Serum Half-life Research Articles

Phosphorylation as an Effective Tool to Improve Stability and Reduce Toxicity of Antimicrobial Peptides.

Developing a straightforward and effective strategy to modify antimicrobial peptides (AMPs) is crucial in overcoming the challenges posed by their instability and toxicity. Phosphorylation can reduce toxicity and improve the stability of AMPs. Based on these, we designed a series of peptides and their corresponding phosphorylated forms. The results showed that all phosphorylated peptides displayed reduced toxicity and enhanced stability compared to their unphosphorylated counterparts. Among them, W3BipY8-P stood out as the most promising peptide, exhibiting similar antibacterial activity as its unphosphorylated analog W3BipY8 but with significantly reduced hemolytic activity (19-fold decrease), cytotoxicity (3.3-fold decrease), and an extended serum half-life 6.3 times longer than W3BipY8. W3BipY8-P exerted bactericidal effects by disrupting bacterial membranes. Notably, W3BipY8-P significantly prolonged the survival of bacteria-infected animals while its LD50 was 4.2 times higher than that of W3BipY8. These findings highlight phosphorylation as an effective strategy for improving the antimicrobial properties of AMPs.

N-Terminal Capping of the αO-Conotoxin Analogue GeX-2 Improves the Serum Stability and Selectivity toward the Human α9α10 Nicotinic Acetylcholine Receptor.

α9α10 nicotinic acetylcholine receptors (nAChRs) are a promising nonopioid analgesic target, with α9α10 nAChR antagonists showing efficacy against chemotherapy-induced hyperalgesia and allodynia. GeX-2, a potent analgesic conotoxin antagonist of α9α10 nAChRs, has limited serum stability. This study improved GeX-2 stability by capping its N-terminal with fatty acids or polyethylene glycol chains, which enhanced its serum stability but eliminated activity at G protein-coupled γ-aminobutyric acid type B (GABAB) receptor-coupled CaV2.2 channels while preserving activity at α9α10 nAChRs. In vivo, α9α10 nAChRs antagonism alone did not alleviate neuropathic pain, highlighting the importance of GABAB receptor-coupled CaV2.2 channels in GeX-2's antinociceptive effects in the chronic constriction injury rat model. The GeX-2 analogue, with an N-terminal methyl group, showed improved activity and selectivity for α9α10 nAChRs, increased serum half-life, and strong analgesic effects in oxaliplatin-induced cold allodynia models. AlphaFold3 and molecular dynamics simulations provided insights into the binding modes and the effects of N-terminal capping, which informed future peptide therapeutic developments.

A novel format of TNF-α binding affibody molecule ameliorate coronary artery endothelial injury in a mouse model of Kawasaki disease

Kawasaki disease (KD) is a disease characterized by systemic immune vasculitis that often involves coronary arteries and can result in long-term cardiovascular sequelae. Different strategies for treatment of KD-and KD-induced coronary artery lesions are currently under investigation, including passive immunization with anti-TNFα monoclonal antibodies (mAbs). Herein, we examine the potential therapeutic capabilities of a novel type of TNFα-targeting agent based on an affibody molecule possessing fundamentally different properties than mAbs. Using phage display technology, we successfully screened and obtained three TNF-α binding affibody molecules and confirmed their high binding affinity and specificity for recombinant and native TNF-α by surface plasmon resonance (SPR), confocal double immunofluorescence and coimmunoprecipitation assays. Moreover, by binding to TNF-α, the affibody molecules could effectively neutralize TNFα-induced L929 cytotoxicity. To increase the targeting properties and serum half-life, one preferred affibody molecule ZTNF-α263 was redesigned to assemble drugs with bivalent TNFα binding with added specificity for serum albumin (ZTNF-α263-ABD035-ZTNF-α263, hereinafter denoted ZTAT). We further determined its binding ability, TNF-α signal blocking and neutralizing capacity, serum half-life and immunogenicity. Most importantly, our study provides strong evidence that the engineered ZTAT protein was therapeutically effective against KD induced-endothelial injury, as judged by both in vitro and in vivo assessments. These data suggested that because of the flexibility inherent, low-molecular weight anti-TNFα affibody construct ZTAT, can be developed into a potent therapeutic agent that can be produced and purified cost-effectively.

