Astodrimer sodium antiviral nasal spray for reducing respiratory infections is safe and well tolerated in a randomized controlled trial.

Astodrimer sodium is a dendrimer molecule with antiviral and virucidal activity against SARS-CoV-2 and other respiratory viruses in vitro, and has previously been shown to be safe and well tolerated, and not systemically absorbed, when applied to the vaginal mucosa. To investigate its potential utility as a topical antiviral, astodrimer sodium has been reformulated for application to the nasal mucosa to help reduce viral load before or after exposure to respiratory infection. The current investigation assessed the safety, tolerability and absorption of astodrimer sodium 1% antiviral nasal spray. This was a single-centre, double-blinded, randomized, placebo-controlled, exploratory clinical investigation. Forty healthy volunteers aged 18 to 65 years with no clinically significant nasal cavity examination findings were randomized 3:1 to astodrimer sodium nasal spray (N = 30) or placebo (N = 10) at an Australian clinical trials facility. An initial cohort of participants (N = 12 astodrimer, N = 4 placebo) received a single application (one spray per nostril) to assess any acute effects, followed by a washout period, before self-administering the spray four times daily for 14 days to represent an intensive application schedule. Extent of absorption of astodrimer sodium via the nasal mucosa was also assessed in this cohort. A second cohort of participants (N = 18 astodrimer, N = 6 placebo) self-administered the spray four times daily for 14 days. The primary endpoint was safety, measured by frequency and severity of treatment emergent adverse events (TEAEs), including clinically significant nasal cavity examination findings, in the safety population (all participants randomized who administered any spray). Participants were randomized between 6 January 2021 and 29 March 2021. TEAEs occurred in 8/10 (80%) participants in the placebo arm and 19/30 (63.3%) participants in the astodrimer sodium arm; all were of mild intensity. TEAEs considered potentially related to study product occurred in 5/10 (50%) participants receiving placebo and 10/30 (33.3%) of participants receiving astodrimer sodium. No participants experienced serious AEs, or TEAEs leading to withdrawal from the study. No systemic absorption of astodrimer sodium via the nasal mucosa was detected. Astodrimer sodium nasal spray was well tolerated and is a promising innovation warranting further investigation for nasal administration to potentially reduce infection and spread of community acquired respiratory virus infections.Trial Registration: ACTRN12620001371987, first registered 22-12-2020 (Australia New Zealand Clinical Trials Registry, https://anzctr.org.au/ ).

Protective Effects of Astodrimer Sodium 1% Nasal Spray Formulation against SARS-CoV-2 Nasal Challenge in K18-hACE2 Mice.

Strategies to combat COVID-19 require multiple ways to protect vulnerable people from infection. SARS-CoV-2 is an airborne pathogen and the nasal cavity is a primary target of infection. The K18-hACE2 mouse model was used to investigate the anti-SARS-CoV-2 efficacy of astodrimer sodium formulated in a mucoadhesive nasal spray. Animals received astodrimer sodium 1% nasal spray or PBS intranasally, or intranasally and intratracheally, for 7 days, and they were infected intranasally with SARS-CoV-2 after the first product administration on Day 0. Another group was infected intranasally with SARS-CoV-2 that had been pre-incubated with astodrimer sodium 1% nasal spray or PBS for 60 min before the neutralisation of test product activity. Astodrimer sodium 1% significantly reduced the viral genome copies (>99.9%) and the infectious virus (~95%) in the lung and trachea vs. PBS. The pre-incubation of SARS-CoV-2 with astodrimer sodium 1% resulted in a significant reduction in the viral genome copies (>99.9%) and the infectious virus (>99%) in the lung and trachea, and the infectious virus was not detected in the brain or liver. Astodrimer sodium 1% resulted in a significant reduction of viral genome copies in nasal secretions vs. PBS on Day 7 post-infection. A reduction in the viral shedding from the nasal cavity may result in lower virus transmission rates. Viraemia was low or undetectable in animals treated with astodrimer sodium 1% or infected with treated virus, correlating with the lack of detectable viral replication in the liver. Similarly, low virus replication in the nasal cavity after treatment with astodrimer sodium 1% potentially protected the brain from infection. Astodrimer sodium 1% significantly reduced the pro-inflammatory cytokines IL-6, IL-1α, IL-1ß, TNFα and TGFß and the chemokine MCP-1 in the serum, lung and trachea vs. PBS. Astodrimer sodium 1% nasal spray blocked or reduced SARS-CoV-2 replication and its sequelae in K18-hACE2 mice. These data indicate a potential role for the product in preventing SARS-CoV-2 infection or for reducing the severity of COVID-19.

Virucidal and antiviral activity of astodrimer sodium against SARS-CoV-2 in vitro.

