Orphan drug development: an economically viable strategy for biopharma R&D.

Orphan drug incentives have stimulated research into diseases with significant unmet medical need. Although the targeting of orphan diseases is seen by industry as an attractive strategy, there are limited economic data available to support its use. In this paper we show that the revenue-generating potential of orphan drugs is as great as for non-orphan drugs, even though patient populations for rare diseases are significantly smaller.

HTLV-1 integration into transcriptionally active genomic regions is associated with proviral expression and with HAM/TSP.

Human T-lymphotropic virus type 1 (HTLV-1) causes leukaemia or chronic inflammatory disease in approximately 5% of infected hosts. The level of proviral expression of HTLV-1 differs significantly among infected people, even at the same proviral load (proportion of infected mononuclear cells in the circulation). A high level of expression of the HTLV-1 provirus is associated with a high proviral load and a high risk of the inflammatory disease of the central nervous system known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).

Histone deacetylase inhibitors increase virus gene expression but decrease CD8+ cell antiviral function in HTLV-1 infection.

The dynamics of human T-lymphotropic virus type-1 (HTLV-1) provirus expression in vivo are unknown. There is much evidence to suggest that HTLV-1 gene expression is restricted: this restricted gene expression may contribute to HTLV-1 persistence by limiting the ability of the HTLV-1-specific CD8(+) cell immune response to clear infected cells. In this study, we tested the hypothesis that derepression of HTLV-1 gene expression would allow an increase in CD8(+) cell-mediated lysis of HTLV-1-infected cells.