Bioanalysis of therapeutic monoclonal antibody by peptide adsorption-controlled LC-MS.

Aim: We aimed to develop an easy, low-cost and versatile mass spectrometric method for the bioanalysis of a therapeutic monoclonal antibody (mAb) in human serum that employs peptide adsorption-controlled (PAC)-LC/MS using selected reaction monitoring mode (LC-MS/MS-SRM). Materials & methods: Rituximab was used as a model mAb. To apply the method to human serum samples, a peptide of the complementarity-determining region was selected as the surrogate peptide. The usefulness of PAC-LC-MS/MS-SRM was evaluated by a collaborative study. Results: The calibration curve ranged from 0.5 (or 1.0) to 1000.0 µg/ml. The selectivity, linearity, accuracy and precision met the predefined acceptance criteria. Conclusion: Our method could be a useful bioanalytical method for the quantification of mAbs in clinical samples.

Pharmacokinetics and pharmacodynamics of JR-051, a biosimilar of agalsidase beta, in healthy adults and patients with Fabry disease: Phase I and II/III clinical studies.

Fabry disease is a rare X-linked lysosomal disease, in which mutations in the gene encoding α-galactosidase A result in progressive cellular accumulation of globotriaosylceramide (GL-3) in various organs including the skin, kidney, and heart, often leading to life-threatening conditions. Enzyme replacement therapy is currently the standard therapy for the disease, to which two α-galactosidase A formulations have been approved: agalsidase α (Replagal®, Shire) and agalsidase ß (Fabrazyme®, Sanofi). We have recently developed a biosimilar of agalsidase ß, JR-051, and investigated its pharmacokinetics and pharmacodynamics to assess its bioequivalence to agalsidase ß. In a randomized phase I study, healthy adult male volunteers were treated with JR-051 or agalsidase ß and the pharmacokinetics of the drugs were compared. The ratio of geometric means (90% confidence interval [CI]) of the AUC0-24 and Cmax for JR-051 over agalsidase ß were 0.91 (0.8294, 1.0082) and 0.90 (0.7992, 1.0125), respectively. In a 52-week, single-arm, phase II/III study, patients with Fabry disease switched therapy from agalsidase ß to JR-051 to evaluate its pharmacodynamics. The mean (95% CI) plasma GL-3 concentrations at weeks 26 and 52 relative to pre-JR-051 administration were 1.03 (0.91, 1.15) and 0.96 (0.86, 1.06), respectively, which were within the pre-determined bioequivalence acceptance range (0.70, 1.43). The mean (95% CI) plasma globotriaosylsphingosine (lyso-GL-3) concentrations at weeks 26 and 52 relative to pre-JR-051 administration were 1.07 (0.92, 1.23) and 1.13 (1.03, 1.22), respectively. Estimated glomerular filtration rate and left ventricular mass index, as renal and cardiac function indicators, showed no notable changes from baseline throughout the study period, and no new safety concerns were identified. In conclusion, these studies demonstrated bioequivalence of JR-051 to agalsidase ß in terms of its pharmacokinetics and pharmacodynamics. JR-051 offers a potential new treatment option for patients with Fabry disease.

Bone marrow-derived mesenchymal stem cells (JR-031) for steroid-refractory grade III or IV acute graft-versus-host disease: a phase II/III study.

Following a phase I/II study using mesenchymal stem cells (MSCs; JR-031) for steroid-refractory grade II or III acute graft-versus-host disease (aGVHD), a phase II/III study using the cells focused on steroid-refractory grade III or IV aGVHD was conducted. The number of infused MSCs and the number of MSC infusions were the same as the phase I/II study. No additional immunosuppressant was given for steroid-refractory aGVHD during the course of MSC infusions. Twenty-five patients (grade III, 22 patients and grade IV, 3 patients) were enrolled in this study. At 4 weeks after the first MSC infusions, six (24 %) and nine patients (36 %) achieved a complete response (CR) and partial response (PR), respectively. Durable CR by 24 weeks, which was the primary end-point, was obtained in 12 of 25 patients (48 %). At 52 weeks, 12 patients (48 %) treated with MSCs only (six patients) and MSCs plus additional treatments (six patients) were alive in CR. The survival was significantly better in patients showing overall response (OR; CR+PR) than in those showing no OR at 4 weeks. Adverse effects commonly associated with MSC infusions were not observed. Taken together, our two clinical trials suggest JR-031 to be effective for steroid-refractory aGVHD.