MENLO PARK, CA, USA I September 16, 2015 I Geron Corporation (Nasdaq: GERN) today announced the dosing of the first patient in a Phase 2 clinical trial to evaluate imetelstat in patients with myelofibrosis (MF). This clinical trial, also referred to as the IMbarkTM study, is being conducted by Janssen Biotech, Inc. (Janssen), under the terms of the exclusive worldwide imetelstat license and collaboration agreement between the companies.

Phase 2 Clinical Trial Design

The purpose of the Phase 2 clinical trial is to assess the efficacy, safety and tolerability of two dose levels of single-agent imetelstat in patients with MF. The trial is designed to enroll approximately 200 patients (approximately 100 patients per dosing arm) with DIPSS intermediate-2 or high risk MF who have relapsed after or are refractory to Janus Kinase (JAK) inhibitor treatment. At the time of enrollment, patients must have measurable splenomegaly and symptoms of MF. Patients will be assigned randomly on a blinded basis on a 1:1 ratio to one of two dosing arms – 9.4 mg/kg every three weeks or 4.7 mg/kg every three weeks. Dose reductions for adverse events are allowed and will follow protocol-specified algorithms. An interim review of data from the trial is planned after approximately 20 patients per arm have been randomized and followed for at least 12 weeks, in order to assess the adequacy of one or both of the initial dosing arms. As a result of this interim review, one or both dosing arms could continue as planned, be stopped or modified, or alternative doses could be selected.

The co-primary efficacy endpoints for the trial are spleen response rate and symptom response rate. Spleen response rate is defined as the percentage of patients who achieve ≥ 35% reduction in spleen volume from baseline at the Week 24 visit, as measured by imaging scans and assessed at a central imaging facility and by an Independent Review Committee. Symptom response rate is defined as the percentage of patients who have ≥ 50% reduction in Total Symptom Scores from baseline at the Week 24 visit, based on patient-reported outcomes on a modified Myelofibrosis Symptom Assessment Form version 2.0 electronic diary. The primary efficacy analysis of the co-primary endpoints will occur after all treated patients have been followed for at least 24 weeks.

Secondary efficacy endpoints include the number of patients achieving complete remission (CR) or partial remission (PR), clinical improvement (CI), and anemia, spleen and symptom responses as assessed using the modified 2013 International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) criteria. These secondary endpoints will be assessed at the time of the primary efficacy analysis. Exploratory endpoints include cytogenetic and molecular responses, as well as leukemia-free survival.

Safety outcomes will be monitored throughout the trial and will include enhanced data collection and reporting for adverse events of interest, including hepatobiliary-associated laboratory findings and hepatic adverse events.

Multiple medical centers across North America, Europe and Asia are planned to participate in the trial. For more information about the IMbarkTM study being conducted by Janssen, please visit http://clinicaltrials.gov/ct2/show/NCT02426086.

About Imetelstat

Imetelstat (GRN163L; JNJ-63935937) is a potent and specific inhibitor of telomerase that is administered by intravenous infusion. This first-in-class compound, discovered by Geron, is a specially designed and modified short oligonucleotide, which targets and binds directly with high affinity to the active site of telomerase. Preliminary clinical data suggest imetelstat has disease-modifying activity by inhibiting the progenitor cells of the malignant clone associated with hematologic malignancies in a relatively select manner. Most commonly reported adverse events in imetelstat clinical studies conducted to date include fatigue, gastrointestinal symptoms and cytopenias. Patients in these studies also experienced elevated liver enzymes, which resolved to normal or baseline in the majority of patients followed after imetelstat treatment was withdrawn. Imetelstat has not been approved for marketing by any regulatory authority.

About the Collaboration with Janssen

On November 13, 2014, Geron entered into an exclusive worldwide license and collaboration agreement with Janssen to develop and commercialize imetelstat for oncology, including hematologic myeloid malignancies, and all other human therapeutics uses. Under the terms of the agreement, Geron received an upfront payment of $35 million and is eligible to receive additional payments up to a potential total of $900 million for the achievement of development, regulatory and commercial milestones, as well as royalties on worldwide net sales. Certain regulatory, development, manufacturing and promotional activities are being managed through a joint governance structure, with Janssen responsible for these activities.

About Geron

Geron is a clinical stage biopharmaceutical company focused on the collaborative development of a first-in-class telomerase inhibitor, imetelstat, in hematologic myeloid malignancies. For more information about Geron, visit www.geron.com.

SOURCE: Geron