Imetelstat Development in Solid Tumors Associated with Short Telomeres
MENLO PARK, Calif., December 3, 2012
"Published non-clinical data have demonstrated that tumor cells with short telomeres are more sensitive to telomerase inhibition with imetelstat than tumor cells with longer telomeres. To evaluate this hypothesis clinically, Geron included a pre-specified sub-group analysis of results by tumor telomere length in its randomized Phase 2 trial of imetelstat in non-small cell lung cancer. In September 2012, Geron reported that an unplanned interim safety and efficacy analysis of the data from that trial suggested a modest but not statistically significant trend in progression-free survival in favor of the imetelstat treatment arm in the overall study population (hazard ratio = 0.78). However, the pre-specified sub-group analysis suggested that imetelstat-treated patients whose tumors had short telomeres at baseline experienced a clinically meaningful, statistically significant increase in progression-free survival compared to patients in the control arm (n = 19; hazard ratio = 0.32; p = 0.042), which was not observed in imetelstat-treated patients whose tumors had medium-to-long telomeres (n = 38; hazard ratio = 0.83; p = 0.62). The company expects to present the data from the full sub-group analysis at a scientific conference in 2013. The company is working on a refined assay to prospectively measure telomere length in individual patient tumor samples, which would be required if Geron conducts a Phase 3-enabling clinical study of the effect of imetelstat in patients with solid tumors that have short telomeres."