Characterization of a recombinant factor IX molecule fused to coagulation factor XIII-B subunit

INTRODUCTION AND AIM

Severe haemophilia B (HB) is characterized by spontaneous bleeding episodes, mostly into joints. Recurrent bleeds lead to progressive joint destruction called haemophilic arthropathy. The current concept of prophylaxis aims at maintaining the FIX level >3-5 IU/dL, which is effective at reducing the incidence of haemophilic arthropathy. Extended half-life FIX molecules make it easier to achieve these target trough levels compared to standard FIX concentrates. We previously reported that the fusion of a recombinant FIX (rFIX) to factor XIII-B (FXIIIB) subunit prolonged the half-life of the rFIX-LXa-FXIIIB fusion molecule in mice and rats 3.9- and 2.2-fold, respectively, compared with rFIX-WT. However, the mechanism behind the extended half-life was not known.

MATERIALS AND METHODS

Mass spectrometry and ITC were used to study interactions of rFIX-LXa-FXIIIB with albumin. Pharmacokinetic analyses in fibrinogen-KO and FcRn-KO mice were performed to evaluate the effect of albumin and fibrinogen on in-vivo half-life of rFIX-LXa-FXIIIB. Finally saphenous vein bleeding model was used to assess in-vivo haemostatic activity of rFIX-LXa-FXIIIB.

RESULTS AND CONCLUSION

We report here the key interactions that rFIX-LXa-FXIIIB may have in plasma are with fibrinogen and albumin which may mediate its prolonged half-life. In addition, using the saphenous vein bleeding model, we demonstrate that rFIX-FXIIIB elicits functional clot formation that is indistinguishable from that of rFIX-WT.

Dissipation kinetics, decontamination, consumer risk assessment and monitoring of flonicamid and imidacloprid residues in capsicum under open field and polyhouse condition

Liquid chromatography mass spectrometry (LC-MS)-based detection of flonicamid, imidacloprid and 6-chloronicotinic acid residues was validated and analysed in capsicum fruit, processed products and soil. The standard concentrations (0.0025 to 0.25 μg mL-1) of insecticides had a good linear curve (r2>0.99). Limit of detection and limit of quantification values were 0.0025 and 0.01 mg kg-1, respectively. The accuracy (80.53 to 100.33 %) of capsicum matrices and soil (89.41 to 100.52 %) and precision (RSD <10%) were established. Dissipation of imidacloprid (20 and 40 g a.i. ha-1) and flonicamid (75 and 150 g a.i. ha-1) at single (X) and double dose (2X) was studied under open field and polyhouse conditions. Under open field conditions, the flonicamid and imidacloprid residues persisted with half-life of 1.98, 2.90 days (X) and 2.80, 3.14 (2X) days, respectively. While under polyhouse conditions, the flonicamid and imidacloprid residues persisted with a half-life of 2.84, 3.66 (X) and 3.24, 3.97 (2X) days, respectively. The metabolite, 6-CNA, was not detected in any samples under open field and polyhouse condition. Among decontamination treatments, cooking in boiling water for 10 minutes reduced 78 to 81.60 percent of imidacloprid and flonicamid residues in both doses. The estimated dietary risk assessment of imidacloprid and flonicamid residues (RQ <1) indicated that the risk is within the acceptable limit. In farmgate capsicum samples, residues of flonicamid (7 samples) and imidacloprid (11 samples) were detected. Market samples of capsicum products (powder, flakes and sauce) were not detected with residues of selected insecticides.

Influence of CYP3A5 and ABCB1 polymorphisms on the pharmacokinetics of vincristine in adult patients receiving CHOP therapy

PURPOSE

This study aims to clarify the impact of CYP3A5 and ABCB1 polymorphisms on the pharmacokinetics of vincristine (VCR) in adult patients receiving CHOP therapy.

METHODS

Plasma samples were collected immediately after the end of VCR administration and at 1.5, 2.5, 3.5, 5.5, 9.5, 13.5, and 25.5 h after the start of administration. Areas under the plasma concentration-time curves of VCR in the elimination phase (AUC1.5-25.5) were calculated using the linear trapezoidal rule. Half-lives of VCR during the early phase (1.5-5.5 h) and terminal phase (5.5-25.5 h; t1/2γ) were determined according to the log-linear regression of the concentration-time data for at least 3 sampling points.

RESULTS

A total of 41 adult patients were enrolled in this study. The median t1/2γ and AUC1.5-25.5 were significantly longer and higher in CYP3A5 non-expressers (CYP3A5*3/*3) than in CYP3A5 expressers (CYP3A5*1/*1 or *1/*3) (21.3 vs 13.8 h, P = 0.005 and 35.5 vs 30.0 ng･h/mL, P = 0.006, respectively). Conversely, there were no significant differences in pharmacokinetic parameters among the ABCB1 c.1236C>T, c.2677G>A/T, c.3435C>T genotype groups. A stepwise selection multiple linear regression analysis showed that the dose of VCR administered and CYP3A5 non-expresser status were independent factors influencing the AUC1.5-25.5 (partial R2 = 0.212, P = 0.002 and partial R2 = 0.143, P = 0.010, respectively).

