Saponin Micelles Lead to High Mucosal Permeation and In Vivo Efficacy of Solubilized Budesonide.

Due to fast nasal mucociliary clearance, only the dissolved drug content can effectively permeate the mucosa and be pharmaceutically active after intranasal application of suspensions. Therefore, the aim of this study was to increase the budesonide concentration in solution of a nasal spray formulation. Budesonide, a highly water-insoluble corticosteroid, was successfully solubilized using a micellar formulation comprising escin, propylene glycol and dexpanthenol in an aqueous buffered environment ("Budesolv"). A formulation based on this micellar system was well-tolerated in the nasal cavity as shown in a good laboratory practice (GLP) local tolerance study in rabbits. Ex vivo permeation studies into porcine nasal mucosa revealed a faster and more efficient absorption. Budesolv with 300 µg/mL solubilized budesonide resulted in a budesonide concentration of 42 µg/g tissue after only 15 min incubation. In comparison, incubation with the marketed product Rhinocort® aqua 64 (1.28 mg/mL budesonide as suspension) led to 15 µg/g tissue. The in vivo tumor-necrosis-factor (TNF)-α secretion in an acute lung inflammation mouse model was significantly reduced (p < 0.001) following a prophylactic treatment with Budesolv compared to Rhinocort® aqua 64. Successful treatment 15 min after the challenge was only possible with Budesolv (40% reduction of TNF-α, p = 0.0012) suggesting a faster onset of action. The data reveal that solubilization based on saponin micelles presents an opportunity for the development of products containing hardly soluble substances that result in a faster onset and a better topical treatment effect.

Fast effectiveness of a solubilized low-dose budesonide nasal spray in allergic rhinitis.

BACKGROUND: Budesonide, a poorly water-soluble corticosteroid, is currently marketed as a suspension. Budesolv is a novel aqueous formulation containing dissolved budesonide showing increased local availability in preclinical models. Budesolv contains ~85% less corticosteroid than the marketed comparator. OBJECTIVE: The study (EudraCT:2018-001324-19) was designed to assess non-inferiority of Budesolv compared to Rhinocort® Aqua 64 (RA) and early onset of action. METHODS: In a three-way cross-over double-blinded randomized trial, Budesolv 10 was compared to RA and placebo in grass pollen allergic rhinoconjunctivitis volunteers (n = 83 (ITT); n = 75 (PP)). On day 1, participants entered the Vienna Challenge Chamber (VCC) for 6 hours; first treatment took place at 1:45 hours after entry. Participants treated themselves for further 6 days; on day 8, the last treatment was applied before entering the VCC. Subjective symptom scores, nasal airflow and nasal secretion were measured regularly during allergen challenge. RESULTS: Budesolv 10 was equally effective compared to RA with respect to TNSS and nasal airflow after eight days of treatment with a strongly reduced dose (more than 80% reduction). After first dose, only Budesolv 10 showed a significant reduction of nasal and respiratory symptoms starting 90 minutes (P < .05) and 15 minutes (P < .05) after application onwards, respectively, demonstrating an early onset of efficacy. A clinically significant 1 point reduction in nasal symptom score was reached at 195 minutes (P < .05) after application. CONCLUSIONS AND CLINICAL RELEVANCE: The novel preservative-free, aqueous low-dose budesonide formulation is highly efficacious even after an initial single treatment. Thus, Budesolv 10 appears to be an effective acute treatment for allergic rhinitis as well as for AR comorbidities like mild asthma and conjunctivitis.

Pharmacokinetics of topically applied tacrolimus dissolved in Marinosolv, a novel aqueous eye drop formulation.

Corticosteroids and macrolide immunomodulators such as tacrolimus are effective drugs for the topical treatment of inflammatory eye diseases like allergic conjunctivitis or dry eye. However, tacrolimus is practically insoluble in aqueous solutions and is therefore currently formulated as dispersion. This leads to low bioavailability. Here, we present a novel pharmacologically acceptable, aqueous formulation of tacrolimus based on the "Marinosolv formulation platform". Marinosolv allows the solubilization and thereby improvement of the bioavailability of many otherwise practically insoluble drugs, since dissolved drugs permeate faster into tissues, including ocular tissues. To visualize the benefits of Marinosolv in ophthalmic formulations, we investigated the permeation of a fluorescently labeled estradiol dissolved in Marinosolv compared to a formulation containing the compound as dispersion. Permeation was studied ex-vivo and in-vivo in porcine eyes. Further, we evaluated the improved permeation of topically applied tacrolimus dissolved in Marinosolv compared to a commercially available topically applied tacrolimus dispersion. The Marinosolv formulation was also compared to oral tacrolimus treatment, the standard application route for this drug in case of severe posterior uveitis. Finally, the ocular tissue levels of tacrolimus in all groups were determined using HPLC/MS. We demonstrated that tacrolimus dissolved in Marinosolv reached significantly higher levels in ocular tissues compared to the marketed topical product or after oral application and thus may be a suitable novel option for the treatment of several eye diseases, such as allergic conjunctivitis or uveitis. Thus, Marinosolv may be considered as a new vehicle for tacrolimus eye drops.

