N-glycan PK Profiling Using a High Sensitivity nanoLCMS Work-Flow with Heavy Stable Isotope Labeled Internal Standard and Application to a Preclinical Study of an IgG1 Biopharmaceutical.

PURPOSE: In this study an innovative, highly sensitive work-flow is presented that allows the analysis of a possible influence of individual glyco-variants on pharmacokinetics already during pre-clinical development. Possible effects on the pharmacokinetics caused by glyco-variants have been subject of several studies with in part contradictory results which can be related to differences in the set-up. METHODS: Using 96-well plate based affinity purification an IgG1 antibody was isolated from preclinical samples and glycans were analyzed individually by nanoLCMS. Prerequisite was a reference standard based on stable heavy isotope labeled glycans. The high sensitivity and low sample consumption enabled the integration into the preclinical development program. RESULTS: The data of an IgG1 biopharmaceutical from a preclinical rabbit study showed that some N-glycoforms have a different PK profile compared with the average of all molecule variants as determined by ELISA. IgG1 high mannose glycoforms M5 and M6 were removed from circulation at a higher rate. CONCLUSION: The results of the preclinical study demonstrated the applicability of the developed innovative workflow. The PK profile of glyco-variants could be determined individually. It was concluded that M6 was converted by mannosidases in circulation to M5 which in turn was selectively cleared by mannose receptor binding which is in-line with previously published results. Therefore the developed technology delivers reliable results and can be applied for PK profiling of other mAbs and other types of biopharmaceuticals.

Factor XIIa inhibitor recombinant human albumin Infestin-4 abolishes occlusive arterial thrombus formation without affecting bleeding.

BACKGROUND: Blood coagulation is a tightly regulated process of sequentially activated serine proteases culminating in fibrin formation, which is critical for limiting posttraumatic blood loss but also may contribute to acute thrombotic diseases, most notably myocardial infarction and stroke. Recent studies with factor XII-deficient mice revealed that the factor XII-induced intrinsic coagulation pathway is essential for pathological thrombus formation but dispensable for hemostasis. Consequently, these findings led to the hypothesis that factor XII could be a promising pharmacological target for safe antithrombotic therapy. METHODS AND RESULTS: The complementary DNA of the previously described factor XIIa inhibitor Infestin-4, cloned from the midgut of Triatoma infestans, was fused to recombinant human albumin (rHA) and analyzed in vitro. The resulting protein rHA-Infestin-4 specifically inhibits factor XIIa and causes prolonged activated partial thromboplastin time in human, mouse, and rat plasma. To assess its inhibitory potency in vivo, mice and rats were injected with rHA-Infestin-4 and challenged in pathological thrombus formation models. In addition, bleeding assays were performed. rHA-Infestin-4 completely abolished occlusive arterial thrombus formation in mice and rats while leaving hemostasis fully intact. Furthermore, rHA-Infestin-4 was highly protective in a murine model of ischemic stroke. CONCLUSIONS: These results identify rHA-Infestin-4 as a promising agent to achieve powerful protection from ischemic cardiovascular and cerebrovascular events without affecting hemostasis.

Genetic fusion to albumin improves the pharmacokinetic properties of factor IX.

Haemophilia B is a X-chromosome linked disease characterised by a deficiency of functionally active coagulation Factor IX (FIX). Patients with severe haemophilia B at risk of recurrent bleeding are treated approximately twice a week in a prophylactic setting by application of FIX concentrates. To increase convenience and compliance of the therapy it is desirable to reduce the dosing frequency by improving the pharmacokinetic properties of FIX. Here a concept of rFIX (recombinant factor IX) albumin fusion proteins (rIX-FPs) with cleavable linker peptides derived from the FIX activation sequence is presented. Constructs of the genetic fusion of FIX to albumin via cleavable linkers were expressed in mammalian cells and characterised after purification. In vitro activation studies with FXIa demonstrated that cleavage of the linker and the activation peptide proceeded comparably well. In a clotting assay the rIX-FPs with cleavable linker showed a 10- to 30-fold increase in the molar specific clotting activity compared to fusion proteins with non-cleavable linkers. Furthermore, in-vivo recovery, terminal half-life and the AUC of rIX-FPs in rats and rabbits as determined by FIX antigen measurements were significantly increased compared to rFIX (BeneFIX). In FIX deficient (FIX(-/-)) mice the in-vivo recovery and the AUC were also significantly increased. The efficacy in reducing bleeding time was shown in FIX(-/-) mice by a tail tip bleeding model. The results suggest that rIX-FPs with a cleavable linker between FIX and albumin are a promising concept that may support the use of the albumin fusion technology to extend the half-life of FIX.

Prolonged in-vivo half-life of factor VIIa by fusion to albumin.

