Pfizer links with Monogram to offer assay

Pfizer and Monogram Biosciences have formed a nonexclusive collaboration under which the firms will make Monogram's HIV Co-Receptor Tropism Assay—a diagnostic tool to show the path taken by the virus to access human CD4 cells—available to patients worldwide. As part of the agreement, Pfizer will invest $25 million in Monogram. Tropism information is intended to help identify patients most likely to respond to a new class of investigational drugs called CCR5 antagonists. Pfizer currently has a CCR5 candidate, maraviroc, in Phase III clinical trials and uses Monogram's tropism assay to select patients for enrollment in late-stage clinical studies.