CONCLUSION

The CYP3A5*3 polymorphism was found to be an indicator for predicting exposure to VCR in adult patients receiving CHOP therapy. This information may be useful for the individualization of VCR dosages.

Identification and in vivo detection of side-chain hydroxylated metabolites of 4β-hydroxycholesterol

Oxysterols are oxidized derivatives of cholesterol that are formed by enzymatic processes or through the action of reactive oxygen species. Several of these bioactive lipids have been shown to be affected and/or play a role in inflammatory processes. 4β-hydroxycholesterol is one of the major oxysterols in mice and humans and its levels are affected by inflammatory diseases. However, apart from its long half-life, little is known about its catabolism. By incubating 4β-hydroxycholesterol with mouse mitochondria-enriched liver fractions, as well as 25-hydroxycholesterol and 27-hydroxycholesterol with recombinant CYP3A4, we identified 4β,25-dihydroxycholesterol and 4β,27-dihydroxycholesterol as 4β-hydroxycholesterol metabolites. Supporting the biological relevance of this metabolism, we detected both metabolites after incubation of J774, primary mouse peritoneal macrophages and PMA-differentiated THP-1 cells with 4β-hydroxycholesterol. Across our experiments, the incubation of cells with lipopolysaccharides differentially affected the levels of the 25- and 27-hydroxylated metabolites of 4β-hydroxycholesterol. Finally, 4β,27-dihydroxycholesterol was also detected in mice liver and plasma after intraperitoneal administration of 4β-hydroxycholesterol. To our knowledge, this is the first report of the in vitro and in vivo detection and quantification of 4β-hydroxycholesterol metabolites.

Pharmacokinetics of Nifedipine-Sustained Release Tablets in Healthy Subjects After a Single Oral Administration: Bioequivalence Analysis and Food Effects

We compared newly developed delayed-release oral tablets (test) of 30-mg nifedipine (NFP) with its marketed counterpart (30 mg; reference) in healthy adult Chinese volunteers to assess the former's bioequivalence. This was a randomized, open-label, four-period, crossover trial study including fasting and fed trials. The participants were randomly administered test or reference formulations (1:1 ratio) throughout each period, with a 7-day washout period. In the next session, they were administered the alternate products. Liquid chromatography-tandem mass spectrometry and WinNonlin software were used to evaluate the bioequivalence of the maximum plasma concentration (Cmax ) of NFP and the area under the concentration-time curve (AUC). In total, 46 and 48 people participated in the fasting and postprandial trials. In both groups, the 90% confidence intervals of geometric mean ratios of Cmax , AUC from time zero to time t, and AUC from time zero to infinity were in the equivalence range (80%-125%). When NFP was administered concomitantly with a high-fat meal, time to maximum concentration was approximately twofold earlier, absorption was approximately 4.8% less, and Cmax exhibited a slight change relative to those under fasting conditions. Moreover, no serious adverse events were recorded in the participants. The present findings confirm the bioequivalence of test and reference formulations of NFP tablets under fasting and postprandial conditions.

Safety, tolerability, and pharmacokinetics of half-life extended SARS-CoV-2-neutralizing monoclonal antibodies AZD7442 (tixagevimab/cilgavimab) in healthy Japanese adults

INTRODUCTION

The aim of this study was to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of AZD7442 (tixagevimab/cilgavimab) in healthy Japanese adults.

METHODS

In this randomized, double-blind, placebo-controlled, phase 1 study, AZD7442 was administered intramuscularly (300 or 600 mg) or intravenously (300 or 1000 mg) to healthy Japanese adults. Primary endpoints were safety, tolerability, and pharmacokinetics. Anti-drug antibodies and neutralizing antibody activities were secondary endpoints.

RESULTS

A total of 40 participants were randomized to receive AZD7442 (n = 30) or placebo (n = 10). Adverse events (AEs) occurred in 12 (40%) and 3 (30%) participants, respectively; there were no deaths, serious AEs, or AEs leading to study withdrawal. Tixagevimab and cilgavimab had mean half-lives of 82.1-95.9 and 77.9-92.0 days, respectively, which were generally similar regardless of administration route. SARS-CoV-2-neutralizing antibody titers were >4-fold higher than baseline levels from Day 8 to Day 211 in participants receiving AZD7442.

CONCLUSIONS

AZD7442 was well tolerated in healthy Japanese adults, with predictable pharmacokinetics and an extended half-life, consistent with previous studies.

CLINICALTRIALS

gov, NCT04896541.

