NCT04676529

Study to Evaluate Safety, Pharmacokinetic and Pharmacodynamic Dose Escalation and Expansion Study of PXS-5505 in Patients With Primary, Post-polycythemia Vera or Post-essential Thrombocythemia Myelofibrosis

A Phase 1/2a Study to Evaluate Safety, Pharmacokinetic and Pharmacodynamic Dose Escalation and Expansion Study of PXS-5505 in Patients With Primary, Postpolycythemia Vera or Post-essential Thrombocythemia Myelofibrosis

• Status: Completed
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 43 (actual)
• Sponsor: Syntara · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study will be an open-label phase 1/2a study to evaluate the safety and tolerability of PXS-5505 in patients with primary, postpolycythemia vera (PV) or post-essential thrombocythemia (ET) myelofibrosis.

Detailed description

The study consists of three phases: a dose escalation phase, a cohort expansion phase, and an add-on phase. The dose escalation phase will follow a 3+3 design with a starting dose of 100 mg twice daily, and a treatment duration of 4 weeks. Patients will be able to participate in more than one dose level. During the cohort expansion phase, up to 24 patients will be treated at the dose determined appropriate based on safety, pharmacokinetic and pharmacodynamic results from the dose escalation phase, for a period of up to 6 months. Patients from the dose escalation phase will be able to participate in the cohort expansion phase. In the add-on phase PXS-5505 will be given to patients, already receiving a stable dose of ruxolitinib, for a period of 12 months. Up to 15 patients will enrol in the add-on phase in order to obtain 12 patients with at least 1 month's exposure to PXS-5505 on top of ruxolitinib. Note: The decision to include an add-on phase, where PXS-5505 is to be given on top of a stable ruxolitinib dose, was taken following a review of the data (safety, PK and PD) from the cohort expansion phase. There will be no washout period between dose escalation and dose expansion cohorts.

Conditions

• Myelofibrosis

Interventions

Type	Name	Description
DRUG	PXS-5505	PXS-5505 is a hard capsule (size 0) with the additional excipients mannitol and magnesium stearate.

Timeline

• Start date: 2021-02-18
• Primary completion: 2025-07-09
• Completion: 2025-07-09
• First posted: 2020-12-21
• Last updated: 2025-08-24

Locations

23 sites across 4 countries: United States, Australia, South Korea, Taiwan

Regulatory

• FDA-regulated drug study