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Avatrombopag for the Treatment of Thrombocytopenia After Donor Hematopoietic Stem Cell Transplant

Phase 2
Withdrawn
Conditions
Platelet Disorder
Interventions
Registration Number
NCT04312789
Lead Sponsor
Ayman Saad
Brief Summary

This phase II trial studies the side effects and how well avatrombopag works for the treatment of thrombocytopenia after donor hematopoietic stem cell transplant. Thrombocytopenia is defined as abnormally low level of platelets in the blood. Avatrombopag is a small molecule thrombopoietin receptor agonist which stimulates thrombopoietin receptor leading to increase production of platelets.

Detailed Description

PRIMARY OBJECTIVE:

I. To determine the safety and efficacy of avatrombopag for the treatment of thrombocytopenia after allogenic hematopoietic stem cell transplantation.

SECONDARY OBJECTIVE:

I. To identify predictors of response to avatrombopag.

OUTLINE:

Patients receive avatrombopag orally (PO) once daily (QD) for up to 1 year in the absence of disease progression or unacceptable toxicity. Avatrombopag will be titrated weekly until platelet count of greater than or equal to 60,000/uL is achieved and persists for 7 consecutive days, and the patient remains free from platelet transfusion.

After completion of study treatment, patients are followed up weekly for 4 weeks and then monthly up to 1 year.

Recruitment & Eligibility

Status
WITHDRAWN
Sex
All
Target Recruitment
Not specified
Inclusion Criteria
  • Failure to engraft platelets by day 30 (D30) after hematopoietic cell transplantation (HCT) defined as: Platelet count less than 20,000/uL and patient is still dependent on platelet transfusion support
  • Patient must be able to start treatment with avatrombopag within 30-60 days following transplant
  • Able to provide written informed consent from patient or legal representative
Exclusion Criteria
  • Serious uncontrolled infections
  • Steroid refractory graft versus host disease (GVHD)
  • Patients with thrombotic microangiopathy
  • Pregnant or lactating women
  • Creatinine clearance < 30 ml/min
  • Active thromboembolism requiring anticoagulation
  • Unable to understand the investigational nature of the study or provide informed consent
  • Evidence of disease relapse by flow cytometry of chimerisms
  • Concomitant use of other thrombopoietin receptor agonists (TPO-RA) medication during the treatment phase of the study or two weeks prior to enrollment

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Treatment (avatrombopag)AvatrombopagPatients receive avatrombopag PO QD for up to 1 year in the absence of disease progression or unacceptable toxicity. Avatrombopag will be titrated weekly until platelet count of greater than or equal to 60,000/uL is achieved and persists for 7 consecutive days, and the patient remains free from platelet transfusion.
Primary Outcome Measures
NameTimeMethod
Failure rate of platelet recoveryAt day 90

The proportion will be provided with 95% exact binomial confidence interval.

Incidence of adverse events of avatrombopag treatmentUp to 30 days after the last dose

Toxicities will be evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version (v).5 standard toxicity grading. Frequency and other descriptive statistics will be used to present the toxicity pattern.

Secondary Outcome Measures
NameTimeMethod
Transplant-related mortalityAt day 100 and 1 year post-hematopoietic stem cell transplant (HCT)
Independence from platelet transfusionUp to 1 year
Duration of exposure to avatrombopagUp to 1 year

Will be presented in a descriptive manner.

Progression-free survival (PFS) of underlying malignant hematologic disorderFrom the time of HCT to progression and death, assessed up to 1 year

The method of Kaplan-Meier will be used to estimate PFS.

Duration of platelet responseUp to 1 year

Will be presented in a descriptive manner.

Overall survival (OS)From the time of HCT to death from any cause, assessed up to 1 year

The method of Kaplan-Meier will be used to estimate OS.

Incidence of adverse events associated with avatrombopag treatmentUp to 30 days after last dose
Platelet count >= 50,000/uL for 7 consecutive days without transfusion supportUp to 1 year
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