A Phase 3 interventional study of Pimicotinib(ABSK021) and Placebo in Tenosynovial Giant Cell Tumor, Pigmented Villonodular Synovitis and Giant Cell Tumor of Tendon Sheath, sponsored by Abbisko Therapeutics Co, Ltd. Active, not recruiting at 40 sites in 7 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by Abbisko Therapeutics Co, Ltd (part of Abbisko Cayman Limited) · Phase 3, Interventional, and Treatment
The goal of this clinical trial is to assess the efficacy and safety of Pimicotinib (ABSK021) in patients with Tenosynovial Giant Cell Tumor (TGCT). The main questions it aims to answer are:
Participants will be asked to complete the study procedures:
This study consists of part 1 and part 2. Part 1 is a double-blind phase, eligible patients will be randomized to Pimicotinib(ABSK021) treatment group or matching placebo group and will receive Pimicotinib(ABSK021) or matching placebo until completion of Part 1.
Part 2 is an open-label treatment phase, and all patients entering this phase will receive open-label Pimicotinib(ABSK021) until completion of 24 weeks of dosing or withdrawal from the study.
Part 3 is an open-label extension treatment phase, and patients who completed the part 2 and continuted to be eligible, will go to the Part 3. Patients will receive the open-label Pimicotinib(ABSK021) until all patients withdraw from the study, or the sponsor decides to terminate the study, whichever occurs first.
20 studies on the registry are indexed under Synovitis, Pigmented Villonodular; 2 are open to participants now.
This study's enrollment of 94 is above the median of 36 across 17 interventional studies indexed under Synovitis, Pigmented Villonodular.
Browse Synovitis, Pigmented Villonodular studies →Abbisko Therapeutics Co, Ltd is the lead sponsor of 38 studies on the registry; 19 are open to participants now.
Compared within Synovitis, Pigmented Villonodular, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Giant Cell Tumor of Tendon Sheath. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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.
Exclusion Criteria:
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.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
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.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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 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 B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
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.
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.
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.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
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.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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 B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
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.
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.
Participants receive the blinded treatment of ABSK021 for 24 weeks in Part 1 and continue on the open-label Pimicotinib(ABSK021) in Part 2 and Part 3.
Drug: Pimicotinib(ABSK021)
Participants receive the blinded treatment of matching placebo for 24 weeks in Part 1 and have option to receive the open-label Pimicotinib(ABSK021) in Part 2.
Drug: Pimicotinib(ABSK021) · Drug: Placebo
capsule
capsule
Objective Response Rate (ORR)
Assessed by central read using Response Evaluation Criteria in Solid Tumors (RECIST) (Version 1.1)
Time frame: Baseline to Week 25
Objective Response Rate (ORR) Per Tumor Volumn Score (TVS)
TVS is a semi-quantitative magnetic resonance imaging (MRI) scoring system that describes tumor mass and is based on 10% increments of the estimated volume of the maximally distended synovial cavity or tendon sheath involved. A tumor that is equal in volume to that of a maximally distended synovial cavity or tendon sheath was scored 10; a score of 0 indicated no evidence of tumor. ORR was the percentage of participants who achieved either Complete Response (CR) or Partial Response (PR) as assessed by Blinded Independent Review Committee using TVS.
Time frame: Baseline to Week 25
Change From Baseline in Active Range of Motion (ROM) at Week 25
Presented here is the change from baseline in ROM to Week 25. Measurement of the affected and contralateral, non-affected joint was assessed by goniometer and measured in degrees. At baseline, the motion with the smallest relative ROM value (worst) was identified, and this motion was used for evaluating the change in relative ROM subsequently. The affected joint measurement was used to derive a relative ROM based on the measurement relative to reference standard value provided by the American Medical Association. Relative ROM is expressed in percent: 100 x (joint ROM measure)/(reference ROM standard).
