Viral safety of coagulation factor concentrates: memoirs from an insider.

The purpose of this essay is to recall the actions taken globally to improve the viral safety of coagulation factor concentrates, mainly in the years 1985-1990, at a time of confusing and often contradictory information on bloodborne viral infections in multitransfused patients with hemophilia (PWHs). I shall first recall the problem of the transmission and control of the hepatitis viruses, and then that of HIV: not only for temporal reasons, but also because understanding the progress of knowledge on hepatitis and the poor success of the early measures taken to tackle this problem in PWHs is essential to understand how the problem of HIV transmission was ultimately dealt with successfully.

The early days of PEG and PEGylation (1970s-1990s).

UNLABELLED: The idea to conjugate PEG [poly(ethylene glycol)] to a protein, i.e., to "PEGylate" a protein, was first proposed by Prof. Frank Davis (Rutgers Univ.) in the late 1960s. He wanted to make the new recombinant proteins less immunogenic in our bodies, and thereby enhance their circulation and activity lifetimes. He thought that if he could conjugate a hydrophilic polymer to the "new" protein, it might not be recognized by the immune system as a foreign molecule. This article is a contribution to the Zwitterionic Special Issue as a personal commentary tracing the story of PEGylation from its beginning with Dr. Davis through a current day post-script. STATEMENT OF SIGNIFICANCE: The author knows (or knew) personally most of the early workers in the fields of PEG, PEGylation and non-fouling surfaces, and he has also been personally active in the field since its early days.

Treatment of haemophilia patients in East Germany prior to and after reunification in 1990.

The reunification of Germany in 1990 brought with it major challenges in terms of unifying the care offered to haemophilia patients. At that time, most of the treatment centres belonged to the largest regional hospitals. The centre for paediatric haemophilia patients in Leipzig was at the University Hospital. In this centre, early prophylaxis was offered to all patients with severe haemophilia A or B. For over 20 years, the treatments of choice in the German Democratic Republic were cryoprecipitate for haemophilia A and prothrombin complex concentrate for haemophilia B. Cryoprecipitate was relatively effective during minor surgery, in cases of mild to moderate bleeding, and for prophylaxis; however, unpleasant, relevant side-effects and hepatitis virus transmission were frequently encountered in clinical practice. Reunification coincided with the availability of virus-safe, high-purity plasma-derived factor VIII concentrates (e.g. Beriate(®) P), which changed the outlook for patients in terms of convenience, tolerability, and virus safety; and these new products quickly became the treatments of choice for haemophilia A patients at the Leipzig Children's Hospital. Today, 20 years later, nearly all of the patients initiated on Beriate(®) P at the time of reunification continue with that treatment, and are still benefitting from its excellent efficacy, tolerability, and virus-safety profile.

[Recombinant α-2 interferon in preventing the progression of melanoma].

A brief history of interferon application in the treatment of cutaneous melanoma is represented.

Overview and discovery of IgNARs and generation of VNARs.

Immunoglobulin new antigen receptors (IgNARs) from sharks are a distinct class of immune receptors, consisting of homodimers with no associated light chains. Antigen binding is encapsulated within single VNAR immunoglobulin domains of 13-14 kDa in size. This small size and single domain format means that they exhibit considerable stability and are readily produced in heterologous protein expression systems. In this chapter, I describe the history and discovery of IgNARs, the development of VNAR biotechnology, and highlight important factors in VNAR protein production.

The biopharmaceutical industry in China: history and future perspectives.

Biopharmaceuticals reflect the rapid progress achieved in modern biomedical research. This area has also become one of the main criteria for assessing the development level of biotechnology for a particular country. Although it has been only three decades since the first biopharmaceutical, recombinant human insulin, was licensed by the US Food and Drug Administration, the biopharmaceutical industry has become the fastest growing, most dynamic and technology-intensive sector in the biomedical field. Since the licensing of recombinant human interferon α1b in 1989, the biopharmaceutical industry in China has gone through initial developments and gradually entered a period of rapid growth. This paper provides an overview of the status and development trends of biopharmaceuticals in China, and compares them with those observed in developed countries.

History of growth hormone therapy.