Cases of less-than-expected FVIII activity in previously treated patients during post-marketing surveillance of N8-GP

INTRODUCTION

Turoctocog alfa pegol (N8-GP) is a glycoPEGylated, extended half-life (EHL), human recombinant factor VIII (FVIII) approved for the treatment and prevention of bleeding episodes in patients with haemophilia A. Since its launch in August 2019, > 800 patients have been treated worldwide.

AIM

To present data from identified post-marketing cases of less-than-expected FVIII activity in previously treated patients (PTPs) without inhibitors after switching to N8-GP.

METHODS

The post-marketing safety database was searched using keywords such as 'coagulation FVIII level decreased'. Identified cases reported prior to 13 October 2021 were included in this report. Cases in which patients had FVIII inhibitors were excluded.

RESULTS

Here we report 14 cases of less-than-expected FVIII activity. Details varied greatly amongst the cases. At presentation, FVIII activity ranged from 1% (15 min post-dose) to 51% (2 days post-dose). Seven patients experienced bleeding episodes after switching to N8-GP with heterogeneity in bleeding presentations. Six out of seven patients who were tested for anti-PEG IgG and/or IgM antibodies were positive. In all known cases, FVIII activity returned to the expected range when switched to an alternative FVIII replacement product.

CONCLUSION

In conclusion, the 14 reported cases of less-than-expected FVIII activity, without presence of detectable FVIII inhibitors, presented with heterogenous characteristics, and wide variations in FVIII activity and anti-PEG antibody titre. FVIII activity returned to the expected range after switching to alternative FVIII products. In line with WFH guidelines, monitoring of FVIII activity can ensure FVIII activity in the expected range. The safety surveillance of N8-GP continues.

Safety Evaluation of Chlorantraniliprole in Lychee Based on Residue and Dietary Risk Assessment

This report presents the development of a highly effective method employing high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to investigate chlorantraniliprole's dissipation, risk assessment, and residue distribution in whole lychee fruit and its pulp. Mean recoveries of the samples ranged from 80 to 105%, exhibiting a relative standard deviation (RSD) of below 8%. The limits of quantification (LOQ) for lychee and pulp were determined as 0.001 mg/kg, and half-lives (t1/2) ranged from 8.0 to 12.2 days. Terminal residue concentrations in whole litchi and pulp were determined as 0.008-0.45 mg/kg and ≤0.001 mg/kg. These residues were treated twice and thrice at two different dosage levels with pre-harvest intervals (PHIs) of 7, 14, and 21 days. The potential chronic risk posed by chlorantraniliprole to humans was non-negligible, as indicated by the risk quotient (RQ) value not exceeding 1. Therefore, this study provides significant fresh data about the safe application of chlorantraniliprole in the production of lychee, which will help China develop maximum residual limits (MRLs).

Biliary excretion and pharmacokinetics of several fluoroquinolones after intravenous injection in rabbits

The aim of this study was to measure the concentrations of enrofloxacin (ERFX) and other fluoroquinolones; orbifloxacin (OBFX), marbofloxacin (MBFX), and ofloxacin (OFLX) in the plasma and bile of rabbits after a single intravenous (IV) injection. Twenty male rabbits were divided into four groups and given each drug by IV injection into the ear vein at a dose of 5.0 mg/kg BW. The concentration of ERFX, ciprofloxacin (CPFX), OBFX, MBFX and OFLX in plasma and bile were determined by HPLC. CPFX, metabolite of ERFX, was also measured by HPLC in plasma and bile of rabbits receiving ERFX. Several pharmacokinetic parameters in plasma were calculated and biliary clearance (CLbile) was calculated from extent of biliary excretion and accumulation of AUC of each drug. After IV injection, elimination half-life (t1/2β) was 4.13, 3.68, 6.60, 5.14 hr; volume of distribution at a steady state (Vdss) was 1.24, 0.503, 0.771, 1.02 L/kg; and total body clearance (CLtot) was 1.05, 0.418, 0.271, 0.453 L/kg/hr, respectively. The values for CLbile for ERFX, OBFX, MBFX, and OFLX were 0.0048, 0.0050, 0.0057, and 0.0094 L/kg/hr, respectively. These values represent 0.48%, 1.2%, 2.1%, and 2.3% of the total body clearance (CLtot) of each drug, respectively. The biliary clearance of CPFX was also measured and found to be 0.0199 L/kg/hr with ERFX administration. The results showed that ERFX, OBFX, MBFX, and OFLX were not excreted into the bile to a significant extent, making them safe drugs to use in rabbits.