An effective response to the ongoing coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will involve a range of complementary preventive modalities. The current studies were conducted to evaluate the in vitro SARS-CoV-2 antiviral and virucidal (irreversible) activity of astodrimer sodium, a dendrimer with broad spectrum antimicrobial activity, including against enveloped viruses in in vitro and in vivo models, that is marketed for antiviral and antibacterial applications. We report that astodrimer sodium inhibits replication of SARS-CoV-2 in Vero E6 and Calu-3 cells, with 50% effective concentrations (EC50) for i) reducing virus-induced cytopathic effect of 0.002-0.012 mg/mL in Vero E6 cells, and ii) infectious virus release by plaque assay of 0.019-0.032 mg/mL in Vero E6 cells and 0.030-0.037 mg/mL in Calu-3 cells. The selectivity index (SI) in these assays was as high as 2197. Astodrimer sodium was also virucidal, irreversibly reducing SARS-CoV-2 infectivity by >99.9% (>3 log10) within 1 min of exposure, and up to >99.999% (>5 log10) shown at astodrimer sodium concentrations of 10-30 mg/mL in Vero E6 and Calu-3 cell lines. Astodrimer sodium also inhibited infection in a primary human airway epithelial cell line. The data were similar for all investigations and were consistent with the potent antiviral and virucidal activity of astodrimer sodium being due to irreversible inhibition of virus-host cell interactions, as previously demonstrated for other viruses. Further studies will confirm if astodrimer sodium binds to SARS-CoV-2 spike protein and physically blocks initial attachment of the virus to the host cell. Given the in vitro effectiveness and significantly high SI, astodrimer sodium warrants further investigation for potential as a topically administered agent for SARS-CoV-2 therapeutic applications.

A phase 3, randomized, controlled trial of Astodrimer 1% Gel for preventing recurrent bacterial vaginosis.

OBJECTIVE: The objective of the study was to confirm the efficacy and safety of Astodrimer 1% Gel to prevent recurrence of bacterial vaginosis. STUDY DESIGN: 864 women with a diagnosis of bacterial vaginosis and a history of recurrent bacterial vaginosis were enrolled in North America and first received oral metronidazole (500 mg twice daily for 7 days). Women successfully treated with metronidazole were randomly assigned 1:1 to Astodrimer 1% Gel (N = 295) or placebo (N = 291) at a dose of 5 g vaginally every second day for 16 weeks, and followed for a further 12 weeks off-treatment. The primary endpoint was recurrence of bacterial vaginosis (presence of ≥3 Amsel criteria) at or by Week 16. Secondary endpoints included time to recurrence, and recurrence of subject-reported symptoms. Adverse events were monitored throughout the study. RESULTS: Astodrimer 1% Gel was superior to placebo for the primary and many secondary efficacy measures. At or by Week 16, bacterial vaginosis recurred in 44.2 % (130/294) of women receiving astodrimer and 54.3 % (158/291) receiving placebo (P = .015). Time to recurrence of bacterial vaginosis was significantly longer for women receiving astodrimer compared with placebo (Kaplan-Meier survival curves, P = .007). Recurrence of subject-reported symptoms at or by Week 16 was also significantly lower in the astodrimer arm compared with placebo (vaginal odor and/or discharge, 27.9 % [75/269] vs 40.6 % [108/266], P = .002). A significantly lower proportion of patients receiving astodrimer compared with placebo had recurrence of bacterial vaginosis at or by Week 16 by other secondary measures, including individual Amsel criteria (vaginal discharge and clue cells) and Nugent score 7-10. Recurrence of subject-reported vaginal odor and/or discharge was significantly lower in the astodrimer arm compared with placebo up to 8 weeks after cessation of therapy (36.1 % [97/269] vs 45.5 % [121/266], P = .027).Adverse events were infrequent, and rates were generally similar between placebo and astodrimer groups. Vulvovaginal candidiasis and urinary tract infection occurred more often in women receiving astodrimer. CONCLUSIONS: Astodrimer 1% Gel, administered every second day for 16 weeks, was effective and superior to placebo for prevention of recurrent bacterial vaginosis in women with a history of recurrent BV, and was well-tolerated.

A phase 2, double-blind, multicenter, randomized, placebo-controlled, dose­ranging study of the efficacy and safety of Astodrimer Gel for the treatment of bacterial vaginosis.

