Continuous freeze-drying of messenger RNA lipid nanoparticles enables storage at higher temperatures.

Messenger RNA (mRNA) lipid nanoparticles (LNPs) have emerged at the forefront during the COVID-19 vaccination campaign. Despite their tremendous success, mRNA vaccines currently require storage at deep freeze temperatures which complicates their storage and distribution, and ultimately leads to lower accessibility to low- and middle-income countries. To elaborate on this challenge, we investigated freeze-drying as a method to enable storage of mRNA LNPs at room- and even higher temperatures. More specifically, we explored a novel continuous freeze-drying technique based on spin-freezing, which has several advantages compared to classical batch freeze-drying including a much shorter drying time and improved process and product quality controlling. Here, we give insight into the variables that play a role during freeze-drying by evaluating the impact of the buffer and mRNA LNP formulation (ionizable lipid to mRNA weight ratio) on properties such as size, morphology and mRNA encapsulation. We found that a sufficiently high ionizable lipid to mRNA weight ratio was necessary to prevent leakage of mRNA during freeze-drying and that phosphate and Tris, but not PBS, were appropriate buffers for lyophilization of mRNA LNPs. We also studied the stability of optimally lyophilized mRNA LNPs at 4 °C, 22 °C, and 37 °C and found that transfection properties of lyophilized mRNA LNPs were maintained during at least 12 weeks. To our knowledge, this is the first study that demonstrates that optimally lyophilized mRNA LNPs can be safely stored at higher temperatures for months without losing their transfection properties.

Lyophilization provides long-term stability for a lipid nanoparticle-formulated, nucleoside-modified mRNA vaccine.

Lipid nanoparticle (LNP)-formulated nucleoside-modified mRNA vaccines have proven to be very successful in the fight against the coronavirus disease 2019 (COVID-19) pandemic. They are effective, safe, and can be produced in large quantities. However, the long-term storage of mRNA-LNP vaccines without freezing is still a challenge. Here, we demonstrate that nucleoside-modified mRNA-LNPs can be lyophilized, and the physicochemical properties of the lyophilized material do not significantly change for 12 weeks after storage at room temperature and for at least 24 weeks after storage at 4°C. Importantly, we show in comparative mouse studies that lyophilized firefly luciferase-encoding mRNA-LNPs maintain their high expression, and no decrease in the immunogenicity of a lyophilized influenza virus hemagglutinin-encoding mRNA-LNP vaccine was observed after 12 weeks of storage at room temperature or for at least 24 weeks after storage at 4°C. Our studies offer a potential solution to overcome the long-term storage-related limitations of nucleoside-modified mRNA-LNP vaccines.

Stochastic ice nucleation governs the freezing process of biopharmaceuticals in vials.

Biopharmaceuticals commonly require freezing to ensure the stability of the active pharmaceutical ingredients (APIs). At commercial scale, freezing is typically carried out over the course of days in pallets comprising tens of thousands of vials. The selected process conditions have to ensure both complete freezing in all vials and a satisfactory manufacturing throughput. Current process design, however, is mainly experimental, since no mechanistic understanding of pallet freezing and its underlying phenomena has been achieved so far. Within this work, we derive a mechanistic modeling framework and compare the model predictions with engineering run data from the Janssen COVID-19 vaccine. The model qualitatively reproduced all observed trends and reveals that stochastic ice nucleation governs both process duration and batch heterogeneity. Knowledge on the ice nucleation kinetics of the formulation to be frozen thus is required to identify suitable freezing process conditions. The findings of this work pave the way towards a more rational design of pallet freezing, from which a plethora of frozen drug products may benefit. For this reason, we provide open source access to the model in the form of a python package (Deck et al., 2021).

Capillary-Mediated Vitrification: Preservation of mRNA at Elevated Temperatures.

RNA is a fundamental tool for molecular and cellular biology research. The recent COVID-19 pandemic has proved it is also invaluable in vaccine development. However, the need for cold storage to maintain RNA integrity and the practical and economic burden associated with cold chain logistics highlight the need for new and improved preservation methods. We recently showed the use of capillary-mediated vitrification (CMV), as a tool for stabilizing temperature-sensitive enzymes. Here, we demonstrate the use of CMV as a method to preserve mRNA. The CMV process was performed by formulating a green fluorescent protein (GFP)-encoding mRNA with common excipients, applying the solution to a porous support, referred to as the scaffold, and drying the samples under vacuum for 30 min. The CMV preserved samples were stored at 55 °C for up to 100 days or 25 °C for 60 days and analyzed by electrophoresis and for transfection efficiency in a cell-based assay. The 55 °C-stressed mRNA exhibited comparable electrophoresis banding patterns and band intensity when compared to a frozen, liquid control. Additionally, the CMV stabilized mRNA maintained 97.5 ± 8.7% transfection efficiency after 77 days and 78.4 ± 3.9% after 100 days when stored 55 °C and analyzed using a cell-based assay in the CHO-K1 cell line. In contrast, a liquid control exhibited no bands on the electrophoresis gel and lost all transfection activity after being stored overnight at 55 °C. Likewise, after 60 days at 25 °C, the CMV-processed samples had full transfection activity while the activity of the liquid control was reduced to 40.1 ± 4.6%. In conclusion, CMV is a simple formulation method that significantly enhances the thermal stability of mRNA, requires minimal processing time, and could enable formulation of mRNA that can tolerate exposure to temperatures well above 25 °C during shipment and deployment in extreme environments.