Dynamic modeling of pesticide residue in proso millet under multiple application situations

Proso millet (Panicum miliaceum L.) is a cereal crop with potential resistance to drought and heat stress, making it a promising alternative crop for regions with hot and dry climates. Because of its importance, it is crucial to investigate pesticide residues in proso millet and assess their potential risks to the environment and human health to protect it from insects or pathogens. This study aimed to develop a model for predicting pesticide residues in proso millet using dynamiCROP. The field trials consisted of four plots, with each plot containing three replicates of 10 m2. The applications of pesticides were conducted two or three times for each pesticide. The residual concentrations of the pesticides in the millet grains were quantitatively analyzed using gas and liquid chromatography-tandem mass spectrometry. The dynamiCROP simulation model, which calculates the residual kinetics of pesticides in plant-environment systems, was employed for predicting pesticide residues in proso millet. Crop-specific, environment-specific, and pesticide-specific parameters were utilized to optimize the model. Half-lives of pesticides in grain of proso millet, which were needed to input for dynamiCROP, were estimated using a modified first-order equation. Proso millet-specific parameters were obtained from previous studies. The accuracy of the dynamiCROP model was assessed using statistical criteria, including the coefficient of correlation (R), coefficient of determination (R2), mean absolute error (MAE), relative root mean square error (RRMSE), and root mean square logarithmic error (RMSLE). The model was then validated using additional field trial data, which showed that it could accurately predict pesticide residues in proso millet grain under different environmental conditions. The results demonstrated the accuracy of the model in predicting pesticide residues in proso millet after multiple applications.

Pharmacokinetics, pharmacodynamics, safety and tolerability of FTP-198, a novel, selective Autotaxin inhibitor, in healthy subjects: A phase I randomized placebo-controlled trial

BACKGROUND

Autotaxin (ATX) and lysophosphatidic acid (LPA) play an important role in pathogenesis of idiopathic pulmonary fibrosis (IPF). FTP-198 is an oral, novel and selective ATX inhibitor indicated for treating IPF. The study aimed to investigate the pharmacokinetics, pharmacodynamics, safety and tolerability of FTP-198 in healthy subjects.

METHODS

A single-center, randomized, double-blind, placebo-controlled, single ascending-dose Phase I study was performed. Pharmacokinetics, pharmacodynamics, food effect on pharmacokinetics, elimination, safety and tolerability of FTP-198 were evaluated.

RESULTS

A total of 30 subjects were enrolled and completed the study. After oral administration of single ascending-dose of 100 mg, 300 mg and 400 mg FTP-198 under fasted condition, FTP-198 was absorbed with median time to reach peak concentration (Tmax) of 1.75, 2.75 and 3.5 h, respectively and eliminated with mean elimination half-life (t1/2) of 8.77, 10.58 and 10.57 h, respectively. Peak concentration (Cmax), plasma area under concentration-time curve from time 0 to the last measurable concentration (AUC0-t) and to infinity (AUC0-∞) increased in dose-proportional manner for 100 mg to 400 mg FTP-198. Food intake slightly increased the Cmax, AUC0-t and AUC0-∞ and prolonged Tmax, but not affecting t1/2 of FTP-198 compared with fasted state. The pharmacodynamic biomarker plasma lysophosphatidic acid (LPA) 18:2 decreased significantly for 100 mg to 400 mg FTP-198, with inhibition rate from baseline reaching approximately 80% at 24 h post dosing, and higher dose of FTP-198 increased the time to maintain inhibitory plateau. FTP-198 was eliminated from the body almost with no unchanged drug excreted in urine and a small amount of unchanged drug detected in feces of human. Moreover, FTP-198 exhibited favorable safety and tolerability in healthy subjects.

CONCLUSION

Pharmacokinetics, pharmacodynamics, safety and tolerability of FTP-198 support further subsequent clinical development of FTP -198 in IPF patients.

Assessment of pharmacokinetics, safety, and tolerability following twice-daily administration of molnupiravir for 10 days in healthy participants

Molnupiravir is an orally administered, small-molecule ribonucleoside prodrug of β-D-N4-hydroxycytidine (NHC) that has demonstrated potent, broad-spectrum preclinical activity against RNA viruses and has a high barrier to the development of resistance. A double-blind, placebo-controlled, phase I trial was conducted to evaluate the pharmacokinetics (PKs), safety, and tolerability of 10.5-day administration of multiple doses of molnupiravir and its metabolites in healthy, adult participants. Participants were randomly assigned (3:1) to receive molnupiravir (400 mg [n = 6], 600 mg [n = 6], and 800 mg [n = 12]) or matching placebo (n = 8) every 12 h (q12h) for 10.5 days. Blood was collected to evaluate the PKs of NHC in plasma and of its active metabolite, NHC-triphosphate (NHC-TP), in peripheral blood mononuclear cells (PBMCs). Molnupiravir was generally well-tolerated. All adverse events were mild or moderate in severity and none led to treatment discontinuation. No clinically meaningful dose-related safety findings were observed. Mean time to maximal concentration was ~1.50 to 1.98 h for plasma NHC and ~4.00 to 8.06 h for PBMC NHC-TP. Accumulation was minimal (<1.2) for NHC and ~2- to 2.5-fold for NHC-TP. Plasma NHC PKs was generally dose proportional, and PBMC NHC-TP PKs was less than dose proportional over the dose range studied. NHC and NHC-TP PK support twice-daily administration. Overall, molnupiravir administered at up to 800 mg q12h for 10.5 days was generally well-tolerated in healthy participants with dose-linear PKs, supporting the evaluation of longer molnupiravir dosing up to 10 days in future clinical trials.

