A Phase 1 interventional study of Imetelstat sodium and Ruxolitinib in Myelofibrosis, sponsored by Geron Corporation. Active, not recruiting at 6 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-26.
Sponsored by Geron Corporation · Phase 1, Interventional, and Treatment
The purpose of the study is to identify the recommended Part 2 dose (R2PD) of imetelstat sodium in combination with ruxolitinib in participants with myelofibrosis (MF) in Part 1, and to evaluate the safety and preliminary clinical activity of the R2PD of imetelstat sodium in combination with ruxolitinib in participants with MF in Part 2.
625 studies on the registry are indexed under Primary Myelofibrosis; 124 are open to participants now.
This study's enrollment of 30 is below the median of 43 across 489 interventional studies indexed under Primary Myelofibrosis.
Browse Primary Myelofibrosis studies →Geron Corporation is the lead sponsor of 16 studies on the registry; none are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Candidate for ruxolitinib treatment:
Active symptoms of MF on the MFSAF v4.0 demonstrated by:
Exclusion Criteria:
Diagnosis or treatment for other than MF, except:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants who have received ruxolitinib orally (PO) as part of standard of care (SOC) for at least 12 weeks prior to Screening will be enrolled. After enrollment, participants will initiate imetelstat sodium therapy. Dose levels of imetelstat sodium may include 4.7, 6, 7.5, 9.4 mg/kg, until a RP2D is established.
Drug: Imetelstat sodium · Drug: Ruxolitinib
Cohort A: Janus Kinase (JAK) inhibitor naive participants will receive initial treatment with ruxolitinib on study for at least 12 weeks, including 4 consecutive weeks at a stable dose, prior to the addition of imetelstat sodium. Participants can begin imetelstat sodium treatment after sponsor review and approval and meet the following requirements: platelet value is ≥75 x 10\^9/L for two consecutive measurements, at least 1 week apart, and the participant does not meet criteria for dose delay. Note that the study will no longer recruit participants into Cohort A. Cohort B: Participants will receive treatment with ruxolitinib for 12 weeks with at least 4 consecutive weeks at a stable dose prior to enrollment and will start combination treatment with imetelstat on study.
Drug: Imetelstat sodium · Drug: Ruxolitinib
Imetelstat sodium will be administered as intravenous (IV) every 28 days.
Also known as: GRN163L
Ruxolitinib will be administered, orally (PO), twice daily (BID) in cohort B as the standard of care per local prescribing guidelines.
Part 1: Incidence, Type, and Severity of Adverse Events, Including Dose-limiting Toxicity (DLT) During the DLT Observation Period and/or Study Treatment
Time frame: 28 days after first dose
Part 2: Number of Participants With Treatment-emergent Adverse Event (AE)
Safety will be assessed based on incidence and severity (according to Common Terminology Criteria for Adverse Events) of treatment emergent adverse events from the first dose of study treatment until 30 days after completion of treatment.
Time frame: First dose of study treatment until 30 days after the last dose of study treatment (up to approximately 5 years)
Part 2: Symptom Response Rate at Week 24
Symptom response rate is defined as percentage of participants with \>=50% reduction in the Total Symptom Score (TSS) measured by the Myelofibrosis Symptom Assessment Form (MFSAF) v4.0 e-diary at 24 week compared to baseline.
Time frame: Week 24
Part 1: Pharmacokinetic Profile of Ruxolitinib (Maximum Observed Plasma Concentration [Cmax]
Time frame: From first dose of Ruxolitinib treatment up to approximately 5 years
Part 1: Pharmacokinetic Profile of Ruxolitinib Time to Reach Maximum Plasma Concentration [Tmax])
Time frame: From first dose of imetelstat treatment up to approximately 5 years
Part 1 and Part 2: Pharmacokinetic Profile of Imetelstat Sodium Maximum Observed Plasma Concentration [Cmax]
Time frame: From first dose of imetelstat treatment up to approximately 5 years
Part 1 and Part 2: Pharmacokinetic Profile of Imetelstat Time to Reach Maximum Plasma Concentration [Tmax])
Time frame: From first dose of imetelstat treatment up to approximately 5 years
Part 1 and Part 2: Percentage of Participants with Anti-imetelstat Antibodies
Time frame: From first dose of imetelstat treatment up to approximately 5 years
Part 1: Symptom Response at Week 24
Symptom response rate is defined as percentage of participants with \>50% reduction in the TSS measured by the MFSAF v4.0 e-diary at 24 week compared to baseline.
Time frame: Baseline, Week 24
Part 1 and Part 2: Absolute Change From Baseline in TSS at Week 24
Absolute change is defined as change in total symptom score from baseline to week 24 as measured by the MFSAF v4.0 e-diary.
Time frame: Baseline, Week 24
Part 1 and Part 2: Average Absolute Change in TSS Over 24 weeks
Average absolute change in TSS is defined as change in the average of absolute change in total symptom score from week 1(baseline) to week 24 as measured by the MFSAF v4.0 e-diary.
Time frame: Baseline, Week 24
Part 1 and Part 2: Spleen Response at Week 24
Spleen response is the proportion of participants who achieve a reduction in spleen volume of ≥35% from baseline confirmed by magnetic resonance imaging (MRI) or computed tomography (CT).
Time frame: Week 24
Part 1 and Part 2: Progression Free Survival (PFS)
The time interval from start of study treatment date to the first date of disease progression or death from any cause, whichever occurs first.
Time frame: From start of study treatment date to the disease progression or death (up to approximately 5 years)
Part 1 and Part 2: Percentage of Participants With Complete Remission (CR), Partial Remission (PR), Clinical Improvement (CI) Per the Modified 2013 International Working Group - Myeloproliferative Neoplasms Research and Treatment (IWG-MRT) Criteria.
Time frame: From first dose to end of the treatment (up to approximately 5 years)
Part 1 and Part 2: Time to Response
Time to response was defined as the duration from first dose of study treatment to the earliest date that a response is first documented. The response CI/CR/PR was assessed by IWG-MRT criteria.
Time frame: From first dose of study treatment to the earliest date that a response was first documented (Up to approximately 5 years)
Part 1 and Part 2: Duration of Response (DOR) Per IWG-MRT Criteria
DOR measured from time of initial response (CR/PR/CI) until documented PD or death whichever occurs first.
Time frame: From time of initial response to PD or death whichever occurs first (up to approximately 5 years)
Part 1 and Part 2: Reduction of Bone Marrow Fibrosis
Reduction of bone marrow fibrosis is defined as the percentage of participants with a post-baseline bone marrow fibrosis degree smaller than the baseline fibrosis degree prior to start of subsequent anticancer therapy.
Time frame: From first dose to end of the treatment (up to approximately 5 years)
Part 1 and Part 2: Time to Progression to Acute Myeloid Leukemia (AML)
Time to progression to AML, defined as the time interval from the start of study treatment date to the first date of documented progression to AML or death from any cause, whichever occurs first.
Time frame: From first dose to end of the treatment (up to approximately 5 years)
Plan to share: No
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This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Imetelstat · Ruxolitinib
Geron Corporation