The Intranasal Application of Zanamivir and Carrageenan Is Synergistically Active against Influenza A Virus in the Murine Model.

BACKGROUND: Carrageenan is a clinically proven and marketed compound for the treatment of viral upper respiratory tract infections. As infections caused by influenza virus are often accompanied by infections with other respiratory viruses the combination of a specific anti-influenza compound with the broadly active antiviral polymer has huge potential for the treatment of respiratory infections. Thus, the combination of the specific anti-influenza drug Zanamivir together with carrageenan in a formulation suitable for intranasal application was evaluated in-vitro and in-vivo. PRINCIPAL FINDINGS: We show in-vitro that carrageenan and Zanamivir act synergistically against several influenza A virus strains (H1N1(09)pdm, H3N2, H5N1, H7N7). Moreover, we demonstrate in a lethal influenza model with a low pathogenic H7N7 virus (HA closely related to the avian influenza A(H7N9) virus) and a H1N1(09)pdm influenza virus in C57BL/6 mice that the combined use of both compounds significantly increases survival of infected animals in comparison with both mono-therapies or placebo. Remarkably, this benefit is maintained even when the treatment starts up to 72 hours post infection. CONCLUSION: A nasal spray containing carrageenan and Zanamivir should therefore be tested for prevention and treatment of uncomplicated influenza in clinical trials.

Egg- or cell culture-derived hemagglutinin mutations impair virus stability and antigen content of inactivated influenza vaccines.

Egg-derived viruses are the only available seed material for influenza vaccine production. Vaccine manufacturing is done in embryonated chicken eggs, MDCK or Vero cells. In order to contribute to efficient production of influenza vaccines, we investigate whether the quality of inactivated vaccines is influenced by the propagation substrate. We demonstrate that H3N2 egg-derived seed viruses (A/Brisbane/10/07, IVR147, and A/Uruguay/716/07) triggered the hemagglutinin (HA) conformational change under less acidic conditions (0.2-0.6 pH units) than antigenically similar primary isolates. This phenotype was associated with HA1 (A138S, L194P) and HA2 (D160N) substitutions, and strongly related to decreased virus stability towards acidic pH and elevated temperature. The subsequent propagation of H3N2 and H1N1 egg-derived seed viruses in MDCK and Vero cells induced HA2 N50K (H1N1) and D160E (H3N2) mutations, improving virus growth in cell culture but further impairing virus stability. The prevention of the loss or recovery of stability was possible by cultivation at acidified conditions. Viruses carrying less stable HAs are more sensitive for HA conformational change during concentration, purification and storage. This results in decreased detectable HA antigen content - the main potency marker for inactivated influenza vaccines. Thus, virus stability can be a useful marker for predicting the manufacturing scope of seed viruses.

Antimycotic-antibiotic amphotericin B promotes influenza virus replication in cell culture.

In general, antibiotics are not rated as substances that inhibit or support influenza virus replication. We describe here the enhancing effect of the polyene antibiotic amphotericin B (AmB) on influenza virus growth in Vero cells. We show that isolation rates of influenza A and B viruses from clinical samples can be dramatically enhanced by adding AmB to the culture medium. We demonstrate that AmB promotes the viral uptake and endocytic processing of the virus particles. This effect is specific for Vero and human nasal epithelial cells and was not observed in Madin-Darby canine kidney cells. The effect of AmB was subtype specific and more prominent for human seasonal influenza strains but absent for H5N1 human viruses. The AmB-enhancing effect seemed to be solely due to the viral hemagglutinin function. Our results indicate that the use of AmB may facilitate influenza virus isolation and production in Vero cells.

Single HA2 mutation increases the infectivity and immunogenicity of a live attenuated H5N1 intranasal influenza vaccine candidate lacking NS1.

