A Phase 2/3 interventional study of Avatrombopag 20 mg Oral Tablet in Aplastic Anemia, sponsored by Swedish Orphan Biovitrum. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-26.
Sponsored by Swedish Orphan Biovitrum · Phase 2/3, Interventional, and Treatment
This research study is testing a medicine called avatrombopag in adults with aplastic anemia, a rare condition where the bone marrow does not produce enough blood cells. The study will include about 26 participants from Japan, South Korea, and Taiwan whose disease has not responded to standard treatment, who cannot receive standard treatment, or whose disease has returned after previous treatment. The goal is to learn how well avatrombopag works and how safe it is for these patients.
This phase 2/3 open-label trial will evaluate the efficacy and safety of avatrombopag in adult patients with AA refractory to or ineligible f or immunosuppressive therapy or with relapsed AA after immunosuppressive therapy. Approximately 26 patients in Japan, South Korea and Taiwan who meet all the eligibility requirements will be enrolled to evaluate the efficacy and safety of avatrombopag. The trial will consist of 3 phases: Screening Phase, Primary Investigation Phase (Core Phase), and Extension Phase. The Screening Phase lasts 6 weeks. The Primary Investigation Phase (Core Phase) will be 26 weeks in duration, and the Extension Phase will be conducted for at least 52 weeks and continue until product is commercially available in Japan, South Korea and Taiwan, respectively.
Informed consent must be obtained from each patient in writing prior to screening. Their eligibility should be confirmed at screening and prior to the first avatrombopag administration.
All trial participants will receive an initial dose of 60 mg avatrombopag once daily with food. The dose and dosing frequency will be adjusted upwards or downwards (maximum dose: 80 mg once daily; minimum dose: 20 mg three times a week) based on their individual responses for platelet counts. However, trial participants who are being treated with moderate or strong dual inhibitors of CYP2C9 and CYP3A4/5 will receive an initial dose of 60 mg avatrombopag three times a week with food, and their dose and dosing frequency can be adjusted (maximum dose: 80 mg three times a week; minimum dose: 20 mg once weekly) based on their individual platelet counts.
The overall goal of dose adjustment is to identify the minimum dose that maintains platelet counts within the target range of ≥50×10⁹/L and \<200×10⁹/L.
Trial participants will have visits weekly (Visits 2, 3, 4, 5, 6), bi-weekly (Visits 7, 8, 9, 10, 11), then every 4 weeks (Visits 12, 13, 14) during the 26-week Primary Investigation Phase (Core Phase) to collect the required data on platelet count, reticulocyte count (absolute and/or %), hemoglobin level, neutrophil count (absolute neutrophil count; ANC), bleeding events, and other adverse events (AEs). All trial participants who complete the Primary Investigation Phase (Core Phase) can continue to receive avatrombopag in the Extension Phase until product is commercially available. Safety and efficacy data will be collected every 4 weeks in the Extension Phase, which will be conducted for at least 52 weeks.
371 studies on the registry are indexed under Anemia, Aplastic; 98 are open to participants now.
This study's planned enrollment of 26 is below the median of 37 across 281 interventional studies indexed under Anemia, Aplastic.
Browse Anemia, Aplastic studies →Swedish Orphan Biovitrum is the lead sponsor of 82 studies on the registry; 6 are open to participants now.
Of its 17 completed or terminated interventional studies of FDA-regulated products, 15 (88%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Primary Investigation Phase (Core Phase)
Extension Phase
1. No significant safety or tolerability concerns with the trial participant's participation in the Primary Investigation Phase (Core Phase) as determined by the Investigator.
Exclusion Criteria:
Primary Investigation Phase (Core Phase)
Patients receiving any medication or treatment for AA, including the following before avatrombopag treatment initiation:
Extension Phase
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Avatrombopag 20 mg oral tablet
Drug: Avatrombopag 20 mg Oral Tablet
Trial participants will receive avatrombopag as 20 mg film-coated tablets. On-site administration by the trial team is required on (1) Day 1/Visit 2 (first dose) and (2) the first day a participant is titrated to 80 mg once daily (earliest Visit 6).
The effect of avatrombopag on the proportion of trial participants achieving a hematological response at Week 26 in trial participants diagnosed with AA.
Time frame: at Week 26
Time to first hematological response defined as the number of days from baseline to first improvement in at least one of the three blood cell lineages (RBCs, platelets, and neutrophils).
Time frame: From baseline until the date of first documented progression up to 78 weeks
Hematological response at Weeks 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26 in the Primary Investigation Phase (Core Phase) and every 4 weeks in the Extension Phase.
Time frame: Up to 78 weeks
Duration of hematological response: Time from first documented response to loss of response on two consecutive scheduled assessments or at End of treatment (EOT).
Time frame: Up to 78 weeks
Changes from baseline in Quality of Life (QOL) assessed using the EORTC QLQ-C30 questionnaire at Weeks 4, 8, 12, 18, and 26 in the Primary Investigation Phase (Core Phase) and every 4 weeks in the Extension Phase.
Time frame: Up to 78 weeks
Transfusion requirements (RBC and platelet units) at Weeks 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26 in the Primary Investigation Phase (Core Phase) and every 4 weeks in the Extension Phase.
Time frame: Up to 78 weeks
Need for medical resource utilization, including the number, reason for, and duration of hospitalizations and admissions to intensive care units 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, and 26 in the Primary Investigation Phase (Core Phase)and every 4 weeks
Time frame: Up to 78 weeks
No study locations are listed for this record.
Plan to share: Yes — Yes, Qualified researchers may request access to patient level data and related trial documents. Patient level data will be anonymized and trial documents, if applicable will be redacted to protect the privacy of trial participants.
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Avatrombopag