Efgartigimod works through an elegant molecular trick. It is a human immunoglobulin G1 (IgG) antibody Fc fragment, engineered to bind with unusually high affinity to the neonatal Fc receptor (FcRn), the cellular recycling machinery that normally protects IgG antibodies from degradation and gives them their characteristically long half-life in the bloodstream. By occupying FcRn, efgartigimod interrupts this recycling loop, so circulating IgG, including the pathogenic autoantibodies that drive diseases like gMG and CIDP, is cleared faster. Importantly, the drug does not suppress antibody production or blunt immune responses to vaccination, and it does not lower albumin levels or raise cholesterol, distinguishing it from broadly immunosuppressive therapies such as glucocorticoids, azathioprine, mycophenolate mofetil, or B cell-depleting agents.

The original subcutaneous formulation contained a fixed 1000-mg dose of efgartigimod at 180 mg/ml in a 5.6-ml volume, supplied in a single-dose vial that a health care provider had to draw up with a separate syringe. The new prefilled syringe packs the same 1000-mg dose into 5.0 ml at a higher concentration of 200 mg/ml, and it was approved in the United States in April 2025 for adults with acetylcholine receptor autoantibody-positive generalized myasthenia gravis and for adults with CIDP. The coformulation with recombinant human hyaluronidase PH20 is what makes such a large subcutaneous volume feasible: the enzyme locally depolymerizes hyaluronan in the subcutaneous space, temporarily dissolving the structural barrier to bulk fluid flow so the drug can disperse and be absorbed more readily.

The first question the researchers tackled was whether the prefilled syringe is pharmacologically interchangeable with the vial-and-syringe presentation. In a Phase 1, open-label, randomized, two-period crossover bioequivalence study (ClinicalTrials.gov identifier NCT05817435), 72 healthy participants each received a single health care provider-administered injection by both routes, serving as their own controls. Serum efgartigimod concentrations were measured with a validated ligand-binding electrochemiluminescence immunoassay with a lower limit of quantification of 200 ng/ml, and the primary endpoints were the maximum observed concentration (Cmax) and the area under the concentration-time curve from zero to infinity (AUC0-inf).

The bioequivalence criterion was met decisively. The 90 percent confidence intervals for the geometric least-squares mean ratios of both Cmax and AUC0-inf fell entirely within the predefined acceptance range of 80.0 to 125.0 percent, the regulatory standard for demonstrating that two formulations deliver equivalent systemic exposure. After injection, efgartigimod concentrations rose to a plateau, with a median time to peak concentration of 48.0 hours for the prefilled syringe versus 72.0 hours for the vial and syringe, and individual values ranging from 12.0 to 119.3 hours. Once the plateau was reached, serum concentrations declined gradually with similar half-lives for both presentations, and other pharmacokinetic parameters were likewise comparable between the two arms.

Safety in the bioequivalence study was reassuring. The drug was well tolerated by both routes, with no fatal or serious adverse events and no discontinuations attributed to adverse events. A single grade 3 or higher event, a blood pressure increase in one participant who received the vial-and-syringe formulation, was judged unrelated to treatment. Injection site reactions occurred in 50.7 percent of participants using the prefilled syringe and 59.7 percent using the vial and syringe, all of grade 1 or 2 severity, and all resolved by the end of the study except one that was resolving. A post hoc analysis showed mean injection durations of roughly 31 seconds in both groups, and no anaphylactic or hypersensitivity reactions were observed.

A second Phase 1 study asked a deceptively simple question: how fast can a large, viscous subcutaneous volume be pushed without causing problems? All 48 randomized healthy participants completed this randomized, open-label crossover trial, in which efgartigimod PH20 SC was delivered over 20, 30, 45, or 60 seconds using an infusion pump with a disposable syringe and a 27-gauge ultra-thin-wall needle. Every participant across every speed group received at least 90 percent of the full injection volume in both dosing periods, and mean fluid leakage or backflow at the injection site was negligible and essentially identical across groups, at 0.0122 ml in the first period and 0.0085 ml in the second. More than 87 percent of participants said one hour after injection that they would be willing to receive the administration again, local pain scores dropped significantly within five minutes across all speed groups, and all adverse events were mild to moderate, with no serious events or discontinuations.

The third component comprised two human factors validation studies, designed according to US Food and Drug Administration guidance for combination products, that tested whether real users could handle the device safely. Fifteen participants with gMG, fifteen with CIDP, and fifteen lay caregivers of family members with these diseases were given the prefilled syringe and its instructions for use, but no training whatsoever. In a simulated home environment, each participant stored the device overnight and then performed an unaided simulated injection into an injection pad, placed over their own clothes for patients or on a manikin for caregivers. The results were striking: all 45 participants successfully refrigerated, prepared, injected, and disposed of the prefilled syringe, delivering the full dose in an average of 30 seconds, with no performance differences between patients and caregivers and no use errors that could cause harm. All 45 also correctly located and identified 28 pieces of critical safety information in the instructions, and every participant said they believed they could give weekly injections with the product if needed.

