Benitec RNA hopes body produce HIV-resistant white blood cells indefinitely

[bimazek]

Benitec's three-pronged RNA attack on HIV
By Mike Nagle
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25/07/2007 - Australian biotech company, Benitec, is about to start dosing patients in the first ever human trial of its RNA therapy, which attacks HIV on three separate fronts.

During a talk at this week's International Aids Society (IAS) meeting in Sydney, Dr John Rossi from the Beckman Research Institute, City of Hope, California, outlined Benitec's RNA interference (RNAi) therapy, which he has collaborated on, and said that the first patient in the Phase I clinical trial will be dosed "sometime this week."

Although HIV/AIDS can build up resistance to existing drugs alarmingly quickly, Rossi explained that attacking the virus on three fronts could enable the drug to fend off resistance for longer; it's easy to mutate around one thing but much more difficult if there's three to contend with. Also, the mutations that he has observed so far "make the virus weak," he said, and it later reverts back to the original sequence.

He explained that the drug uses a lentivirus vector to deliver genes that encode for three different forms of RNA to battle the virus: RNAi in the form of short hairpin RNA (shRNA) that targets an exon in the transactivator of transcription (Tat) and Regulator of Virion (Rev) gene (shI), a decoy for the HIV TAT-reactive element (TAR), and a ribozyme that targets the host cell CCR5 chemokine receptor (CCR5RZ).

The scientists are using two different techniques to introduce the DNA into the body. The first one is where they remove a patient's own bone marrow progenitor cells, genetically modify them using the virus and then reinfuse them into the patient during a bone marrow transplant.

The company claims that "if successful, the new treatment could allow patients' bodies to produce HIV-resistant white blood cells indefinitely."

Not only does the drug attempt to knock back virus levels, Rossi said it also aims to destroy the lymphoma that develops in many HIV-positive patients. The trial itself will be treating five patients in this subgroup, with the results expected within a year.

http://www.drugresearcher.com/news/ng.asp?n=78485-benitec-city-of-hope-international-aids-society-hiv-rna-interference


http://www.drugresearcher.com/news/ng.asp?n=77155-medical-marketing-international-pfizer-merck-co-hiv-aids-entry-inhibitor

[powerpuff]

thats great, however didn't someone in the usa do something similar like stem cells resistant to hiv reinfused into bone marrow to produce  hiv resistant cells?...it worked for about up to two years and only produced 30% resistant cells ...you could not remove all your bone marrow to produce all the new resistant cells in your body. perhaps partial...so your bone marrow would keep producing the 30%-40% resistant cells ant the 70% your regular cells not modified cells  because your  body would have to remove all the bone marrow to produce these resistant cells ..which is impossible..it would kill you..
however it may give you partial resistance to hiv1 for prolonged periods of  time...I don't know what happed to that trial iof they followed them after 2-3 years but it wasn't worth it to have  30% resistant cells reproduceing they said..howver they wanted to up the  bone marrow amount...might be risky....
the indefinitely sounds good but i don't know how long the bone marrow would produce these resistant cells..like i said they followed some patients up to two three years and SOME resistant cells were still present..
Plus this would be costly bone marrow transplant for all hiv people would be impossible i don't see it as a major treatment in every hospital.