BACKGROUND: H5N1 influenza vaccines, including live intranasal, appear to be relatively less immunogenic compared to seasonal analogs. The main influenza virus surface glycoprotein hemagglutinin (HA) of highly pathogenic avian influenza viruses (HPAIV) was shown to be more susceptible to acidic pH treatment than that of human or low pathogenic avian influenza viruses. The acidification machinery of the human nasal passageway in response to different irritation factors starts to release protons acidifying the mucosal surface (down to pH of 5.2). We hypothesized that the sensitivity of H5 HA to the acidic environment might be the reason for the low infectivity and immunogenicity of intranasal H5N1 vaccines for mammals. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate that original human influenza viruses infect primary human nasal epithelial cells at acidic pH (down to 5.4), whereas H5N1 HPAIVs lose infectivity at pH ≤ 5.6. The HA of A/Vietnam/1203/04 was modified by introducing the single substitution HA2 58K→I, decreasing the pH of the HA conformational change. The H5N1 reassortants containing the indicated mutation displayed an increased resistance to acidic pH and high temperature treatment compared to those lacking modification. The mutation ensured a higher viral uptake as shown by immunohistochemistry in the respiratory tract of mice and 25 times lower mouse infectious dose50. Moreover, the reassortants keeping 58K→I mutation designed as a live attenuated vaccine candidate lacking an NS1 gene induced superior systemic and local antibody response after the intranasal immunization of mice. CONCLUSION/SIGNIFICANCE: Our finding suggests that an efficient intranasal vaccination with a live attenuated H5N1 virus may require a certain level of pH and temperature stability of HA in order to achieve an optimal virus uptake by the nasal epithelial cells and induce a sufficient immune response. The pH of the activation of the H5 HA protein may play a substantial role in the infectivity of HPAIVs for mammals.

Mutations affecting the stability of the haemagglutinin molecule impair the immunogenicity of live attenuated H3N2 intranasal influenza vaccine candidates lacking NS1.

The isolation and cultivation of human influenza viruses in embryonated hen eggs or cell lines often leads to amino acid substitutions in the haemagglutinin (HA) molecule. We found that the propagation of influenza A H3N2 viruses on Vero cells may trigger the appearance of HA destabilising mutations, affecting viral resistance to low pH or high temperature treatment. Two ΔNS1 reassortants, containing the HA sequences identical to the original human H3N2 influenza virus isolates were constructed. Passages of these viruses on Vero cells led to the appearance of single mutations in the HA(1) L194P or HA(2) G75R subunits that impaired virus stability. The original HA sequences and the stable phenotypes of the primary isolates were preserved if reassortants were passaged by infection at pH 5.6 and cultivation in medium at pH 6.5. Corresponding ΔNS1 reassortants were compared for their immunogenicity in ferrets upon intranasal immunisation. Vaccine candidates containing HA mutations demonstrated significantly lower immunogenicity compared to those without mutations. Thus, the retaining of the original HA sequences of human viruses during vaccine production might be crucial for the efficacy of live attenuated influenza vaccines.

Swine-origin pandemic H1N1 influenza virus-like particles produced in insect cells induce hemagglutination inhibiting antibodies in BALB/c mice.

Recent outbreaks of influenza A highlight the importance of rapid and sufficient supply for pandemic and inter-pandemic vaccines. Classical manufacturing methods for influenza vaccines fail to satisfy this demand. Alternatively, cell culture-based production systems and virus-like particle (VLP)-based technologies have been established. We developed swine-origin pandemic H1N1 influenza VLPs consisting of hemagglutinin (A/California/04/2009) and matrix protein. Hemagglutinin and matrix protein were co-expressed in insect cells by the baculovirus expression system. VLPs were harvested from infection supernatants, purified and used for intraperitoneal immunization of BALB/c mice. Immunization induced high serum antibody titers against A/California/04/2009 as well as hemagglutination inhibiting antibodies. Additionally, we compared VLP production in two different insect cell lines, Sf9 and BTI-TN5B1-4 (High Five). Taken together VLPs represent a potential strategy for the fight against new pandemic influenza viruses.

Preclinical evaluation of a replication-deficient intranasal DeltaNS1 H5N1 influenza vaccine.

BACKGROUND: We developed a novel intranasal influenza vaccine approach that is based on the construction of replication-deficient vaccine viruses that lack the entire NS1 gene (DeltaNS1 virus). We previously showed that these viruses undergo abortive replication in the respiratory tract of animals. The local release of type I interferons and other cytokines and chemokines in the upper respiratory tract may have a "self-adjuvant effect", in turn increasing vaccine immunogenicity. As a result, DeltaNS1 viruses elicit strong B- and T- cell mediated immune responses. METHODOLOGY/PRINCIPAL FINDINGS: We applied this technology to the development of a pandemic H5N1 vaccine candidate. The vaccine virus was constructed by reverse genetics in Vero cells, as a 5:3 reassortant, encoding four proteins HA, NA, M1, and M2 of the A/Vietnam/1203/04 virus while the remaining genes were derived from IVR-116. The HA cleavage site was modified in a trypsin dependent manner, serving as the second attenuation factor in addition to the deleted NS1 gene. The vaccine candidate was able to grow in the Vero cells that were cultivated in a serum free medium to titers exceeding 8 log(10) TCID(50)/ml. The vaccine virus was replication deficient in interferon competent cells and did not lead to viral shedding in the vaccinated animals. The studies performed in three animal models confirmed the safety and immunogenicity of the vaccine. Intranasal immunization protected ferrets and mice from being infected with influenza H5 viruses of different clades. In a primate model (Macaca mulatta), one dose of vaccine delivered intranasally was sufficient for the induction of antibodies against homologous A/Vietnam/1203/04 and heterologous A/Indonesia/5/05 H5N1 strains. CONCLUSION/SIGNIFICANCE: Our findings show that intranasal immunization with the replication deficient H5N1 DeltaNS1 vaccine candidate is sufficient to induce a protective immune response against H5N1 viruses. This approach might be attractive as an alternative to conventional influenza vaccines. Clinical evaluation of DeltaNS1 pandemic and seasonal influenza vaccine candidates are currently in progress.

