mutations in the glutamine-valine-threonine (QVT) motif of the SP1 peptide are also known to cause bevirimat resistance. In addition, V362I mutations have been shown to confer strong resistance to bevirimat, where the S373P and I376V mutations may confer low resistance to bevirimat. A further complication of the use of bevirimat is that, since bevirimat targets the CA/SP1 cleavage site, it could also be used in the treatment of protease inhibitor resistant patients. Except for A364V, mutations in the CA/SP1 cleavage site have showed to result in fitness deficits when combined with protease inhibitor resistance. This proposes that these mutations may develop slowly. It has been shown that protease inhibitor resistance can result in an increase in the occurrence of mutations within the downstream QVT motif. Clinical trials In December 2007, some results of the Phase IIb trial were released. Thomson Financial News reported that, "some patients respond 'very well' to the drug, while another population 'does not respond as well at current dose levels.'" Panacos said it intends to add a group to the study at a higher dosage. The drug manufacturer, Panacos, has stated that success with bevirimat hinges on a patient's particular HIV not having a specific group of genetic mutations in HIV’s Gag protein. When they evaluated the study participants’ virus and found that the participant’s virologic response depended greatly on whether or not the Gag protein of a participant’s virus had polymorphisms—multiple mutations in the protein’s structure. After sampling the virus of 100 patients in the company’s database, they found that about 50 percent did not have Gag polymorphisms, meaning that about 50 percent would likely respond well to the drug. See also BMS-955176 References External links AIDSmeds Bevirimat An animation illustrating Bevirimat's mechanism of action Overview and Publication Listing for Bevirimat from Panacos Carboxylic acids Maturation inhibitors Triterpenes Experimental drugs Cyclopentanes