Major efforts have been made in the search for effective treatments since the outbreak of the COVID-19 infection in December 2019. Extensive research has been conducted on drugs that are already available and new treatments are also under development. Within this context, therapeutic monoclonal antibodies (mAbs) have been the subject of widespread investigation focusing on two target-based groups, i.e., non-SARS-CoV-2 specific mAbs, that target immune system responses, and SARS-CoV-2 specific mAbs, designed to neutralize the virus protein structure. Here we review the latest literature about the use of mAbs in order to describe the state of the art of the clinical trials and the benefits of using these biotherapeutics in the treatment of COVID-19. The clinical trials considered in the present review include both observational and randomized studies. We begin by presenting the studies conducted using non-SARS-CoV-2 specific mAbs for treating different immune disorders that were already on the market. Within this group of mAbs, we focus particularly on anti-IL-6/IL-6R. This is followed by a discussion of the studies on SARS-CoV-2 specific mAbs. Our findings indicate that SARS-CoV-2 specific mAbs are significantly more effective than non-specific ones.

Nivolumab, formulated in the medicine Opdivo^® (10 mg/mL), is a therapeutic monoclonal antibody (mAb) used in the treatment of different types of cancer. Currently, there is insufficient knowledge about the behaviour of this protein with regards to the risk associated with its routine handling or unintentional mishandling, or when subjected to stress conditions in hospitals. These conditions can be simulated in forced degradation studies, which provide an in-depth understanding of the biophysical and biochemical properties of mAbs. In this study, we carried out a physicochemical and functional characterisation of nivolumab, which was subjected to various stress conditions: heat, freeze/thaw cycles, agitation, light exposure and high hypertonic solution. We used a wide range of analytical techniques: Far-UV CD, IT-FS, DLS, SE/UHPLC(UV)-[Native]MS, and ELISA. The results show that exposure to light was the stress test with the greatest impact on the samples, revelling the formation of non-natural dimers and a different isoform profile. In addition, nivolumab (Opdivo^®) demonstrated stability up to 60 °C (1 h). As regards functionality all the nivolumab (Opdivo^®) stressed samples were found to be stable except for those subjected to light and agitation, and to a lesser extent, those subjected to FTC 5 and NaCl stresses.

Teduglutide (Revestive (R)) is a glucagon-like peptide-2 analogue used for the treatment of short bowel syndrome, a rare life-threatening condition in which the amount of functional gut is too short to enable proper absorption of nutrients and fluids. During handling prior to administration to the patient in hospital, it is possible that peptide -based medicines may be exposed to environmental stress conditions that could affect their quality. It is therefore essential to carry out stress testing studies to evaluate how such medicines respond to these stresses. For this reason, in this paper we present a strategy for a comprehensive analytical characterization of a peptide and a stress testing study in which it was subjected to various stress conditions: heating at 40 degrees C and 60 degrees C, light exposure and shaking. Several complementary analytical techniques were used throughout this study: Far UV circular dichroism, intrinsic protein fluorescence spectroscopy, dynamic light scattering, size-exclusion chro-matography and intact and peptide mapping reverse-phase chromatography coupled to mass spectrometry. To the best of our knowledge, this is the first study to offer an in-depth description of the chemical structure of teduglutide peptide and its physicochemical characteristics after stress stimuli were applied to the reconstituted medicine Revestive (R).

Background/Objectives: Cetuximab, formulated in Erbitux^® (5 mg/mL), is a therapeutic monoclonal antibody (mAb) widely used in several cancer treatments. Currently, there is insufficient knowledge about the behavior of cetuximab with regard to the risk associated with its routine handling or unintentional mishandling in hospitals. Forced degradation studies can simulate these conditions and provide insights into the biophysical and biochemical properties of mAbs. Methods: In this study, we conducted a deep physicochemical and functional characterization of the critical quality attributes of cetuximab in control samples and under controlled degraded conditions, including freeze–thaw cycles, heat, agitation, and light exposure. To achieve this purpose, we used a set of proper analytical techniques, including CD, IT-FS, DLS, SE/UHPLC-UV, UHPLC-MS/MS, and ELISA, to check functionality based on antigen–antibody binding. Results: The results revealed that light exposure was the stress stimuli with the greatest impact on the drug product, leading to the formation of non-natural oligomers, fragmentation, and oxidation of methionine residues. Additionally, cetuximab (Erbitux^®, 5 mg/mL) showed a tendency to aggregate when submitted to 60 °C for 1 h. In terms of functionality, cetuximab (Erbitux^®, 5 mg/mL) samples were found to be affected when subjected to freeze–thaw cycles, 60 °C (1 h), and when exposed to light (daylight with room temperature excursion and accelerated light exposure). Conclusions: Thus, we suggest that Erbitux^® (5 mg/mL) should be shielded from these environmental conditions, as they compromise both the safety and efficacy of the drug product.

Background and importance Nivolumab (Opdivo) is a human IgG4 monoclonal antibody from the group of immunomodulators which bind to the programmed death receptor 1 (PD-1). As a complex protein, physical aggregation and chemical degradation can occur throughout its life, and even modest environmental stresses can cause extensive damage.¹ As indicated in its technical report,² the unopened vials can be stored at a controlled room temperature up to 25°C with room light for up to 48 hours. Aim and objectives To assess the impact on the isoform profile of nivolumab 10 mg/mL (Opdivo) promoted by exposure to light in its own opened vial at a controlled temperature of 25°C to evaluate likely risks from unintentional mishandling in real hospital conditions. Material and methods Nivolumab (Opdivo, 10 mg/mL) was placed in an accelerated stress test chamber to simulate sunlight (Solarbox 3000e RH, Cofomegra, Milan, Italy) for 24 hours at 25°C. Irradiation was set at 250 W/m², between 320 and 800 nm.³ A validated reverse phase ultra high resolution liquid chromatography coupled to high resolution mass spectrometry and exact mass ((RP)UHPLC-UV-(HESI/Orbitrap)-MS) method was used to analyse intact nivolumab. UV-chromatograms and total ion chromatograms (TICs) were recorded and the deconvoluted mass spectra gave the nivolumab mass isoform profile. Results UV chromatograms and TICs suggested no degradation products after light exposure. However, isoform profiles clearly showed changes in the light submitted nivolumab samples. An important increase in the number of isoforms even with changes in their masses, including the main isoform, was detected. Conclusion and relevance Exposure to light may cause modifications in the nivolumab isoform profile which suggests protein degradation. This work shows the importance of protecting opened vials of the medicine Opdivo from light (and by extension, bags for infusion) when they are at room temperature (up to 25°C). References and/or acknowledgements Nejadnik MR, et al. J Pharm Sci 2018;107:2013–19. Nivolumab Technical Report. https://www.ema.europa.eu/en/documents/product-information/opdivo-epar-product-information_en.pdf Scientific discussion ICH Q1B photostability testing of new active substances and medicinal products. European Medicines Agency (EMEA) 1998 https://www.ema.europa.eu/en/documents/scientific-guideline/ich-q-1-b-photostability-testing-new-active-substances-medicinal-products-step-5_en.pdf References and/or acknowledgementsFunded by project FIS: PI-17/00547 (Instituto Carlos III, Spain), which means that it was also partially supported by European Regional Development Funds. AT-L is currently receiving an FPU predoctoral grant (reference FPU18/03131) from the Ministry of Universities, Spain. Conflict of interest No conflict of interest