As part of the company's commitment to fight HIV/AIDS, Merck has conducted extensive research and development efforts to bring forth pediatric formulations for its ARVs.

Our commitment extends to ongoing collaborations to help improve access to ARV treatment for children living with HIV in resource-limited settings.

Extensive R&D Efforts for Pediatric Formulations for Merck ARVs

In 2007, Merck began collaborating with NIAID, the National Institute of Child Health and Human Development (NICHD), and the International Maternal, Pediatric, Adolescent AIDS Clinical Trials (IMPAACT) Group, to conduct a Phase I/II, multicenter, open-label, noncomparative study to evaluate the safety, tolerability, pharmacokinetics and antiretroviral activity of ISENTRESS^® (raltegravir) in children and adolescents: IMPAACT P1066. The trial involves HIV-infected children ranging from 4 weeks to 18 years of age in the United States, Latin America and Africa.

This is a study of three formulations: the adult tablet, a chewable tablet and an investigational granule formulation for oral suspension. The study is designed to collect intensive pharmacokinetics and short-term safety data in order to make a dose selection, and also provide data on safety and efficacy at the selected dose with chronic use over 48 weeks. There is a protocol extension to five years. The study was initiated in older children and has sequentially enrolled younger patients.

On the basis of results from this ongoing study (IMPAACT P1066), in December Merck gained FDA approval of ISENTRESS for use in children 2 to 18 years of age who weigh at least 10 kg (the chewable formulation for ages 2 to 11 years (based on age and weight) and the film-coated tablet for ages 6 to 18). Through this study, a second pediatric formulation (oral granules for suspension) in children less than 2 years of age is being evaluated.

Also in collaboration with IMPAACT, one study in neonates is ongoing (examining raltegravir levels in infants born to mothers who have taken raltegravir in pregnancy) and another study of active raltegravir dosing to neonates is in development, which aims to define the safety and appropriate dose for neonates at risk for acquiring HIV infection. Merck is dedicated to continuing the work necessary to obtain regulatory approval for the oral granules for suspension pediatric formulation of ISENTRESS.

STOCRIN^® (efavirenz) is indicated for the treatment of HIV-1 infection and has pediatric indications for patients ages 3 to 17 years in many countries, particularly in the developing world. For many of the countries, for which Merck has the right to distribute STOCRIN under our agreement with Bristol-Myers Squibb, we are currently marketing four formulations: STOCRIN oral solution, STOCRIN 50mg, STOCRIN 200mg and STOCRIN 600mg tablets.

CRIXIVAN^® (indinavir) is indicated for the treatment of HIV-1 infection and has pediatric indications in some countries. CRIXIVAN has not been evaluated in children under 3 years of age.

Working to Improve Access in Resource-Limited Settings

Merck is also working in partnership with the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) Partnership for Pediatric AIDS Treatment to identify scientific and technical solutions to improve access to ARV treatment for children living with HIV in resource-limited settings. Participating in this effort are the U.S. government, multilateral organizations such as the United Nations Children's Fund (UNICEF) and the United Nations Joint Programme on HIV/AIDS (UNAIDS), research-based pharmaceutical companies and generic-drug companies. The partners have committed to work toward identifying scientific obstacles to treatment, share best practices and take concrete, practical steps to address barriers to access.