The authors acknowledge one methodological caveat: the injection speed study used an infusion pump rather than the prefilled syringe device itself, which prevents firm conclusions about the optimal speed of the PFS specifically. However, the formulation tested had the same volume and viscosity as that used in the bioequivalence and human factors studies, which did employ the device, so the data collectively support the feasibility and safety of a rapid, roughly 30-second injection of efgartigimod PH20 SC in general. The researchers also note that the studies were funded by argenx, the drug’s developer, and that several of the authors are company employees, factors readers should weigh when interpreting the uniformly positive findings.

Even with those caveats, the implications for patients are substantial. For chronic conditions like gMG and CIDP, where treatment continues indefinitely, aligning therapy with patient preferences for route of administration has been linked to greater satisfaction, better quality of life, and improved adherence. A prefilled syringe eliminates the steps of vial handling and dose drawing, improves dosing accuracy, and particularly benefits patients with impaired manual dexterity, coordination, or vision, while reducing health care resource utilization and waste. Taken together, the bioequivalence, injection speed, and human factors data indicate that a rapid, high-volume subcutaneous injection of efgartigimod PH20 from a prefilled syringe is safe, feasible, and usable, offering patients and their caregivers a quick, flexible option for receiving treatment either in a clinic or at home, and potentially easing the daily burden of living with IgG-mediated autoimmune disease.

Subject of Research: Pharmacokinetics, injection speed, and usability of a prefilled syringe for subcutaneous efgartigimod PH20 in IgG-mediated autoimmune diseases

Article Title: Investigating the Pharmacokinetics, Injection Speed, and Usability of Subcutaneous Efgartigimod PH20 Administered with a Prefilled Syringe

Article References: De Muynck, C., Noukens, J., Allosery, K., Cettour-Rose, C., Pastouret, S., Andre, A. D., & Borgions, F. (2026). Investigating the Pharmacokinetics, Injection Speed, and Usability of Subcutaneous Efgartigimod PH20 Administered with a Prefilled Syringe. Advances in Therapy. https://doi.org/10.1007/s12325-026-03733-x

Image Credits: AI Generated

DOI: 10.1007/s12325-026-03733-x

Keywords: efgartigimod, prefilled syringe, bioequivalence, myasthenia gravis, CIDP, neonatal Fc receptor, hyaluronidase PH20, subcutaneous injection, pharmacokinetics, human factors study, autoimmune disease, self-administration

Teneligliptin belongs to a family of medicines known as dipeptidyl peptidase-4, or DPP-4, inhibitors. These drugs work by blocking an enzyme that normally degrades incretin hormones, the gut-derived chemical messengers that prompt the pancreas to release insulin after a meal and to suppress glucagon when blood sugar is already adequate. By preserving incretin activity, DPP-4 inhibitors produce a glucose-dependent enhancement of insulin secretion, which gives them a comparatively favorable safety profile relative to some older antidiabetic agents. Teneligliptin in particular has gained a substantial foothold in Asian markets, where it is prescribed for adults with type 2 diabetes whose glycemic control is inadequate through diet and exercise alone.

The scientific rationale for the new study rests on a fundamental principle of generic drug approval: before a copycat tablet can be substituted for the branded original, regulators demand quantitative proof that the two formulations behave identically inside the body. This property, called bioequivalence, is assessed by comparing how much drug reaches the bloodstream, how quickly it gets there, and how long it lingers. The standard benchmarks are the area under the plasma concentration-time curve, abbreviated AUC, which captures total systemic exposure, and the maximum observed plasma concentration, known as Cmax, which reflects the peak level achieved after a dose. Because a generic can be manufactured and sold at a fraction of the brand-name price, demonstrating bioequivalence is the gateway to cost savings that can ripple across entire health systems, a consideration that is especially acute in countries with large diabetic populations and constrained drug budgets.

To generate that proof, the researchers recruited 52 healthy Chinese adults and enrolled them in a randomized, open-label, single-dose, two-sequence, two-period crossover trial, with 26 participants assigned to each treatment sequence. In a crossover design, every volunteer eventually receives both formulations, with the order of administration randomized; this arrangement is prized in bioequivalence work because each participant serves as his or her own control, stripping away much of the noise introduced by individual differences in metabolism, body composition, and physiology. The washout interval between the two doses was set at seven days, long enough for the first dose to be fully eliminated before the second was taken, ensuring that lingering drug from one period could not contaminate measurements in the other.

