Solving the Delivery Challenge
The field of gene and RNA therapy holds great promise. However, most of these promises have been unfulfilled due to challenges in developing a system capable of delivering genetic and therapeutic payloads into targeted cells efficiently, reproducibly and permanently.
Vectors are vehicles that deliver genetic material into cells. Viruses are very effective at doing this; so they frequently are used as vectors. Viral vectors use the backbone of viruses for this purpose after removing disease-causing elements from the virus, leaving behind a natural delivery vehicle. VIRxSYS' HIV-based lentiviral vector platform has achieved this goal and has also overcome other existing challenges, such as high-efficiency gene transfer, stable transfer of genetic material into dividing and non-dividing cells, and a reduced risk of immunogenicity and insertional oncogenesis (cancer).
Lentiviral vectors are one of the most effective deliver systems for RNA-based gene therapies and vaccines, and VIRxSYS has become the world’s leader in the design, development and manufacturing of lentiviral vectors. VIRxSYS also has the largest database of patient safety data on subjects who have participated in clinical trials using human lentiviral vectors. The Company’s lentiviral vector platform, currently used in Phase II clinical trials, is based on technology first developed by and exclusively licensed from The Johns Hopkins University. The platform is based on the “lentivirus” class of virus which has remarkable properties for safe, efficient, predictable, and sustained delivery of payloads into cells. Other viral vectors (e.g. adeno-associated viral vectors and mouse leukemia retroviral vectors) have faced serious challenges such as limited efficiency of gene insertion, limited persistence in cells, and insufficient duration of transgene expression, and in some tragic cases, serious vector-induced adverse side effects.
As compared to all other vectors previously and currently used, payloads delivered via a lentiviral vector generally (i) have longer staying power within a cell, (ii) can be delivered repeatedly, and (iii) have among the highest delivery efficiency of any viral vector. Importantly, the Company’s lentiviral vector system has a demonstrated safety profile with more than 175 patient-years data (as of July 2009) with no treatment-related serious adverse event; this safety record increases with each passing month. VIRxSYS’ vector platform may be useful in therapies against viral infections, genetic disorders, cardiovascular diseases and others. The applications include vaccines, autologous cellular therapy, and injectable therapies, each of which has in vivo proof of principle in VIRxSYS’ hands.
Relating to direct injectable therapies, the Company is currently developing next generation lentiviral vectors with affinities for specific cell types. With such vectors, specific cells could be targeted more predictably in vivo, resulting in lower costs, more convenient therapy application, and improved patient outcomes.
"VIRxSYS is the only company currently testing a lentiviral vector in Phase II clinical trials."
Gary McGarrity, VIRxSYS EVP Scientific and Clinical Affairs