Freeze-dried plasma: From damage control resuscitation to coronavirus disease 2019 therapy.

BACKGROUND: Freeze-dried plasma (FDP) is a promising blood component for prehospital resuscitation given its logistic advantages over fresh frozen plasma (FFP). COVID-19 convalescent (CC) plasma has been used to treat coronavirus disease 2019 (COVID-19) patients, and its corresponding FDP has potential use during future pandemics. Therefore, we conducted the study to determine if the hemostatic and immunological properties of plasma can be retained after lyophilization. STUDY DESIGN AND METHODS: Hemostatic tests were conducted with Rotational Thromboelastometry (ROTEM) and a Stago analyzer. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG (Immunoglobulin G) and neutralizing activity were analyzed using Meso Scale Diagnostics immunoassay kits. RESULTS: There were no differences in ROTEM parameters and Stago measurements for prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen and D-dimer concentrations, and antithrombin, factor V, VIII, and protein S activities between FFP and FDP for either pre-COVID-19 or CC samples. Differences were observed in INTEM clotting time and PT and PTT when comparing reconstituted FDP stored at 4°C for 24 h or room temperature for 4 h to healthy control. Both CC-FFP and CC-FDP showed two orders of magnitude higher concentrations of IgG antibodies against SARS-CoV-2 antigens than pre-COVID-19-FFP and pre-COVID-19-FDP and healthy control. Similarly, the CC samples showed approximately 4-fold higher %-inhibition of receptor binding than the pre-COVID-19 samples. There were no differences in either the antibody levels or neutralization activity between CC-FFP and CC-FDP. DISCUSSION: We demonstrated that FDP and CC-FDP retained the same hemostatic and antibody functional activities relative to their initial plasma sources, supporting clinical evaluation of their benefits in severe trauma and COVID-19 patients.

Retention of hemostatic and immunological properties of frozen plasma and COVID-19 convalescent apheresis fresh-frozen plasma produced and freeze-dried in Canada.

BACKGROUND: Randomized clinical trial data show that early plasma transfusion may save lives among trauma patients. Supplying plasma in remote environments is logistically challenging. Freeze-dried plasma (FDP) offers a possible solution. STUDY DESIGN AND METHODS: A Terumo BCT plasma freeze-drying system was evaluated. We compared pooled frozen plasma (FP) units with derived Terumo BCT FDP (TFDP) units and pooled COVID-19 convalescent apheresis fresh-frozen plasma (CC-AFFP) with derived CC-TFDP units. Parameters measured were: coagulation factors (F) II; V; VII; VIII; IX; XI; XIII; fibrinogen; Proteins C (PC) and S (PS); antithrombin (AT); α2 -antiplasmin (α2 AP); ADAMTS13; von Willebrand Factor (vWF); thrombin-antithrombin (TAT); D-dimer; activated complement factors 3 (C3a) and 5 (C5a); pH; osmolality; prothrombin time (PT); and activated partial thromboplastin time (aPTT). Antibodies to SARS-CoV-2 in CC-AFFP and CC-TFDP units were compared by plaque reduction assays and viral protein immunoassays. RESULTS: Most parameters were unchanged in TFDP versus FP or differed ≤15%. Mean aPTT, PT, C3a, and pH were elevated 5.9%, 6.9%, 64%, and 0.28 units, respectively, versus FP. CC-TFDP showed no loss of SARS-CoV-2 neutralization titer versus CC-AFFP and no mean signal loss in most pools by viral protein immunoassays. CONCLUSION: Changes in protein activities or clotting times arising from freeze-drying were <15%. Although C3a levels in TFDP were elevated, they were less than literature values for transfusable plasma. SARS-CoV-2-neutralizing antibody titers and viral protein binding levels were largely unaffected by freeze-drying. In vitro characteristics of TFDP or CC-TFDP were comparable to their originating plasma, making future clinical studies appropriate.

