Characterisation of a novel high-purity, double virus inactivated von Willebrand Factor and Factor VIII concentrate (Wilate).

This study summarises the biochemical and functional properties of a new generation plasma-derived, double virus inactivated von Willebrand Factor/Factor VIII (VWF/FVIII) concentrate, Wilate, targeted for the treatment of both von Willebrand disease (VWD) and haemophilia A. The manufacturing process comprises two chromatographic steps based on different performance principles, ensuring a high purity of the concentrate (mean specific activity in 15 consecutive production batches: 122 IU FVIII:C/mg total protein) and, thus, minimising the administered protein load to the patient (specification: < or = 15 mg total protein per 900 IU Wilate). The optimised solvent/detergent (S/D) treatment and prolonged terminal dry-heat (PermaHeat) treatment of the lyophilised product at a specified residual moisture (RM) provide two mechanistically independent, effective and robust virus inactivation procedures for enveloped viruses and one step for non-enveloped viruses. These process steps are aggressive enough to inactivate viruses efficiently, but yet gentle enough to maintain the structural integrity and function of the VWF and FVIII molecules, as proven by state-of-the-art assays covering the diverse features of importance. The VWF multimeric pattern is close to the one displayed by normal plasma, with a consistent content of more than 10 multimers, but a relatively lower portion of the very high multimers. The multimeric triplet structure is normal, underlining the gentle and effective manufacturing process, which does not require the addition of protein stabilisers at any step. The balanced activity ratio of VWF to FVIII is close to that of plasma from healthy subjects, rendering Wilate suitable also for the safe and effective treatment of patients with VWD.

Solvent/detergent treatment of human plasma--a very robust method for virus inactivation. Validated virus safety of OCTAPLAS.

OCTAPLAS is a cell-free standardized blood group specific human coagulation active plasma for transfusion. The viral safety is mainly based on the treatment with solvent/detergent. SD is known to irreversibly inactivate the lipid enveloped viruses including HIV 1 + 2, HBV and HCV and has been recommended both by European guidelines and the FDA. The potential limitation of each inactivation method should be validated according to the current EU-guidelines CPMP/BWP/268/95 and CPMP/BWP/269/95. Our studies demonstrate that the SD method inactivates lipid enveloped viruses within a few minutes to below the limit of detection. The concentration of the SD reagents as well as several other process parameters chosen for the virus inactivation step of plasma pools of different protein and lipid composition result in a high safety margin towards the clinically relevant viruses.

Viral safety of a new highly purified factor VIII (OCTATE).

The inactivation of both transfusion-relevant and model viruses by modified pasteurisation (10 hours at 63 degrees C in solution) has been evaluated following the established guidelines of the EU CPMP Ad Hoc Working Party on Biotechnology/Pharmacy. This heat treatment was introduced into the manufacturing process of OCTAVI, a very high purity factor VIII concentrate stabilized only by von Willebrand factor, in the presence of a proprietary mixture of low molecular weight stabilizers. Both enveloped (human immunodeficiency virus, Sindbis virus, herpes simplex virus, pseudorabies virus) and nonenveloped viruses (poliovirus, Coxsackievirus, hepatitis A virus) were inactivated by this heating step by more than 4.7 log10. The combination of the solvent/detergent step used in the manufacture of OCTAVI with this modified pasteurization leads to a double virus-inactivated factor VIII concentrate (OCTATE) with a viral safety distinctly superior to monoinactivated products.

Synthesis and bioactivity studies of 1-adamantanamine derivatives of peptides.

Small enkephalin-related peptides containing a 1-adamantanamine moiety coupled through an amide linkage at the C-terminus were synthesized. Several of the compounds showed high mu opioid activity and mu receptor selectivity. The new adamantanamine derivatives were also examined for antiviral activity against HIV-1 in a cell culture system. Some of them inhibited syncytia formation even when the antigen assay gave evidence for viral replication.

Virus validation experiments on the production process of OCTAVI SDPlus.

The inactivation of both transfusion-relevant and model viruses by modified pasteurization has been evaluated following the established guidelines of the European Union Committee for Proprietary Medical Products Ad Hoc Working Party on Biotechnology/Pharmacy. This heat treatment in solution for 10 h at 63 degrees C was introduced into the manufacturing process of OCTAVI, a very high purity factor VIII concentrate stabilized by von Willebrand factor. It could be demonstrated that both enveloped (human immunodeficiency virus, herpes simplex virus, pseudorabies virus) and non-enveloped viruses (poliovirus, coxsackievirus, hepatitis A virus) were inactivated by this heating step with an efficacy of greater than 4.5 log10 TCID50. The combination of the solvent/detergent step already used in the manufacture with this modified pasteurization leads to a double virus-inactivated factor VIII concentrate (OCTAVI SDPlus) with a viral safety distinctly superior to monoinactivated products.

[Pyrido(3,2-e)(1,4)diazepines--synthesis and testing of anti-HIV-1 activity]. / Pyrido[3,2-e][1,4]diazepine-Synthese und Prüfung auf Anti-HIV-1-Wirkung.

Starting from the commercially available 6-methyl-2-pyridylamine (1) the pyrido[3,2-e][1,4]diazepine 14a was synthesized in 12 steps with 7% total yield. 14a, the N-methyl derivative 14b, the thiolactam 15a, the amidine 16, and the 1,2,4-triazole 17 were tested for anti-HIV-1-activity. None of the compounds tested possesses antiviral activity comparable to that of zidovudine (3'-azido-3'-desoxythymidine = AZT).

Biochemical and genetical analysis of AZT-resistant HIV-mutants.