In vitro model to simulate multiple drugs with distinct elimination half-lives

OBJECTIVE

The prevalence of drug resistance in pathogens such as HIV and selected bacteria has been steadily rising, resulting in an increased need for using multiple agents concurrently. Agents used in these combination therapies may have different elimination half-lives in humans. There is an unmet need for in vitro models to evaluate the efficacy of these combinations to guide early drug development. In order to realistically reflect in vivo conditions, useful in vitro model systems must be capable of simulating multiple pharmacokinetic profiles with distinct elimination half-lives. The goal of this study was to experimentally simulate four pharmacokinetic profiles with distinct elimination half-lives in an in vitro hollow-fibre system.

METHODS

For illustrative purposes, fluctuating exposures of ceftriaxone were simulated with distinct half-lives of 1, 2.5, 8, and 12 hours. A parallel experimental setup was used to independently connect four supplemental reservoirs to a central reservoir. Target maximum concentration was achieved by direct drug dosing into the central reservoir; supplemental reservoirs were also dosed to offset the rapid drug elimination rate from the central reservoir. Serial pharmacokinetic samples were obtained from the central reservoir, assayed by a spectrophotometric method, and characterized by a one-compartment model.

RESULTS

The observed maximum concentrations and elimination half-lives were in agreement with the expected values obtained from the mathematical predictions.

CONCLUSIONS

This in vitro experimental system can be used to evaluate the efficacy of up to four-drug combinations against multidrug-resistant bacteria or HIV-infected mammalian cells. The established framework represents an adaptable tool to advance the field of combination therapy.

Dissipation, residue distribution, and risk assessment of ethiprole and its metabolites in rice under various open field conditions

BACKGROUND

Ethiprole has been registered to control planthoppers in rice fields for many years in Asia. However, its dissipation and residues in rice under natural field conditions and health hazards are largely unclear. In the present study, a modified QuEChERS (i.e. Quick Easy Cheap Effective Rugged Safe) and high-performance liquid chromatography-tandem mass spectrometry method was established to detect ethiprole and its metabolites, ethiprole amide and ethiprole sulfone, in brown rice, rice husks, and rice straw. The field experiments were implemented in 12 representative provinces of China under Good Agricultural Practices aiming to investigate the fate and terminal residues of ethiprole and its metabolites in rice. Finally, the dietary risk of ethiprole was evaluated.

RESULTS

The average recoveries of these analytes in all matrices were 86.4-99.0% with a repeatability of 0.575-9.38%. The limits of quantification for each compound were 0.01 mg kg-1 . Dissipation of ethiprole followed the single first-order, first + first-order, and first-order multi-compartment kinetic models with a half-life of 2.68-8.99 days in rice husks. The dissipation half-life of ethiprole combining all metabolites was 5.20-16.2 days in rice husks. The terminal residues of ethiprole and its metabolites at preharvest intervals of 21 days were < 0.011, 0.25, and 0.20 mg kg-1 in brown rice, rice husks, and rice straw, respectively. Ethiprole amide was undetectable in all matrices, and the risk quotient of ethiprole was far less than 100%.

CONCLUSION

Ethiprole rapidly converted to ethiprole sulfone in rice, and ethiprole and ethiprole sulfone mainly remained in rice husks and straws. The dietary risk of ethiprole was acceptable for Chinese consumers. © 2023 Society of Chemical Industry.

Report on 4 cases with decreased recovery due to neutralizing antibodies specific for PEGylated recombinant factor VIII

BACKGROUND

The immunogenicity, safety, and efficacy of recombinant factor VIII (rFVIII) have gained increasing interest after the introduction of extended half-life products with various modifications of the rFVIII molecule, such as covalent attachment of polyethylene glycol (PEG). Anti-PEG antibodies may be associated with a temporary reduction of FVIII recovery, but according to previous studies, they usually disappear after continuous dosing. Anti-PEG antibodies with an inhibitory capacity have never been demonstrated in patients treated with PEGylated rFVIII products.

OBJECTIVES

To routinely switch from standard half-life to PEGylated extended half-life rFVIII products in patients with hemophilia A.

METHODS

From December 2022 until May 2023, 83 adults with hemophilia A attending Oslo Haemophilia Comprehensive Care Centre received a test dose with a PEGylated rFVIII product to switch treatment. Four patients presented with decreased recovery without the presence of an FVIII inhibitor. Accordingly, we performed a variant inhibitor test utilizing different rFVIII concentrates as a source of FVIII and enzyme-linked immunosorbent assay to search for anti-PEG antibodies.

