Scientific Data Highlights Pivotal Role of Monogram’s Molecular Diagnostics in Development and Use of New HIV Treatments

SOUTH SAN FRANCISCO, Calif., March 5 /PRNewswire-FirstCall/ — Monogram Biosciences, Inc. today announced 20 presentations related to its portfolio of HIV diagnostic assays at the 14th Annual Conference on Retroviruses and Opportunistic Infections (CROI). Data presented at the conference demonstrate the pivotal role played by Monogram’s HIV assays in delivering personalized patient care by providing critical information that facilitates physician management of patient treatment regimens and assists pharmaceutical companies in their ability to develop new drugs and new drug classes. Full text of the presentations can be found at http://www.retroconference.org/.

“Important phase III data was presented at CROI by Pfizer on their investigational CCR5 antagonist and by Merck on their investigational integrase inhibitor,” said William Young, CEO of Monogram. “The advent of two new classes of HIV drugs is potentially the most significant development for HIV patients in a decade and I am proud that Monogram’s assays are playing a critical enabling role in the development of these drugs and in determining their clinical utility.”

Monogram’s assays were used to optimize background therapy in the clinical trials of both new drugs and in the case of maraviroc, Pfizer’s CCR5 antagonist, Monogram’s Trofile Assay was used for patient selection and enabled the positive results reported by Pfizer at CROI. “Pfizer’s phase III results indicate that patients, when properly selected with our assay, responded to maraviroc, and experienced a significant reduction in viral load,” continued Young. “Data previously reported by Pfizer indicate that patients who are identified with our Trofile Assay as not being appropriate for the drug, in fact, did not respond to maraviroc.” Maraviroc has been granted accelerated review by U.S., Canadian and European regulators, and if approved, would be the first new oral class of HIV medicines in more than a decade.

“The breadth and depth of the scientific data presented at CROI by Monogram scientists and collaborators demonstrate the position of strong scientific leadership that is Monogram’s hallmark,” said Christos Petropoulos, Chief Scientific Officer at Monogram.

Data presented at CROI highlight important new findings related to Monogram’s advanced HIV assays:

   Monogram’s Co-Receptor Tropism Assay, Trofile   — Maraviroc phase III trials validated the positive predictive value of      the Trofile assay. Because maraviroc cannot inhibit the replication of      all HIV strains, Trofile was used to select those subjects most likely      to respond to the drug (individuals with a viral strain that only      enters cells via the CCR5 co-receptor.) Subjects unlikely to respond to      maraviroc (those with a viral strain that uses the CXCR4 co-receptor to      enter cells) were excluded from the trials. This allowed Pfizer to      demonstrate maraviroc’s compelling antiviral activity using a specific      subset of study subjects that are infected with HIV strains that      utilize the CCR5 co-receptor, the target of maraviroc. .  Without pre-      screening for co-receptor tropism, the antiviral activity of maraviroc      would have been diluted by the inclusion of subjects unlikely to      respond to the drug, especially in the highly treatment experienced      subjects that were targeted in the Pfizer trials.  In a head to head      comparative study, Trofile assay results were highly concordant with      the results generated by well-established conventional testing that is      more tedious and time consuming to perform.  Notably, the conventional      assay (MT2 cell syncytia formation assay) failed to generate results      for approximately 50% of the samples that were successfully tested by      the Trofile assay.  This demonstrates how valuable Trofile will be to      clinicians should maraviroc and other co-receptor inhibitors receive      regulatory approval.   — The 20-40% of HIV strains classified as dual or mixed tropic (that is,      can use CCR5 and/or CXCR4 receptors to enter cells) by the Trofile      assay display a broad range of ability to use either co-receptor to      infect healthy cells. To begin to understand whether viral entry      inhibitors (CCR5 or CXCR4 antagonists) will work in some fraction of      patients infected with dual-mixed tropic HIV, two studies from Monogram      evaluated different subgroups of dual tropic virus populations. These      different dual tropic subgroups were shown to utilize CXCR4 and CCR5      co-receptors with different efficiencies and respond differently to      CCR5 or CXCR4 inhibitors. This variation could impact patient responses      to co-receptor inhibitors, such as maraviroc, in subjects infected with      dual-mixed tropic virus.    Optimizing Antitretroviral (ARV) treatment using PhenoSense GT Assay   — Sustaining durable patient response to new drugs in development      requires a potent background regimen that includes active protease and      reverse transcriptase inhibitors. Clinical programs by Pfizer, Merck      and Gilead continued to use Monogram’s assay to optimize background      regimens, ensuring durable and potent responses to their drug      candidates.   — Data from late stage clinical trials of several new antiretroviral      drugs including maraviroc (Pfizer, CCR5 antagonist), raltegravir      (Merck, integrase inhibitor), elvitegravir (Gilead, integrase      inhibitor) continued to demonstrate the clinical benefit of selecting      ARV treatment regimens using the PhenoSense GT Assay.   — Placebo arms of these trials further demonstrated the clinical benefit      of optimizing ARV therapy with PhenoSense GT. Several large studies      have now demonstrated that even subjects who only receive an optimized      background regimen (with no investigational drug candidate) on average      experience a 10-fold reduction in viral replication (1 log reduction in      viral load). Furthermore, nearly half of treatment-experienced patients      who initiate a new PhenoSense GT-selected regimen will fully suppress      viral activity despite multiple prior treatment failures.    Monogram’s virus library and database   — Testing Tibotec, Inc.’s recently approved protease inhibitor darunavir      (DRV) along with other protease inhibitors against many thousands of      drug-resistant strains selected from Monogram’s virus library      (currently comprised of >175,000 viruses), investigators were able to      demonstrate that DRV exhibits potent antiviral activity against HIV      strains resistant to most other drugs in this class.   — Monogram and Tibotec investigators also reported lower and upper      cutoffs for darunavir activity. The PhenoSense assay reports HIV      susceptibility to drugs, correlating full ARV activity to      susceptibility below the lower cutoff, partial activity to      susceptibility between lower and upper cutoffs, and no activity to      susceptibility above the upper cutoff. PhenoSense and PhenoSense GT      assays are the only HIV drug resistance test that directly correlates      clinical response to a direct measure of drug susceptibility.   — A panel of viruses selected using Monogram’s database representing      viruses resistant to currently used protease inhibitors was used to      demonstrate the favorable susceptibility profile of Gilead Science’s      novel protease inhibitor (GS-9137).    Virus diversity and evolution   — Several Monogram studies at CROI describe the characteristics of HIV      strains and patient response over progressive stages of infection.      According to these studies, acute and early stages of infection are      characterized by relatively homogeneous virus populations that later      diversify in the face of evolving immune responses.   — By further characterizing those viruses that efficiently spread, or      that manage to evade ongoing immune surveillance, we expect to      contribute to the improved design and development of an effective      vaccine.    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 http://www.monogrambio.com/.

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, expected protection provided by patents, 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 or recommend a molecular diagnostic for patient selection for an HIV drug, 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 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 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; 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 the draft guidance on Multivariate Index Assays recently issued by FDA applies 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 and Merrill Lynch debt agreements; 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, Phenosense, Phenosense GT, and Geneseq are trademarks of Monogram Biosciences, Inc.

   contacts:  Alfred G. Merriweather           Jeremiah Hall              Chief Financial Officer          Feinstein Kean Healthcare              Tel: 650 624 4576                Tel: 415 677-2700              amerriweather@monogrambio.com    jeremiah.hall@fkhealth.com  

Monogram Biosciences, Inc.

CONTACT: Alfred G. Merriweather, Chief Financial Officer,+1-650-624-4576, amerriweather@monogrambio.com; Jeremiah Hall, Feinstein KeanHealthcare, +1-415-677-2700, jeremiah.hall@fkhealth.com

Web site: http://www.monogrambio.com/http://www.retroconference.org/