B-318 Serum PSA in Extracellular Vesicles: Immunoreactivity to Commercial Kits and Elimination Kinetics

Abstract Background Prostate Specific Antigen (PSA) also circulates in blood bound to extracellular vesicles (EVs), and observed higher ratio of PSA in EVs respect total serum PSA when serum concentrations are <4 μg/L, and can represent up to 59% of total circulating PSA. Moreover, this molecular form of PSA (ev-PSA) is recognized and can be quantified with commercial methodologies designed for serum quantification. We aimed to characterize ev-PSA studying its immunoreactivity to different commercial assays and analyzing its presence in international standards used for assays standardization. Serum half-life and elimination kinetics of ev-PSA were also studied. Methods Serum EVs from 32 prostate cancer (PCa) patients were isolated by ultracentrifugation (100,000xg, 90 minutes). PSA was assessed in serum (srm-), serum supernatant free of EVs (sn-) and EVs (ev-) with total PSA (T-PSA) commercial immunoassays (Elecsys® from Roche Diagnostics and Immulite® 2000 from Siemens Healthineers), and Immulite/Elecsys ratio was calculated in all samples. The analysis of the differences between methods was performed with Bland-Altman test, representing the percentage of the difference respect the mean. WHO 96/670 PSA Standard was ultracentrifuged and analyzed by Nanoparticle Tracking Analysis (NTA) in a NanoSight LM20.For half-life estimation, serum samples from 10 localized PCa patients were collected basal and 2 days after radical prostatectomy, and EVs were isolated by Size Exclusion Chromatography using Exo-spinTM kit (Cell Guidance System). The Research Ethic Committee approved the study. Results Significant differences were observed between Elecsys and Immulite immunoassays in ev-T-PSA (p<0.001) concentrations. ev-T-PSA was quantified in all samples with Elecsys (median: 0.134 μg/L; Q1-Q3: 0.033-0.391 μg/L), but only in 22 patients (68.75%) with Immulite (median: 0.206 μg/L; Q1-Q3: 0.074-0.340 μg/L). In those 22 quantifiable patients, the median Immulite/Elecsys ratio was similar (p=0.057) between sn-T-PSA and srm-T-PSA (0.96 and 0.92, respectively), but much lower for ev-T-PSA (0.77; p<0.001). Bland-Altman graphical analysis showed that Elecsys overestimates the concentrations of T-PSA in all samples compared to Immulite, being this overestimation more marked in the case of PSA contained in EVs, and amplified at lower PSA concentrations. Besides, NTA analysis of WHO 96/670 PSA Standard showed that it does not contain EVs, and therefore, ev-PSA. The percentage of remnant PSA calculated in samples obtained post-surgery respect to baseline concentration in prostatectomized patients, was significantly higher for ev-T-PSA compared to soluble srm-T-PSA (p=0.014) and srm-F-PSA (p=0.002). The elimination half-life of ev-T-PSA was 3.99 days, much higher than those estimated for serum T-PSA and F-PSA, that were 1.76 days and 0.64 days, respectively. Conclusions The quantification of ev-PSA is affected by the different immunoreactivity of the diverse commercial assays. Thus, Elecsys T-PSA immunoassay shows higher immunoreactivity compared to Immulite technique, being this different reactivity more marked at lower PSA concentrations. ev-PSA is not considered in the International WHO 96/670 PSA Standard used for methods standardization. PSA bound to EVs remains longer in circulation than soluble serum PSA.

