The market didn't think much of yesterday's announcement by Geron. Perhaps one of our scientifically literate might comment on the significance of this one - thanks in advance:
Geron Announces New Data on the Effects of Its Telomerase Inhibitor Drugs on Multiple Myeloma
Tuesday December 9, 1:01 pm ET
MENLO PARK, Calif.--(BUSINESS WIRE)--Dec. 9, 2003--Geron Corporation (Nasdaq:GERN - News) announced the presentation of additional positive data from studies of its two telomerase inhibitor drug candidates, GRN163 and GRN163L, in animal models of human multiple myeloma. The results were presented at the American Society of Hematology (ASH) annual meeting in San Diego, California, by Eunice Wang, M.D. and Malcolm Moore, Ph.D. of Memorial Sloan-Kettering Cancer Center, lead investigators of the studies and Geron collaborators.
GRN163 Data
In mice bearing disseminated human myeloma that invades the bone marrow much like in human disease, systemic administration of GRN163 resulted in substantially decreased tumor burden and significantly increased survival compared either to a saline control or to the maximum tolerated dose of doxorubicin, a powerful chemotherapy agent. Geron's previously reported data on GRN163 in multiple myeloma involved administration of the drug directly to tumors grafted to the flanks of animals. In the newly reported studies, the human cancer cells were injected into the animals and allowed to disseminate into the bone marrow, spinal cord, kidneys, and elsewhere, as frequently occurs in human patients with multiple myeloma. After tumor dissemination, the drug was administered systemically each day for 30 days. Control animals with similarly disseminated myeloma cancer cells were treated with either a saline control solution or the maximum tolerated dose of doxorubicin, a widely-used chemotherapy agent that the researchers had previously found to be the most effective agent for treating this type of cancer in their animal models. GRN163 treatment decreased tumor burden substantially after seven days compared to either the saline control or doxorubicin, and by 70% after 30 days compared to the saline control (the doxorubicin-treated animals all died within 10 days). GRN163 treatment also increased overall survival by up to 50% compared to the saline control.
GRN163L Data
In a separate series of in vitro and in vivo studies using the same human myeloma tumor cells, GRN163L (formerly called GRN719) showed substantially greater effects on telomerase activity, telomere length, and cancer cell proliferation and apoptosis than GRN163. The researchers also compared GRN163L to GRN163 in the same multiple myeloma line both in vitro and in the mouse model. In vitro, GRN163L decreased telomerase activity to a greater extent than comparable doses of GRN163, and was superior to GRN163 in inducing apoptosis and inhibiting cancer cell growth over two weeks. In the in vivo model, systemically administered GRN163L was also superior to a 67% higher dose of GRN163 in inhibiting telomerase activity (83% vs. 41%) and reducing telomere restriction fragment length (1480 base pairs vs. 50 base pairs) in flank xenografts of multiple myeloma tumors.
Both GRN163 and GRN163L are oligonucleotide drugs that bind to telomerase with high affinity and specificity, and potently inhibit telomerase in cancer cells with little impact on normal cells. They have the same nucleic acid sequence, but GRN163L contains a lipid (a fatty substance) to enhance cellular uptake. The enhancement of cellular uptake means an increase in potency of the drug, which would reduce the doses required to achieve efficacy.
"We are very encouraged by this additional evidence for efficacy of our telomerase inhibitor drugs in treating multiple myeloma," said Thomas B. Okarma, Ph.D., M.D., Geron's president and chief executive officer. "This complements the positive in vivo data previously reported in five other cancer types, including glioblastoma, lymphoma and cancers of the cervix, prostate and liver. We plan to do a head-to-head comparison of GRN163 and GRN163L in the disseminated myeloma model used in these studies, as well as in combination studies with existing cancer drugs. We are also continuing our studies to confirm the safety profile of these compounds." |
