Monogram Biosciences, Inc. (Nasdaq: MGRM) announced today that its collaborator Pfizer, Inc. (NYSE: PFE) has separately announced plans to establish a multi-national Expanded Access Program (EAP) that will make its investigational CCR5 antagonist maraviroc available to HIV/AIDS patients who have limited treatment options due to resistance or intolerance. Monogram's co-receptor tropism assay, Trofile, was used for patient selection for maraviroc's clinical development program, and the two companies are engaged in a collaboration agreement to make Monogram's assay available for patient use on a global basis.

"This investigational therapy represents a potential milestone in the treatment of HIV," said Monogram CEO William Young. "We applaud Pfizer's vision to sculpt a new model for drug development that so closely integrates advanced diagnostics into the clinical program. We are proud to be a part of this ground-breaking effort."

Pfizer also confirmed plans to submit applications for marketing approval of maraviroc in both the U.S. and EU following review of the data from the two currently ongoing Phase 3 clinical trials of the drug. The company expects to submit these study results for presentation at an upcoming HIV conference.

Maraviroc is designed to work differently from other available HIV medications. CCR5 antagonists block the virus from gaining access into healthy cells via the CCR5 co-receptor, a common pathway for viral entry. Monogram's Trofile co-receptor tropism assay identifies whether individual strains of HIV use the CCR5 co-receptor, the CXCR4 co-receptor or both co- receptors to infect healthy cells. This helps clinicians determine whether a CCR5 antagonist like maraviroc may be a good therapeutic option for treating individual patients.

Pfizer's EAP is intended to provide access to maraviroc for patients who, in the opinion of the program investigators, have an urgent need for novel medicines because of viral resistance or intolerance to currently available therapies. To be eligible for the program, patients must be clinically stable with documented CCR5- tropic HIV-1 infection.

In a study presented at the International AIDS Conference in Toronto in August 2006 by scientists from Pfizer, the negative predictive value of Monogram's Trofile co-receptor tropism assay was assessed for maraviroc (Study 1029). Results show that patients identified by the assay as having virus using both the CXCR4 and CCR5 receptors (dual/mixed tropic) did not respond virologically to the investigational (CCR5) therapy. These data suggest that screening patients with the Trofile assay will allow physicians to optimize treatment regimens for their HIV patients.

Maraviroc and other entry inhibitors currently in development come at a time when increasing drug resistance makes treating HIV more difficult than ever. Highly sensitive and precise diagnostic tools are playing an ever more important role in the development of new therapeutic approaches that give new hope to physicians and patients running low on options.

About Monogram Biosciences, Inc.

Monogram is advancing individualized medicine by discovering, developing and marketing innovative products to guide and improve treatment of serious infectious diseases and cancer. The Company's products are designed to help doctors optimize treatment regimens for their patients that lead to better outcomes and reduced costs. The Company's technology is also being used by numerous biopharmaceutical companies to develop new and improved antiviral therapeutics and vaccines as well as targeted cancer therapeutics. More information about the Company and its technology can be found on its web site at monogrambio/.

Forward Looking Statements

Certain statements in this press release are forward-looking. These forward-looking statements include references to the potential for an HIV drug that requires a molecular diagnostic for patient selection, the ability of the Company to advance its opportunities in HIV, and activities expected to occur in connection with the Pfizer collaboration. These forward-looking statements are subject to risks and uncertainties and other factors, which may cause actual results to differ materially from the anticipated results or other expectations expressed in such forward-looking statements. These risks and uncertainties include, but are not limited to: the risk that regulatory authorities may not require a molecular diagnostic for patient selection for an HIV drug, risks related to the implementation of the collaboration with Pfizer; risks related to progress Pfizer's clinical trial and any ultimate approval of maraviroc, risks related to our ability to recognize revenue from activities under the collaboration with Pfizer; risks and uncertainties relating to the performance of our products; the growth in revenues; the size, timing and success or failure of any clinical trials for CCR5 antagonists, entry inhibitors or integrase inhibitors; the use of our Trofile co-receptor tropism assay for patient use in the event of approval of any CCR5 antagonists; our ability to successfully conduct clinical studies and the results obtained from those studies; whether larger confirmatory clinical studies will confirm the results of initial studies; our ability to establish reliable, high-volume operations at commercially reasonable costs; expected reliance on a few customers for the majority of our revenues; the annual renewal of certain customer agreements; actual market acceptance of our products and adoption of our technological approach and products by pharmaceutical and biotechnology companies; our estimate of the size of our markets; our estimates of the levels of demand for our products; the impact of competition; the timing and ultimate size of pharmaceutical company clinical trials; whether payors will authorize reimbursement for our products and services; whether the FDA or any other agency will decide to further regulate our products or services; whether we will encounter problems or delays in automating our processes; the ultimate validity and enforceability of our patent applications and patents; the possible infringement of the intellectual property of others; whether licenses to third party technology will be available; whether we are able to build brand loyalty and expand revenues. For a discussion of other factors that may cause our actual events to differ from those projected, please refer to our most recent annual report on Form 10-K and quarterly reports on Form 10-Q, as well as other subsequent filings with the Securities and Exchange Commission. We do not undertake, and specifically disclaim any obligation, to revise any forward-looking statements to reflect the occurrence of anticipated or unanticipated events or circumstances after the date of such statements.

Monogram Biosciences, Inc.
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