Recruiting

Phase 1

JNJ-88549968A Study of JNJ-88549968 for the Treatment of Calreticulin (CALR)-Mutated Myeloproliferative Neoplasms

Sponsor:

Janssen Research & Development, LLC

Code:

NCT06150157

Conditions

Neoplasms

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

JNJ-88549968

Ruxolitinib

Momelotinib

Study Details

Brief summary:

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.

Conditions

Neoplasms

Study ID

NCT06150157

Start date

Dec 20, 2023

Status verified date

Jul, 2026

Completion date

Jun 14, 2028

Anticipated

Primary completion date

Dec 4, 2026

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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:

1. Prior treatment with allogenic stem cell transplant less than or equal to (<=) 6 months before the first dose of JNJ-88549968 or
2. 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

Study Design

Enrollment

241 participants

Anticipated

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Dose Escalation (Part 1), Dose Expansion (Part 2) and Part 1b (US only), Part 2b (US only)

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. 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 \[US only\]).

Interventions

JNJ-88549968

JNJ-88549968 will be administered.

Ruxolitinib

For US sites: Ruxolitinib will be administered for participants with MF only.

Momelotinib

For US sites: Momelotinib will be administered for participants with MF only.

Primary outcome measure

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 ]
Part 1, 2, Part 1b (US Only), Part 2b (US Only): Number of Participants with Adverse Events (AEs) [ 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 [ Time Frame: Up to 2 years ]

Central Contacts and Locations

Central contacts

Study Contact

844-434-4210 Participate-In-This-Study1@its.jnj.com

Locations

City of Hope

Recruiting

Duarte, California, United States, 91010

UCHealth Cancer Care Anschutz Medical Campus University of Colorado Cancer Center

Recruiting

Aurora, Colorado, United States, 80045

Moffit Cancer center

Recruiting

Tampa, Florida, United States, 33612

Emory University

Recruiting

Atlanta, Georgia, United States, 30322

University of Michigan

Recruiting

Ann Arbor, Michigan, United States, 48109

Start Midwest

Recruiting

Grand Rapids, Michigan, United States, 49546

START New Jersey

Recruiting

East Brunswick, New Jersey, United States, 08816

Memorial Sloan Kettering Cancer Center

Recruiting

New York, New York, United States, 10065

Montefiore Medical Center

Recruiting

The Bronx, New York, United States, 10467

Levine Cancer Institute

Recruiting

Charlotte, North Carolina, United States, 28204

University of Pennsylvania

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Sarah Cannon Cancer Institute

Recruiting

Nashville, Tennessee, United States, 37203

MD Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

Princess Margaret Cancer Centre University Health Network

Recruiting

Toronto, Ontario, Canada, M5G 1Z5

Jewish General Hospital

Recruiting

Montreal, Quebec, Canada, H3T 1E2

More Information

Sponsor

Janssen Research & Development, LLC

Last update posted

Jul 31, 2026

Last verified

Jul, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Janssen Research & Development, LLC on 2026-07-31.