Clinical assessment of Optivate®, a high-purity concentrate of factor VIII with von Willebrand factor, in the management of patients with haemophilia A.

Factor VIII (FVIII) concentrates have revolutionized the treatment of patients with haemophilia A. Concerns over the transmission of viral infections through these products have been addressed through stringent, donor-screening procedures and robust antiviral manufacturing steps. Bio Products Laboratory has developed a high-purity FVIII product with von Willebrand factor, Optivate(®). Its safety, tolerability and efficacy as prophylaxis and treatment of bleeds have been established in long-term studies. Seventy previously treated patients with severe haemophilia A, with ≥ 20 exposure days, were recruited into two long-term, multicentre, open-label studies. The protocols were virtually identical. Patients received Optivate(®) either prophylactically or on-demand. A mean of 159.0 EDs were experienced over 11,320 infusions. Under both conditions, Optivate(®) was well tolerated. Only 10% of patients experienced a treatment-related adverse event; the most commonly reported were headache (4% of patients) and dizziness (3% of patients). The mean number of bleeds/patient over the 2 year treatment period was 23.5 during prophylactic use and 70.4 during on-demand use. In patients treated prophylactically, clinical responses to breakthrough bleeds were rated by physicians as excellent or good and as very helpful or helpful by patients in 95% of bleeds. Clinical responses for on-demand patients were rated as excellent or good by physicians and helpful or very helpful by the patients for 91% of bleeds. There were no viral transmissions or inhibitors. The studies confirm the clinical efficacy and safety of Optivate(®) in both prophylactic and on-demand management of patients with haemophilia A.

Pharmacokinetics of Optivate(®), a high-purity concentrate of factor VIII with von Willebrand factor, in patients with severe haemophilia A.

Optivate(®) is a high purity factor VIII/von Willebrand factor (FVIII/VWF) concentrate, which is manufactured using two antiviral processes: solvent/detergent and terminal dry heating (80 °C for 72 h). A multicentre, non-randomized open-label study in 15 patients was conducted to test the pharmacokinetics (PK) of Optivate(®). PK variables were analysed for the patients' prior FVIII product (PK1), their first dose of Optivate(®) (PK2) and at 3 months therapy (PK3). Mean non-compartmental half-lives (h) were 14.1, 12.4 and 12.1, respectively (P = 0.45), mean clearances (mL h(-1) kg(-1)) were 3.6, 3.2 and 3.1, respectively (P = 0.051), MRTs (h) were 19.0, 17.3 and 17.4, respectively (P = 0.39) and mean AUC(0-48h) (h IU mL(-1)) were 14.3, 15.4 and 16.6, respectively (P = 0.051) and mean AUC(0-∞) (h IU mL(-1)) were 15.9, 16.4 and 17.9, respectively (P = 0.18). The recovery data from this PK study was aggregated with recovery data collected from another study, with similar design but devoid of the other PK measurements. A total of 309 recoveries were conducted in 70 patients. The overall mean recovery per subject across 27 Optivate(®) batches was 2.7 IU dL(-1) per IU kg(-1). There were no clinical differences between Optivate(®) and other FVIII products, and except for volume of distribution (Vd), no statistically significant differences were seen with respect to any of the other PK variables, or in recovery between weeks 0 and 12. Therefore, the PK of FVIII is not affected by the processes used to manufacture Optivate(®), which can be expected to be effective in the management of patients with haemophilia A.

Experience of using human albumin solution 4.5% in 1195 therapeutic plasma exchange procedures.

The aim of the study was to document the incidence of adverse reactions (ADRs) in subjects undergoing therapeutic plasma exchange with human albumin 4.5% solution (Zenalb 4.5) and to explore whether there were any differences in tolerability with a change from UK to US plasma and a subsequent manufacturing modification. Zenalb 4.5 was initially manufactured from recovered plasma from UK blood donations and later from source plasma from US donors. The modification was a salt diafiltration step. A prospective survey was conducted at three UK aphaeresis units; data from 154 subjects undergoing 1195 plasma exchanges using Zenalb 4.5 were collected. Adverse events with at least a possible relationship to treatment were recorded. There were 20 ADRs per 1195 exchanges (1.7%), experienced by 14 subjects (9.1%). The most common reaction was rigours in 17 exchanges (1.4%) and 12 subjects (7.8%). ADRs occurred in 0.8% (2/250) of plasma exchanges with UK plasma, 0.2% (1/539) using US plasma/original manufacturing method, 4.3% (16/370) using US plasma/modified method and 12.5% (1/8) using US plasma/mixed original and modified methods. Data were incomplete for the remaining 28 exchanges, but no ADRs were reported. Moreover, 17 ADRs occurred over a 14-month period and involved 10 batches manufactured from US plasma (1 original, 9 by modified method). The incidence then returned to the previously lower level. There was no explanation for this cluster of events. Overall, there was no evidence that plasma source or manufacturing method affected tolerability and it was concluded that human albumin 4.5% solution (Zenalb 4.5) is well tolerated during plasma exchange therapy.

A retrospective survey on the safety of Replenate, a high-purity factor VIII concentrate.

