Species-specific inflammatory responses as a primary component for the development of glomerular lesions in mice and monkeys following chronic administration of a second-generation antisense oligonucleotide.

Chronic administration of drisapersen, a 2'-OMe phosphorothioate antisense oligonucleotide (AON) to mice and monkeys resulted in renal tubular accumulation, with secondary tubular degeneration. Glomerulopathy occurred in both species with species-specific characteristics. Glomerular lesions in mice were characterized by progressive hyaline matrix accumulation, accompanied by the presence of renal amyloid and with subsequent papillary necrosis. Early changes involved glomerular endothelial hypertrophy and degeneration, but the chronic glomerular amyloid and hyaline alterations in mice appeared to be species specific. An immune-mediated mechanism for the glomerular lesions in mice was supported by early inflammatory changes including increased expression of inflammatory cytokines and other immunomodulatory genes within the renal cortex, increased stimulation of CD68 protein, and systemic elevation of monocyte chemotactic protein 1. In contrast, kidneys from monkeys given drisapersen chronically showed less severe glomerular changes characterized by increased mesangial and inflammatory cells, endothelial cell hypertrophy, and subepithelial and membranous electron-dense deposits, with ultrastructural and immunohistochemical characteristics of complement and complement-related fragments. Lesions in monkeys resembled typical features of C3 glomerulopathy, a condition described in man and experimental animals to be linked to dysregulation of the alternative complement pathway. Thus, inflammatory/immune mechanisms appear critical to glomerular injury with species-specific sensitivities for mouse and monkey. The lower observed proinflammatory activity in humans as compared to mice and monkeys may reflect a lower risk of glomerular injury in patients receiving AON therapy.

The thalidomide disaster, lessons from the past.

It is close to 60 years since thalidomide was created by the German company, Chemie-Grünenthal, and launched as "Contergan." This was soon to be followed in England by the launch of "Distaval." Of all the drugs developed in the intervening years, thalidomide has undoubtedly had the greatest influence on shaping the Pharmaceutical Industry as we know it today.Strong marketing pressure in an Industry hungry for new medicines brought an inadequately tested drug to the market, targeted outsourcing quickly expanded the client base and finally market forces prevented timely withdrawal, even when evidence was emerging of disastrous side-effects. The full story of thalidomide was told by the Sunday Times in "Suffer The Children" (Kingsley et al., Suffer the children: the story of thalidomide, the insight team of the Sunday times (UK), 1979).Many preventative measures have been taken in the intervening years in light of the lessons learned with thalidomide. However, many of the pressures that led to the thalidomide disaster exist today with record high management and shareholder pressures to achieve success, parallel worldwide marketing, increased numbers of targeted outsourcing by small companies forming alliances with "Big Pharma" and, according to some commentators, a breakdown in the system of checks and balances that have existed in the regulatory authorities in the intervening years.Using thalidomide as a point of reference, this chapter looks at drug development and testing, regulatory authorities and guidelines, outsourcing and in-licensing, pharmacovigilance, and factors that influence withdrawal of a drug from the market.