Preventing osteoporotic bone loss in mice by promoting balanced bone remodeling through M-CSFRGD, a dual antagonist to c-FMS and αvβ3 receptors

Osteoporosis is a common, age-related disease caused by imbalanced bone remodeling. Current treatments either shut down bone resorption or robustly stimulate bone formation. Here, we describe a novel compound that inhibits osteoclast activity without causing apparent disruptions to bone formation by targeting both c-FMS (i.e., osteoclast differentiation) and αvβ3 integrin (i.e., osteoclastic bone resorption) receptors. We show that human serum albumin (HSA)-conjugated M-CSFRGD protein (M-CSFRGD-HSA) effectively inhibits the activity of both receptors, with a three-fold higher serum half-life compared to the unconjugated M-CSFRGD. We then treated ovariectomized mice with different doses of M-CSFRGD-HSA, alendronate, or a monospecific control protein. The bispecific M-CSFRGD-HSA was superior to a monospecific control in alleviating bone loss and reducing osteoclast distribution and function. M-CSFRGD-HSA and alendronate effectively prevented ovariectomy-induced bone loss, but M-CSFRGD-HSA had a milder inhibitory effect on osteoclast distribution and activity. Moreover, alendronate halted bone formation, while M-CSFRGD-HSA-treated mice showed an increased level of serum amino-terminal propeptide of type I collagen, a bone formation marker. Our data indicate that the mild reduction in osteoclast activity facilitated by the bispecific M-CSFRGD-HSA allows the maintenance of certain levels of bone formation and may be superior to treatments that induce osteoclast depletion.

Biochemical Amenability in Fabry Patients Under Chaperone Therapy-How and When to Test?

Current recommendations for Fabry disease include α-galactosidase A (AGAL) activity measurements to assess the biochemical response in migalastat-treated patients. Owing to contradictory data from laboratories, we aimed to analyze why AGAL activity measures from dried blood spots (DBS) often fail to detect migalastat-mediated enzymatic activity increases in treated patients. 43 patients with 58 visits under migalastat were consecutively recruited. Enzymatic AGAL activities were measured from DBS and peripheral blood mononuclear cells (PBMCs). Migalastat concentrations in sera were determined using modified serum-mediated inhibition assays to assess Cmax and serum half-life. Results were set in relation to the time of last migalastat intake and blood sampling to assess an optimal timepoint for AGAL activity measures. DBS-based AGAL activity measurements of 21 (42.0%) amenable patients were below the limit of detection. Serum samples from migalastat-treated patients showed significant AGAL inhibition, depending on the time between migalastat intake and blood sampling (r2 = 0.8140, p < 0.0001). Migalastat concentrations were determined in serum samples confirming a Cmax at 3 h and a serum half-life of 4 h. At 24 h after intake, migalastat clearance was significantly associated with renal function (r2 = 0.3135, p = 0.0102). Enzymatic AGAL activities were higher in samples from DBS and PBMCs 24 h after migalastat intake (both p < 0.05). The optimal time for enzymatic AGAL activity measurement in migalastat-treated patients appears to be 24 h after the last migalastat intake. Since migalastat is a competitive inhibitor of AGAL, enzymatic AGAL activity measurements should be better performed from PBMCs to reduce migalastat-mediated interferences.

Engineered cytokine/antibody fusion proteins improve IL-2 delivery to pro-inflammatory cells and promote antitumor activity.

Progress in cytokine engineering is driving therapeutic translation by overcoming these proteins' limitations as drugs. The IL-2 cytokine is a promising immune stimulant for cancer treatment but is limited by its concurrent activation of both pro-inflammatory immune effector cells and antiinflammatory regulatory T cells, toxicity at high doses, and short serum half-life. One approach to improve the selectivity, safety, and longevity of IL-2 is complexing with anti-IL-2 antibodies that bias the cytokine toward immune effector cell activation. Although this strategy shows potential in preclinical models, clinical translation of a cytokine/antibody complex is complicated by challenges in formulating a multiprotein drug and concerns regarding complex stability. Here, we introduced a versatile approach to designing intramolecularly assembled single-agent fusion proteins (immunocytokines, ICs) comprising IL-2 and a biasing anti-IL-2 antibody that directs the cytokine toward immune effector cells. We optimized IC construction and engineered the cytokine/antibody affinity to improve immune bias. We demonstrated that our IC preferentially activates and expands immune effector cells, leading to superior antitumor activity compared with natural IL-2, both alone and combined with immune checkpoint inhibitors. Moreover, therapeutic efficacy was observed without inducing toxicity. This work presents a roadmap for the design and translation of cytokine/antibody fusion proteins.

