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Home Treatment Options Treatment Options New Class of Drug Moves on to Clinical Trials

New Class of Drug Moves on to Clinical Trials

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The herpes treatment neighborhood may welcome a new kid on the block—ASP2151 and it’s in a class of its own. Currently, the three FDA-approved antiviral medications for HSV—acyclovir, famciclovir, and valcyclovir—work by targeting specific enzymes (viral DNA polymerase and thymidine kinase) that play a role in HSV replication. However, there are additional proteins needed for this process, including the helicase?primase complex, consisting of three viral proteins. The new class of drug, to which ASP2151 belongs, targets the helicase-primase complex and is considered a helicase-primase inhibitor.


Because it targets different proteins, it can be useful in patients who have not responded to acyclovir or have developed HSV drug resistance. (For more information on drug resistant HSV, see this month’s Ask the Herpes Resource Center column.)

How else does the drug differ from current treatments? Prior animal studies suggest ASP2151 may increase the time between outbreaks. This may be welcome news for those who experience frequent recurrences.

Under development by Astellas Pharmaceuticals, ASP2151, recently entered phase II clinical trials to simultaneously study the safety and efficacy of ASP2151 compared to valcyclovir. If this new class of drug proves to be as or more effective than current treatments, it will be a significant advance in the treatment of herpes. Not only will it offer an additional treatment option, it may provide an alternative to intravenous treatment for those who develop HSV drug resistance. Perhaps, it may also foster the emergence of more drugs in its class.

If you would like to participate in the clinical trial of ASP2151, please visit, call Astellas Pharmaceuticals 1-800-727-7003 or e-mail This e-mail address is being protected from spambots. You need JavaScript enabled to view it . They are seeking those 18 years or older who will test positive for genital HSV (documented at time of screening), not immunocomprised and who have had at least four or more outbreaks in the past 12 months.

Source: Deseret Morning News


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