BACKGROUND: Astodrimer Gel contains a novel dendrimer intended to treat and prevent bacterial vaginosis. We assessed the efficacy and safety of Astodrimer Gel for treatment of bacterial vaginosis. METHODS: 132 women with bacterial vaginosis were randomized 1:1:1:1 to Astodrimer 0.5% (N = 34), 1% (N = 33), or 3% (N = 32) Gel or hydroxyethyl cellulose placebo gel (N = 33) at a dose of 5 g vaginally once daily for 7 days at 6 centers in the United States. The primary endpoint was clinical cure (no bacterial vaginosis vaginal discharge and no more than one of 1) vaginal pH ≥4.5; 2) ≥20% clue cells; or 3) positive whiff test) at study days 21-30. Secondary analyses included clinical cure at study days 9-12, patient-reported symptoms, acceptability and adverse events. RESULTS: The Astodrimer 1% Gel dose was superior to placebo for the primary and selected secondary efficacy measures in the modified intent-to-treat population. Clinical cure rates at day 9-12 were superior to placebo for the Astodrimer 3%, 1% and 0.5% Gel groups (62.5% [15/24; P = .002], 74.1% [20/27; P < .001], and 55.2% [16/29; P = .001], respectively, vs. 22.2% [6/27]). At day 21-30, clinical cure rates were 46.2% (12/26) for the 1% dose vs. 11.5% for placebo (3/26; P = .006). A greater proportion of patients reported absence of vaginal discharge and vaginal odor at day 9-12 and day 21-30 for Astodrimer Gel groups compared with placebo. Adverse events considered potentially treatment-related occurred in only 25% of Astodrimer Gel-treated patients vs. 22% of placebo patients. CONCLUSION: Astodrimer Gel once daily for 7 days was superior to placebo for treatment of bacterial vaginosis and was well-tolerated. The 1% dose consistently showed the strongest efficacy across endpoints. These results support a role for Astodrimer Gel, 1%, as an effective treatment for bacterial vaginosis.

Two phase 3, double-blind, placebo-controlled studies of the efficacy and safety of Astodrimer 1% Gel for the treatment of bacterial vaginosis.

OBJECTIVE: Astodrimer is a dendrimer formulated in a vaginal gel to treat bacterial vaginosis (BV) and prevent recurrence. The objective of these studies was to confirm the efficacy and safety of Astodrimer 1 % Gel for treatment of BV. STUDY DESIGN: Women with bacterial vaginosis were randomized 1:1 to Astodrimer 1 % Gel (Study 1 conducted in the United States, N = 127; Study 2 conducted in the United States, Germany and Belgium, N = 128) or placebo gel (Study 1, N = 123; Study 2, N = 123) at a dose of 5 g vaginally once daily for 7 days. The primary endpoint was clinical cure, defined as i) absence of bacterial vaginosis vaginal discharge; ii) <20 % clue cells; and iii) negative whiff test at day 9-12. Secondary efficacy analyses included clinical cure at day 21-30. Other endpoints at days 9-12 and 21-30 included Nugent cure (Nugent score ≤3), absence of symptoms, and adverse events. The primary analysis in the modified intent-to-treat population used the Cochran Mantel Haenszel test stratified by analysis center with a two-sided significance level of α = .05. RESULTS: Astodrimer 1 % Gel was superior to placebo for the primary and selected secondary efficacy measures. Clinical cure rates at day 9-12 were 50.4 % (59/117) vs 16.5 % (19/115, P < .001) (Study 1) and 56.7 % (68/120) vs 21.4 % (25/117, P < .001) (Study 2) for astodrimer vs placebo. At day 21-30, clinical cure results showed a similar trend but the difference to placebo was not statistically significant. Nugent cure rates at day 9-12 were 12.8 % (15/117) vs 2.6 % (3/115, P = .004) (Study 1) and 13.3 % (16/120) vs 5.1 % (6/117, P = .030) (Study 2) for astodrimer vs placebo. A greater proportion of women receiving astodrimer reported absence of vaginal discharge and absence of vaginal odor at day 9-12 and day 21-30 compared with placebo. Adverse events were generally mild and self-limiting. For the combined studies, adverse events potentially related to treatment occurred in 14.7 % (37/252) of astodrimer patients vs 9.4 % (23/244) for placebo, including vulvovaginal candidiasis reported for 2.4 % (6/252) of astodrimer patients. CONCLUSION: These results support a role for Astodrimer 1 % Gel as an effective, safe and well-tolerated treatment for women with bacterial vaginosis.

Real-time Kt/V determination by ultraviolet absorbance in spent dialysate: technique validation.

Real-time determination of Kt/V can be provided by monitoring ultraviolet absorbance of solutes in spent dialysate. This not only overcomes dependency on error-prone pre- and post-dialysis blood sampling; it circumvents inaccuracies associated with estimating the urea distribution volume and its high measurement frequency tightly reflects the course of the dialysis. Our study compared the ultraviolet-based spKt/V and eKt/V with the commonly used blood-based counterparts. A first study of 16 patients compared ultraviolet Kt/Vs against blood Kt/Vs obtained by using the 'gold standard' of serial blood samples. A second study included 18 patients and compared the ultraviolet and blood values under routine conditions. Both studies showed mean blood-based spKt/V and eKt/V values statistically indistinguishable from their ultraviolet-based counterparts. Hence, on-line monitoring of ultraviolet absorption of spent dialysate is applicable in routine hemodialysis allowing continuous measure of removed solutes from spent dialysate without disturbing the patient or treatment session.