Reduction of circulating IgE and allergens by a pH-sensitive antibody with enhanced FcγRIIb binding

Allergen-crosslinked IgE triggers allergy by interacting with its receptor on basophils and mast cells. The anti-IgE monoclonal antibody omalizumab can alleviate allergy by competing with the receptor for IgE binding. However, along with neutralization, omalizumab also inhibits IgE degradation, which is clinically associated with high dose and total IgE accumulation problems. In this study, we have developed an IgE-eliminating antibody on the basis of omalizumab, which has pH-dependent Fabs and an Fc with high affinity for FcγRIIb. In mice, the antibody rapidly eliminated total serum IgE to baseline levels and caused lower free IgE levels than omalizumab. At low dosages, the antibody also exhibited favorable IgE elimination effects. In addition, the antibody can degrade the corresponding allergen with the removal of IgE, addressing the allergy from its source. Introduction of the M252Y/S254T/T256E (YTE) mutation into this antibody prolongs its serum half-life without reducing potency. Thus, this engineered antibody holds a promising therapeutic option for allergy patients. Mechanistic insights are also included in this study.

A broadly cross-reactive i-body to AMA1 potently inhibits blood and liver stages of Plasmodium parasites

Apical membrane antigen-1 (AMA1) is a conserved malarial vaccine candidate essential for the formation of tight junctions with the rhoptry neck protein (RON) complex, enabling Plasmodium parasites to invade human erythrocytes, hepatocytes, and mosquito salivary glands. Despite its critical role, extensive surface polymorphisms in AMA1 have led to strain-specific protection, limiting the success of AMA1-based interventions beyond initial clinical trials. Here, we identify an i-body, a humanised single-domain antibody-like molecule that recognises a conserved pan-species conformational epitope in AMA1 with low nanomolar affinity and inhibits the binding of the RON2 ligand to AMA1. Structural characterisation indicates that the WD34 i-body epitope spans the centre of the conserved hydrophobic cleft in AMA1, where interacting residues are highly conserved among all Plasmodium species. Furthermore, we show that WD34 inhibits merozoite invasion of erythrocytes by multiple Plasmodium species and hepatocyte invasion by P. falciparum sporozoites. Despite a short half-life in mouse serum, we demonstrate that WD34 transiently suppressed P. berghei infections in female BALB/c mice. Our work describes the first pan-species AMA1 biologic with inhibitory activity against multiple life-cycle stages of Plasmodium. With improved pharmacokinetic characteristics, WD34 could be a potential immunotherapy against multiple species of Plasmodium.

Engineering and Characterization of a Long-Half-Life Relaxin Receptor RXFP1 Agonist.

Relaxin-2 is a peptide hormone with important roles in human cardiovascular and reproductive biology. Its ability to activate cellular responses such as vasodilation, angiogenesis, and anti-inflammatory and antifibrotic effects has led to significant interest in using relaxin-2 as a therapeutic for heart failure and several fibrotic conditions. However, recombinant relaxin-2 has a very short serum half-life, limiting its clinical applications. Here, we present protein engineering efforts targeting the relaxin-2 hormone in order to increase its serum half-life while maintaining its ability to activate the G protein-coupled receptor RXFP1. To achieve this, we optimized a fusion between relaxin-2 and an antibody Fc fragment, generating a version of the hormone with a circulating half-life of around 3 to 5 days in mice while retaining potent agonist activity at the RXFP1 receptor both in vitro and in vivo.

Infection and the Glycome─New Insights into Host Response.

Glycans play critical roles in the host-pathogen interactions leading to infection. However, we still understand very little about the dynamic nature of glycosylation in response to infection and its function in modulating host immunity. Many of the host proteins involved in immune defense are glycoproteins. Furthermore, the innate immune system recognizes glycans. The glycoform of a protein can impact proteolytic stability, receptor interactions, serum half-life, and other aspects. New, cutting-edge chemical biology tools are shedding light on the interplay between infection and the host glycome. In this review, we highlight new work on the importance of dynamic glycosylation of host proteins in the innate and adaptive immune pathways in response to infection. These include recent findings on altered glycoprofiles of mucins, complement components, and antibodies.

