Pfizer Presents New Data from HIV/AIDS Portfolio at Conference on Retroviruses and Opportunistic Infections

At this week’s major HIV/AIDS research meeting, Pfizer presented new data on two investigational second generation HIV compounds – a CCR5 antagonist and a non-nucleoside reverse transcriptase inhibitor (NNRTI). Pfizer also presented additional data on SelzentryTM (maraviroc) tablets, its first-in-class medicine approved last year for use in treatment-experienced HIV patients infected with a certain type of HIV. Selzentry is known as Celsentri® outside of the United States. The data highlight potential advances in the treatment of HIV that has become resistant to currently available therapies. "Viral resistance is a major issue in treating HIV. This past year, the community welcomed breakthrough therapies, including Selzentry, that are giving patients infected with resistant virus new hope of controlling this disease,” said Dr. Martin Mackay, president of Pfizer Global Research and Development. "Pfizer is continuing to invest in research that we hope will help physicians remain one step ahead in their fight against HIV.” Data Presentations on Pfizer’s Investigational HIV Compounds New data from phase I studies on PF-232,798, a second generation CCR5 antagonist, suggest that this molecule is well tolerated in healthy volunteers with a dosing profile that holds the potential for once daily administration. Preclinical data on PF-232,798 demonstrated the molecule’s activity against a broad spectrum of HIV-1 subtypes with similar in vitro potency to Selzentry, the first member of the CCR5 antagonist class to receive approval. PF-232,798 also showed activity against isolates of HIV that demonstrated resistance to Selzentry. Pfizer is further characterizing the clinical profile of PF-232,798 with phase II studies. Additionally, phase I data on UK 453,061 further characterized the profile of this molecule in combination with other commonly used HIV medicines. UK 453,061 is a second generation NNRTI that has demonstrated in vitro activity against a variety of HIV-1 subtypes, including strains resistant to first generation NNRTI treatments. Based on these data, Pfizer continues to explore how to further characterize the clinical profile of UK 453,061 with longer-term phase II studies. Data Presentations on Selzentry New data that were presented from the ongoing Selzentry clinical program reinforce its sustained efficacy and tolerability in treatment-experienced adults infected with CCR5-tropic HIV-1. A combined 48-week analysis of the MOTIVATE 1 and 2 trials shows that nearly three times as many patients receiving Selzentry in addition to an optimized background regimen achieved undetectable levels of virus compared with those receiving an optimized regimen alone. A subanalysis from the 48-week results of the MERIT trial, which was conducted in treatment-naïve patients, was also presented. The analysis suggests that Selzentry may have minimal impact on lipid profiles and is at least lipid neutral compared with efavirenz in this patient population. Additional data examining the pharmacology of Selzentry in the female genital tract and treatment failures on Selzentry in the MOTIVATE and MERIT trials were also presented during CROI. In 2007, Selzentry / Celsentri was approved in the U.S., the EU, and other regions as the first in a new class of oral HIV medicines in over a decade. In the U.S., Selzentry is indicated for combination antiretroviral treatment of adults infected with only CCR5-tropic HIV-1 detectable, who have evidence of viral replication and have HIV-1 strains resistant to multiple antiretroviral agents. Pfizer is committed to bringing meaningful improvement to the lives of people living with HIV/AIDS and those at risk around the world. This commitment is embodied in Pfizer’s products, partnerships, pipeline and philanthropy. Important Safety Information Selzentry does not cure HIV infection or AIDS, and does not prevent passing HIV to others. Although there was no overall increase in serious liver function test abnormalities in patients treated with Selzentry, hepatotoxicity has been reported with Selzentry use. Evidence of a systemic allergic reaction (e.g., pruritic rash, eosinophilia or elevated IgE) prior to the development of hepatotoxicity may occur. Patients with signs or symptoms of hepatitis or allergic reaction following use of Selzentry should be evaluated immediately. The safety and efficacy of Selzentry have not been specifically studied in patients with significant underlying liver disorders. However, caution should be used when administering Selzentry to patients with pre-existing liver dysfunction or who are co-infected with viral hepatitis B or C. In clinical studies, more cardiovascular events, including myocardial ischemia and/or infarction, were observed in patients who received Selzentry as compared to placebo. Selzentry should be used with caution in patients at increased risk for cardiovascular events. Caution should be used when administering Selzentry in patients with a history of postural hypotension or who receive concomitant medication known to lower blood pressure. Patients should be advised that if they experience dizziness while receiving Selzentry, they should avoid driving or operating machinery. Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. Selzentry antagonizes the CCR5 co-receptor located on some immune cells, and therefore could potentially increase the risk of developing infections and malignancy. For full prescribing information for Selzentry, including boxed warning, go to www.Selzentry.com. For more information on Pfizer’s patient assistance program in the U.S., call 1-888-327-RSVP (7787) or visit the RSVP section of www.PfizerHelpfulAnswers.com. DISCLOSURE NOTICE: The information contained in this release is as of February 6, 2008. Pfizer assumes no obligation to update any forward-looking statements contained in this release as the result of new information or future events or developments. This release contains forward-looking information about two investigational HIV compounds, including their potential benefits, that involves substantial risks and uncertainties. Such risks and uncertainties include, among other things, the uncertainties inherent in research and development; decisions by regulatory authorities regarding whether and when to approve any drug applications that may be filed for such compounds as well as their decisions regarding labeling and other matters that could affect their availability or commercial potential; and competitive developments. A further description of risks and uncertainties can be found in Pfizer’s Annual Report on Form 10-K for the fiscal year ended December 31, 2006 and in its reports on Form 10-Q and Form 8-K.