Sequential virus isolates from an HIV-1-infected woman treated orally with 3'-azido-3'-deoxythymidine (AZT) for over two years showed a 10-fold reduced sensitivity for AZT after 8 months and a 100-fold resistance after 24-32 months of drug therapy. These AZT-resistant mutants were totally sensitive in vitro to other reverse transcriptase (RT)-inhibitors like the AZT-analogue 3'-fluoro-3'-deoxythymidine (FdT) or the chemically less related nucleoside analogue 2',3'-dideoxycytosine (ddC). Even the benzodiazepin derivative 4,5,6,7-tetrahydro-5-methyl-6-(3-methyl-2-butenyl)-imidazo [4,5,1-jk][1,4]-benzodiazepin-2(1H)-thione (TIBO), a new drug specific for HIV-1 RT, was inhibitory for these virus strains. Moreover, compounds with different modes of action, e.g. polysulfated polyxylan, exhibited full antiviral activity as well. Thus, AZT resistance seems to be highly specific and should allow to develop further drugs to be used when AZT resistance has emerged. 5.9 kb fragments of the 5'-genomic halves of these sequential HIV-isolates were amplified by PCR and cloned. DNA sequence analysis revealed that the RT gene of the two highly AZT-resistant isolates carried two of the mutations described by Larder et al. [Science 246, (1989)], the Lys 70----Arg and the Thr 215----Tyr transitions. The isolate obtained after 32 months of AZT-therapy in addition contained a third mutation at position 67 (Asp----Asn); in contrast to Larder's report, no mutation was found at position 219. Thus, although these virus isolates showed at least a 100-fold reduced susceptibility for AZT in vitro, the four mutations postulated to be relevant for highly resistant strains were only partially confirmed.

Markers for HIV-disease progression in untreated patients and patients receiving AZT: evaluation of viral activity, AZT resistance, serum cholesterol, beta 2-microglobulin, CD4+ cell counts, and HIV antigen.

In order to find parameters which allow the assessment of the clinical state of HIV patients with or without antiviral therapy, viral cultures on lymphocytes and monocytes/macrophages, CD4-cell counts, HIV antigen, beta 2-microglobulin and serum cholesterol were evaluated for their predictive value. As had been shown previously for lymphocytes, the efficiency of viral isolation on macrophages also depends on the disease stage (CDC) of the patients and thus has a high predictive value. A multivariant discriminant analysis showed that the combination of beta 2-microglobulin, viral antigen, CD4+ cell count and HDL cholesterol predicted the outcome of viral cultures with 80% accuracy. While viral antigen, CD4+ cell counts and beta 2-microglobulin had been known, HDL cholesterol deserves further evaluation as prognostic parameter. The analysis of HIV derived from patients with AZT showed a 20-200-fold in vitro drug resistance after seven to 24 months of therapy. DNA sequence determination of such strains isolated from AZT patients over time showed only two of the amino acid exchanges described in the literature for resistant strains and an additional Val60-Ile transition after 32 months of therapy.

Anti-human immunodeficiency virus (HIV) drug HOE/BAY946 increases membrane hydrophobicity of human lymphocytes and specifically suppresses HIV-protein synthesis.

The polysulfated polyxylan HOE/BAY946, which has been tested in two pilot studies in ARC/AIDS patients and in asymptomatic HIV carries in Germany, was believed to act by inhibiting virus attachment to the cell. However, the drug was also found to reduce the amount of HIV particles released from infected peripheral blood mononuclear cells (PBMC) in vitro. Furthermore, preincubation of PBMC with the drug led to a partial inhibition of a following HIV infection, suggesting that the drug also affects virus entry. Electron Paramagnetic Resonance (EPR) measurements on uninfected human lymphocytes using 5-proxyl-nonane as spin label demonstrated smaller hyperfine coupling constant (aN) values in the presence of HOE/BAY946 or dextran sulfate 5000. Accordingly, h-1p/h-1H ratios were decreased, indicating increased plasma membrane hydrophobicity and a membrane-stabilizing effect of the drugs. Culture of the chronically HIV-infected monocytic cell line U937/HIV-2D194 in the presence of HOE/BAY946 specifically and drastically reduced the release of virions and the intracellular synthesis of viral proteins as determined by radioimmunoprecipitation and reverse transcriptase assays. In conclusion, although the EPR studies showed a physico-chemical effect on membrane polarity, HOE/BAY946 and dextran sulfate clearly affect processes beyond the cell membrane. Thus, in contrast to previous reports suggesting that polysulfated sugars affect HIV only by inhibiting virus binding to uninfected cells, they clearly inhibit HIV in infected cells as well and appear to have a pleiotropic mode of action. Such drugs may be less likely to result in viral resistance after prolonged application than substances acting only on one step in the life cycle of the virus.

Inhibition of HIV and virus replication by polysulphated polyxylan: HOE/BAY 946, a new antiviral compound.

Xylanpoly-(hydrogen sulphate) disodium salt with a molecular weight of about 6000 daltons (HOE/BAY 946) completely inhibited syncytium formation induced by the infection of T lymphocytes with HIV as well as viral replication at concentrations above 25 micrograms/ml. This dose was found to be inhibitory for several strains of HIV-1 and HIV-2. Low molecular weight fractions of the compound were less active against HIV, and high molecular derivatives were as active as HOE/BAY 946. A direct influence of the drug on the infectivity of the virus could not be demonstrated. The drug inhibited the reverse transcriptase of HIV. Treatment of permanently HIV-infected U937 cells resulted in a drastic reduction of virus particles released into the supernatant and points to an additional mode of action. A therapeutic effect of HOE/BAY 946 against retroviruses in vivo could be demonstrated in Friend leukaemia virus-infected mice. A clinical pilot study with the compound was started recently in Germany with AIDS patients who did not tolerate or refused to take zidovudine and with asymptomatic virus carriers.