A phase 1, randomized, double-blind, placebo-controlled, dose escalation study to evaluate the safety, tolerability, pharmacokinetics and immunogenicity of SHR-1905, a long-acting anti-thymic stromal lymphopoietin antibody, in healthy subjects.

Thymic stromal lymphopoietin (TSLP) is integral to inducing innate and T helper two cell inflammation that leads to clinical symptoms of asthma. SHR-1905 is a humanized immunoglobulin G1 kappa monoclonal antibody that inhibits TSLP bioactivity, developed for the treatment of severe uncontrolled asthma. This phase 1, randomized, double-blind, placebo-controlled single ascending dose study assessed the safety, tolerability, pharmacokinetics (PK), and immunogenicity of subcutaneous SHR-1905 in healthy subjects. Five dose cohorts were planned (50, 100, 200, 400, and 600mg) and subjects were randomized (8:2) in each cohort to receive SHR-1905 or placebo with a follow-up period up to Day 253. The majority of treatment-emergent adverse events (TEAEs) were mild and the incidence of TEAEs was comparable between the SHR-1905 and the placebo groups. The maximum serum concentration was reached 7.0-17.6days after injection. The serum concentration of SHR-1905 increased with increasing dose level, and SHR-1905 exposure exhibited in a slightly greater-than-dose-proportional manner from 50 to 600mg. SHR-1905 had a prolonged serum half-life around 80days supporting every 6-month dosing. In SHR-1905 treated subjects, 15% tested positive for anti-drug antibodies post-dose with no apparent effect on corresponding PK profiles or safety. SHR-1905 demonstrated a good safety and tolerability profile with a long half-life in healthy subjects after a single administration in the dose range of 50-600mg. clinicaltrials.gov, identifier NCT04800263.

The antiherpetic and anti-inflammatory activity of the frog-derived peptide Hylin-a1.

The high incidence of virus-related infections and the large diffusion of drug-resistant pathogens stimulate the search and identification of new antiviral agents with a broad spectrum of action. Antivirals can be designed to act on a single target by interfering with a specific step in the viral lifecycle. On the contrary, antiviral peptides (AVPs) are known for acting on a wide range of viruses, with a diversified mechanism of action targeting virus and/or host cell. In the present study, we evaluated the antiviral potential of the peptide Hylin-a1 secreted by the frog Hypsiobas albopunctatus against members of the Herpesviridae family. The inhibitory capacity of the peptide was evaluated in vitro by plaque assays in order to understand the possible mechanism of action. The results were also confirmed by real-time PCR and Western blot evaluating the expression of viral genes. Hylin-a1 acts to block the herpetic infection interfering at the early stages of both herpes simplex virus type 1 (HSV-1) and type 2 infection. Its mechanism is mainly directed on the membrane, probably by damaging the viral envelope. The same effect was also observed against HSV-1 strains resistant to acyclovir. The data presented in this study, such as the increased activity of the peptide when combined to acyclovir, a weak hemolytic profile, an anti-inflammatory effect, and a tolerable half-life in serum, indicates Hylin-a1 as a novel antiherpetic molecule with promising potential in the clinical setting.

In-situ gel injection of poloxamer-based metamizole provides long-acting antipyretic effects.

