Concluding remarks

t is perhaps surprising that only one patent has been granted in the United States in this area. Identification and isolation of stem cells, such as hematopoietic, embryonic, and tissue-specific stem cells, has been a fertile area of scientific pursuit for many years. Moreover, many patents have been granted for markers of stem cells, methods of isolation, methods of propagating, and uses of stem cells. With the cloning of telomerase in 1997 – 10 years ago – and the discovery that telomerase is active in stem cells, it would seem a natural progression to attempt to increase the longevity of stem cells in culture by transforming the cells with an exogenous telomerase gene.

While it might appear that freedom-to-operate is readily available in this area, caution is warranted. Besides any patents that claim some aspect of stem cells, use of the sequences encoding wild-type telomerase, related molecules and splice variants is governed by the patents granted on this subject matter. Geron’s major position could be seen as a barrier to entry for commercial entities, unless Geron licenses its intellectual property. On the other hand, patents claiming splice variants of telomerase is in the hands of CAMBIA, an organization that historically has licensed its intellectual property. The splice variants exhibit a range of activities, including addition of nucleotides to telomeres and inhibition of endogenous telomerase activity. For those seeking to develop a commercial product in which human telomerase is used, a careful choice of the telomerase sequence along with a license to use and a legal opinion regarding its use is a necessary avenue of pursuit.