RESULTS

We found inhibitory anti-PEG/anti-PEGylated rFVIII antibodies in 4 patients (5%), both persistent and transient, explaining the impaired recovery. The patients had neutralizing anti-PEG antibodies prior to the first dosing of PEGylated rFVIII. We demonstrated neutralizing antibodies (mainly immunoglobuline G) specific for PEG and all 3 commercially available PEGylated rFVIII products.

CONCLUSION

The number of patients with inhibitory anti-PEG antibodies was significant, and the presence of inhibitors against PEGylated rFVIII emphasizes the importance of individual monitoring when switching FVIII concentrates to ensure safety and efficacy of the treatment.

Development and characterization of fused human arginase I for cancer therapy

Recombinant human arginase I (rhArg I) have emerged as a potential candidate for the treatment of varied pathophysiological conditions ranging from arginine-auxotrophic cancer, inflammatory conditions and microbial infection. However, rhArg I have a low circulatory half-life, leading to poor pharmacokinetic and pharmacodynamic properties, which necessitating the rapid development of modifications to circumvent these limitations. To address this, polyethylene glycol (PEG)ylated-rhArg I variants are being developed by pharmaceutical companies. However, because of the limitations associated with the clinical use of PEGylated proteins, there is a dire need in the art to develop rhArg I variant(s) which is safe (devoid of limitations of PEGylated counterpart) and possess increased circulatory half-life. In this study, we described the generation and characterization of a fused human arginase I variant (FHA-3) having improved circulatory half-life. FHA-3 protein was engineered by fusing rhArg I with a half-life extension partner (domain of human serum albumin) via a peptide linker and was produced using P. pastoris expression system. This purified biopharmaceutical (FHA-3) exhibits (i) increased arginine-hydrolyzing activity in buffer, (ii) cofactor - independency, (iii) increased circulatory half-life (t1/2) and (iv) potent anti-cancer activity against human cancer cell lines under in vitro and in vivo conditions.

Sustained antidepressant effect of ketamine through NMDAR trapping in the LHb

Ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist1, has revolutionized the treatment of depression because of its potent, rapid and sustained antidepressant effects2-4. Although the elimination half-life of ketamine is only 13 min in mice5, its antidepressant activities can last for at least 24 h6-9. This large discrepancy poses an interesting basic biological question and has strong clinical implications. Here we demonstrate that after a single systemic injection, ketamine continues to suppress burst firing and block NMDARs in the lateral habenula (LHb) for up to 24 h. This long inhibition of NMDARs is not due to endocytosis but depends on the use-dependent trapping of ketamine in NMDARs. The rate of untrapping is regulated by neural activity. Harnessing the dynamic equilibrium of ketamine-NMDAR interactions by activating the LHb and opening local NMDARs at different plasma ketamine concentrations, we were able to either shorten or prolong the antidepressant effects of ketamine in vivo. These results provide new insights into the causal mechanisms of the sustained antidepressant effects of ketamine. The ability to modulate the duration of ketamine action based on the biophysical properties of ketamine-NMDAR interactions opens up new opportunities for the therapeutic use of ketamine.

Nanosuspension-based microneedle skin patch of baclofen for sustained management of multiple sclerosis-related spasticity

Baclofen (BAC) is the first-line recommendation to treat spasticity in people with multiple sclerosis whose treatment goals include improving mobility or easing pain. The short half-life of BAC calls for multiple daily dosing which may be eliminated by the development of a transdermal system. This study aimed to assess the effect of transdermal microneedle patches on improving the skin permeation of BAC. Nanosuspension-loaded microneedle patch containing BAC was fabricated and characterized. In vitro permeation of BAC across intact and microneedle-treated dermatomed porcine ear skin was evaluated. In vitro passive permeation of BAC solution after 72 h was observed to be 92.56 ± 11.24 µg/cm2. A near 9-fold enhancement was observed when employing the strategy of microneedle-mediated delivery of the solution. To increase drug loading, two strategies, nanosizing and microneedle-mediated delivery, were combined and permeation of BAC after 72 h resulted to be 1951.95 ± 82.01 µg/cm2 (p < 0.05). Microneedle-mediated transdermal delivery of BAC holds potential for sustained management of multiple sclerosis-related spasticity. Nanosizing of BAC particles facilitated higher drug loading in MN patches and an eventual increase in cumulative drug permeation from the patches.

