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

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.

NCT Number	NCT06150157
Lead Sponsor	Janssen Research & Development, LLC
Conditions	Neoplasms
Enrollment	241 participants
Start Date	2023-12-20
Primary Completion	2026-12-04 (estimated)
Study Completion	2028-06-14 (estimated)
Updated on ClinicalTrials.gov	2026-07-06