Monogram Biosciences Announces Immediate Availability of Enhanced Sensitivity Trofile(TM) HIV Tropism Assay

SOUTH SAN FRANCISCO, Calif., June 5 /PRNewswire-FirstCall/ -- Monogram Biosciences, Inc. (Nasdaq: MGRM) today announced immediate availability of enhanced sensitivity in its Trofile assay. Trofile was introduced commercially upon FDA approval of Selzentry(TM) (maraviroc), Pfizer's first in class CCR5 antagonist, in August 2007. Optimization of Monogram's Trofile(TM) HIV co-receptor tropism assay has made it substantially more sensitive at identifying very low levels of CXCR4 using virus (X4 or dual/mixed tropic) in HIV-1 patient samples while maintaining a high degree of accuracy. The assay can now detect X4 virus present at levels less than 0.3% of the total virus population, and at that level of X4 virus, the assay is 100% sensitive. This improvement in sensitivity should give physicians a greater level of confidence that the Trofile assay is selecting the most appropriate patients for CCR5 antagonist therapy.

Tropism refers to the chemokine co-receptor on the surface of CD4+ cells that a particular variant of HIV uses to enter the cell. "R5" variants use the CCR5 co-receptor, "X4" viruses use the CXCR4 co-receptor, and dual/mixed HIV uses both co-receptors. New CCR5 antagonist therapies, such as Pfizer's Selzentry block the "R5" variants of HIV from entering through the CCR5 co-receptor. CCR5 antagonists have not been shown to be effective against X4 or dual/mixed variants.

Trofile is now 100% sensitive at detecting CXCR4 minor variants as low as 0.3%, a sensitivity increase of 30-fold on average. Monogram says that with this increase in sensitivity, the assay remains highly accurate.

"Pfizer welcomes advances and innovation in tropism detection, such as the enhanced sensitivity of Trofile, which will give physicians important information when deciding whether or not to incorporate a CCR5 antagonist like Selzentry into a patient's treatment regimen," said Dr. Howard Mayer, MD, Executive Director, Pfizer Development Team Leader for HIV/AIDS. Pfizer and Monogram have a collaboration agreement for commercialization of Trofile outside of the U.S.

"Detection of CXCR4-using minority variants has been shown as an important indicator of CCR5 antagonist treatment success and Trofile is the only clinically validated assay to identify co-receptor tropism, a step the FDA and EMEA has determined is critical in selecting patients for treatment with a CCR5 antagonist," said Monogram CEO William Young. "Trofile is the gold standard in tropism testing and the enhanced sensitivity version now available sets a new standard for performance so that the thousands of physicians who rely on our assay can better direct patient selection."

Trofile examines the complete gp160 coding region of the HIV-1 envelope protein, ensuring that all of the determinants of tropism are tested. In a retrospective analysis reported at the recent Conference on Retroviruses and Opportunistic Infections, the enhanced assay improved patient selection by identifying more cases of dual / mixed virus, and more accurately predicted virologic outcomes. In addition to providing patient selection for Selzentry's pivotal trials, Trofile has been used for patient selection and monitoring in all Phase II and III clinical trials of co-receptor antagonists.

About Trofile

Trofile is a clinically validated patient selection tropism assay that determines whether a patient is infected with a strain of HIV that uses either the CCR5 co-receptor, the CXCR4 co-receptor, or a combination of CCR5 and CXCR4 to enter cells. The use of CCR5, CXCR4 or both co-receptors 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.

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

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 Selzentry, the size and timing of clinical trials utilizing our products, the outlook for Selzentry 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 Selzentry, expected protection provided by patents, possible regulation of Trofile and our other products by the FDA, 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 physicians may not use a molecular diagnostic for patient selection for Selzentry or other HIV drugs; risks related to the implementation of the collaboration with Pfizer; 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 inhibitors, entry inhibitors or integrase inhibitors; the risk that our Trofile Assay may not be utilized for patient use with Selzentry and other CCR5 inhibitors; 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 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.

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

SOURCE Monogram Biosciences, Inc.