The Lentiviral Vector Reference Working Group (LVRWG) was created at the conclusion of a meeting organized by The Williamsburg BioProcessing Foundation in June 2002, in conjunction with the American Society of Gene Therapy (ASGT) annual conference. The meeting participants were gathered to evaluate the need for developing reference material to ensure comparability of lentiviral and retroviral vectors, in a similar spirit to the Adenovirus Reference Material program that had just been completed. The concensus at the conclusion of this meeting was that the diversity in the lentiviral vector field, which includes vectors derived from different parental viruses and with various designs, does not allow for identification of a single reference material that would benefit more than a single or very few investigators…
Category: <span>Viral Reference Materials</span>
A prerequisite for producing medicinal products is ensuring their quality and safety. This requires appropriately controlled and standardised manufacture and testing procedures that result in consistent potency, safety, and efficacy. Assuring the quality and safety of gene therapy products in particular presents a great challenge because they are cell-based, multi-gene products which include viral and therapeutic proteins as well as modified cells. Although more than 860 gene transfer clinical trials are in progress and the first gene therapy product is already on the market (in China), the development of reference materials for gene therapy products is at an early stage with only a few accessible reference materials. Standardisation of gene therapy products to ensure their quality and safety is clearly necessary and has become increasingly important. Standardisation and other issues specifically related to gene therapy products are discussed in this article…
The Adenovirus Reference Material Working Group (ARMWG) oversaw development of an adenovirus reference material (ARM) with the intent to provide a way to standardize assay measurements from different laboratories. The ARM, which was manufactured in stages by various organizations including Canji (San Diego, CA) and Introgen Therapeutics (Houston, TX), is available from American Type Culture Collection (Manassas, VA). Upon completion of its manufacture, the characterization phase primarily defined viral particle concentration as well as infectious titer for this product. However, many other concurrent characterization studies were conducted including an assessment of vector purity (e.g., host cell DNA, host cell protein, reversed-phase HPLC), a short-term field use and shipping stability study, and a long-term stability study. Also included in these studies was a coordinated effort to determine the complete DNA sequence of the ARM vector genome…
Through the tremendous efforts of the Adenovirus Reference Material Working Group (ARMWG), an adenovirus reference material (ARM) is now available from the American Type Culture Collection (ATCC). The history and progress of the ARM production and characterization has been presented at many meetings and published in numerous journal articles. Although general statements have been made regarding how the ARM should be used, there is no formal directive or specific set of instructions detailing its application in the field. The goals of this paper are (1) to briefly review the objectives for development and implementation of the ARM, (2) to describe a critical assumption necessary to meet those objectives, (3) to outline specific approaches for using the ARM, and (4) to highlight the need for a working group to address the issues raised in the process…
With the continued progress of adenoviral vectors in gene therapy studies it is increasingly evident that a more formalized approach to the characterization and analysis of these viral vectors is urgently needed. Today, adenoviral vectors are beginning to be considered “well characterized biologics,” as shown by numerous publications describing sophisticated analytical approaches for recombinant adenovirus product candidates. Because the analytical definitions of adenoviral vectors currently lack comparison to a common standard, the problem for regulatory agencies is how to objectively evaluate safety in relation to the administered dose. This well-recognized need for an adenovirus standard has been addressed by a consortium of representatives from regulatory agencies, industry, and academic organizations — the Adenoviral Reference Material (ARM) Working Group. Its work has come to fruition in the recent public availability of the ARM, a purified wild type 5 adenovirus. Many aspects of the history, production, and characterization of the ARM have been published in detail…
As advanced analytical techniques become more widely used for product testing, and as more biological products become better characterized, the expectations increase that all biological products will become well characterized. Certainly, the trend is for all regulated products to become better characterized, and for a growing set of analytical methods to attain common usage. As more data is presented in regulatory submissions and reviews, similar data is expected, or desired, in most future product submissions. Furthermore, the techniques being used are opening additional avenues of product testing that regulators may want to see, or that the larger companies could establish as commonly accepted practice…
As development proceeds for adenoviral vectors in gene transfer clinical trials, it becomes increasingly important that these products demonstrate a good safety profile, and thereby build confidence in those who must make decisions about risk/benefit ratios, dose escalation, and efficacy. Currently, safety and efficacy are based predominantly upon the analysis of data generated by non-standardized methods, resulting in inconsistent values being reported for virus titer and particle counts…
The Adenovirus Reference Material (ARM) was developed under the guidance of the Adenovirus Reference Material Working Group (ARMWG) and the U.S. Food and Drug Administration (FDA), and was made possible through the donation of services and supplies by a large number of laboratories and institutions from the United States, Canada, France, The Netherlands, Germany, and the United Kingdom. The purpose of the ARM is to provide a reference material for use in validating assays and internal standards for adenoviral particle concentration and infectious titer. The NIH Recombinant DNA Advisory Committee recommended the development of such a reference-testing agent in their report issued January 2002. The ARM consists of purified wild type 5 Adenovirus as described by ATCC’s catalog number VR-5…
The Adenovirus Reference Material (ARM) is a purified and well-characterized wild type adenovirus (Ad5) now available to researchers worldwide. Due to the need for a common reference material, the ARM was produced with the purpose of validating assay methods and internal standards for use in developing recombinant adenovirus for gene therapy. Analysis of ARM by RP-HPLC, however, detected the presence of a contaminant peak with a distinctive A240 local wavelength maximum. The contaminant was found in all of the vials, with some variability in amount between vials. It appears that the contaminant is not associated with the virus and it is unlikely that it will interfere with the use of the ARM as a reference material. The source of the contaminant was probably a leachate or plasticizer from the tubing or containers used during the final processing step…
A Short-Term Field Use and Shipping Stability Study of a Wild Type Ad5 Adenoviral Reference Material
Adenoviral vectors for gene delivery are being tested in the clinic for a number of indications and therapeutic uses. In order to facilitate the comparison of studies from different laboratories, the Adenovirus Reference Material Working Group (ARMWG) has developed a reference testing reagent, which will be referred to as the Wild Type Ad5 Adenoviral Reference Material (ARM). This ARM will allow laboratories to standardize in-house controls employed in assays for the determination of particle concentration and infectious titer of their own adenoviral preparations. As part of this project, short-term field use and shipping studies were performed on the ARM. The virus was found to be stable under simulated shipping conditions, for one thaw after shipping, and at 4 °C for up to four hours after thawing. However, there was evidence of aggregation in some vials with repeated freeze-thaw cycles. Therefore, we recommend that each vial be treated as a single-use aliquot, and that it be used within four hours of thawing…