NCT06150157 · Janssen Research & Development, LLC
A Study of JNJ-88549968 for the Treatment of Calreticulin (CALR)-Mutated Myeloproliferative Neoplasms
What this study is about
The purpose of this study is to characterize safety and to determine the Recommended Phase 2 Dose (RP2D\[s\]) and optimal dosing schedule(s) of JNJ-88549968 in part 1 (gradually increasing doses); to characterize the safety of JNJ- 88549968 at RP2D(s) in part 2 (group of participants Expansion). For U.S.
View original scientific description
The purpose of this study is to characterize safety and to determine the Recommended Phase 2 Dose (RP2D\[s\]) and optimal dosing schedule(s) of JNJ-88549968 in part 1 (Dose Escalation); to characterize the safety of JNJ- 88549968 at RP2D(s) in part 2 (Cohort Expansion). For U.S. sites: the purpose of this study is to characterize the safety and to determine the RP2D(s) and optimal dosing schedule(s) of JNJ-88549968 in Part 1 and part 1b (Dose Escalation), and to characterize the safety of JNJ-88549968 at the RP2D(s) in Part 2 and part 2b (Cohort Expansion), when given as monotherapy in essential thrombocythemia (ET) or myelofibrosis (MF), and with ruxolitinib or momelotinib in MF only.
Interventions
DRUG
JNJ-88549968
JNJ-88549968 will be administered.
DRUG
Ruxolitinib
For US sites: Ruxolitinib will be administered for participants with MF only.
DRUG
Momelotinib
For US sites: Momelotinib will be administered for participants with MF only.
Primary outcome measures
Part 1, Part 1b (US Only): Number of Participants With Dose Limiting Toxicity (DLT)
Time frame: Approximately up to 35 days after first dose of study treatment
Number of participants with DLT will be reported. The DLTs are specific adverse events and are defined as any of the following: high grade non-hematologic toxicity, or hematologic toxicity. For US only: A DLT is any adverse event attributed to study treatment that meets the criteria for severity and duration and that occurs during the evaluation periods unless it can be incontrovertibly attributed to disease or other extraneous cause such as an accident.
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants with Adverse Events (AEs)
Time frame: Up to 2 years
An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study.
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants with Adverse Events (AEs) by Severity
Time frame: Up to 2 years
An adverse event is any untoward medical occurrence in a clinical study participant that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Severity will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 5.0. Severity scale ranges from grade 1 (mild) to grade 5 (death). Grade 1= mild, Grade 2= moderate, Grade 3= severe, Grade 4= life-threatening and Grade 5= death related to adverse event. Cytokine release syndrome (CRS) and associated neurologic toxicity events (immune effector cell-associated neurotoxicity syndrome events \[ICANS\]) will be graded according to the American Society for Transplantation and Cellular Therapy (ASTCT) guidelines.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Be greater than or equal to (\>=) 18 years of age (or the legal age of majority in the jurisdiction in which the study is taking place, whichever the greater) at the time of informed consent
- Positive for a calreticulin (CALR) driver mutation of essential thrombocythemia (ET) or myelofibrosis (MF)
- Participants with ET and MF with risk characteristics as described in the protocol
- Have an Eastern Cooperative Oncology Group (ECOG) performance status grade of less than or equal to (\<=) 2
- For US sites: Eligible for ruxolitinib therapy as per drug label for participants naive to a janus kinase (JAK) inhibitor
Exclusion criteria
- Known allergies, hypersensitivity, or intolerance to the excipients of the study treatment
- Concurrent or recently diagnosed or treated malignancies present at the time of participant screening. Exceptions are squamous and basal cell carcinoma of the skin, carcinoma in situ of the cervix, and any malignancy that is considered cured or has minimal risk of recurrence within 1 year of first dose of study treatment in the opinion of both the investigator and sponsor's medical monitor. Participants cured of another malignant disease with no sign of relapse greater than or equal to (\>=) 3 years after treatment ended are allowed to enter the study
- Prior solid organ transplantation
- Either of the following regarding hematopoietic stem cell transplantation:
- Prior treatment with allogenic stem cell transplant less than or equal to (\<=) 6 months before the first dose of JNJ-88549968 or
- Evidence of graft versus host disease (GVHD) that requires immunosuppressant therapy
- History of clinically significant cardiovascular disease within 6 months prior to the first dose of study treatment
Where
- Duarte, California
- Aurora, Colorado
- Tampa, Florida
- Atlanta, Georgia
- Ann Arbor, Michigan
- Grand Rapids, Michigan
- East Brunswick, New Jersey
- New York, New York
- The Bronx, New York
- Charlotte, North Carolina
- Philadelphia, Pennsylvania
- Nashville, Tennessee
And 1 more location — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 31, 2026 · Source of record for eligibility and locations