Analytical and Functional Similarity of Aflibercept Biosimilar ABP 938 with Aflibercept Reference Product

INTRODUCTION

ABP 938 is being developed as a biosimilar candidate to aflibercept reference product (RP), a biologic used for certain angiogenic eye disorders. This study was designed to provide a comparative analytical assessment of the structural and functional attributes of ABP 938 and aflibercept RP sourced from the United States (US) and the European Union (EU).

METHODS

Structural and functional characterization studies were performed using state-of-the-art analytical techniques that were appropriate to assess relevant quality attributes and capable of detecting qualitative and quantitative differences in primary structure, higher-order structure and biophysical properties, product-related substances and impurities, general properties, and biological activities.

RESULTS

ABP 938 had the same amino acid sequence and exhibited similar secondary and tertiary structures, and biological activity as aflibercept RP. There were minor differences in a small number of biochemical attributes which are not expected to impact clinical performance. In addition, aflibercept RP sourced from the US and EU were analytically similar.

CONCLUSIONS

ABP 938 was structurally and functionally similar to aflibercept RP. Since aflibercept RP sourced from the US and EU were analytically similar, this allows for the development of a scientific bridge such that a single-source RP can be used in nonclinical and clinical studies.

Process Development of a SARS-CoV-2 Nanoparticle Vaccine

One of the outcomes from the global COVID-19 pandemic caused by SARS-CoV-2 has been an acceleration of development timelines to provide treatments in a timely manner. For example, it has recently been demonstrated that the development of monoclonal antibody therapeutics from vector construction to IND submission can be achieved in five to six months rather than the traditional ten-to-twelve-month timeline using CHO cells [1], [2]. This timeline is predicated on leveraging existing, robust platforms for upstream and downstream processes, analytical methods, and formulation. These platforms also reduce; the requirement for ancillary studies such as cell line stability, or long-term product stability studies. Timeline duration was further reduced by employing a transient cell line for early material supply and using a stable cell pool to manufacture toxicology study materials. The development of non-antibody biologics utilizing traditional biomanufacturing processes in CHO cells within a similar timeline presents additional challenges, such as the lack of platform processes and additional analytical assay development. In this manuscript, we describe the rapid development of a robust and reproducible process for a two-component self-assembling protein nanoparticle vaccine for SARS-CoV-2. Our work has demonstrated a successful academia-industry partnership model that responded to the COVID-19 global pandemic quickly and efficiently and could improve our preparedness for future pandemic threats.

A chemical and computational approach to comprehensive glycation characterization on antibodies

Non-enzymatic glycation is a challenging post-translational modification to characterize due to the structural heterogeneity it generates in proteins. Glycation has become increasingly recognized as an important product quality attribute to monitor, particularly for the biotechnology sector, which produces recombinant proteins under conditions that are amenable to protein glycation. The elucidation of sites of glycation can be problematic using conventional collision-induced dissociation (CID)-based mass spectrometry because of the predominance of neutral loss ions. A method to characterize glycation using an IgG1 monoclonal antibody (mAb) as a model is reported here. The sugars present on this mAb were derivatized using sodium borohydride chemistry to stabilize the linkage and identified using CID-based MS(2) mass spectrometry and spectral search engines. Quantification of specific glycation sites was then done using a targeted MS(1) based approach, which allowed the identification of a glycation hot spot in the heavy chain complementarity-determining region 3 of the mAb. This targeted approach provided a path forward to developing a structural understanding of the propensity of sites to become glycated on mAbs. Through structural analysis we propose a model in which the number and 3-dimensional distances of carboxylic acid amino acyl residues create a favorable environment for glycation to occur.

Stimulus-response versus stimulus-stimulus-response learning in cerebellar patients

Ample evidence exists that the cerebellum is involved in associative motor learning, particularly in eyeblink-conditioning. In visuomotor associative learning the role of the cerebellum is less clear. One open question is whether cerebellar patients' deficits in visuomotor learning are present both in a stimulus-response and a stimulus-stimulus-response association task. Twelve patients with cerebellar degeneration and 12 healthy matched control subjects participated. A magnetic resonance imaging (MRI) volumetric analysis of the cerebellum was performed to assess the degree of cerebellar atrophy. In a blocked design, subjects had to learn the association between one color square or two color squares and a right or left key press. In the latter condition, the two colors were shown one after the other in the same sequence except for two blocks at the end of the experiment. Overall, cerebellar subjects reacted significantly slower than controls. In both groups, reaction time decreased over blocks, and the learning effect was more pronounced in the stimulus-response than in the stimulus-stimulus-response condition. Post hoc analyses revealed that learning differences between conditions were significant in cerebellar patients but not control subjects. Furthermore, only healthy subjects were irritated, i.e., they significantly increased reaction times in the blocks with reversed sequence in the stimulus-stimulus-response condition. Cerebellar subjects tended to name less correct stimulus-stimulus-response associations after the experiment. Finally, cerebellar volume correlated with parameters of motor performance, but not learning. In conclusion, cerebellar patients showed deficits in stimulus-stimulus-response, but not stimulus-response learning. Future experiments are needed to differentiate between possible deficits in learning the stimulus-stimulus association, use of sequence information, and/or impaired motor performance interfering with learning.