For the treatment of haemophilia patients with inhibitors, recombinant factor VIIa (rFVIIa) is available as a therapeutic option to control bleeding episodes with a good balance of safety and efficacy. However, the short in-vivo half-life of approximately 2.5 hours makes multiple injections necessary, which is inconvenient for both physicians and patients. Here we describe the generation of a recombinant FVIIa molecule with an extended half-life based on genetic fusion to human albumin. The recombinant FVII albumin fusion protein (rVII-FP) was expressed in mammalian cells and upon activation displayed a FVII activity close to that of wild type FVIIa. Pharmacokinetic studies in rats demonstrated that the half-life of the activated recombinant FVII albumin fusion protein (rVIIa-FP) was extended six- to seven-fold compared with wild type rFVIIa. The in-vitro and in-vivo efficacy was evaluated and was found to be comparable to a commercially available rFVIIa (NovoSeven((R))). The results of this study demonstrate that it is feasible to develop a half-life extended FVIIa molecule with haemostatic properties very similar to the wild-type factor.

Comparative functional and pharmacological characterization of Sandoz proposed biosimilar adalimumab (GP2017): rationale for extrapolation across indications.

BACKGROUND: Biosimilars are approved biologics that match reference medicine in quality, safety, and efficacy. The development of Sandoz proposed biosimilar adalimumab (SPBA; GP2017) involved a target-directed, iterative state-of-the-art quality-by-design development program. Here, we describe the functional and pharmacological characterization of SPBA and its proposed mechanism of action in immune-mediated inflammatory diseases. METHODS: Sensitive in vitro binding and functional characterization studies, and nonclinical evaluations (pharmacokinetics, pharmacodynamics, and safety/toxicology) were performed as part of a stepwise approach to confirm the biosimilarity of SPBA with reference adalimumab. RESULTS: Matching values were reported for SPBA and reference adalimumab in binding assays involving tumor necrosis factor (TNF)-α, complement 1q and human immune effector cell Fcγ receptor subtypes in cell-based bioassays for Fc receptor function (complement- and antibody-dependent cytotoxicity), and in apoptosis inhibition. Furthermore, SPBA and reference adalimumab were equivalent in terms of membrane TNF binding and induction of reverse signaling. Pharmacokinetics of SPBA and reference adalimumab were comparable in rabbits, and the two biologics were equally effective in a human TNF transgenic mouse model of polyarthritis. CONCLUSION: SPBA matches reference adalimumab with regards to target binding, functional, pharmacokinetic, and pharmacodynamic properties at the nonclinical level supporting its approval in all indications of the reference adalimumab.

Characterization and non-clinical assessment of the proposed etanercept biosimilar GP2015 with originator etanercept (Enbrel(®)).

BACKGROUND AND OBJECTIVE: Biosimilars are approved biologics that are comparable to an originator product with respect to quality, safety and efficacy. Herein, the authors describe the functional and non-clinical studies designed to determine the biosimilarity of GP2015 and originator etanercept (Enbrel®). METHODS: The development of an Enbrel biosimilar (GP2015) involved extensive characterization of the originator. A step-wise target-directed and iterative technical development program involving state-of-the-art functional characterization studies and non-clinical evaluations (pharmacokinetics, pharmacodynamics and safety/toxicology) was applied with the aim of confirming that GP2015 is comparable to originator (Enbrel) at the non-clinical level. RESULTS: In in vitro tests, GP2015 and Enbrel had comparable binding affinities to TNF-α, C1q complement and a complete panel of Fc-Receptors. Comprehensive functional characterization testing confirmed the comparability of GP2015 with Enbrel in terms of its ability to bind to and neutralize TNF-α, which reflects the primary mechanism of action of etanercept. Non-clinical data confirmed that the proposed biosimilar to Enbrel, GP2015, is comparable with regards to its pharmacokinetic properties and pharmacodynamic activity, and efficacy as well as safety/toxicity. CONCLUSION: The proposed Enbrel biosimilar, GP2015, was shown to be comparable to its originator product in studies designed to confirm biosimilarity.

Target-directed development and preclinical characterization of the proposed biosimilar rituximab GP2013.

Biosimilar development involves a target-directed iterative process to ensure a similar product to the originator. Here we report the preclinical development of the proposed biosimilar rituximab (GP2013). Post-translational modifications and bioactivities of GP2013 versus originator rituximab were engineered and monitored to ensure similar pharmacological profiles. Antibody-dependent cellular cytotoxicity (ADCC) was used to illustrate how different glycosylation patterns and structure-function relationships were controlled during process development. Pharmacological comparability between GP2013 and originator rituximab were confirmed in preclinical studies using clinical scale drug product. Similar in vitro ADCC potency was demonstrated when compared in a dose-response manner against two lymphoma cell lines using freshly purified human natural killer (NK) cells. In vivo efficacy was demonstrated in two well characterized mouse xenograft models, testing at sensitive sub-therapeutic dose levels. Pharmacokinetics and pharmacodynamics (CD20 cell depletion) were likewise comparable in cynomolgus monkeys. This preclinical comparability exercise confirms that GP2013 and originator rituximab are pharmacologically similar.