Site-Specific Antibody Conjugation Using Modified Bisected N-Glycans: Method Development and Potential toward Tunable Effector Function

Antibody-drug conjugates (ADCs) have garnered worldwide attention for disease treatment, as they possess high target specificity, a long half-life, and outstanding potency to kill or modulate the functions of targets. FDA approval of multiple ADCs for cancer therapy has generated a strong desire for novel conjugation strategies with high biocompatibility and controllable bioproperties. Herein, we present a bisecting glycan-bridged conjugation strategy that enables site-specific conjugation without the need for the oligosaccharide synthesis and genetic engineering of antibodies. Application of this method is demonstrated by conjugation of anti-HER2 human and mouse IgGs with a cytotoxic drug, monomethyl auristatin E. The glycan bridge showed outstanding stability, and the resulting ADCs eliminated HER2-expressing cancer cells effectively. Moreover, our strategy preserves the feasibility of glycan structure remodeling to fine-tune the immunogenicity and pharmacokinetic properties of ADCs through glycoengineering.

Nuclear NPM-ALK Protects Myc from Proteasomal Degradation and Contributes to Its High Expression in Cancer Stem-Like Cells in ALK-Positive Anaplastic Large Cell Lymphoma

In ALK-positive anaplastic large cell lymphoma (ALK+ALCL), a small subset of cancer stem-like (or RR) cells characterized by high Myc expression have been identified. We hypothesize that NPM-ALK contributes to their high Myc expression. While transfection of NPM-ALK into HEK293 cells effectively increased Myc by inhibiting its proteosomal degradation (PD-Myc), this effect was dramatically attenuated when the full-length NPM1 (FL-NPM1) was downregulated using shRNA, highlighting the importance of the NPM-ALK:FL-ALK heterodimers in this context. Consistent with this concept, immunoprecipitation experiments showed that the heterodimers are abundant only in RR cells, in which the half-life of Myc is substantially longer than the bulk cells. Fbw7γ, a key player in PD-Myc, is sequestered by the heterodimers in RR cells, and this finding correlates with a Myc phosphorylation pattern indicative of ineffective PD-Myc. Using confocal microscopy and immunofluorescence staining, we found that the fusion signal between ALK and FL-NPM1, characteristic of the heterodimers, correlates with the Myc level in ALK+ALCL cells from cell lines and patient samples. To conclude, our findings have revealed a novel oncogenic function of NPM-ALK in the nucleus. Specifically, the NPM-ALK:FL-NPM1 heterodimers increase cancer stemness by blocking PD-Myc and promoting Myc accumulation in the cancer stem-like cell subset.

Optimal site of care for administration of extended half-life respiratory syncytial virus (RSV) antibodies to infants in the United States (US)

INTRODUCTION

New extended half-life antibodies for the single-dose prevention of medically attended (MA) respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) have been developed for administration to all infants before or during their first RSV season. For infants born during the season, administration as soon as feasible after birth would provide optimal protection and minimize access disparities. The objective of this study was to assess the time from birth hospitalization discharge to the first outpatient visit (FOV) among US infants in order to determine optimal site of administration for the extended half-life antibody.

MATERIAL AND METHODS

This retrospective, observational, time-to-event analysis uses the Merative™ MarketScan® Commercial and Multi-State Medicaid Databases. Time to FOV is reported separately for the COVID-19 and recent pre-COVID-19 eras and for commercially insured and Medicaid infants.

RESULTS

Overall, 73.8 % of Medicaid infants had an FOV within 5 days as compared to 84.7 % of commercially insured infants. Estimates were higher during the COVID-19 era. Urban commercially insured infants had much higher FOV completion than their counterparts. Among Medicaid infants, urban Black and rural White infants were least likely to complete their FOV within 5 days of birth hospitalization discharge.

DISCUSSION AND CONCLUSION

FOV within 5 days after birth hospitalization discharge for Medicaid infants is substantially lower than that of commercially insured infants. Approximately 1 in 4 Medicaid infants and 1 in 8 infants with commercial insurance did not have an outpatient visit within 5 days of birth hospitalization discharge. For US infants born during the RSV season, administration of extended half-life RSV antibodies in the newborn nursery prior to discharge would ensure optimal uptake and minimize access disparities.

Co-administration of an effector antibody enhances the half-life and therapeutic potential of RNA-encoded nanobodies

The incidence of Clostridioides difficile infection (CDI) and associated mortality have increased rapidly worldwide in recent years. Therefore, it is critical to develop new therapies for CDI. Here we report on the development of mRNA-LNPs encoding camelid-derived VHH-based neutralizing agents (VNAs) targeting toxins A and/or B of C. difficile. In preclinical models, intravenous administration of the mRNA-LNPs provided serum VNA levels sufficient to confer protection of mice against severe disease progression following toxin challenge. Furthermore, we employed an mRNA-LNP encoded effector antibody, a molecular tool designed to specifically bind an epitopic tag linked to the VNAs, to prolong VNA serum half-life. Co-administration of VNA-encoding mRNA-LNPs and an effector antibody, either provided as recombinant protein or encoded by mRNA-LNP, increased serum VNA half-life in mice and in gnotobiotic piglets. Prolonged serum half-life was associated with higher concentrations of serum VNA and enhanced prophylactic protection of mice in challenge models.

