Trial Outcomes & Findings for Evaluation of Avatrombopag for the Treatment of Thrombocytopenia in Japanese Adults With Chronic ITP (NCT NCT05369208)

NCT ID: NCT05369208

Last Updated: 2026-01-15

Results Overview

Cumulative number of weeks in which the platelet count is ≥50×10\^9/L during 26 weeks of treatment in the absence of rescue therapy.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 19 participants
• Primary outcome timeframe: 26 weeks of active treatment
• Results posted on: 2026-01-15

Participant Flow

Participant milestones

Measure	Avatrombopag Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Core Phase STARTED	19
Core Phase COMPLETED	15
Core Phase NOT COMPLETED	4
Extension Phase STARTED	15
Extension Phase COMPLETED	0
Extension Phase NOT COMPLETED	15

Reasons for withdrawal

Measure	Avatrombopag Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Core Phase Prohibited Medication Required	2
Core Phase Adverse Event	1
Core Phase Lack of Efficacy	1

Baseline Characteristics

Evaluation of Avatrombopag for the Treatment of Thrombocytopenia in Japanese Adults With Chronic ITP

Baseline characteristics by cohort

Measure	Avatrombopag n=19 Participants Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dose adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with the overseas labeling.
Age, Categorical <=18 years	0 Participants n=14 Participants
Age, Categorical Between 18 and 65 years	12 Participants n=14 Participants
Age, Categorical >=65 years	7 Participants n=14 Participants
Age, Continuous	56.0 years STANDARD_DEVIATION 16.70 • n=14 Participants
Sex: Female, Male Female	15 Participants n=14 Participants
Sex: Female, Male Male	4 Participants n=14 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=14 Participants
Race (NIH/OMB) Asian	19 Participants n=14 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=14 Participants
Race (NIH/OMB) Black or African American	0 Participants n=14 Participants
Race (NIH/OMB) White	0 Participants n=14 Participants
Race (NIH/OMB) More than one race	0 Participants n=14 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=14 Participants
Region of Enrollment Japan	19 participants n=14 Participants

PRIMARY outcome

Timeframe: 26 weeks of active treatment

Population: Full analysis set of core phase

Cumulative number of weeks in which the platelet count is ≥50×10^9/L during 26 weeks of treatment in the absence of rescue therapy.

Outcome measures

Measure	Avatrombopag n=19 Participants Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Cumulative Number of Weeks of Platelet Response	13.47 cumulative number of weeks Standard Deviation 9.002

SECONDARY outcome

Timeframe: Day 8

Population: Full analysis set of core phase

Proportion of subjects with a platelet response ≥50×10^9/L at Day 8 in the absence of rescue therapy

Outcome measures

Measure	Avatrombopag n=19 Participants Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Response Rate at Day 8	12 Participants

Adverse Events

Avatrombopag

Serious events: 3 serious events

Other events: 18 other events

Deaths: 0 deaths

Serious adverse events

Measure	Avatrombopag n=19 participants at risk Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Hepatobiliary disorders Autoimmune Hepatitis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Diffuse Large B-Cell Lymphoma	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Reproductive system and breast disorders Heavy Menstrual Bleeding	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.

Other adverse events

Measure	Avatrombopag n=19 participants at risk Avatrombopag 20 mg oral tablet Avatrombopag 20 mg given once daily (initial dose). Dosage adjustments were determined by the physician to maintain a platelet count between 50 x 10\^9 to 200 x 10\^9 as defined in the protocol and in accordance with overseas labeling.
Investigations Blood Pressure Decreased	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Blood and lymphatic system disorders Anaemia	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Blood and lymphatic system disorders Leukocytosis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Cardiac disorders Palpitations	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Endocrine disorders Cushingoid	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Eye disorders Scleral Haemorrhage	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Gastrointestinal disorders Nausea	10.5% 2/19 • Number of events 2 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Gastrointestinal disorders Tooth Fracture	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
General disorders Malaise	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
General disorders Oedema Peripheral	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
General disorders Pyrexia	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Bacterial Infection	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations COVID-19	15.8% 3/19 • Number of events 3 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Chronic Sinusitis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Cystitis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Nasopharyngitis	10.5% 2/19 • Number of events 4 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Upper Respiratory Tract Infection	15.8% 3/19 • Number of events 3 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Injury, poisoning and procedural complications Contusion	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Investigations Blood Lactate Dehydrogenase Increased	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Investigations Blood Pressure Increased	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Musculoskeletal and connective tissue disorders Back Pain	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Musculoskeletal and connective tissue disorders Intervertebral Disc Protrusion	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Musculoskeletal and connective tissue disorders Rheumatoid Arthritis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Nervous system disorders Headache	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Nervous system disorders Sciatica	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Psychiatric disorders Insomnia	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Reproductive system and breast disorders Uterine Haemorrhage	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Respiratory, thoracic and mediastinal disorders Cough	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Respiratory, thoracic and mediastinal disorders Oropharyngeal Pain	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Skin and subcutaneous tissue disorders Alopecia	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Skin and subcutaneous tissue disorders Purpura	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Skin and subcutaneous tissue disorders Urticaria	10.5% 2/19 • Number of events 3 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Vascular disorders Hypotension	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.
Infections and infestations Pyelonephritis	5.3% 1/19 • Number of events 1 • Up to 26 weeks of treatment and a 4 week follow up period (Core Phase) Avatrombopag reported as a single group. Adverse events were not grouped by dose since the dosage regimen could be adjusted frequently throughout the study.

Additional Information

Medicine Development Leader

Sobi Inc.

Phone: 1-781-786-7370

Email: medinfo.us@sobi.com

Results disclosure agreements

• Principal investigator is a sponsor employee PIs are not allowed to publish clinical trial data on their own after trial completion.
• Publication restrictions are in place

Restriction type: OTHER