Stephen M. Kelsey
Analyst · Stifel
Thank you, Olivia. At the end of last year, we reported data from 2 studies in imetelstat and hematologic malignancies, in a central thrombocythemia and in multiple myeloma. I'd like to start by briefly mentioning the data from the multiple myeloma study. We designed this study to directly measure the effect of imetelstat on malignant progenitor cells to provide evidence that imetelstat can impact the malignant cells responsible for driving myeloma. Preliminary data, which were reported in the ASH supplements of blood, showed a rapid and significant decrease in myeloma progenitor cells that were detected in the blood over the course of imetelstat treatment in 8 out of 9 patients. In addition, several patients experienced delayed but sustained clinical responses as measured by standard criteria. The trial is no longer enrolling patients, and we expect the full clinical data from all patients enrolled in the multiple myeloma trial will be available in 2013. We are currently not prioritizing further development of imetelstat in lymphoid malignancies and have no plans for further development in multiple myeloma. Data from the Phase II study in essential thrombocythemia were presented at the 2012 Annual Meeting of the American Society for Hematology in December. Top line results were reported from the first 14 patients enrolled in the study, all of whom were refractory to or intolerant of standard therapies. The rate of cancer were reduced in all patients producing a 100% hematologic response rate, and 13 of the 14 patients achieved a complete hematologic response with normalized platelet counts. Among the 7 patients who had a JAK2 V617F mutation, the molecular response rate was 86% and responses were achieved within 3 to 6 months after beginning treatment with imetelstat. As we saw in the multiple myeloma trial, the ET data suggests a relatively selective inhibition of the malignant progenitor cells responsible for the disease. In the ET study, imetelstat was initially administered weekly by intravenous infusion during an induction phase. After achieving a complete hematologic response, which occurred in a median time of approximately 6 weeks, a maintenance phase was begun in which dosing frequency was modified based on a patient's individual response profile, generally decreasing with time. The responses observed have been durable. All patients who achieved a complete hematologic response remained on therapy, including 6 for more than 1 year. I can also add that one patient has just begun year 3 on the study. The last patient enrolled in December has just begun dosing. Median time on the study is currently approximately 33 weeks. As of the latest data cut for safety from the first 16 patients in the trial, long-term administration of imetelstat was generally well-tolerated. Of those 16 patients, 15 patients remained in the trail and no patients have discontinued due to adverse events. The majority of the non-hematologic adverse events were mild to moderate in severity, with the most frequently reported being gastrointestinal events, infections, muscular and joint pain and fatigue. Infections appear to be increased in incidence, although without a comparator arm, it is difficult to assess this accurately. Most infections were considered grade 1 to 2 or mild to moderate in severity, and all were managed easily with conventional therapies. No drug-related non-hematologic grade 4 adverse events were reported. Neutropenia was the most frequently observed hematologic abnormality. Two patients had grade 4 neutropenia and no cases febrile neutropenia were reported. No patients with grade 4 neutropenia had a concurrent infection. One suspected thromboembolic event, which was assessed as not being related to imetelstat, has been reported. No bleeding events associated with thrombocytopenia were reported. At least one abnormal liver function test was observed in most patients. The majority were grade 1 or 2 elevations in ALT or AST. Reversible grade 2 to 3 elevations in ALT, with grade 1 to 3 elevations in AST were observed in 4 patients within a few weeks of starting imetelstat. These abnormalities resolve and did not reoccur with ongoing imetelstat treatment. With longer dosing, grade 1 increases in alkaline phosphatase were observed in 7 patients, associated with mostly grade 1 and in some cases, grade 2, unconjugated hyperbilirubinemia in 4 of the patients. The etiology of this is unclear and is currently being further investigated. The ET study was closed to new patients enrollment in December last year when we determined that we have sufficient number of patients to be confident of the hematologic and molecular response data that we had observed and reported at ASH. A total of 20 patients have been enrolled in the trial, which includes 18 patients with ET and 2 patients with