Metamizole easily decomposes in the body and has a short action time and low bioavailability. Hence, frequent injection administrations are needed to maintain its plasma concentration. This study aimed to design and develop an in-situ gel based on poloxamer 407 and 188 to assess its long-acting antipyretic effects. The in-situ gel-forming systep00m with optimum sol-gel transition temperature of 35.9°C to 36.3°C could be formed using a combination of P407 at a ratio of 21-23% (w/v) and P188 at a ratio of 2-4% (w/v). In vitro erosion test showed that the in-situ gel's erosion curve and the metamizole release rate both reached about 90% at 6h, revealing a good linear relationship between the in-situ gel erosion and the drug release. In vitro release test with dialysis tube showed that the release of metamizole from the in-situ gel was remarkably slower than that from the metamizole solution. Approximately 85% of metamizole was released in the dialysis tube within 7h, implying a good sustained release effect. Pharmacodynamic study showed that the in-situ gel injection extended the action time of metamizole relative to that when using the metamizole solution. Pharmacokinetic study revealed that the in-situ gel significantly increased the blood serum half-life and area under the curve), contributing to a sustained release and improved bioavailability. This study demonstrated that in-situ gel injection could prolong the action of metamizole in the body to reduce the number of administration times and has good clinical application.

Lipid-encapsulated mRNA encoding an extended serum half-life interleukin-22 ameliorates metabolic disease in mice

ObjectiveInterleukin (IL)-22 is a potential therapeutic protein for the treatment of metabolic diseases such as obesity, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease due to its involvement in multiple cellular pathways and observed hepatoprotective effects. The short serum half-life of IL-22 has previously limited its use in clinical applications; however, the development of mRNA-lipid nanoparticle (LNP) technology offers a novel therapeutic approach that uses a host-generated IL-22 fusion protein. In the present study, the effects of administration of an mRNA-LNP encoding IL-22 on metabolic disease parameters was investigated in various mouse models. MethodsC57BL/6NCrl mice were used to confirm mouse serum albumin (MSA)-IL-22 protein expression prior to assessments in C57BL/6NTac and CETP/ApoB transgenic mouse models of metabolic disease. Mice were fed either regular chow or a modified amylin liver nonalcoholic steatohepatitis–inducing diet prior to receiving either LNP-encapsulated MSA-IL-22 or MSA mRNA via intravenous or intramuscular injection. Metabolic markers were monitored for the duration of the experiments, and postmortem histology assessment and analysis of metabolic gene expression pathways were performed. ResultsMSA-IL-22 was detectable for ≥8 days following administration. Improvements in body weight, lipid metabolism, glucose metabolism, and lipogenic and fibrotic marker gene expression in the liver were observed in the MSA-IL-22–treated mice, and these effects were shown to be durable. ConclusionsThese results support the application of mRNA-encoded IL-22 as a promising treatment strategy for metabolic syndrome and associated comorbidities in human populations.

A phase I clinical study to evaluate the safety, tolerability, immunogenicity, pharmacokinetics and preliminary efficacy of SCB-219M in patients with chemotherapy-induced thrombocytopenia (CIT): An interim analysis.

e15015 Background: CIT is a serious, chemotherapy-associated complication observed in a wide range of cancer patients with various types of cancer. Incidence of CIT can occur in about 15-25% of patients undergoing standard chemotherapy regiments with platinum, taxane and/or gemcitabine-based regimen. CIT can lead to chemotherapy dose delay or dose reduction, and potentially bleeding events. Currently, there is no FDA-approved therapy for CIT. SCB-219M, a thrombopoietin receptor agonist (TPO-RA) mimetic bispecific Fc-fusion protein produced from CHO cells can efficiently raise PLT count under normal and pathological conditions in laboratory animals. Methods: This is a single-arm, multi-center, open-label, dose escalation Phase Ia clinical study to evaluate the safety, tolerability, and immunogenicity, PK profile and preliminary efficacy of a single ascending dose of SCB-219M administered one day after a chemotherapy in prior CIT patients with malignant solid tumors and lymphoma. The study design of accelerated titration combined with "3 + 3" is used, and the number of subjects planned to enroll is 12 to be assigned to 4 cohorts with 2, 6, 10 and 15 mg/kg subcu administration of SCB-219M, respectively. Enrollment criteria include episode of CIT experienced (&lt;75 × 109/L in PLT count) in prior cycle of chemotherapies and PLT count has recovered to &gt;75 × 109/L prior to initiation of this study . The chemotherapy regimen allowed include either mono or combination chemotherapy (including targeted therapy and/or immunotherapy). The observation period of dose-limiting toxicities (DLTs) is 21 days. Chemotherapy is planned at each study site. There will be no change in the planned dose or frequency of chemotherapy in the study. Results: As of Dec 20, 2023, 9 prior CIT patients including 3 at 15 mg/kg were enrolled. SCB-219M was well tolerated. There were no SAEs or AESIs (Adverse Event of Special Interest) observed. DLT was not reached. A favorable PK profile, in particular in serum availability (AUC) and half-life (T1/2) was obtained. All 9 prior CIT patients in the study maintained PLT counts &gt;75 x 109/L from 1-week following chemotherapies with a single dose of SCB-219M, and durable responses experienced through at least 3 weeks. Conclusions: In this interim analysis, drug safety, PK profile and durable efficacy are expected to support SCB-219M dosing interval of ≥2-weeks or a single dosing regimen within a chemotherapy cycle. Accordingly, a Phase Ib trial evaluating repeated dosing of SCB-219M is planned to initiate in 2024. Clinical trial information: NCT05426369 .