Impaired activation of the baroreflex loop as early sign of sympathetic damage in diabetics with normal heart rate variability at rest

The objective of the study was to define the impairment of sympathovagal balance in patients with diabetes mellitus (DM) and coronary heart disease (CHD) compared to healthy controls (HC) showing similar heart rate variability (HRV) at supine rest. 88 DM (41 m, 47 f; age 62 +/- 1 years; BMI 27.1 +/- 1.5 kg/m2; HbA1c 7.9 +/- 0.4%), 49 CHD (27 m, 22 f; age 62 +/- 1 years; BMI 27.1 +/- 1.6 kg/m2; HbA1c 5.2 +/- 0.1%) and 16 HC (8 m, 8 f; age 59 +/- 1 years; BMI 26.4 +/- 0.5 kg/m2; HbA1c 5.0 +/- 0.1%) were investigated. Time series of heart period duration (HPD) were obtained during 2 min deep breathing (6/min), 5 min of supine rest and for 5 min at upright position using a RR memory device (BHL 6000, Baumann-Haldi Switzerland, modified ECG lead, 1 kHz). Mean HPD, coefficient of variation (CV), total power (TP) and integral power in the HF (0.15 to 0.5 Hz), MF (0.05 to 0.15 Hz) and LF (0.015 to 0.05 Hz) frequency bands as well as (MF-HF)/(MF + HF) as spectral index were calculated. As to be expected we found significantly lower values of CV, TP and HPD in DM compared to HC. The CV of HRV did not differ significantly between DM and CHD but TP and HPD of CHD patients were significantly higher in comparison to DM. Therefore, the deterioration of HRV was most pronounced in the DM group. For further analysis we calculated data of subjects with CV's in the upper quartile (> or = 3.52) of the CV at supine rest. The aim of this procedure was to compare subjects with similar high HRV at supine rest. With this method we obtained from all subjects 12 HC, 11 DM and 12 CHD. These DM had a significant decrease of CV, TP and the integral power at the HF frequency band during active orthostasis compared to HC and CHD. The spectral index increased significantly during standing in HC and CHD but was unchanged in DM. These changes were accompanied by a nearly similar increase of HRV during deep breathing. In conclusion, DM with normal reaction to deep breathing did not activate the sympathetic baroreflex loop during active orthostasis. This could be an early sign of sympathetic dysfunction in DM with normal HRV at supine rest.

Reduced gastric emptying and mesenteric blood flow in IDDM with cardiac autonomic neuropathy

Our objective was to investigate the relationship between gastric emptying and mesenteric blood flow in type 1 diabetic patients with (CAN+) and without (CAN-) cardiac autonomic neuropathy. CAN was determined by a series of cardiovascular reflex tests and power spectral analysis of heart rate variations (HRV) using a computerized system. We calculated from these data a score for cardiac autonomic neuropathy with a maximum of 7 points (1 point for abnormal value of: CV of HRV at supine rest, CV of HRV during deep breathing, Valsalva ratio, lying-to-standing ratio, PSA of HRV in the low frequency band, PSA of HRV in the mid frequency band, blood pressure response to standing). Patients were considered to have CAN if at least 3 of the 7 parameters were found to be abnormal (CAN score > or = 3). The resulting groups (CAN-, n = 14 vs. CAN+, n = 16) were well matched with respect to age (53 +/- 11 vs. 51 +/- 12 years), BMI (27.2 +/- 3.3 vs. 25.9 +/- 3.6 kg/m2), duration of diabetes (162 +/- 157 vs. 158 +/- 100 months), fasting blood glucose (6.9 +/- 2.6 vs. 6.8 +/- 2.4 mmol/l) and HbA1c (7.2 +/- 1.5 vs. 7.3 +/- 2.0%). Gastric emptying was determined by real-time ultrasonography (antral planimetry) during 60 min after a semiliquid test meal (Fresubin diabetes 300 ml, 53% carbohydrate, 32% lipid, 15% protein) and the blood flow of the superior mesenteric artery was measured by Doppler ultrasound technique. Type I diabetic patients with CAN had a significantly higher CAN score than those without CAN (6.1 +/- 0.4 vs. 1.3 +/- 0.7). Mean preprandial (before ingestion of the test meal) as well as postprandial (immediately after ingestion of test meal) antral areas of CAN+ (5.2 +/- 2.0v/10.9 +/- 2.8 cm2) and CAN- (5.1 +/- 1.5/10.8 +/- 2.2 cm2) were comparable. CAN+ had significantly slower decrease of postprandial antral areas at 15, 30, 45 and 60 min after ingestion of test meal (-1.7 +/- 0.4/-8.3 +/- 1.2/-9.5 +/- 0.9/-19.5 +/- 2.0 delta % compared to postprandial value) compared to CAN- (-8.9 +/- 1.8/-22.5 +/- 2.6/-29.1 +/- 2.9/-35.5 +/- 2.9 delta %). The increase in mesenteric blood flow at 15, 30 and 45 min after the meal was significantly reduced in CAN+ compared to CAN- patients. Significantly negative correlations were found between the CAN score and the decrease of antral area as well as between CAN score and the increase of diastolic mesenteric blood flow and significantly positive correlations between the decrease of antral area and the increase of diastolic mesenteric blood flow. In conclusion, type 1 diabetic patients with cardiac autonomic neuropathy showed delayed gastric emptying and diminished mesenteric blood flow during 60 min after ingestion of a semiliquid test meal.