On-line electrochemistry–bioaffinity screening with parallel HR-LC-MS for the generation and characterization of modified p38α kinase inhibitors

In this study, an integrated approach is developed for the formation, identification and biological characterization of electrochemical conversion products of p38α mitogen-activated protein kinase inhibitors. This work demonstrates the hyphenation of an electrochemical reaction cell with a continuous-flow bioaffinity assay and parallel LC-HR-MS. Competition of the formed products with a tracer (SKF-86002) that shows fluorescence enhancement in the orthosteric binding site of the p38α kinase is the readout for bioaffinity. Parallel HR-MSn experiments provided information on the identity of binders and non-binders. Finally, the data produced with this on-line system were compared to electrochemical conversion products generated off-line. The electrochemical conversion of 1-{6-chloro-5-[(2R,5S)-4-(4-fluorobenzyl)-2,5-dimethylpiperazine-1-carbonyl]-3aH-indol-3-yl}-2-morpholinoethane-1,2-dione resulted in eight products, three of which showed bioaffinity in the continuous-flow p38α bioaffinity assay used. Electrochemical conversion of BIRB796 resulted, amongst others, in the formation of the reactive quinoneimine structure and its corresponding hydroquinone. Both products were detected in the p38α bioaffinity assay, which indicates binding to the p38α kinase

Development of an online p38α mitogen-activated protein kinase binding assay and integration of LC–HR-MS

A high-resolution screening method was developed for the p38α mitogen-activated protein kinase to detect and identify small-molecule binders. Its central role in inflammatory diseases makes this enzyme a very important drug target. The setup integrates separation by high-performance liquid chromatography with two parallel detection techniques. High-resolution mass spectrometry gives structural information to identify small molecules while an online enzyme binding detection method provides data on p38α binding. The separation step allows the individual assessment of compounds in a mixture and links affinity and structure information via the retention time. Enzyme binding detection was achieved with a competitive binding assay based on fluorescence enhancement which has a simple principle, is inexpensive, and is easy to interpret. The concentrations of p38α and the fluorescence tracer SK&F86002 were optimized as well as incubation temperature, formic acid content of the LC eluents, and the material of the incubation tubing. The latter notably improved the screening of highly lipophilic compounds. For optimization and validation purposes, the known kinase inhibitors BIRB796, TAK715, and MAPKI1 were used among others. The result is a high-quality assay with Z′ factors around 0.8, which is suitable for semi-quantitative affinity measurements and applicable to various binding modes. Furthermore, the integrated approach gives affinity data on individual compounds instead of averaged ones for mixtures

Is the EU ready for non-biological complex drug products?

Comment on the Regulatory paper by Dr Falk Ehmann and Dr Ruben Pita: The EU is ready for non-biological complex medicinal products, published in GaBI Journal, 2016;5(1):30-5

Different pharmaceutical products need similar terminology

In the last decade, discussions on the development of the regulatory framework of generic versions of complex drugs such as biologicals and non-biological complex drugs have attracted broad attention. The terminology used is far from harmonized and can lead to multiple interpretations of legal texts, reflection papers, and guidance documents regarding market introduction as well as reimbursement. This article describes the meaning of relevant terms in different global regions (Europe, USA, WHO) and offers a proposal for a globally accepted terminology regarding (non-) biological complex drugs

Different pharmaceutical products need similar terminology

In the last decade, discussions on the development of the regulatory framework of generic versions of complex drugs such as biologicals and non-biological complex drugs have attracted broad attention. The terminology used is far from harmonized and can lead to multiple interpretations of legal texts, reflection papers, and guidance documents regarding market introduction as well as reimbursement. This article describes the meaning of relevant terms in different global regions (Europe, USA, WHO) and offers a proposal for a globally accepted terminology regarding (non-) biological complex drugs

How to regulate nonbiological complex drugs (NBCD) and their follow-on versions: points to consider

The aim of this critical review is to reach a global consensus regarding the introduction of follow-on versions of nonbiological complex drugs (NBCD). A nonbiological complex drug is a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by state of the art physicochemical analytical means and where the clinical meaning of the differences is not known. The composition, quality and in vivo performance of NBCD are highly dependent on manufacturing processes of both the active ingredient as well as in most cases the formulation. The challenges posed by the development of follow-on versions of NBCD are illustrated in this paper by discussing the 'families' of liposomes, iron-carbohydrate ('iron-sugar') drugs and glatiramoids. It is proposed that the same principles for the marketing authorization of copies of NBCD as for biosimilars be used: the need for animal and/or clinical data and the need to show similarity in quality, safety and efficacy. The regulatory approach of NBCD will have to take into consideration the specific characteristics of the drugs, their formulation and manufacturing process and the resulting critical attributes to achieve their desired quality, safety and efficacy. As with the biosimilars, for the NBCD product, family-specific methods should be evaluated and applied where scientifically proven, including sophisticated quality methods, pharmacodynamic markers and animal models. Concerning substitution and interchangeability of NBCD, it is also advisable to take biosimilars as an example, i.e. (1) substitution without the involvement of a healthcare professional should be discouraged to ensure traceability of the treatment of individual patients, (2) keep an individual patient on a specific treatment if the patient is doing well and only switch if unavoidable and (3) monitor the safety and efficacy of the new product if switching occurs