New drugs to prevent oxaliplatin-induced peripheral neuropathy: A double-blind, randomized study.

3568 Background: Postoperative adjuvant chemotherapy for colorectal cancer reduces postoperative recurrence; however, it often causes undesirable adverse events. Oxaliplatin, the mainstay of postoperative adjuvant chemotherapy is particularly likely to cause chemotherapy-induced peripheral neuropathy (CIPN) and hypersensitivity reactions (HSR) that may make it difficult to continue treatment. Various agents have been tested for prevention or treatment of CIPN caused by oxaliplatin, but none have proven effective. Reactive oxygen species contribute oxaliplatin-induced PN; therefore, super oxide dismutase (SOD) could potentially suppress them, but its very short serum half-life has made clinical application difficult. We developed a lecithinized human copper/zinc SOD (Cu/Zn-SOD) (PC-SOD) in which four phosphatidylcholine derivative molecules are bound covalently to each SOD dimer. Compared with SOD, PC-SOD enhanced stability in plasma and stronger tissue affinity, and exerts therapeutic effects in animal models of several diseases, including CIPN. Methods: This double-blind, randomized study included 90 patients with stage II/III colorectal cancer. All patients were slated to receive 12 cycles of mFOLFOX6. In each cycle, patients received PC-SOD or a placebo immediately before oxaliplatin. The primary endpoint of this study was the number of cycles before NCI-CTCAE Grade 2 (G2) CIPN occurred. One of the secondary endpoints was the number of cycles before DEB-NTC G2 PN occurred. Results: Forty-three patients received PC-SOD. No serious adverse events were observed that could be related to PC-SOD. The incidence of neutropenia, diarrhea, stomatitis, and malaise were lower in the study group, but the differences were not significant. Additionally, 3 patients (7.0%) in the study group and 11 (23.4%) in the placebo group had HSR. Although there was no difference in the number of cycles between the two groups until NCI-CTCAE G2 PN occurred, the study group had a significantly greater number of cycles before DEB-NTC G2 PN compared to the placebo group (P=0.08). The study group had a significantly greater number of cycles before NCI-CTC G1 PN (P=0.01) and HSR (P=0.03) compared to the placebo group. The number of cycles before HSR or NCI-CTCAE G2 PN occurred was greater in the study group , but the difference was not significant. The average total oxaliplatin dose was higher in the study group but the difference was not statistically significant. Conclusions: The primary endpoint did not occur; however, the study group had a significantly greater number of cycles before DEB-NTC G2 PN. Notably, the study group also had a significantly greater number of cycles before HSR. These results show that PC-SOD may suppress HSR as well as PN, both of which limit administration of oxaliplatin. Thus, this drug is expected to improve not only patient quality of life, but also the prognosis of patients. Clinical trial information: 2031210466.

Mirror-Image Human Serum Albumin Domain III as a Tool for Analyzing Site II-Dependent Molecular Recognition.

