HALF = Efficacy and safety of TKI withdrawal after a two-step dose reduction in patients with CML [Czechia]

Type of study

Treatment discontinuation trial

Current status


Study title

HALF (HALF2019) = Efficacy and safety of TKIs‘ withdrawal after a two-step dose reduction in patients with chronic myeloid leukemia (CML)

Scientific title

A prospective phase II clinical trial evaluating the efficacy and the safety of tyrosine kinase inhibitors withdrawal after a previous two-step dose reduction in patients with chronic myeloid leukemia in deep molecular remission (ClinicalTrials.gov NCT04147533)

What is the purpose of the study

This study will evaluate the safety and efficacy of stopping treatment with a TKI (imatinib, dasatinib or nilotinib) in patients with CML in deep molecular remission after after the dose has been reduced in two steps: during the first 6 months after study entry by 50% of standard dose; during the second 6 months this already reduced dose will be given every other day; the medication is discontinued then and the patients are followed every month in the first 6 months after withdrawal, every 1.5 month in the next 6 months, and every 3 months in the next 12 months.

What will happen during the study

Key inclusion criteria

This study includes male or female patients 18 years and older with Ph1-positive and/or BCR-ABL1-positive CML in chronic phase who have been receiving treatment with a tyrosine kinase inhibitor (TKI) for more than 4 years. Treatment of TKI may have been given either in the first line or in the second or other lines for intolerance only. Previous interferon-α treatment is allowed with any treatment effect (intolerance/failure).

Patients can be considered for inclusion if they have been in molecular remission (MR4.0) or better for at least 2 years.

Additional criteria may apply.

Key exclusion criteria

Where can I find additional information

Study description in the US register ClinicalTrials.gov, a service of the U. S. National Institutes of Health

Study sponsor

Masaryk University
Žerotínovo náměstí 617/9
601 77 Brno
Czech Republic

Scientific lead / contact

Daniela Zackova, MD, PhD
Dpt. of Internal Medicine Hematology and Oncology
University Hospital Brno
Jihlavska 20
625 00 Brno
Czech Republic
Tel.: +420 53223 3642
E-mail: zackova.daniela@fnbrno.cz

Principal investigator

Daniela Zackova, University Hospital Brno

Study centers / principal investigators


University Hospital Brno
Jihlavska 20
Brno, 62500
PI: Daniela Zackova, MD, PhD

University Hospital Hradec Kralove
Sokolská 581
Hradec Králové, 50005
PI: Petra Belohlavkova, MD, PhD

University Hospital Olomouc
I. P. Pavlova 185/6
Olomouc, 77900
PI: Prof. Edgar Faber, MD, PhD

University Hospital Ostrava
17. listopadu 1790/5
Ostrava, 70852
PI: Lukas Stejskal, MD

University Hospital Plzen
Edvarda Beneše 1128/13
Plzen, 30599
PI: Michal Karas, MD, PhD

University Hospital Kralovske Vinohrady
Šrobárova 1150/50
Praha 10, 10034
PI: Olga Cerna, MD

Insitute of Hematology and Blood Transfusion
U Nemocnice 2094/1
Praha 2, 12800
PI: Hana Klamova, MD, PhD

General University Hospital in Prague
U nemocnice 2
Praha 2, 12808
PI: Eduard Cmunt, MD, PhD