The first human to receive GH therapy was in 1956; it was of bovine origin and was given for 3 wk for metabolic balance studies revealing no effects. By 1958, three separate laboratories utilizing different extraction methods retrieved hGH from human pituitaries, purified it and used for clinical investigation. By 1959 presumed GHD patients were being given native hGH collected and extracted by various methods. Since 1 mg of hGH was needed to treat one patient per day, >360 human pituitaries were needed per patient per year. Thus, the availability of hGH was limited and was awarded on the basis of clinical research protocols approved by the National Pituitary Agency (NPA) established in 1961. hGH was dispensed and injected on a milligram weight basis with varied concentrations between batches from 0.5 units/mg to 2.0 units/mg of hGH. By 1977 a centralized laboratory was established to extract all human pituitaries in the US, this markedly improved the yield of hGH obtained and most remarkably, hGH of this laboratory was never associated with Creutzfeld-Jacob disease (CJD) resulting from the injection of apparently prior- contaminated hGH produced years earlier. However, widespread rhGH use was not possible even if a pituitary from each autopsy performed in the US was collected, this would only permit therapy for about 4,000 patients. Thus, the mass production of rhGH required the identification of the gene structure of the hormone, methodology that began in 1976 to make insulin by recombinant technology. Serendipity was manifest in 1985 when patients who had received hGH years previously were reported to have died of CJD. This led to the discontinuation of the distribution and use of hGH, at a time when a synthetic rhGH became available for clinical use. The creation of a synthetic rhGH was accompanied by unlimited supplies of hGH for investigation and therapy. However, the appropriate use and the potential abuse of this hormone are to be dealt with. The illegitimate use of rhGH, unequivocally the abuse by athletes is, and should be, of primary concern to society and should be halted. The abuse of prescribing rhGH in an attempt to retard the aging process also should receive attention.

Insulin preparations with prolonged effect.

The discovery of insulin and its clinical application early in the last century dramatically improved the prospects of people with diabetes. However, the limitations of those initial, unmodified insulin preparations were quickly recognized; most notably, their relatively "short action" meant that multiple daily subcutaneous injections were required. This stimulated a concerted effort to modify the properties of insulin in order to extend the duration of its blood glucose-lowering effect, minimize dosing frequency, and decrease the burden of treatment. The first successful attempts to prolong insulin's action were achieved by modifying its formulation with additives such as protamine and zinc, culminating in the production of "intermediate-acting" neutral protamine Hagedorn (NPH) insulin in the 1940s and the lente family of insulins in the 1950s. However, NPH and lente insulins were still associated with several limitations, including considerable variability of effect and a pronounced peak in their time-action profile. In the 1980s, the focus of research moved toward the modification of insulin itself with the aim of producing a "long-acting" insulin that would better satisfy basal insulin requirements over the entire day. Once-daily insulin glargine was the first "long-acting" insulin analog in clinical practice, followed by once- or twice-daily insulin detemir and, more recently, insulin degludec, which is now being evaluated for administration at less frequent intervals. These analogs demonstrate several benefits over "intermediate-acting" insulins, including a lower risk of both overall hypoglycemia and nocturnal hypoglycemia and reduced day-to-day glucose variability, making it more feasible to achieve better fasting and overall glycemic control. Long-acting insulin analogs (insulin glargine and insulin detemir) are now firmly established as key tools in the battle against diabetes, and ongoing clinical research of insulin-based therapy should focus on treatment strategies to maximize their benefits. To date, the clinical experience with insulin degludec is limited but demonstrates it has comparable efficacy to insulin glargine.

The tissue-type plasminogen activator story.

Milestones in the development of tissue-type plasminogen activator (t-PA) as a fibrin-specific thrombolytic agent include: purification of human t-PA from the culture fluid of the Bowes melanoma cell line, elucidation of the molecular basis of fibrin-specific plasminogen activation, first experimental animal models of thrombosis, first patient (renal allograft) treated with melanoma t-PA, pilot studies in patients with acute myocardial infarction, cloning and expression of recombinant t-PA providing sufficient amounts for large scale clinical use, and demonstration of its therapeutic benefit in large multicenter clinical trials.

History and diagnostic significance of C-peptide.