Human serum albumin (HSA) as a drug carrier can significantly improve the pharmacokinetic profiles of short-lived therapeutics. Conjugation of albumin-binding moieties (ABMs) to therapeutic agents may prolong their serum half-life by promoting their association with endogenous HSA. To discover a new molecular class of ABMs from mirror-image chemical space, a preparation protocol for bioactive HSA domain III and its d-enantiomer (d-HSA domain III) was established. Structural and functional analyses suggested that the synthetic protein enantiomers exhibited mirror-image structures and stereoselective neonatal fragement crystallizable receptor (FcRn) recognition. Additionally, the ligand-binding properties of synthetic l-HSA domain III were comparable with those of site II in native HSA, as confirmed using site II-selective fluorescent probes and an esterase substrate. Synthetic d-HSA domain III is an attractive tool for analyzing the site II-dependent molecular recognition properties of HSA.

HPN328, a Trispecific T Cell-Activating Protein Construct Targeting DLL3-Expressing Solid Tumors.

Delta-like ligand 3 (DLL3) is expressed in more than 70% of small cell lung cancers (SCLCs) and other neuroendocrine-derived tumor types. SCLC is highly aggressive, and limited therapeutic options lead to poor prognosis for patients. HPN328 is a trispecific T cell-activating construct (TriTAC) consisting of three binding domains: a CD3 binder for T-cell engagement, an albumin binder for half-life extension, and a DLL3 binder for tumor cell engagement. In vitro assays, rodent models, and non-human primates were used to assess the activity of HPN328. HPN328 induces potent dose-dependent killing of DLL3-expressing SCLC cell lines in vitro, concomitant with T-cell activation and cytokine release. In an NCI-H82 xenograft model with established tumors, HPN328 treatment led to T-cell recruitment and anti-tumor activity. In an immunocompetent mouse model expressing a human CD3ε epitope, mice previously treated with HPN328 withstood tumor rechallenge, demonstrating long-term anti-tumor immunity. When repeat doses were administered to cynomolgus monkeys, HPN328 was well tolerated up to 10 mg/kg. Pharmacodynamic changes, such as transient cytokine elevation, were observed, consistent with the expected mechanism of action of T-cell engagers. HPN328 exhibited linear pharmacokinetics in the given dose range with a serum half-life of 78 to 187 hours, supporting weekly or less frequent administration of HPN328 in humans. Preclinical and nonclinical characterization suggests that HPN328 is a highly efficacious, safe, and novel therapeutic candidate. A phase 1/2 clinical trial is currently underway testing safety and efficacy in patients with DLL3-expressing malignancies.

AlbuCatcher for Long-Acting Therapeutics.

Therapeutic proteins, pivotal for treating diverse human diseases due to their biocompatibility and high selectivity, often face challenges such as rapid serum clearance, enzymatic degradation, and immune responses. To address these issues and enable prolonged therapeutic efficacy, techniques to extend the serum half-life of therapeutic proteins are crucial. The AlbuCatcher, a conjugate of human serum albumin (HSA) and SpyCatcher, was proposed as a general technique to extend the serum half-life of diverse therapeutic proteins. HSA, the most abundant blood protein, exhibits a long intrinsic half-life through Fc receptor (FcRn)-mediated recycling. The SpyTag/SpyCatcher (ST/SC) system, known for forming irreversible isopeptide bonds, was employed to conjugate HSA and therapeutic proteins. Site-specific HSA conjugation to SC was achieved using an inverse electron-demand Diels-Alder (IEDDA) reaction, minimizing activity loss. Using urate oxidase (Uox) as a model protein with a short half-life, the small ST was fused to generate Uox-ST. Then, HSA-conjugated Uox (Uox-HSA) was successfully prepared via the Uox-ST/AlbuCatcher reaction. In vitro enzyme assays demonstrated that the impact of ST fusion and HSA conjugation on Uox enzymatic activity is negligible. Pharmacokinetics studies in mice revealed that Uox-HSA exhibits a significantly longer serum half-life (about 18 h) compared to Uox-WT (about 2 h). This extended half-life is attributed to FcRn-mediated recycling of HSA-conjugated Uox, demonstrating the effectiveness of the AlbuCatcher strategy in enhancing the pharmacokinetics of therapeutic proteins.