Recruiting
Phase 1

PRT12396

Sponsor:

Prelude Therapeutics

Code:

NCT07469891

Conditions

Polycythemia Vera (PV)

Myelofibrosis (MF)

Myeloproliferative Neoplasms (MPNs)

Post-Polycythemia Vera Myelofibrosis

Post-Essential Thrombocythemia Myelofibrosis

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

PRT12396

Study Details

Brief summary:

This is a first-in-human, open-label, multi-center Phase 1 study designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of PRT12396 in participants with high-risk polycythemia vera (PV) and myelofibrosis (MF), and to determine the maximum tolerated dose (MTD) and recommended dose(s) for expansion (RDE\[s\]). The study consists of a dose-escalation phase followed by a dose-expansion phase to further evaluate selected dose level(s).

Conditions

Polycythemia Vera (PV)

Myelofibrosis (MF)

Myeloproliferative Neoplasms (MPNs)

Post-Polycythemia Vera Myelofibrosis

Post-Essential Thrombocythemia Myelofibrosis

Study ID

NCT07469891

Start date

Apr 29, 2026

Status verified date

May, 2026

Completion date

Apr, 2028

Anticipated

Primary completion date

Apr, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations (including contraception requirements), and other study procedures.
  • Confirmed diagnosis of PV or MF according to WHO 2016 or revised ICC/WHO 2022 criteria
  • Documented presence of a JAK2 V617 mutation
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
  • Estimate life expectancy of ≥12 weeks per investigator assessment.
  • Negative serum or urine pregnancy test and agree to use contraception or maintain true abstinence.
  • Adequate organ function and bone marrow reserves (hematology, renal, and hepatic)

Exclusion Criteria:

  • History of another malignancy within 3 years prior to enrollment, except for malignancy considered cured with low risk of recurrence.
  • Clinically significant anemia due to nutritional deficiency or hemolytic disorders.
  • Active or uncontrolled infection requiring systemic therapy or hospitalization.
  • Any other medical or psychiatric conditions that, in the Investigator's judgment, would increase risk or interfere with study participation or interpretation of results.
  • Clinically significant or uncontrolled medical conditions, including active infection or cardiovascular disease, that would increase risk or interfere with study participation.
  • Unresolved toxicity > Grade 1 from prior anticancer therapy, except for alopecia or peripheral neuropathy ≤ Grade 2.
  • Pregnancy or breastfeeding
  • Known sensitivity or contraindication to any component of study, or the excipients of study treatment.
  • Prior systemic therapy for PV or MF, prior or planned allogeneic hematopoietic stem-cell transplantation, recent major surgery, prior splenectomy or prior splenic irradiation, or use of hematopoietic growth factors within protocol-defined washout periods.
  • Use of strong or moderate cytochrome P450 (CYP) 3A4 inhibitor or inducer, sensitive CYP3A substrates with narrow therapeutic range, or acid-reducing agents that cannot be discontinued prior to study treatment.
  • Participation in another interventional clinical study.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: PRT12396: MF

Participants with myelofibrosis receive PRT12396, an investigational oral capsule, administered twice daily. The study includes a dose-escalation followed by dose-expansion at the recommended dose for expansion (RDE)

experimental: PRT12396: PV

Participants with polycythemia vera receive PRT12396, an investigational oral capsule, administered twice daily. The study includes a dose-escalation followed by dose-expansion at the recommended dose for expansion (RDE)

Interventions

PRT12396

PRT12396 is an investigational oral capsule administered twice daily at the assigned dose level or RDE. Capsules are swallowed whole with water and may be taken one hour before or two hours after meals.

Primary outcome measure

  • Dose limiting toxicity (DLT) of PRT12396 [ Time Frame: Through cycle 1 (4 weeks) ]
  • Incidence and severity of Adverse events [ Time Frame: Through study completion, an average of 2 years ]
  • Adverse Events Leading to Dose Modifications or Discontinuation [ Time Frame: Through study completion, an average of 2 years ]
  • Maximum tolerated dose (MTD) and Recommended Dose(s) for Expansion (RDE[s]) of PRT12396 [ Time Frame: Through study completion, an average of 2 years ]

Central Contacts and Locations

Central contacts

Study Contact (Please Do Not Disclose Personal Information)

See Emailclinicaltrials@preludetx.com

Locations

Colorado Blood Cancer Institute

Recruiting

Denver, Colorado, United States, 80218

BRCR Global - Coral Springs

Recruiting

Coral Springs, Florida, United States, 33065

Moffitt Cancer Center

Recruiting

Tampa, Florida, United States, 33612

START Midwest, LLC

Recruiting

Grand Rapids, Michigan, United States, 49546

Thomas Jefferson University, Sidney Kimmel Cancer Center, Clinical Trials Office

Recruiting

Philadelphia, Pennsylvania, United States, 19107

Tennessee Oncology, PLLC - Investigational Drug Services

Recruiting

Nashville, Tennessee, United States, 37203

Tristar BMT

Recruiting

Nashville, Tennessee, United States, 37203

The University of Texas, MD Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

More Information

Sponsor

Prelude Therapeutics

Last update posted

Sep 1, 2026

Last verified

May, 2026

Keywords

  • High-Risk Polycythemia Vera (PV)
  • Intermediate-1 or Intermediate-2 Risk Primary MF
  • High-Risk Primary MF
  • Post-Polycythemia Vera MF
  • Post-Essential Thrombocythemia MF
  • PRT12396
  • JAK Inhibitor
  • Myeloproliferative Neoplasms (MPN)

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Prelude Therapeutics on 2026-09-01.