Development of a live-attenuated influenza B DeltaNS1 intranasal vaccine candidate.

We discovered a unique, single amino acid mutation in the influenza B M1 protein promoting viral growth of NS1 truncation mutants in Vero cells. Due to this mutation, we were able to generate an influenza B virus lacking the complete NS1 open reading frame (DeltaNS1-B virus) by reverse genetics, which was growing to titers of 8log(10)TCID(50)/ml in a Vero cell culture-based micro-carrier fermenter. The DeltaNS1-B vaccine candidate was attenuated in IFN-competent hosts such as human alveolar epithelial cells (A549) similar to influenza A DeltaNS1 viruses. In ferrets, the DeltaNS1-B virus was replication-deficient and did not provoke any clinical symptoms. Importantly, a single intranasal immunization of ferrets at a dose as low as 6 log(10)TCID(50)/animal induced a significant HAI response and provided protection against challenge with wild-type influenza B virus. So far, the lack of a DeltaNS1-B virus component growing to high titers in cell culture has been limiting the possibility to formulate a trivalent vaccine based on deletion of the NS1 gene. Our study closes this gap and paves the way for the clinical evaluation of a seasonal, trivalent, live replication-deficient DeltaNS1 intranasal influenza vaccine.

Optimization of baculovirus transduction on FreeStyle293 cells for the generation of influenza B/Lee/40.

Recombinant baculovirus expression vectors derived from the Autographa californica nuclear polyhedrosis virus can serve as efficient gene-transfer vehicles for transient expression of recombinant proteins in a wide range of mammalian cell types and are able to produce multisubunit particles such as viruses or virus like particles. In this study, we constructed eight recombinant baculoviruses each containing one of the influenza B/Lee/40 virus genes in a bidirectional expression cassette for simultaneous mRNA and viral RNA transcription. Baculoviruses were transduced into FreeStyle293 in combination with the specific histone deacetylase inhibitor trichostatin A (TSA). Cotransduction conditions were optimized with a set of five baculoviruses (influenza B/Lee/40 PB1, PB2, PA, and NP and the control construct NCR-NS-minus-sense orientated encoding green fluorescent protein [rGFP]), which led to GFP expression in each host cell transduced with all five constructs. Based on the optimization with five constructs, transduction with eight baculoviruses was performed at MOI 50 and 100 with high yield stocks and 1 microM TSA and led to successful rescue of infectious influenza B/Lee/40 viruses.

HIV-1 mutants escaping neutralization by the human antibodies 2F5, 2G12, and 4E10: in vitro experiments versus clinical studies.

OBJECTIVE: The human monoclonal antibodies (mAb) 2F5, 2G12, and 4E10 are three of the most broadly neutralizing antibodies against HIV-1. Although they have been shown to prevent de novo infection in vivo, their potential for treatment of chronic infection is less clear. One major obstacle may be the emergence of resistant viruses during mAb treatment. DESIGN: To assess whether escape mutants can be generated in vitro which are resistant to all three mAbs, two neutralization-sensitive T-cell line-adapted viruses and two primary isolates were passaged in the presence of increasing concentrations of 2F5, 2G12, 4E10, and a 1: 1: 1 mixture. To get insight into viral escape in vivo, viruses were isolated from eight patients treated with repeated infusions of 2F5/2G12/4E10. RESULTS: In vitro, viruses resistant to a single mAb emerged after 3-22 weeks. Generation of viruses resistant to the triple-combination was a slower process characterized by recurrent loss of virus replication. Some generated triple-resistant viruses seemed to be impaired in their replicative fitness. Neutralization resistance to 2F5 and partly 4E10 could be attributed to amino acid mutations in the mAb epitopes, but not for 2G12. In vivo, none of the patients developed detectable viruses that escaped neutralization by all three mAbs within the 77-day observation period. Virus escape occurred only to 2G12 in three patients. CONCLUSIONS: In summary, the findings of the in vivo study and the difficulty in generating multi-resistance in vitro together with the fact that some generated viruses seemed to have impaired replication fitness indicate that 2F5, 2G12, and 4E10 may be useful for therapy in HIV-1 infection.