Pivotal Open-label Phase 3 Clinical Study of QTX-2101 in Adult Patients With Acute Promyelocytic Leukemia (QUATRO-APL)

June 9, 2026 updated by: Quetzal Therapeutics

A Pivotal Open-label Phase 3 Clinical Study Evaluating the Efficacy and Safety of QTX-2101 in Combination With All-trans Retinoic Acid in Newly Diagnosed, Low-risk Acute Promyelocytic Leukemia

This Phase 3 study in adult participants with newly diagnosed low-risk APL will evaluate the efficacy, safety, and PK of an oral capsule formulation of ATO, in combination with ATRA.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Duarte, California, United States, 91010
      • Stanford, California, United States, 94305
    • New York
      • Buffalo, New York, United States, 14203
      • The Bronx, New York, United States, 10467
    • Texas
      • Houston, Texas, United States, 77030
    • Virginia
      • Charlottesville, Virginia, United States, 22908

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Informed Consent
  2. Participants must be between 18 and under 71 years of age
  3. Participants must have a confirmed diagnosis of APL proven by standard genetic testing (t(15;17) or PML-RARA)
  4. Participants must be classified as low- or intermediate-risk APL
  5. Participants must be willing and able to comply with the scheduled study visits, treatment plans, laboratory tests, contraception guidance, and other procedures

Exclusion Criteria

  1. Participants who have significant heart rhythm problems including long QT syndrome, serious arrhythmias, very slow heart rate, or prolonged QTc on ECG
  2. Participants who have central nervous system leukemia
  3. Participants having serious ongoing medical conditions or infections including uncontrolled infections, severe organ disease, or conditions that make study participation unsafe
  4. Participants who are pregnant, breastfeeding, or unwilling to use contraception
  5. Participants who are unable to safely take study medication, including severe neuropathy, inability to swallow oral medication, malabsorption issues, or known allergy to ATO or ATRA

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: QTX-2101
QTX-2101 (oral arsenic trioxide; ATO) All-trans-retinoic-acid (ATRA; oral)
Drug: QTX-2101 + ATRA
The experimental regimen consists of IV ATO administered once daily during induction, given continuously, for up to a maximum of 60 days. During consolidation, QTX-2101 is administered once daily, per investigator's protocol. ATRA is administered orally in two divided daily doses during induction, given continuously until bone marrow remission (not exceeding 60 days). During consolidation, ATRA is taken orally in two divided daily doses following a 2-weeks-on / 2-weeks-off schedule within each 8-week cycle.
Active Comparator: IV ATO
IV Arsenic Trioxide (ATO) All-trans-retinoic-acid (ATRA; oral)
Drug: IV arsenic trioxide (ATO) + ATRA
The comparator regimen consists of IV ATO administered once daily during induction, given continuously, for up to a maximum of 60 days. During consolidation, IV ATO is administered once daily, per investigator's protocol. ATRA is administered orally in two divided daily doses during induction, given continuously until bone marrow remission (not exceeding 60 days). During consolidation, ATRA is taken orally in two divided daily doses following a 2-weeks-on / 2-weeks-off schedule within each 8-week cycle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Maximum observed plasma (concentration (Cmax) of QTX-2101 for ASIII
Time Frame: Up to 1 cycle of consolidation therapy (each cycle is 8 weeks)
Cmax is defined as the maximum observed plasma concentration following administration of [investigational product], determined from plasma concentration-time data.
Up to 1 cycle of consolidation therapy (each cycle is 8 weeks)
Molecular complete remission (molecular CR) rate
Time Frame: Up to 60 days of induction and 3 8-week cycles of consolidation treatment
mCR is defined as the absence of detectable PML-RARA fusion transcript in bone marrow assessed by a validated quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay .The mCR rate is defined as the proportion of participants achieving molecular remission at the specified assessment time point following induction and consolidation therapy.
Up to 60 days of induction and 3 8-week cycles of consolidation treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To characterize the safety and tolerability of QTX-2101/ATRA and IV ATO/ATRA
Time Frame: Throughout approximately 10 months of study treatment
Treatment emergent adverse events
Throughout approximately 10 months of study treatment
To characterize the event-free survival (EFS) of QTX-2101/ATRA
Time Frame: Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first
Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first
Area under the plasma concentration-time curve (AUC) of QTX-2101 for ASIII
Time Frame: Up to 10 months
AUC is defined as the area under the plasma concentration-time curve from time zero to the last measurable concentration (AUC₀-t) and/or extrapolated to infinity (AUC₀-∞), calculated using noncompartmental methods.
Up to 10 months
To complete a model-based concentration QT relationship evaluation
Time Frame: Up to 10 months
Time-matched difference in change from baseline in QTcF interval between active treatment and placebo, derived from triplicate 12-lead ECGs at each post-dose time point
Up to 10 months
EORTC QLQ-C30 domain unit of measure and measurement tool
Time Frame: Up to 10 months
Change from baseline in EORTC QLQ-C30 global health status (0-100 scale)
Up to 10 months
EQ-5D-5L domain unit of measure and measurement tool
Time Frame: Up to 10 months
Change from baseline in EQ-5D-5L index score (0-100)
Up to 10 months
Overall Survival
Time Frame: Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first
OS is defined as the time from randomization to death from any cause. Participants who are alive at the time of analysis will be censored at the date last known to be alive.
Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first
Event Free Survival (EFS)
Time Frame: Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first
EFS is defined as the time from randomization to the first occurrence of any of the following events: failure to achieve hematologic or molecular remission, relapse (hematologic or molecular), or death from any cause. Participants without an event at the time of analysis will be censored at the date of last adequate disease assessment.
Assessed for up to 3 years after the first dose of treatment, or until treatment failure (disease progression), death, or study completion, whichever occurs first

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Quetzal Therapeutics

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 8, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

December 1, 2030

Study Registration Dates

First Submitted

March 16, 2026

First Submitted That Met QC Criteria

March 26, 2026

First Posted (Actual)

March 31, 2026

Study Record Updates

Last Update Posted (Actual)

June 11, 2026

Last Update Submitted That Met QC Criteria

June 9, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • QTX-2101-301
  • 2025-524810-28-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Acute Promyelocytic Leukemia

Clinical Trials on QTX-2101 + ATRA

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Philippines

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe