Studies confirm utility of Monogram's Trofile assay

USA-based Monogram Biosciences has reported four studies at the 16th International AIDS Conference, held in Toronto, Canada, which it says demonstrate the utility and clinical significance of its Trofile co-receptor tropism assay, which is able to directly and accurately determine whether a patient's virus is able to gain entry into cells via the CCR5 or CXCR4 co-receptor. This means that it could become useful efficacy predictors for the emerging class of drugs which block entrythrough these receptors, such as Schering-Plough's CCR5 antagonist, vicrivirocor.

At the conference, Monogram presented Phase IIb trial results showing that patients identified by its Trofile assay as having virus utilizing only the CCR5 co-receptor demonstrated clinical responses to vicriviroc. The assay has also been used for patient selection in Pfizer's Phase III trial of maraviroc, another investigational CCR5 antagonist, and the firm is collaborating with the US giant to make its co-receptor tropism assay available for patient use ahead of the drug's approval by US and European regulators.

In a second Monogram study presented in Toronto, the assay accurately measured the tropism of 46 well-characterized strains of HIV-1 that included multiple subtypes (CCR5, CXCR4, or dual/mixed tropism).