Coverage of CROI 2008 (Conference on Retroviruses and Opportunistic Infections)

February 4–6, 2008, Boston, MA

Experimental NtRTI may cause fewer kidney problems

February 5, 2008

A poster presented at CROI suggests that GS-9148, an experimental NtRTI being developed by Gilead, might cause fewer kidney problems than Viread (tenofovir) and might have very good penetration into lymph nodes.

GS-9148 is a nucleotide reverse transcriptase inhibitor (NtRTI). Other nucleotides have caused damage to kidneys, including Viread, cidofovir and adefovir. This poster showed data, from both lab and animal studies looking, at GS-9148’s affect on kidney cells. Compared to other nucleotides, GS-9148 was taken up into kidney cells. This suggests it’s less likely to harm those cells.

Gilead also looked at how well GS-9148 got into lymph node cells. Lymph nodes are a major site of HIV replication. Most HIV drugs fail to penetrate into this important area of the immune system.

The NRTI class of HIV drugs has lagged in development for some years now. As a class they have been hampered by relatively low potency and high toxicity. A new NRTI with low toxicity would be welcome, if it is shown to reduce HIV levels well. More research will be needed to see if the promise of this new NRTI can be reached.