First New Oral Class of HIV Medicine in Over a Decade Launched Today
19 November 2007
Pfizer’s Celsentri® (maraviroc) now available for UK treatment of experienced HIV patients
Pfizer’s Celsentri® (maraviroc), an important new HIV medicine and the first new oral class of HIV treatment in more than a decade, has today been made available for treatment experienced patients in the UK. Discovered and developed by Pfizer scientists in Sandwich, Kent, maraviroc represents a significant innovation in the treatment of HIV infection.
Maraviroc was licensed by the European regulator, the European Agency for the Evaluation of Medicinal Products (EMEA) in September 2007(1).
Maraviroc works in an entirely new way. It is the first in a new class of HIV medicines called CCR5 antagonists (see notes to editors) and is licensed for treatment experienced patients infected with only CCR5-tropic HIV-1 (in combination with other antiretroviral medicinal products)1. It is the first HIV treatment that works on the body rather than on the virus. Maraviroc works by blocking the virus entry into human immune (CD4) cells, preventing HIV from entering and replicating(2). All other currently available oral HIV medicines work on the HIV virus once it has entered the immune cells.
This development now enables clinicians to build treatment regimens that work on the body and the virus at the same time and target HIV both inside and outside the cell.
Dr David Gillen, Medical Director at Pfizer Limited, comments: “Maraviroc is Pfizer’s pioneering contribution to the fight against HIV / AIDS. It represents cutting edge science and is a significant innovation in the treatment of HIV infection. We are proud of this achievement and will continue to work tirelessly to discover and develop other medicines for difficult to treat diseases”.
Professor Margaret Johnson, Clinical Director HIV/AIDS Services, Royal Free Hospital, London and Chair of the British HIV Association comments: “The introduction of maraviroc is incredibly important for the HIV community. HIV is known to mutate aggressively and some patients become resistant to the treatments available. New drugs and particularly new classes of treatment are fundamental for continued good health.”
In large clinical trials, maraviroc demonstrated significant efficacy, both reducing the levels of virus circulating in the blood stream to undetectable levels and increasing the numbers of immune CD4 cells when added to the standard optimised treatment regimen(1). In addition, maraviroc demonstrated an acceptable tolerability profile; the most commonly reported adverse reactions were diarrhoea, nausea and headache(1) (see notes to editors for further information on clinical trial data).
Notes to Editors
About the launch of maraviroc
Following authorisation from the EMEA in September 2007, Pfizer has today made maraviroc available for treatment experienced patients living with HIV throughout the UK.
About CCR5 antagonists
CCR5 antagonists form a class in a broader group of HIV antiretrovirals known as entry inhibitors. Rather than fighting HIV inside CD4 immune cells, CCR5 antagonists are designed to prevent the virus entering uninfected cells2.
About maraviroc clinical trial data
Pooled results from the multicenter, double-blind, placebo-controlled phase 3 clinical trials MOTIVATE 1 (Maraviroc Plus Optimized Therapy in Viremic Antiretroviral Treatment Experienced Patients) and MOTIVATE 2 showed that at 48 weeks1.
· Approximately twice the percentage of patients who were treated with maraviroc 300mg twice daily plus optimised background therapy (OBT) achieved undetectable viral loads (<50 copies/mL HIV RNA) compared with those receiving placebo plus OBT (45.5% versus 16.7%, respectively, p<0.0001) · Patients receiving maraviroc 300mg twice daily with OBT had a mean increase in CD4 cells, which was significantly higher than that of patients receiving placebo plus OBT (124 cells/mm3 versus 61 cells/mm3, p<0.0001) · The group receiving maraviroc 300mg twice daily plus OBT had a low rate of discontinuation due to adverse events, similar to the group receiving OBT plus placebo · The reported frequencies for the most commonly experienced adverse events were similar in patients receiving maraviroc 300mg twice daily plus OBT compared to those receiving OBT plus placebo · In the MOTIVATE 1 and MOTIVATE 2 trials, patients were randomised to receive OBT combined with either placebo or maraviroc dosed once or twice daily. OBT included 3-6 antiretrovials, with or without low-dose ritonavir · MOTIVATE 1: clinical investigations sites in the USA and Canada3 · MOTIVATE 2: clinical investigations sites in Europe, Australia and North America4 Pfizer is also currently studying the use of maraviroc in treatment naive patients – who have never received any HIV anti-retroviral treatment – in the ongoing MERIT study5.
References
1. Celsentri Summary of Product Characteristics. September 2007 2. Dorr P, Westby M, Dobbs S et al. Maraviroc (UK-427,857), a potent, orally bioavailable, and selective small-molecule inhibitor of chemokine receptor CCR5 with broad-spectrum anti-human immunodeficiency virus Type 1 activity. Antimicrobial Agents Chemotherapy 2005;49:4721-32 3. Jacob Lalezari, James M Goodrich, Edwin DeJesus, et al. Efficacy and Safety of Maraviroc plus Optimized Background Therapy in Viremic, ART-Experienced Patients Infected With CCR5-tropic HIV-1: 24-Week Results of a Phase 2b/3 Study in the USA and Canada (MOTIVATE 1). CROI 2007 4. Nelson M, Fätkenheuer G, Konourina I, et al. Efficacy and Safety of Maraviroc (MVC) Plus Optimized Background Therapy (OBT) in Viremic, Antiretroviral Treatment Experienced Patients Infected with CCR5-Tropic (R5) HIV-1 in Europe, Australia and North America (MOTIVATE 2): 24-Week Results. CROI 2007 5. Saag M, Ive P, Heera J et al. A multicenter, randomized, double-blind, comparative trial of a novel CCR5 antagonist, maraviroc versus efavirenz, both in combination with Combivir (zidovudine [ZDV]/ lamivudine [3TC]), for the treatment of antiretroviral naive subjects infected with R5 HIV-1: week 48 results of the MERIT study. IAS 2007