Lyophilised oral faecal microbiota transplantation for ulcerative colitis (LOTUS): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Faecal microbiota transplantation (FMT) delivered via colonoscopic infusion or enemas have been shown to induce remission in a proportion of patients with active ulcerative colitis. Whether orally administered FMT is effective in ulcerative colitis is unknown. We aimed to assess the efficacy of oral lyophilised FMT for the treatment of active ulcerative colitis. METHODS: A double-blind, randomised, placebo-controlled trial was conducted at two centres in Australia. Eligible patients were aged 18-75 years with active ulcerative colitis (defined as clinical and endoscopic active ulcerative colitis, with a total Mayo score of 4-10, and a Mayo endoscopic subscore ≥1). After 2 weeks of amoxicillin, metronidazole, and doxycycline, patients were randomly assigned in a 1:1 ratio to receive either oral lyophilised FMT or placebo capsules for 8 weeks, using a prespecified computer-generated randomisation list with a permuted block size of 8. The primary outcome was corticosteroid-free clinical remission with endoscopic remission or response (total Mayo score ≤2, all subscores ≤1, and ≥1 point reduction in endoscopic subscore) at week 8. At week 8, FMT responders were randomly assigned (in a 1:1 ratio, permuted block size of 8) to either continue or withdraw FMT for a further 48 weeks. Analyses were done by modified intention-to-treat, including all patients who received at least one study dose. This trial is registered with Australian New Zealand Trial Registry, number ACTRN 12619000611123; this is the final report of the trial. FINDINGS: Between May 20, 2019, and March 24, 2020, 35 patients were randomly assigned: 15 to receive FMT and 20 to receive placebo. Recruitment was terminated early due to the COVID-19 pandemic. At week 8, eight (53%) of 15 patients in the FMT group were in corticosteroid-free clinical remission with endoscopic remission or response, as were three (15%) of 20 patients in the placebo group (difference 38·3%, 95% CI 8·6-68·0; p=0·027; odds ratio 5·0, 95% CI 1·8-14·1). Adverse events occurred in 10 (67%) patients in the FMT group and 17 (85%) of those in the placebo group during the 8-week induction period, and were generally mild and self-limiting gastrointestinal complaints. Serious adverse events included worsening ulcerative colitis (two in the FMT group, one in the placebo group) and per-rectal bleeding (one in the placebo group). Ten patients in the FMT group who achieved a clinical or endoscopic response entered the maintenance phase and were randomly assigned to continue open-label FMT (n=4) or withdraw therapy (n=6). All four (100%) patients who continued FMT were in clinical, endoscopic, and histologic remission at week 56 compared with none of the patients who had FMT withdrawn. INTERPRETATION: Antibiotics followed by orally administered FMT was associated with the induction of remission in patients with active ulcerative colitis. Continuing FMT was well tolerated and appeared to demonstrate clinical, endoscopic, and histological efficacy. Oral FMT could be a promising and feasible treatment option for patients with ulcerative colitis. FUNDING: St Vincent's Clinic Foundation, Gastroenterological Society of Australia, Gutsy Group.

Evaluation of formulations to improve SARS-CoV-2 viability and thermostability after lyophilisation.

In the context of the COVID-19 pandemic, virus collections such as EVA-GLOBAL play a key role in the supply of viruses and related products for research. Freeze-drying techniques for viruses represent a method of choice for the preservation of strains and their distribution without the need for a demanding cold chain. Here, we describe an optimised lyophilisation protocol usable for SARS-CoV-2 strains that improves preservation and thermostability. We show that sucrose used as an adjuvant represents a simple and efficient stabilizer providing increased protection for long-term preservation and shipment of the virus under different climatic conditions.

Lyophilization of premixed COVID-19 diagnostic RT-qPCR reactions enables stable long-term storage at elevated temperature.

Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) diagnostic tests for SARS-CoV-2 are the cornerstone of the global testing infrastructure. However, these tests require cold-chain shipping to distribute, and the labor of skilled technicians to assemble reactions and interpret the results. Strategies to reduce shipping and labor costs at the point-of-care could aid in diagnostic testing scale-up and response to the COVID-19 outbreak, as well as in future outbreaks. In this study we test both lab-developed and commercial SARS-CoV-2 diagnostic RT-qPCR mixes for the ability to be stabilized against elevated temperature by lyophilization. Fully assembled reactions were lyophilized and stored for up to a month at ambient or elevated temperature and were subsequently assayed for their ability to detect dilutions of synthetic SARS-CoV-2 RNA. Of the mixes tested, we show that one commercial mix can maintain activity and sensitivity after storage for at least 30 days at ambient temperature after lyophilization. We also demonstrate that lyoprotectants such as disaccharides can stabilize freeze-dried diagnostic reactions against elevated temperatures (up to 50°C) for at least 30 days. We anticipate that the incorporation of these methods into SARS-CoV-2 diagnostic testing will improve testing pipelines by reducing labor at the testing facility and eliminating the need for cold-chain shipping.

