Optimizing Research to Speed Up Availability of Pediatric Antiretroviral Drugs and Formulations.

Globally 1.8 million children are living with human immunodeficiency virus (HIV), yet only 51% of those eligible actually start treatment. Research and development (R&D) for pediatric antiretrovirals (ARVs) is a lengthy process and lags considerably behind drug development in adults. Providing safe, effective, and well-tolerated drugs for children remains critical to ensuring scale-up globally. We review current approaches to R&D for pediatric ARVs and suggest innovations to enable simplified, faster, and more comprehensive strategies to develop optimal formulations. Several approaches could be adopted, including focusing on a limited number of prioritized formulations and strengthening existing partnerships to ensure that pediatric investigation plans are developed early in the drug development process. Simplified and more efficient mechanisms to undertake R&D need to be put in place, and financing mechanisms must be made more sustainable. Lessons learned from HIV should be shared to support progress in developing pediatric formulations for other diseases, including tuberculosis and viral hepatitis.

Meeting the goal of concurrent adolescent and adult licensure of HIV prevention and treatment strategies.

The ability of adolescents to access safe and effective new products for HIV prevention and treatment is optimised by adolescent licensure at the same time these products are approved and marketed for adults. Many adolescent product development programmes for HIV prevention or treatment products may proceed simultaneously with adult phase III development programmes. Appropriately implemented, this strategy is not expected to delay licensure as information regarding product efficacy can often be extrapolated from adults to adolescents, and pharmacokinetic properties of drugs in adolescents are expected to be similar to those in adults. Finally, adolescents enrolled in therapeutic HIV prevention and treatment research can be considered adults, based on US Food and Drug Administration (FDA) regulations and the appropriate application of state law. The FDA permits local jurisdictions to apply state and local HIV/sexually transmitted infection minor treatment laws so that adolescents who are HIV-positive or at risk of contracting HIV may be enrolled in therapeutic or prevention trials without obtaining parental permission.

Ribavirin Reduces Absolute Lymphocyte Counts in Hepatitis C Virus-Infected Patients Treated With Interferon-Free, Direct-Acting Antiviral Regimens.

In clinical trials of interferon-free, direct-acting antiviral treatment of chronic hepatitis C, subjects who received ribavirin had reduced lymphocyte levels (median decline of approximately 0.4-0.5 × 10(9) cells/L). A modest decline in CD4(+) T cells was observed in subjects with human immunodeficiency virus type 1 coinfection without documented opportunistic infections.

Does an increase in serum creatinine always reflect renal injury? The case of Stribild®

Single tablet, once-daily HIV treatment regimens offer patient convenience, the potential for increased adherence, and fewer patient-related dosing errors[1] . Stribild® (manufactured and marketed by Gilead Sciences; referred to as "applicant" in this report), a 4-drug fixed-dose combination (FDC) tablet, is approved for the treatment of HIV-1 infection in treatment-naïve adult patients. Stribild® contains elvitegravir (an integrase strand transfer inhibitor), cobicistat (an inhibitor of cytochrome P450 enzymes), and the nucleoside/nucleotide reverse transcriptase inhibitors emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF).

Extrapolation of adult data and other data in pediatric drug-development programs.

OBJECTIVES: In 1994, the US Food and Drug Administration (FDA) proposed an approach, based on extrapolation of efficacy findings from adults to the pediatric population, to maximize the use of adult data and other data when designing pediatric drug-development programs. We examined the experience of the FDA in using extrapolation to evaluate how and when it was used and any changes in scientific assumptions over time. METHODS: We reviewed 370 pediatric studies submitted to the FDA between 1998 and 2008 in response to 159 written requests (166 products) issued under the Pediatric Exclusivity Provision. We identified cases in which efficacy was extrapolated from adult data or other data, we categorized the type of pediatric data required to support extrapolation, and we determined whether the data resulted in new pediatric labeling. RESULTS: Extrapolation of efficacy from adult data occurred for 82.5% of the drug products (137 of 166). Extrapolation was defined as complete for 14.5% of the products (24 of 166) and partial for 68% of them (113 of 166). Approaches to extrapolation changed over time for 19% of the therapeutic indications studied (13 of 67). When extrapolation was used, 61% of the drug products (84 of 137) obtained a new pediatric indication or extension into a new age group; this number decreased to 34% (10 of 29) when there was no extrapolation. CONCLUSIONS: Extrapolating efficacy from adult data or other data to the pediatric population can streamline pediatric drug development and help to increase the number of approvals for pediatric use.

Ethical and regulatory considerations for the inclusion of adolescents in HIV biomedical prevention research.

Adolescents should be enrolled in ethically appropriate and scientifically rigorous HIV biomedical prevention research involving vaccines, pre-exposure prophylaxis, or microbicides. There is general agreement that children should only be enrolled in a clinical trial if the scientific objectives cannot be met either through enrolling adult subjects who can provide informed consent personally or through conducting research using animal models. In addition, the risks to which children are exposed in a clinical trial without the possibility of direct therapeutic benefit must be low. Children also should not be placed at a disadvantage after being enrolled in a clinical trial by, for example, being exposed to an unnecessarily risky intervention or by failing to receive a comparable treatment that would prevent significant morbidity or mortality. In light of this shared framework, we discuss the timing of enrolling adolescents in HIV prevention trials; some general study design considerations that may be necessary for adequate labeling of products for an adolescent indication; the use of data obtained from international studies for licensure applications in the United States; the role of parental permission and adolescent assent to research participation; and the inclusion of pregnant adolescents in HIV biomedical prevention research.