM intake (OMI; kg/d). Potential activity of methane production was not significantly different among treatments ( > 0.05). However, treatment tended to affect the CH-to-propionate ratio ( = 0.0565), which was highest in the control and lowest in the monensin, B21M, and B14M treatments (0.42 vs. 0.36, 0.36, and 0.33, respectively). The CH:propionate ratio was lowest in wk 2 and 3 ( < 0.05) but the ratio in wk 4 to 12 was not different from the ratio in wk 0. Week also affected total VFA, with total VFA peaking at wk 3 and plummeting at wk 4 (4.02 vs. 2.86 m/kg OMI; < 0.05). A significant treatment × week interaction was observed for the acetate-to-propionate (A:P) ratio, where bambermycin- and rotationally fed steers did not have a reduced A:P ratio compared with monensin-fed steers throughout the feeding period ( < 0.0001). Microbial analysis revealed significant shifts, but several predominant classes showed adaptation between 4 and 6 wk after additive initiation. There was no significant evidence to suggest that rotations of monensin and bambermycin provided additional benefits to steers consuming a moderate-forage diet at the microbial/animal and environmental level versus those continuously fed.

Safety in FIH Trials: A Summary of the Symposium "Fatal Drug Trial in Phase 1: Understanding Risk, Subject Safety, Timelines, and Cost"

A cross-section of clinical research professionals convened at the June 2016 Drug Information Association annual meeting in Philadelphia to discuss and critically analyze the first-in-human (FIH) clinical trial conducted by a French CRO with BIA 10-2474 (BIA) under development for pain relief by Bial-Portela & Ca., S.A., that resulted in 6 healthy volunteers hospitalized with serious adverse events, which resulted in 1 death. This paper summarizes the background, presentations, and discussion points of Symposium no. 107 in an effort to share the learnings of our symposium with others who conduct studies. Novel investigational products studied in phase 1 clinical trials propose a heightened risk of adverse events that may not be foreseeable when relying on animal studies to project outcomes in humans. Novelty of molecular structure, drug class, mechanism of action, proper dose selection, pharmacokinetics, and therapeutic window are all contributing factors that heighten risks when transitioning from animal to human trials. The potential for catastrophic events confronts every sponsor/investigator in clinical trials. Minimizing risks to subjects is an essential ethical and scientific mandate for all those involved in the clinical trials. A complex matrix of planning, conducting, and communicating preclinical and clinical observations need to be considered carefully by the Sponsor, Investigator and others during the planning, execution, and interpretation of FIH studies, in order to promote participant safety and study data integrity. Suggestions may be applied to FIH studies, which may provide a new or improved way to address complex system and prevent or mitigate situations such as what occurred with the Bial FIH trial, where seemingly a number of issues coincided in a "perfect storm" and the system failed to sound a warning or detect an issue before a life was tragically lost.

The dynamics of the metabolism of acetate and bicarbonate associated with use of hemodialysates in the ABChD trial: a phase IV, prospective, single center, single blind, randomized, cross-over, two week investigation

Background

In the United States, hemodialysis (HD) is generally performed via a bicarbonate dialysate. It is not known if small amounts of acid used in dialysate to buffer the bicarbonate can meaningfully contribute to overall buffering administered during HD. We aimed to investigate the metabolism of acetate with use of two different acid buffer concentrates and determine if it effects blood bicarbonate concentrations in HD patients.

Methods

The Acid-Base Composition with use of hemoDialysates (ABChD) trial was a Phase IV, prospective, single blind, randomized, cross-over, 2 week investigation of peridialytic dynamics of acetate and bicarbonate associated with use of acid buffer concentrates. Eleven prevalent HD patients participated from November 2014 to February 2015. Patients received two HD treatments, with NaturaLyte® and GranuFlo® acid concentrates containing 4 and 8 mEq/L of acetate, respectively. Dialysate order was chosen in a random fashion. The endpoint was to characterize the dynamics of acetate received and metabolized during hemodialysis, and how it effects overall bicarbonate concentrations in the blood and dialysate. Acetate and bicarbonate concentrations were assessed before, at 8 time points during, and 6 time points after the completion of HD.

Results

Data from 20 HD treatments for 11 patients (10 NaturaLyte® and 10 GranuFlo®) was analyzed. Cumulative trajectories of arterialized acetate were unique between NaturaLyte® and GranuFlo® (p = 0.003), yet individual time points demonstrated overlap without remarkable differences. Arterialized and venous blood bicarbonate concentrations were similar at HD initiation, but by 240 min into dialysis, mean arterialized bicarbonate concentrations were 30.2 (SD ± 4.16) mEq/L in GranuFlo® and 28.8 (SD ± 4.26) mEq/L in NaturaLyte®. Regardless of acid buffer concentrate, arterial blood bicarbonate was primarily dictated by the prescribed bicarbonate level. Subjects tolerated HD with both acid buffer concentrates without experiencing any related adverse events.