The trial was conducted twice under deliberately different dietary conditions, once in the fasting state and once after food. This dual design matters because meals can alter gastric emptying, bile flow, and the solubility of orally administered compounds, sometimes shifting absorption in ways that change both the speed and the extent of drug uptake. Regulatory agencies typically require bioequivalence testing under fasting conditions, and add a fed arm when a drug is likely to be taken with meals or when food effects are anticipated. A single 40 mg dose of either the test generic or the reference Tenelia was administered in each condition, allowing the investigators to establish that the two tablets perform equivalently regardless of whether a patient swallows the pill before breakfast or alongside it.

Measuring the drug in plasma demanded a highly sensitive analytical technique. The team used liquid chromatography-tandem mass spectrometry, or LC-MS/MS, a method that first separates teneligliptin from the other components of blood plasma and then fragments the molecules in a way that allows precise quantification even at very low concentrations. The assay was validated before use, and the accuracy of the measurements was verified through incurred sample reanalysis, in which selected patient samples are tested a second time to confirm that the original results are reproducible. Such quality-control steps are indispensable, because a bioequivalence verdict is only as trustworthy as the concentration data on which the entire statistical comparison is built.

The statistical framework for the comparison follows internationally harmonized regulatory conventions. For each pharmacokinetic parameter, the researchers calculated the geometric mean ratio between the generic and the branded product, then determined the 90 percent confidence interval around that ratio after logarithmic transformation of the data. Equivalence is declared only when the entire confidence interval falls within the predefined acceptance boundaries of 80 to 125 percent for the parameters AUC from time zero to the last measurable concentration, AUC extrapolated to infinity, and Cmax. The analysis of variance, or ANOVA, framework used for this purpose formally accounts for the crossover structure of the trial, testing whether formulation, period, and sequence effects influence the observed differences. In both the fasting and the fed studies, every confidence interval landed squarely inside the acceptance window, satisfying the regulatory criterion for bioequivalence in full.

Safety was monitored alongside the pharmacokinetic measurements, with adverse events graded according to the Common Terminology Criteria for Adverse Events, version 5.0. No serious adverse events occurred during the trial, an outcome consistent with the generally well-tolerated character of DPP-4 inhibitors at single therapeutic doses in healthy volunteers. While a small crossover study in healthy adults cannot substitute for the broader safety record accumulated through post-marketing surveillance, the absence of serious events provides reassurance that the generic formulation introduces no novel tolerability concerns relative to the established product.

The study was carried out from April through September 2025 at The Affiliated Panyu Central Hospital of Guangzhou Medical University, conducted in accordance with the Declaration of Helsinki and approved in advance by the institution’s Drug Clinical Trial Ethics Committee. Each volunteer provided written informed consent before screening began, and the trial was registered in the Chinese Clinical Trial Registry under identifier ChiCTR2500112749, registered retrospectively on November 19, 2025, with an earlier entry on the Drug Clinical Trial Registration and Information Publicity Platform under CTR20252533. The conduct of the trial and the preparation of the manuscript adhered to the CONSORT 2025 reporting guidelines and their applicable bioequivalence extensions, reflecting the transparency standards now expected of clinical research.

The broader significance of the result extends well beyond a single tablet. Bioequivalence studies of this kind form the backbone of generic substitution policies worldwide, allowing pharmacists and physicians to swap in lower-cost alternatives with confidence that patients will experience the same therapeutic effect. For teneligliptin specifically, the availability of a demonstrated equivalent generic in China could ease the financial burden of long-term diabetes therapy for a patient population that continues to grow. The authors conclude that the pharmacokinetic comparison supports the generic product as an equivalent alternative to Tenelia under both fasting and fed conditions, and that the evidence should help inform the product’s acceptance in clinical practice. The study was funded entirely without external grants, and the authors declare no competing interests, with the article published open access under a Creative Commons license so that clinicians, regulators, and patients can examine the full data for themselves.

Subject of Research: Bioequivalence evaluation of generic teneligliptin hydrobromide tablets in healthy Chinese volunteers

Article Title: Pharmacokinetic and bioequivalence evaluation of teneligliptin hydrobromide tablets following single-dose administration in healthy Chinese volunteers under fasting and fed conditions

Article References: Guan, Z., Chen, M., Wei, B., Su, J., Tan, D., Ke, J., & Huang, G. (2026). Pharmacokinetic and bioequivalence evaluation of teneligliptin hydrobromide tablets following single-dose administration in healthy Chinese volunteers under fasting and fed conditions. BMC Pharmacology and Toxicology. https://doi.org/10.1186/s40360-026-01234-9

Image Credits: AI Generated

DOI: 10.1186/s40360-026-01234-9

Keywords: teneligliptin, bioequivalence, pharmacokinetics, type 2 diabetes, DPP-4 inhibitor, generic drugs, LC-MS/MS, clinical trial, Chinese volunteers, drug safety, crossover study, BMC Pharmacology and Toxicology