Starting with the epoch-making discovery of proinsulin, C-peptide has played an important interdisciplinary role, both as part of the single-chain precursor molecule and as an individual entity. In the pioneering years, fundamental systematic experiments unravelled new biochemical mechanisms and chemical structures. After the first detection of C-peptide in human serum, it quickly became a most useful independent indicator of insulin biosynthesis and secretion, finding application in a rapidly growing number of clinical investigations. A prerequisite was the development of specific immuno assays for proinsulin and C-peptide. Further milestones were: the chemical synthesis of several C-peptides and the accomplishments in the synthesis of proinsulin; the detection of preproinsulin with its bearings on understanding protein biosynthesis; the pioneering role of insulin, proinsulin, C-peptide, and mini-C-peptides in the development of recombinant DNA technology; and the discovery of the enzymes for the endoproteolytic processing of proinsulin into insulin and C-peptide, completing the pathway of biosynthesis. Today, C-peptide continues to serve as a special diagnostic tool in Diabetology and related fields. Thus, its passive role is well established. Evidence for its active role in physiology and pathophysiology is more recent and is subject of the following contributions.

Assessing efficacy and therapeutic claims in emerging indications for recombinant factor VIIa: regulatory perspectives.

When compared with the evidence-based, cost-effectiveness criteria underpinning most government reimbursement schemes in the social market economies, the three regulatory hurdles of safety, quality and efficacy are probably of modest impact in influencing increased usage of recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark). Nevertheless, efficacy claims must be supported if regulatory approval is to be granted for the wider range of indications that have been proposed for rFVIIa. With the refinement of clinical trial designs over the past 40 years, the randomized controlled trial (RCT) has assumed the role of gold standard, providing the highest level of evidence for therapeutic efficacy. However, it is incorrect to assume that regulatory authorities give sole credence to RCTs in assessing claims. It is noteworthy that the indications already accepted for rFVIIa by international regulatory authorities--including the treatment of inhibitors to factor VIII and factor IX, substitution for FVII deficiency, and treatment of Glanzmann's thrombasthenia--were supported not by RCTs but by studies conventionally considered to provide modest evidence levels. Therefore, the use of studies other than RCTs for the more recently proposed indications for rFVIIa in a range of conditions requiring hemostatic correction is perfectly feasible. What regulators expect are well-conducted and well-described studies adhering to principles of good clinical practice, which can be scrutinized for evidence of clinical efficacy and which are based on the initially proven principle for the drug. This paper discusses the regulatory history of rFVIIa in the major regulatory authorities and assesses the route needed to support claims being made in the mainstream literature. Recent episodes where post-market events have forced regulators to be more than usually cautious will be used as examples to suggest possible pitfalls to the extension of approved claims for rFVIIa. The major paths for enhancing access for indications in small patient numbers, where RCTs are even more difficult to perform, will be described and their use for possible extension of rFVIIa indications will be discussed.

Monoclonal and recombinant antibodies, 30 years after ...

In 1975, the hybridoma technology provided, for the first time, an access to murine monoclonal antibodies. During the two following decades, their high potential, as laboratory tools, was rapidly exploited, but in vivo applications were still very limited. Nowadays, antibodies, omnipresent in both diagnostic and research domains, are largely invading the domain of therapy. A wide array of novel technologies, including phage display and transgenic mice, to isolate fully human antibodies and engineer these molecules, has been implemented. The natural propensity, of the antibody molecules, to metamorphosis makes them an ideal response to new applications and therapeutic challenges. The present review is a tentative update of the different antibody "formats" and a walk through the techniques recently applied to antibody engineering. In addition it also addresses some specific issues such as the development of expression systems suitable for large-scale production of recombinant antibodies.

The trials and tribulations of producing the first genetically engineered drug.

Fifty years ago, the determination of the structure of DNA sparked a genetic revolution. Here, I give a personal perspective of the challenges involved in the development of the first biological therapeutic resulting from this revolution: recombinant human insulin.

An adventure in biotechnology: the development of haemophilia A therapeutics -- from whole-blood transfusion to recombinant DNA to gene therapy.

The past decade has seen an explosion in the number of therapeutic proteins available for a wide spectrum of diseases. Some of these proteins are obtained from human plasma. Examples of these therapeutic proteins are albumin, intravenous immunoglobulins and prothrombin complex concentrates. The majority of new therapeutic proteins are, however, derived via recombinant DNA technology. There are other examples where the first therapeutic preparation was a crude preparation derived from plasma or tissue and where subsequent development has resulted in a recombinant form of the therapeutic protein. This article focuses on the development of therapeutics for the treatment of haemophilia A (deficiency of Factor VIII activity). The progression from crude plasma fractions to monoclonal-purified preparations to the more recent development of therapeutic concentrates via recombinant DNA technology is described in some detail. Finally, the current status of gene therapy for haemophilia A is evaluated. Both technical issues as well as market forces are described, as both have had significant impact on the product-development process.