High-concentration buprenorphine exceeds target plasma concentrations for extended periods following subcutaneous administration in American flamingos (Phoenicopterus ruber)

OBJECTIVE

To determine the pharmacokinetic parameters of a high-concentration buprenorphine formulation after a single SC dose in American flamingos (Phoenicopterus ruber).

ANIMALS

6 healthy adult American flamingos (3 males and 3 females).

METHODS

A single dose of high-concentration buprenorphine (1.8 mg/kg) was administered SC to all birds. Blood samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, 24, 48, 72, and 96 hours after drug administration between October 14 and October 18, 2022. Plasma buprenorphine concentrations were determined by liquid chromatography-tandem mass spectrometry and a noncompartmental analysis was used to determine pharmacokinetic parameters.

RESULTS

Mean ± SD peak plasma drug concentration (Cmax) was 195.1 ± 187.4 ng/mL, the mean time to peak plasma concentration (Tmax) was 0.32 ± 0.31 hours, the mean area under the concentration-vs-time curve from time 0 to the last measured concentration (AUC0-last) was 881.4 ± 205.4 ng/mL, and mean terminal half-life (t1/2) was 12.6 ± 3.86 hours. Mean plasma buprenorphine concentrations were >1 ng/mL for at least 48 hours after drug administration. No clinically significant adverse effects were observed.

CLINICAL RELEVANCE

High-concentration buprenorphine dosed at 1.8 mg/kg SC in American flamingos rapidly exceeded plasma drug concentrations reported to have analgesic effects in other avian species and maintained these levels for extended periods. Sedative effects were similar to those reported for other species. Additional studies are needed to evaluate the clinical efficacy of high-concentration buprenorphine at this dose in American flamingos.

Algorithm for optimized mRNA design improves stability and immunogenicity

Messenger RNA (mRNA) vaccines are being used to combat the spread of COVID-19 (refs. 1-3), but they still exhibit critical limitations caused by mRNA instability and degradation, which are major obstacles for the storage, distribution and efficacy of the vaccine products4. Increasing secondary structure lengthens mRNA half-life, which, together with optimal codons, improves protein expression5. Therefore, a principled mRNA design algorithm must optimize both structural stability and codon usage. However, owing to synonymous codons, the mRNA design space is prohibitively large-for example, there are around 2.4 × 10632 candidate mRNA sequences for the SARS-CoV-2 spike protein. This poses insurmountable computational challenges. Here we provide a simple and unexpected solution using the classical concept of lattice parsing in computational linguistics, where finding the optimal mRNA sequence is analogous to identifying the most likely sentence among similar-sounding alternatives6. Our algorithm LinearDesign finds an optimal mRNA design for the spike protein in just 11 minutes, and can concurrently optimize stability and codon usage. LinearDesign substantially improves mRNA half-life and protein expression, and profoundly increases antibody titre by up to 128 times in mice compared to the codon-optimization benchmark on mRNA vaccines for COVID-19 and varicella-zoster virus. This result reveals the great potential of principled mRNA design and enables the exploration of previously unreachable but highly stable and efficient designs. Our work is a timely tool for vaccines and other mRNA-based medicines encoding therapeutic proteins such as monoclonal antibodies and anti-cancer drugs7,8.

Effects of PK-guided prophylaxis on clinical outcomes and FVIII consumption for patients with moderate to severe Haemophilia A

INTRODUCTION

In recent years, there has been increased focus on individualizing treatment for persons with hemophilia including pharmacokinetic-guided (PK) dosing.

AIMS

In this retrospective study clinical outcomes before and after PK-guided prophylaxis were examined.

MATERIALS AND METHODS

Eight Haemophilia Treatment Centres from the United States participated in the study and included 132 patients classified into two cohorts: those undergoing a PK-assessment for product switch (switchers) or to optimize treatment (non-switchers). Subset analyses for the two most common products and patients with dosing per prescription label were included for annual bleeding rates (ABR), mean weekly consumption outcomes, and annualized cost of prophylaxis.

RESULTS

The most common products before and after index date were octocog alfa, rurioctocog alfa pegol, and efmoroctocog alfa. Seventy-four (56%) patients were identified as switchers and 58 (44%) patients were classified as non-switchers. The majority of patients (78.0%) experienced either a decrease in ABR post-index or maintained 0 ABR during pre- and post-index time periods, with similar proportions identified in both switchers (77.0%) and non-switchers (79.3%) populations. Non-switchers were identified as having no significant change in cost of therapy, while switchers experienced increased cost of therapy driven by higher price of extended half-life products. Within subset analyses, patients receiving rurioctocog alfa pegol and efmoroctocog alfa had mean ABR under 1 after index date.

CONCLUSION

PK-guided prophylaxis has the potential to improve clinical outcomes without increase in cost of therapy for patients maintaining product and can aid in maintaining effective protection against bleeds in those switching product.