February 27, 2011
From CROI 2011: In what may become a first of its kind, BMS’ new HIV drug called 663068 may provide similar advantages of two other entry inhibitors, Selzentry and Fuzeon. Both of these drugs interrupt HIV’s reproduction outside immune cells instead of inside, which generally results in fewer systemic side effects. But where 068 differs is that it binds to a receptor on HIV called gp120 instead of directly interacting with immune cells, something no other approved drug currently does. Hence, it’s called an attachment inhibitor.
A series of eight small studies were done in 200 HIV-negative and 50 HIV-positive individuals. These study results focused on HIV-positive people where 068 was given in different amounts over 8 days. All participants had CD4s over 200 (average 432) and viral loads over 5,000 copies. No one had been on treatment for 8 weeks before starting 068, whether or not they had ever been on treatment before. Ritonavir was used as a booster in most of the studies. Average age was 42.
The results showed an average 1.6 log decrease in viral load. (A 1 log drop is considered the minimum desired amount.) The average CD4 increase ranged from 28 to 106 among the 5 groups and average CD8 increase ranged from 69 to 288. The drug appears to be well tolerated with mild side effects such as headache, rash and nausea. No resistance data was available.
As the drug moves further into Phase II study later in 2011, it will need to be used with other HIV meds to check on once- or twice-a-day dosing, drug interactions and its long-term effectiveness at controlling HIV. Since 068 interferes with the virus at a different step in its life cycle than any other current class of drug, it may offer an extra option for people to control their viral loads. Even if it’s found to provide a unique benefit in HIV treatment, it will still be about three more years before it could make it to market.