Monogram Biosciences Data Presented on Monogram HIV Tropism Tests at Retrovirus Conference sets New Standards of Assay Sensitivity Company Continues to Lead Tropism Testing Field

SOUTH SAN FRANCISCO, Calif., Feb. 7 /PRNewswire-FirstCall/ -- Monogram Biosciences, Inc today announced that data related to the company’s advanced HIV tropism assay have been presented as multiple posters during the 15th Conference on Retroviruses and Opportunistic Infections (CROI) this week in Boston, MA. Highlights from the meeting include data on an enhanced version of the Trofile(TM) Assay’s superior ability to identify patients that are not likely to respond to CCR5 antagonist therapy, as well as data that sheds new light on how patients develop resistance to this new class of drugs.

During the “Emerging Patterns of Resistance to New Antiretrovirals” session at CROI, Monogram participated in a number of poster presentations, including:

The first presentation analyzed subjects from the AIDS Clinical Trials Group 5211 study and compared co-receptor tropism results (R5, X4 or dual/mixed DM HIV) of the original Trofile test with those obtained using an enhanced version of the assay. Researchers found that the enhanced Trofile assay would have further optimized patient selection for this new drug class by successfully identifying patients with low levels of DM (non R5) HIV at screening and who subsequently experienced treatment failure on a CCR5 antagonist.

Trofile has been proven to be a critically important tool for ensuring that CCR5 antagonists are administered safely -- and the only such tool currently available. This has been reinforced by the issuance by the Department of Health and Human Services of its updated guidelines for HIV treatment, in which it recommended that a tropism test should be used prior to initiation of CCR5 treatment and may also be considered at failure of therapy. The DHHS guidelines also cited the Trofile assay by Monogram as the assay “used to screen patients who were participating in studies that formed the basis of approval for Selzentry, the only CCR5 inhibitor currently available.

Data from the other presentations show specific markers of HIV resistance to CCR5 antagonists, particularly the role that mutations in the V3 loop play. Based on these and other studies, Monogram has been the first to identify specific changes that have become a standard marker of CCR5 antagonist resistance.

“Monogram tests, particularly our Trofile Assay, have been pivotal to CCR5 drug development programs,” said Monogram CEO William Young. “Trofile is well established as the only clinically validated tropism assay and as the data presented this week reaffirms, our enhanced tropism assay, which we expect to be commercially available soon, sets an even higher standard of sensitivity for CCR5 positive patients.”

Monogram’s tests have been used throughout the development of the CCR5 class of drugs. In addition to the use of Trofile for patient selection and the use of Phenosense for optimization of background therapy in the phase II and phase III clinical trials of Pfizer’s maraviroc (Selzentry(TM)) and Schering Plough’s vicriviroc, Monogram has also recently signed an agreement with Incyte Corporation to provide resistance and tropism testing for Incyte’s investigational CCR5 antagonist, INCB9471. INCB9471 is currently in Phase II development. Two six-month Phase IIb clinical trials are expected to begin in 2008 in which Monogram’s Trofile tropism assay will be used to select and monitor patients, and the PhenoSenseGT(TM) assay will be used to optimize background therapy for patients enrolled in the trial.

“INCB9471 has the potential to become an important tool in the fight against drug-resistance HIV,” said Sue Erickson-Viitanen, Incyte’s Sr. Director of Virology Drug Development. “Selecting the appropriate patients is critical to the success of our clinical development program. We’re confident Monogram’s leadership in HIV diagnostics and the Trofile assay’s established position as the only clinically validated tropism test, provide a solid foundation for successfully progressing INCB9471 forward in these upcoming trials.”

“Incyte’s CCR5 antagonist has the potential to be a very significant addition to HIV therapy, and we are delighted to be working with Incyte on their program,” said Young.

About Trofile

Trofile is a patient selection co-receptor tropism assay that determines whether a patient is infected with a strain of HIV that uses either the CCR5 coreceptor, the CXCR4 coreceptor, or a combination of CCR5 and CXCR4 to enter cells. The use of CCR5, CXCR4 or both coreceptors defines the “tropism” of the virus strain. Trofile amplifies the envelope gene from a patient’s HIV genome (from their blood sample) and then uses it to make HIV particles containing the patient’s virus envelope protein. The resultant HIV particles are then used to infect cells that contain the CCR5 co-receptor or the CXCR4 co-receptor on the cell surface. Once the virus infects the cell, it undergoes a single round of replication. Virus replication results in the production of luciferase from a luciferase gene that is carried into the cell by the virus. The production of luciferase in either CCR5 cells, CXCR4 cells or both cell types defines the co-receptor tropism of the patient virus. Trofile is the only clinically validated tropism assay and has been used to select patients in all phase II and phase III studies of CCR5 antagonists to date.

Trofile is a trademark of Monogram Biosciences. Selzentry is a trademark of Pfizer Inc.

About Monogram

Monogram is a biotechnology company 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 www.monogrambio.com.

Forward Looking Statements

Certain statements in this press release are forward-looking. These forward-looking statements include references to the demand for our Trofile Assay, the potential use of our Trofile Assay for patient selection for the class of HIV drugs known as CCR5 antagonists, the size and timing of our customers’ clinical trials utilizing our products, the outlook for the CCR5 class of drugs and our Trofile Assay, the number of patients each year in the U.S. who potentially could be candidates for new classes of HIV drugs such as CCR5 antagonists, expected protection provided by patents, possible regulation of Trofile and our other products by the FDA. 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 physicians may not use a molecular diagnostic for patient selection for CCR5 antagonists or other HIV drugs; whether an enhanced version of Trofile will be successfully validated, introduced commercially and adopted by physicians; whether larger confirmatory clinical studies will confirm the results of initial studies; 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 inhibitors, entry inhibitors or integrase inhibitors; the risk that our Trofile Assay may not be utilized for patient use with CCR5 inhibitors; our ability to successfully conduct clinical studies and the results obtained from those 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 payers will authorize reimbursement for our products and services and the amount of such reimbursement that may be allowed; whether the FDA or any other agency will decide to further regulate our products or services, including Trofile; whether the draft guidance on Multivariate Index Assays issued by FDA will be subsequently determined to apply to our current or planned products; 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; restrictions on the conduct of our business imposed by the Pfizer, Merrill Lynch and other debt agreements; the impact of additional dilution if our convertible debt is converted to equity; and whether we will be able to raise sufficient capital in the future, if required. For a discussion of other factors that may cause 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.

amerriweather@monogrambio.com jeremiah.hall@fkhealth.com

CONTACT: Alfred G. Merriweather, Chief Financial Officer of Monogram
Biosciences, Inc, +1-650-624-4576, amerriweather@monogrambio.com; or
Jeremiah Hall of Feinstein Kean Healthcare, +1-415-677-2700,
jeremiah.hall@fkhealth.com, for Monogram Biosciences, Inc

Web site: http:///

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