Watch out for a revival of peginesatide in sports

PEGylated therapeutics in the clinic

The covalent attachment of polyethylene glycol (PEG) to therapeutic agents, termed PEGylation, is a well-established and clinically proven drug delivery approach to improve the pharmacokinetics and pharmacodynamics of drugs. Specifically, PEGylation can improve the parent drug's solubility, extend its circulation time, and reduce its immunogenicity, with minimal undesirable properties. PEGylation technology has been applied to various therapeutic modalities including small molecules, aptamers, peptides, and proteins, leading to over 30 PEGylated drugs currently used in the clinic and many investigational PEGylated agents under clinical trials. Here, we summarize the diverse types of PEGylation strategies, the key advantages of PEGylated therapeutics over their parent drugs, and the broad applications and impacts of PEGylation in clinical settings. A particular focus has been given to the size, topology, and functionalities of PEG molecules utilized in clinically used PEGylated drugs, as well as those under clinical trials. An additional section has been dedicated to analyzing some representative PEGylated drugs that were discontinued at different stages of clinical studies. Finally, we critically discuss the current challenges faced in the development and clinical translation of PEGylated agents.

Evaluation of subvisible particles in human immunoglobulin and lipid nanoparticles repackaged from a multi-dose vial using plastic syringes

The multi-dose vial (MDV) is widely used for most biopharmaceuticals that are repackaged in plastic syringes before use. However, subvisible particle formation with the use of plastic syringes containing silicone oil (SO syringes) for handling therapeutic proteins can be problematic. This study aimed to evaluate the extent of and trends in microparticle (>1 μm) formation and accumulation in repackaged syringes from MDVs containing human immunoglobulin (IgG) and lipid nanoparticles (LNPs). Light obscuration (LO) and flow imaging (FI) were used to analyze the microparticles. The number of microparticles observed with the use SO syringes was greater than that with SO-free syringes, and the number of microparticles continuously increased as did the number of times of repackaging in syringes for both drugs. However, a large variation was observed across different brands of SO syringes. In contrast, using a different technique of drug withdrawal from the vial significantly reduced the number of microparticles. Furthermore, the use of filter-integrated needles or the inclusion of stabilizers such as acetyl-arginine and Tween 20 into the formulation also helped reduce particle formation.

Dried blood spots in doping analysis

A series of dried blood spot (DBS) detection methods for doping agents have been developed in the last two decades. The DBS technique minimizes invasiveness and reduces storage and shipping costs. Recently, the World Anti-Doping Agency announced the use of DBS for the 2022 Beijing Winter Olympic Games and Paralympic Games owing to the advantages of the DBS application in routine doping control. Therefore the further development of detection methods for doping agents in DBS is important and urgent. This review summarizes five aspects of DBS application in doping analysis: sample collection, storage conditions, pretreatment, instrumentation and validation according to the Prohibited List issued by the World Anti-Doping Agency, and proposes some suggestions for future studies of DBS in doping analysis.

Activin receptor ligand traps in chronic kidney disease

PURPOSE OF REVIEW

Sotatercept and luspatercept are recombinant soluble activin type-II receptor-IgG-Fc fusion proteins that are tested in clinical trials for the treatment of various types of anemias, including renal anemia. The mechanism of the action of the novel drugs is incompletely understood, but it seems to be based on the inactivation of soluble proteins of the transforming growth factor-ß (TGFß) family. This review considers pros and cons of the clinical use of the drugs in reference to the current therapy with recombinant erythropoiesis-stimulating agents (ESAs).

RECENT FINDINGS

One or more activin type-II receptor (ActRII) ligands appear to inhibit erythroid precursors, for example growth and differentiation factor 11. Trapping of these ligands by the recombinant ActRII fusion proteins, sotatercept and luspatercept increases red blood cell numbers and hemoglobin levels in humans. Reportedly, the novel compounds were well tolerated in trials on healthy volunteers and patients suffering from anemia due to chronic kidney disease or malignancies. On approval, the drugs may prove particularly useful in patients suffering from ineffective erythropoiesis, such as in myelodysplastic syndrome, multiple myeloma or ß-thalassemia, where ESAs are of little use. Independent of their effect on erythropoiesis, ActRII ligand traps were found to exert beneficial effects on renal tissue in experimental animals.

SUMMARY

ESAs are likely to remain standard of care in renal anemia. There is a need for a better understanding of the effects of ActRII ligand traps on TGFß-like proteins. The novel drugs have not been approved for sale as therapeutics so far. Their long-term efficacy and safety still needs to be proven, particularly with respect to immunogenicity. Antifibrotic effects may be worthy to be investigated in humans.