Saturday, January 15, 2011

HIV Drug also effective against herpesviruses

Sept 23, 2010 - Institute for Research in Biomedicine - Barcelona, Spain

It was discovered that the drug Raltegravir (Isentress) is effective against all herpesviruses through a different mechanism than that of HIV.  As it turns out, all Herpesviruses (HHV-1, HHV-2, Eppstein-Barr virus, Cytomegalovirus, HHV-8) contain the UL89 protein, which is responsible for DNA maturation.  Without it, the virus cannot leave the cell to continue infection.  This discovery will lead to the discovery of a class of safer drugs to treat herpesviral infections.  For CFS patients, it provides a one-two punch, knocking out XMRV and Herpesvirus co-infections.

Previously, certain drugs against herpesviruses were trialled in CFS patients with only small improvements at best.  The drawback to the current generation of drugs are that they are fraught with side effects.  Foscarnet is extremely nephrotoxic; Ganciclovir and Valganciclovir (Valcyte) causes myelosuppresion, GI symptoms, as well as neurological symptoms; and Valacyclovir and famciclovir lack broad spectrum anti-viral efficacy.  Many persons taking Valcyte report horrendous side effects, comparable to AZT.  Typically, Valcyte costs $800 a month, and Isentress costs $950 a month.  Raltegravir on the other hand has a very favorable side effect profile - when taken alone, it does not cause fat redistribution or raised cholesterol like other classes of HIV medications.  It is rather unfortunate that very little research has been devoted to developing new classes of antiherpesvirals with better side effect profiles, since there is evidence that XMRV proliferates in EBV transformed B cells.  It is also of note that B cell depletion through Rituximab provides a substantial improvement in CFS patients that lasts 3-4 months, but then returns, which leads to the conclusion that Lymphoblasts may very likely be where the secrets of CFS lie - unfortunately I do not know of any significant ongoing studies that have been conducted using bone marrow aspirations on CFS patients.


  1. But what is the IC50 of raltegravir against herpes viruses, and how effectively does an HIV dose of raltegravir inhibit CMV, EBV, and HHV6 in vivo compared to typical doses of valacyclovir and valganciclovir?

    A company called Epiphany Biosciences is developing a new antiherpetic that they hope will be more broad spectrum against the range of HHVs, specifically EBV, as well as safer than existing drugs.

    I have heard that, unfortunately, when taken alone raltegravir will cause a build-up of unintegrated virus causing possible worsening of the cytokine profile and autoimmunity.

  2. Anonymous,

    Can you please tell you from whom you heard the following statement you made :
    "I have heard that, unfortunately, when taken alone raltegravir will cause a build-up of unintegrated virus causing possible worsening of the cytokine profile and autoimmunity."

    And would you please paste a link to study or any other source you quoted ?

    Thank you

  3. Heh... so is it possible the improvement people report when on isentress is because of supressing herpes viruses and nothing to do with its effect on XMRV? Ugh...

  4. No. Because patients taking Viread alone noted significant improvements, and adding Isentress created an additive effect, and Isentress alone worked.

  5. but isnt the success rate for treating xmrv with ARVs very low ? I read it on brewster's interviews that his results have been 'mixed' and as low as 20%.
    I am guessing that the dose of Isentress is the same for hiv as it is for herpesvirus since they are both viruses anyway. I wonder if my doc will let me take it with my Valcyte.

  6. I had flat warts HPV and they are going away suddenly. so Isentress is working to get rid of my HPV virus also. and also have Viral load of 51 T-cells of 430. So I'm doing great right now

  7. I'm really glad that they've found something that works against all Herpesviruses (HHV-1, HHV-2, Eppstein-Barr virus, Cytomegalovirus, HHV-8), and HIV as well. Certainly having one medication that neutralizes multiple viruses is a step in the right direction for fighting viral infections.

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