Conclusions

A small fraction of acetate was delivered to HD patients with use of NaturaLyte® and GranuFlo® acid buffers; the majority of acetate received was observed to be rapidly metabolized and cleared from the circulation. Blood bicarbonate concentrations appear to be determined mainly by the prescribed concentration of bicarbonate.

Trial registration

This trial was registered on ClinicalTrials.gov on 11 Dec 2014 (NCT02334267).

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0683-6) contains supplementary material, which is available to authorized users.

The clinical spectrum of omega-5-gliadin allergy

BACKGROUND

IgE-mediated allergy to the wheat protein omega-5-gliadin (O5G) is associated with wheat-dependent exercise-induced anaphylaxis (WDEIA), where exercise acts as a cofactor, triggering anaphylaxis after wheat ingestion. The wider application of O5G-specific IgE (sIgE) testing has revealed that the manifestations of O5G allergy extend beyond WDEIA.

AIMS

This study documents clinical manifestations in a large series of patients with sIgE to O5G.

METHODS

A retrospective clinical audit was performed on adult patients with a positive O5G sIgE (>0.35kU/L) between 2007 and 2013 compared with a group who had negative O5G sIgE. Clinical characteristics and skin prick test (SPT) results were examined.

RESULTS

Sixty-seven patients were characterised, 26 of whom presented with food-dependent exercise-induced allergy, whilst others presented with exercise-induced symptoms without apparent food association (16/67), idiopathic anaphylaxis (10/67), food-induced allergic symptoms without exercise (10/67) or recurrent acute urticaria (5/67). Specific IgE to O5G had 91% sensitivity and 92% specificity for wheat-related allergic symptoms. SPT had sensitivity of 92% and specificity of 84%.

CONCLUSION

WDEIA is the most common manifestation of O5G allergy, but patients may present with a variety of allergic manifestations, and wheat allergy is not always obvious on history. Non-exercise cofactors or a lack of cofactors were identified in many patients. A distinctive feature of this allergy is that despite regular wheat ingestion, allergic reactions to wheat occur infrequently. Testing for sIgE to O5G should be considered in patients presenting with exercise-induced urticaria/anaphylaxis, idiopathic anaphylaxis and recurrent acute (but not chronic) urticaria.

Feeding distillers' grains, soybean hulls, or a mixture of both to cows as a forage replacement: Effects on intake, digestibility, and ruminal fermentation characteristics

Coproduct feedstuffs offer a unique and potentially profitable avenue for cattle feeding strategies. However, research is lacking in the evaluation of varying coproducts on ruminal fermentation and digestive characteristics when included as the major component of the diet of cows. Our objective was to determine the effect of coproduct feedstuffs as a forage replacement on digestive and fermentative characteristics of cows. Eight ruminally fistulated cows (672 ± 32.0 kg initial BW and approximately 9 yr of age) were stratified by BW and randomly allocated to 1 of 4 diets (2 cows∙diet∙period) in a 2-period study: soybean hulls (SH), distillers' dried grains with solubles (DG), an isoenergetic mixture of soybean hulls and distillers' dried grains with solubles (MX), or ad libitum hay plus 0.9 kg/d of an isoenergetic mixture of soybean hulls and distillers' dried grains with solubles (HY). Diets were formulated to meet the ME requirements of a similar, companion study. Coproduct amounts were increased over a 14-d period. This was followed by a 14-d adaptation to diet and facilities and 5 d of total fecal collections. On the final day of fecal collections, rumen fluid was sampled immediately prior to feeding and 2, 4, 6, 8, 10 and 12 h after feeding for measurement of rumen VFA and ammonia concentrations. Intake of DM and OM was not different ( ≥ 0.28) among treatments, but digestibilities of DM, OM, NDF, and ADF were improved ( < 0.05) by coproduct feeding and by MX vs. the mean of SH and DG. Ruminal DM and OM fill were greater ( < 0.05) for cows offered HY than for cows offered the coproduct diets, greater for cows offered SH than for cows offered DG, and for the mean of SH and DG vs. MX. Ruminal retention time was greater ( < 0.05) for HY vs. the coproduct diets and for SH vs. DG. Apparent N absorption tended ( < 0.10) to be greater for cows offered the coproduct diets than for cows offered HY and greater for cows offered DG than for cows offered SH. Total VFA averaged across sampling times were greatest ( < 0.05) for cows offered SH, and ruminal ammonia N was greatest ( < 0.05) for cows offered either DG or MX at all sampling times. Based on these data, coproduct feedstuffs may be fed to meet the energy requirement of cows without negative effects on digestion or ruminal fermentation.

Special Populations in Clinical Pharmacology Studies: Evolving Challenges

The clinical research industry is changing, and the number of protocols requiring specialty populations for early-phase clinical studies is increasing. In particular, the demand for studies on renal specialty populations has grown, given the prominent role of the renal system in excreting drugs from the body. Understanding the challenges associated with the use of specialty populations is critical to ensure that the study design will allow for the timely and successful completion of the project, while minimizing costs and safety risks.

