CytRx Inks Collaboration With UMASS for RNA-based CMV Treatments
CytRx said this week that it has signed another exclusive RNAi technology partnership with the University of Massachusetts Medical School, continuing a relationship between the company and the institution that began early last year.
Under the terms of the latest deal, CytRx has agreed to fund research at UMMS into the use of RNAi to treat conditions associated with cytomegalovirus, with an initial focus on CMV retinitis. According to the US Centers for Disease Control and Prevention, between 50 and 85 percent of people over 40 years old are infected with CMV. The infection is not a threat to healthy individuals, but can be dangerous for those with compromised immune systems, such as organ transplant recipients and HIV/AIDS patients. A recent Johns Hopkins report stated that about 5 percent of AIDS patients develop CMV retinitis.
The work will be led by Timothy Kowalik, UMMS associate professor of molecular genetics and microbiology.
All potential products developed under the program will belong to CytRx.
“The key to the UMMS technology for CMV retinitis is the delivery method,” CytRx CEO Steven Kriegsman said in a statement. “Because CMV retinitis is localized in the eyes, it can potentially be treated via direct delivery of RNAi compounds into the eye, itself, at the site of the infection. We are hopeful that this technology will demonstrate that RNAi can work in humans … and plan to quickly move into clinical trials following successful completion of the research that will be funded at UMMS.”
Kriegsman added that once an RNAi therapeutic for CMV retinitis has been developed, the company plans to expand its “collaboration efforts into developing RNAi therapeutics for other CMV indications.”
The CMV deal marks the latest in a string of agreements between CytRx and UMass. The company has already established partnerships with the university to use RNAi to develop treatments for obesity, type II diabetes, and Lou Gehrig’s disease. (See GenomeWeb News, 6/30/03). CytRx has also licensed from UMass the exclusive rights to a DNA-based HIV vaccine, and formed a subsidiary called Araios with UMMS research Michael Czech to use RNAi to discover small molecule therapies for type II diabetes and obesity. (See RNAi News, 9/19/03).
Stanford Researchers Publish siRNA Production Technique in Nature Genetics
Researchers at Stanford School of Medicine claim to have developed a new enzyme-mediated method of generating functional siRNA constructs from any gene or pool of genes, publishing details of their work in the February issue of Nature Genetics.
Essentially, the process involves fragmenting the genes to be silenced using restriction enzymes in order to generate as many siRNA constructs per gene as possible. The fragments are then ligated to an oligonucleotide, which forms a hairpin loop, to link the sense and antisense strands. Next, the 5’ loop is ligated to a 2’ overhang that resulted from previous digestion with the MmeI restriction enzyme, forming a closed circular dumbbell structure.
RCA is then used to amplify the product of the second ligation reaction and create linear double-stranded DNA for cloning. This dsDNA encodes siRNA molecules.
The plasmids are eventually digested with BamHI to eliminate extraneous sequences and then religated, forming expression-ready siRNA vectors.
According to the Stanford researchers, the restriction enzyme-generated siRNA system was tested by silencing a transgene and two endogenous genes. The predicted phenotypes were obtained.
Lorus Releases Interim Data From Phase II Trial of Antisense Cancer Drug
Lorus Therapeutics said this week that interim data from a recently completed exploratory phase II clinical trial of GTI-2040 in 21 patients with end-stage renal cell cancer indicated that the antisense compound was able to help stabilize disease in more than half of the study participants when used in combination with the drug capecitabine.
Lorus also said that it intends to advance GTI-2040 into a phase II/III program as a treatment for early-stage renal cell cancer in combination with a cytokine.
AVI Antisense Drugs Effective Against SARS Virus in Cell Culture Studies
AVI BioPharma presented last week confirmatory data showing its antisense drugs capable of inhibiting the SARS coronavirus in cell cultures.
According to the company, one of the drugs was able to interfere with an RNA processing site unique to the SARS class of coronaviruses and resulted in a greater than 100 fold reduction in viral expression.
“Since [this virus is] closely related due to [its] single-stranded RNA genome, these studies represent a significant advancement in our understanding of optimal strategies for designing [antisense] drugs against all RNA viruses,” Patrick Iversen, AVI’s senior vice president of R&D, said in a statement.