Currently Available Recombinant Alternatives to Horseshoe Crab Blood Lysates: Are They Comparable for the Detection of Environmental Bacterial Endotoxins? A Review.

Endotoxin testing by recombinant factor C (rFC) is increasing with the addition of new suppliers of reagents. By use of a recombinantly produced factor C , based on the sequence of a coagulation enzyme present in horseshoe crab amebocyte lysates, the rFC tests are designed as substitutes for the traditional Limulus amebocyte lysate (LAL)/Tachypleus amebocyte lysate tests based on horseshoe crab blood. Comparative testing of samples with both the LAL and recombinant reagents has shown a high degree of correlation, suggesting that use of rFC is comparable to the more traditional LAL tests and may be technologically superior. Recombinant factor C does not recognize the factor G pathway, the alternate coagulation pathway that the lysate reagents detect. This feature allows rFC to detect endotoxin more selectively. As a recombinantly produced material, it avoids the use of the horseshoe crabs required for lysate production, thereby protecting this species, which is at risk in some parts of the world. Recombinant factor C is expected to further benefit from a more sustainable supply chain based upon a robust biotechnological production process. We summarize here the results of many studies that evaluated the use of recombinant technology for the detection of environmental endotoxin. Additionally, we include a review of the current compendia and regulatory status of the recombinant technologies for use in the quality control of pharmaceutical manufacturing. Our analysis confirms that the recombinant technologies are comparable in protecting patient safety.

The US regulatory and pharmacopeia response to the global heparin contamination crisis.

The contamination of the widely used lifesaving anticoagulant drug heparin in 2007 has drawn renewed attention to the challenges that are associated with the characterization, quality control and standardization of complex biological medicines from natural sources. Heparin is a linear, highly sulfated polysaccharide consisting of alternating glucosamine and uronic acid monosaccharide residues. Heparin has been used successfully as an injectable antithrombotic medicine since the 1930s, and its isolation from animal sources (primarily porcine intestine) as well as its manufacturing processes have not changed substantially since its introduction. The 2007 heparin contamination crisis resulted in several deaths in the United States and hundreds of adverse reactions worldwide, revealing the vulnerability of a complex global supply chain to sophisticated adulteration. This Perspective discusses how the US Food and Drug Administration (FDA), the United States Pharmacopeial Convention (USP) and international stakeholders collaborated to redefine quality expectations for heparin, thus making an important natural product better controlled and less susceptible to economically motivated adulteration.

Role of public standards in the safety and efficacy of biologic medicines.

In this report, we emphasize the importance of public monographs with reference materials, coupled with careful process and change control and attention to GMPs, as a means of advancing access to good quality, safe, and effective medicines, with emphasis on available and incoming biologic medicines. With adequate control of articles covered by a monograph, these public standards can form the basis for a global public quality platform that covers reference products, non-interchangeable reference products, biosimilars, and interchangeable biosimilars. Working collaboratively with all stakeholders, new approaches allow these public standards to emerge nationally and globally in a timely way. Yet, there are increasing limitations in the availability of public standards for biologic medicines, which may reverse many decades of progress. Solutions are considered in this report.

United States Pharmacopeia activities in the area of vaccines, virology and immunology.

The United States Pharmacopeia (USP) develops public standards for medical products that are enforceable by FDA. USP general information chapters have been providing industrial and academic researchers alike with crucial guidance especially in areas where there is absence of regulatory guidance. In an effort to meet the challenge of rapid advances in vaccine research and manufacturing, the Council of Experts Committee for Vaccines, Virology, and Immunology of the US Pharmacopeia has recently initiated two new general chapters to provide advice for researchers and manufacturers in the vaccine and virology fields and beyond. Chapter 1235 Vaccines and Vaccine Test Methods will focus on manufacturing and analytical requirements for the different types of vaccines currently in manufacture and development. Chapter 1237 Virology Test Methods will discuss modern diagnostic virology techniques and a variety of tests as applicable to vaccine and biologics manufacturing.

Structural basis of BLyS receptor recognition.

B lymphocyte stimulator (BLyS), a member of the tumor necrosis factor (TNF) superfamily, is a cytokine that induces B-cell proliferation and immunoglobulin secretion. We have determined the three-dimensional structure of BLyS to 2.0 A resolution and identified receptor recognition segments using limited proteolysis coupled with mass spectrometry. Similar to other structurally determined TNF-like ligands, the BLyS monomer is a beta-sandwich and oligomerizes to form a homotrimer. The receptor-binding region in BLyS is a deeper, more pronounced groove than in other cytokines. The conserved elements on the 'floor' of this groove allow for cytokine recognition of several structurally related receptors, whereas variations on the 'walls' and outer rims of the groove confer receptor specificity.