Biomedical Engineering Reference
In-Depth Information
Other concerns about the safety of hESC-derived products include
the possibility of an immune reaction from allogeneic donor material
(Hentze et al., 2007).
One of the core issues around efficacy of hESC treatment is the
question of how success in treatment is to be determined. It seems
self-evident in some ways that success would mean to be cured, yet
the criterion for efficacy is actually more ambiguous than it might
appear. As discussed previously, emerging patient accounts from
people who undertake stem cell treatments in places like India and
China, for example, show that success can amount to something as
simple as small improvements in day-to-day functioning (Petersen,
2010). For the FDA approved studies, efficacy means improved
clinical indicators, yet this does not explain how much improvement
would have to be registered for the trial to be recognized as being
successful.
Early-phase clinical trials are argued to be effectively an experiment
(Cooper, 2011). The clinical trials being pursued by Geron (until
recently) and Advanced Cell Technology for hESC-based treatments
have no known comparisons and until the outcomes of these trials
have been established, the safety of hESC treatments in humans
remains largely conjectural. Moreover, any adverse event in such
high-profile trials as these has the potential to set back the commercial
development of hESC-derived therapies significantly. The death of
university student Jesse Gelsinger in 1999 as a result of participating
in a clinical trial was a major blow for the development of gene
therapy, with some concern that enough similar factors exist in the
hESC field that might result in the same outcome for stem cell research
(Wilson, 2009). As yet, however, the future remains undetermined.
5.2.1 Geron
The Geron clinical trial was originally approved by the FDA in
January 2009 (Pollack, 2009). The trial was then suspended temporarily
after some concerns with the animal models, but was finally allowed
to start in July 2010 (Pollack, 2010). Geron had approval to conduct
a Phase I safety study of the use of an hESC-derived product for the