Hot Button Protocol and Operational Issues Between Sponsors and Sites in Clinical Pharmacology Studies: A Moderated Forum Session

This paper summarizes a discussion that took place at the 52nd Annual DIA Meeting in Philadelphia, PA, on June 30, 2016, titled "Hot-Button Protocol and Operational Issues between Sponsors and Sites in Clinical Pharmacology Studies." The symposium was a moderated panel of phase 1 clinical research experts representing the sponsor, and investigational sites. Conference attendees of similar experience joined in the discussion after commentary by each panelist. The learning objectives of the symposium were (1) to recognize issues that can provoke sponsor/site conflict or diminish conduct efficiency when they arise in the course of preparing to conduct or execution of phase 1 clinical studies, (2) to discuss how to handle such issues with counterparts when they arise and describe ways to negotiate and formulate a successful resolution. Sponsors and sites both have challenges in executing clinical trials on time and within budget. Both need to set and maintain realistic expectations and communicate with honesty, transparency, and timeliness. Achieving this goal will advance the more important take-away message, that developing new drugs requires sound execution of clinical trials.

Medial compartment knee osteoarthritis: age-stratified cost-effectiveness of total knee arthroplasty, unicompartmental knee arthroplasty, and high tibial osteotomy

PURPOSE

To compare the age-based cost-effectiveness of total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and high tibial osteotomy (HTO) for the treatment of medial compartment knee osteoarthritis (MCOA).

METHODS

A Markov model was used to simulate theoretical cohorts of patients 40, 50, 60, and 70 years of age undergoing primary TKA, UKA, or HTO. Costs and outcomes associated with initial and subsequent interventions were estimated by following these virtual cohorts over a 10-year period. Revision and mortality rates, costs, and functional outcome data were estimated from a systematic review of the literature. Probabilistic analysis was conducted to accommodate these parameters' inherent uncertainty, and both discrete and probabilistic sensitivity analyses were utilized to assess the robustness of the model's outputs to changes in key variables.

RESULTS

HTO was most likely to be cost-effective in cohorts under 60, and UKA most likely in those 60 and over. Probabilistic results did not indicate one intervention to be significantly more cost-effective than another. The model was exquisitely sensitive to changes in utility (functional outcome), somewhat sensitive to changes in cost, and least sensitive to changes in 10-year revision risk.

CONCLUSIONS

HTO may be the most cost-effective option when treating MCOA in younger patients, while UKA may be preferred in older patients. Functional utility is the primary driver of the cost-effectiveness of these interventions. For the clinician, this study supports HTO as a competitive treatment option in young patient populations. It also validates each one of the three interventions considered as potentially optimal, depending heavily on patient preferences and functional utility derived over time.

Development of a Potent and Selective HDAC8 Inhibitor

A novel, isoform-selective inhibitor of histone deacetylase 8 (HDAC8) has been discovered by the repurposing of a diverse compound collection. Medicinal chemistry optimization led to the identification of a highly potent (0.8 nM) and selective inhibitor of HDAC8.

Marking nut anaphylaxis

Marking nut Semecarpus anacardium, so-called because it contains a pigment that has been used in the past to mark fabrics, is a known cause of contact hypersensitivity. It may be ingested as an ingredient of some traditional Hindi foods. We describe the first reported case of anaphylaxis to marking nut.

Modular synthesis and biological activity of pyridyl-based analogs of the potent Class I Histone Deacetylase Inhibitor Largazole

The formation of a series of analogs containing a pyridine moiety in place of the natural thiazole heterocycle, based on the potent, naturally occurring HDAC inhibitor Largazole has been accomplished. The synthetic strategy was designed modularly to access multiple inhibitors with different aryl functionalities containing both the natural depsipeptide and peptide isostere variant of the macrocycle. The cytotoxicity and biochemical activity of the library of HDAC inhibitors is described herein.

Pierre R, Varca AC, Wu L, Marineau JJ, Smith WB, Souza A, Chory EJ, Armstrong SA, Bradner JE. Structure-guided DOT1L probe optimization by label-free ligand displacement

The DOT1L lysine methyltransferase has emerged as a validated therapeutic target in MLL-rearranged (MLLr) acute leukemias. Although S-adenosylmethionine competitive inhibitors have demonstrated pharmacological proof-of-principle in MLLr-leukemia, these compounds require further optimization to improve cellular potency and pharmacokinetic stability. Limiting DOT1L inhibitor discovery and ligand optimization have been complex biochemical methods often using radionucleotides and cellular methods requiring prolonged culture. We therefore developed a new suite of assay technologies that allows comparative assessment of chemical tools for DOT1L in a miniaturized format. Coupling these assays with structural information, we developed new insights into DOT1L ligand binding and identified several functionalized probes with increased cellular potency (IC₅₀ values ∼10 nM) and excellent selectivity for DOT1L. Together these assay technologies define a platform capability for discovery and optimization of small-molecule DOT1L inhibitors.