polycythemia vera. Patients on the study may continue to receive imetelstat for up to 3 years according to the study protocol. We expect to report periodic updates from the study at future scientific meetings. Most ET patients are served well with currently available therapies. The purpose of the study in ET was to provide proof of concept for the potential use of imetelstat as a treatment for various other hematologic myeloid malignancies, including myelofibrosis, myelodysplastic syndromes and acute myeloid leukemia. However, the ET data exceeded our expectations, and we are currently working with expert advisers to assess whether there is any potential for the further development of imetelstat in ET. Based on the results in ET, Dr. Ayalew Tefferi at the Mayo Clinic, who is an expert in myeloproliferative neoplasms has begun an investigator-sponsored trial to evaluate safety and efficacy of imetelstat in patients with myelofibrosis and to determine the dose and schedule for further trials in this indication. Myelofibrosis is a myeloproliferative neoplasm in the same spectrum of diseases as ET. Patients with myelofibrosis often carry the JAK2 V617F mutation in their bone marrow. Occasionally, ET evolves into myelofibrosis. JAK inhibition is currently considered the standard of care for myelofibrosis in countries where ruxolitinib, a JAK inhibitor, is approved. There is no evidence that JAK inhibitors selectively inhibit proliferation of the leukemic clone responsible for the disease and thus, they may not be disease-modifying. The Mayo Clinic trial is evaluating the safety and efficacy of imetelstat in patients with myelofibrosis and determining the optimal dose and schedule for further evaluation. It is an open-label trial in intermediate or high-risk patients with primary or secondary myelofibrosis and may enroll up to 29 patients. Patients receive imetelstat by intravenous infusion over 2 hours, every 21 days. The primary endpoint of this trial is overall response rate measured by a criteria such as clinical improvement, partial remission or complete remission according to international working group criteria. The secondary endpoints include reduction of spleen size, transfusion independence, safety and tolerability. The Mayo Clinic is enrolling and dosing both JAK inhibitor-naive patients and patients who have previously been treated with one or more JAK inhibitors. If no safety or tolerability issues are observed, dose escalation will be considered. We are in the initial planning stages of a Geron-sponsored trial of imetelstat in myelofibrosis, which will be informed by data from the Mayo Clinic trial, if positive. In addition, we intend to expand our directed program of investigator-sponsored trials in 2013 to other hematologic myeloid indications, such as acute myeloid leukemia and myelodysplastic syndromes. Turning to the non-small cell lung cancer study. In September, we reported an unplanned interim analysis of our randomized Phase II trial in advanced non-small cell lung cancer, evaluating imetelstat as maintenance treatment following platinum-based induction chemotherapy compared to observation. The analysis suggested a modest trend of efficacy in favor of the imetelstat arm. Subsequently, in December, we reported the analysis of a prespecified subgroup of non-small cell lung cancer based on a retrospective measurement of tumor telomere length. This analysis suggested that patients whose tumors had short telomeres at baseline experienced an increase in progression-free survival when treated with imetelstat in comparison to patients in the control arm. The treatment effect was not observed in imetelstat-treated patients whose tumors had medium-to-long telomeres. We have been refining and evaluating candidate assays to prospectively measure telomere length in individual patient tumor samples. We recently completed an updated analysis that included a more mature follow-up of the clinical data and a retest of patient tumor samples using the refined prospective assay to measure tumor telomere length. In this updated analysis, the magnitude of the treatment effect in patients whose tumors have short telomeres was not reproduced. We are evaluating the impact of this updated analysis on our plans for the potential development of imetelstat in solid tumors, including non-small cell lung cancer. Data from the non-small cell lung cancer trial have been accepted for presentation at the American Association for Cancer Research annual meeting to be held in April of this year. We have also begun the process of screening tumor banks to identify other solid tumor types where a significant number of patients have tumors with short telomeres. This may help us understand the potential for imetelstat in the treatment of solid tumors outside of non-small cell lung cancer. I will now turn the call back to Chip.