Sulfobutylether-beta-cyclodextrin-enabled antiviral remdesivir: Characterization of electrospun- and lyophilized formulations.

Veklury™ by Gilead Sciences, Inc., containing antiviral drug, remdesivir (REM) has received emergency authorization in the USA and in Europe for COVID-19 therapy. Here, for the first time, we describe details of the non-covalent, host-guest type interaction between REM and the solubilizing excipient, sulfobutylether-beta-cyclodextrin (SBECD) that results in significant solubility enhancement. Complete amorphousness of the cyclodextrin-enabled REM formulation was demonstrated by X-ray diffraction, thermal analysis, Raman chemical mapping and electron microscopy/energy dispersive spectroscopy. The use of solubilizing carbohydrate resulted in a 300-fold improvement of the aqueous solubility of REM, and enhanced dissolution rate of the drug enabling the preparation of stable infusion solutions for therapy. 2D ROESY NMR spectroscopy provided information on the nature of REM-excipient interaction and indicated the presence of inclusion phenomenon and the electrostatic attraction between anionic SBECD and nitrogen-containing REM in aqueous solution.

Engineered Ultra-High Affinity Synthetic Antibodies for SARS-CoV-2 Neutralization and Detection.

The Covid-19 pandemic is a centenarial global catastrophe. Similar events are likely to be recurring with more frequency in the future. The inability to control the virus' impact is caused by many factors, but the lack of a technology infrastructure to detect and impede the virus at an early stage are principal shortcomings. Using phage display mutagenesis, we have generated a cohort of high performance antibody fragments (Fabs) that can be used in a sensitive point of care (POC) assay and are potent inhibitors (IC50-0.5 nM) to viral entry into cells. The POC assay is based on a split-enzyme (ß-lactamase) complementation strategy that detects virus particles at low nM levels. We have shown that this assay is equally effective for detecting other viruses like Ebola and Zika. Importantly, its components can be freeze dried and stored, but becomes fully active when rehydrated.

The Science is There: Key Considerations for Stabilizing Viral Vector-Based Covid-19 Vaccines.

Once Covid-19 vaccines become available, 5-10 billion vaccine doses should be globally distributed, stored and administered. In this commentary, we discuss how this enormous challenge could be addressed for viral vector-based Covid-19 vaccines by learning from the wealth of formulation development experience gained over the years on stability issues related to live attenuated virus vaccines and viral vector vaccines for other diseases. This experience has led -over time- to major improvements on storage temperature, shelf-life and in-use stability requirements. First, we will cover work on 'classical' live attenuated virus vaccines as well as replication competent viral vector vaccines. Subsequently, we address replication deficient viral vector vaccines. Freeze drying and storage at 2-8 °C with a shelf life of years has become the norm. In the case of pandemics with incredibly high and urgent product demands, however, the desire for rapid and convenient distribution chains combined with short end-user storage times require that liquid formulations with shelf lives of months stored at 2-8 °C be considered. In confronting this "perfect storm" of Covid-19 vaccine stability challenges, understanding the many lessons learned from decades of development and manufacturing of live virus-based vaccines is the shortest path for finding promising and rapid solutions.

Room-temperature-storable PCR mixes for SARS-CoV-2 detection.

OBJECTIVES: A novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) emerged in late 2019, causing an outbreak of pneumonia [coronavirus disease 2019 (COVID-19)] globally. Although the use of ready-made reaction mixes can enable more rapid PCR-based diagnosis of COVID-19, the need to transport and store these mixes at low temperatures presents challenges to already overburdened logistics networks. METHODS: Here, we present an optimized freeze-drying procedure that allows SARS-CoV-2 PCR mixes to be transported and stored at ambient temperatures, without loss of activity. Additive-supplemented PCR mixes were freeze-dried. The residual moisture of the freeze-dried PCR mixes was measured by Karl-Fischer titration. RESULTS: We found that the freeze-dried PCR mixes with ~1.2% residual moisture are optimal for storage, transport, and reconstitution. The sensitivity, specificity, and repeatability of the freeze-dried reagents were similar to those of freshly prepared, wet reagents. The freeze-dried mixes retained activity at room temperature (18 ~ 25 °C) for 28 days, and for 14 and 10 days when stored at 37 °C and 56 °C, respectively. CONCLUSION: The uptake of this approach will ease logistical challenges faced by transport networks and make more cold storage space available at diagnosis and hospital laboratories.