PURPOSE: To assess the safety of a highly purified, plasma-derived factor VIII concentrate (Replenate) in routine clinical use. METHODS: Following guidelines entitled safety assessment of marketed medicines (SAMM), safety data were collected in the UK on 194 patients who received an estimated 47.6 million IU of Replenate. This population included 47 patients undergoing 53 surgical operations or dental extractions. RESULTS: The study detected four cases of new factor VIII inhibitor development and twelve other adverse events, five that were unrelated to the product, five whose causality was unknown, one that was possibly product-related and one case due to possible lack of efficacy. Only one of these cases had been notified to the manufacturer through conventional spontaneous reporting procedures. Three patients were switched from Replenate as a result of an adverse event (one case of infusion site irritation and two cases of a rise in titre of an existing inhibitor), but no unexpected adverse reactions were noted and there were no reports of virus transmission. The median factor VIII recovery value was 2.17 IU/dl per IU/kg, but recovery was shown to be dependent on several variables, namely inhibitor status, treatment centre and the patient's body weight. The median factor VIII recovery in inhibitor-free patients was 2.28 IU/dl per IU/kg (range: 1.20-6.62). CONCLUSIONS: The study confirms that Replenate is well tolerated by the majority of patients in routine clinical practice.

A retrospective survey on the safety of Replenine, a high-purity factor IX concentrate.

PURPOSE: To assess the safety of a plasma-derived highly purified factor IX concentrate (Replenine) in routine clinical use. METHODS: Following guidelines entitled Safety Assessment of Marketed Medicines (SAMM), safety data were collected in the UK by retrospective review of the hospital notes of 114 patients who received an estimated 14.8 million IU of Replenine. Included were 40 patients undergoing 44 surgical procedures or dental extractions [corrected]. RESULTS: The study detected a total of nine adverse events (AEs), four of which were possibly product-related, four that were unrelated to the product and one whose causality was unknown. None of these cases had been notified to the manufacturer through conventional spontaneous reporting procedures. One patient was switched from Replenine because of infusion site irritation, but no unexpected adverse reactions were noted. There were no reports of virus transmission or new factor IX inhibitor development. The mean factor IX recovery value was 1.44 IU/dl per IU/kg (95%CI: 1.31-1.57 IU/dl per IU/kg). CONCLUSIONS: The study was a practical application of the SAMM guidelines to the collection of pharmacovigilance data on patients with Haemophilia B. Replenine is well tolerated in routine clinical practice.

Solvent/detergent treatment does not alter the tolerance or uptake of human normal immunoglobulin for intramuscular injection.

BACKGROUND AND OBJECTIVES: The tolerability and pharmacokinetics of a solvent/detergent-treated intramuscular immunoglobulin were compared with those of the standard product. MATERIALS AND METHODS: Single, 750-mg intramuscular (i.m.) injections were administered to a total of 36 healthy individuals: 23 in a double-blind trial and 13 in an open trial. Changes in specific serum hepatitis A and hepatitis B antibodies were monitored for a period of up to 3 months postinjection. RESULTS: No serious adverse reactions were reported, and the bioavailability of the solvent/detergent-treated preparation was equivalent to that of the standard i.m. immunoglobulin. CONCLUSION: There is no evidence that solvent/detergent treatment alters the pharmacokinetics or tolerance of human normal immunoglobulin, but it offers additional assurance against potential virus transmission.

Clinical experience with a new solvent detergent-treated intravenous immunoglobulin free of hypotensive effects.

OBJECTIVE: To see if modifications to the processing of intravenous immunoglobulin to include a virus inactivation stage alter immunoglobulin G (IgG) resulting in hypotension in patients. METHODS: Clinical trials were done involving extensive patient monitoring during infusion: in vitro - testing for markers of hypotension, and in vivo - an animal model which closely simulates clinical use. RESULTS: No hypotensive response was seen in the animal model or clinical trial. CONCLUSIONS: The production process used does not damage IgG or create vaso-active kinins as the preparation was free of hypotensive effects.

Ketoconazole versus nystatin plus amphotericin B for fungal prophylaxis in severely immunocompromised patients.

72 patients severely immunocompromised by their underlying disease (marrow aplasia, acute leukaemia, or solid tumour) or by the treatment they were receiving, or both, were randomised to receive antifungal prophylaxis with either oral ketoconazole or conventional doses of oral amphotericin B and nystatin. All patients also had gut decontamination with non-absorbable antibiotics, skin antisepsis, sterile food, and oral cotrimoxazole. Protection against fungal infection was significantly superior with ketaconazole. When patients who had received allogeneic bone-marrow transplant were studied separately, there was no significant difference between the two treatments, probably because there was a fall-off in ketoconazole absorption from the end of the third week after the transplant. However, ketoconazole greatly reduced the likelihood of fungal infection in non-transplant patients.

The effect of caffeine upon cell survival and post-replication repair of DNA after treatment of BHK 21 cells with either UV irradiation or N-methyl-n-nitrosoguanidine.

It has been found that in BHK 21 cells caffeine potentiates cell killing by both UV irradiation and N-methyl-N-nitrosoguanidine (MNNG). The potentiating effect is greater with UV than with MNNG. While non-toxic concentrations of caffeine inhibit the joining of newly-replicated DNA fragments into large molecular weight DNA (post-replication repair) after UV irradiation, they have no such effect after MNNG treatment. Furthermore, the joining of DNA fragments continues in the cells treated with 3 microgram/ml of MNNG, a dose which leads to less than 5% cell survival. While inhibition of the synthesis of large molecular weight DNA can explain the synergistic effect of caffeine upon cell survival after UV irradiation, it cannot explain the similar effect after MNNG treatment.