A Phase 1 interventional study of JNJ-88549968 and Ruxolitinib in Neoplasms, sponsored by Janssen Research & Development, LLC. Recruiting at 46 sites in 10 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Janssen Research & Development, LLC (part of Johnson & Johnson) · Phase 1, Interventional, and Treatment
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.
10,818 studies on the registry are indexed under Neoplasms; 2,324 are open to participants now.
This study's planned enrollment of 300 is above the median of 60 across 7,703 interventional studies indexed under Neoplasms.
Browse Neoplasms studies →Janssen Research & Development, LLC is the lead sponsor of 932 studies on the registry; 76 are open to participants now.
Of its 285 completed or terminated interventional studies of FDA-regulated products, 136 (48%) have results posted.
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.
Exclusion Criteria:
Either of the following regarding hematopoietic stem cell transplantation:
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
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.
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.
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
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.
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
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.
GVHD (graft-versus-host disease)
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
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.
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.
In dose escalation (Part 1), participants will receive JNJ-88549968. For myelofibrosis (MF) participants only, the study will explore a Phase 1b cohort in which the janus kinase (JAK) inhibitor ruxolitinib or momelotinib is started in combination with JNJ-88549968. The dose will be escalated sequentially to determine the recommended phase 2 dose (RP2D) and optimal dosing schedule (s) based on safety, pharmacokinetic, pharmacodynamic, and preliminary assessment of efficacy across several dose regimens. Additional Cohorts may be added to assess different formulation or delivery methods. In dose expansion (Part 2, Part 2b \[US only\]), participants will receive JNJ-88549968 at the RP2D regimen(s) determined in dose escalation (Part 1, Part 1b \[US only\]).
Drug: JNJ-88549968 · Drug: Ruxolitinib · Drug: Momelotinib
JNJ-88549968 will be administered.
For US sites: Ruxolitinib will be administered for participants with MF only.
For US sites: Momelotinib will be administered for participants with MF only.
Part 1, Part 1b (US Only): Number of Participants With Dose Limiting Toxicity (DLT)
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.
Time frame: Approximately up to 35 days after first dose of study treatment
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants with Adverse Events (AEs)
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.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants with Adverse Events (AEs) by Severity
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.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Serum Concentration of JNJ-88549968
Serum samples will be analyzed to determine concentrations of JNJ-88549968.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants With Presence of Anti-Drug Antibodies to JNJ-88549968
Number of participants with presence of anti-drug antibodies to JNJ-88549968 will be reported.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Overall Response Rate
ORR is defined as the percentage of participants who achieve partial response (PR) and complete response (CR) according to modified International Working Group-Myeloproliferative Neoplasm Research and Treatment (IWG-MRT) criteria and modified European Leukemia Net (ELN) consensus report.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Complete Response (CR) Rate
CR rate is defined as the percentage of participants who achieve a best response of CR according to disease as defined in modified IWG-MRT criteria and modified ELN consensus report.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Time to Response (TTR)
TTR is defined for participants who achieved PR or CR as the time from the first dose of study treatment to first response of PR or CR according to modified IWG-MRT criteria and modified ELN consensus report.
Time frame: Up to 2 years
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Duration of Response (DOR)
DOR is defined for participants who achieved PR or CR as the time between the date of initial documentation of PR or CR to the date of first documented evidence of disease progression, as defined in modified IWG-MRT criteria and modified ELN consensus report, or death, whichever comes first.
Time frame: Up to 2 years
Part 2, Part 2b (US Only): Change From Baseline in Myeloproliferative Neoplasm (MPN) Symptom Burden
Change from baseline in MPN symptom burden assessed using patient reported outcome (PRO) questionnaire will be reported in this outcome measure.
Time frame: Baseline up to 2 years
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Plan to share: Yes — The data sharing policy of Johnson \& Johnson Innovative Medicine is available at www.innovativemedicine.jnj.com/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu
Data sharing details ↗ · innovativemedicine.jnj.com
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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