Time frame: Baseline to Week 25
Change From Baseline in the Worst Stiffness Numeric Rating Scale (NRS) Score at Week 25
The Worst Stiffness NRS is a single question that asks the participant to assess their worst stiffness in the last 24 hours. Participants rate their worst stiffness on a scale of 0 to 10, where 0 is "no stiffness" and 10 is "worst imaginable." Lower scores represented better level of stiffness.
Time frame: Baseline to Week 25
Change From Baseline in Brief Pain Inventory (BPI) Worst Pain NRS Score at Week 25
Participants reported responses to the BPI Worst Pain NRS. The BPI Worst Pain NRS ranged from 0 to 10, where 0 is "no pain" and 10 is "pain as bad as you can imagine."
Time frame: Baseline to Week 25
Change From Baseline in the Patient-reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) Score at Week 25
All participants were asked 11 or 13 questions from the PROMIS-PF item bank. The questions used one of two 5-point verbal rating scales: either 1 = "unable to do", 2 = "with much difficulty", 3 = "with some difficulty", 4 = "with a little difficulty", and 5 = "without any difficulty"; or 1 = "cannot do", 2 = "quite a lot", 3 = "somewhat", 4 = "very little", and 5 = "not at all." The T-score rescales the total raw score into a standardized score with a mean of 50 and a standard deviation (SD) of 10. Therefore, a person with a T-score of 40 is one SD below the mean. The T-score ranges from 0 to 100, with a higher score indicating better physical function status.
Time frame: Baseline to Week 25
| Milestone | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) |
|---|---|---|
| Started | 63 | 31 |
| Completed | 59 | 29 |
| Not completed | 4 | 2 |
| Milestone | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) |
|---|---|---|
| Started | 52 | 31 |
| Completed | 28 | 11 |
| Not completed | 24 | 20 |
| Milestone | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) |
|---|---|---|
| Started | 23 | 11 |
| Completed | 0 | 0 |
| Not completed | 23 | 11 |
Assessed by central read using Response Evaluation Criteria in Solid Tumors (RECIST) (Version 1.1)
| Percentage of participants | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Objective Response Rate (ORR) | 54.0 (40.9 to 66.6) | 3.2 (0.1 to 16.7) |
TVS is a semi-quantitative magnetic resonance imaging (MRI) scoring system that describes tumor mass and is based on 10% increments of the estimated volume of the maximally distended synovial cavity or tendon sheath involved. A tumor that is equal in volume to that of a maximally distended synovial cavity or tendon sheath was scored 10; a score of 0 indicated no evidence of tumor. ORR was the percentage of participants who achieved either Complete Response (CR) or Partial Response (PR) as assessed by Blinded Independent Review Committee using TVS.
| Percentage of participants | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Objective Response Rate (ORR) Per Tumor Volumn Score (TVS) | 61.9 (48.8 to 73.9) | 3.2 (0.1 to 16.7) |
Presented here is the change from baseline in ROM to Week 25. Measurement of the affected and contralateral, non-affected joint was assessed by goniometer and measured in degrees. At baseline, the motion with the smallest relative ROM value (worst) was identified, and this motion was used for evaluating the change in relative ROM subsequently. The affected joint measurement was used to derive a relative ROM based on the measurement relative to reference standard value provided by the American Medical Association. Relative ROM is expressed in percent: 100 x (joint ROM measure)/(reference ROM standard).
| Percent of range of motion | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Change From Baseline in Active Range of Motion (ROM) at Week 25 | 15.64 (10.37 to 20.91) | -0.07 (-7.02 to 6.88) |
The Worst Stiffness NRS is a single question that asks the participant to assess their worst stiffness in the last 24 hours. Participants rate their worst stiffness on a scale of 0 to 10, where 0 is "no stiffness" and 10 is "worst imaginable." Lower scores represented better level of stiffness.
| score on a scale | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Change From Baseline in the Worst Stiffness Numeric Rating Scale (NRS) Score at Week 25 | -3.00 (-3.46 to -2.55) | -0.57 (-1.21 to 0.07) |
Participants reported responses to the BPI Worst Pain NRS. The BPI Worst Pain NRS ranged from 0 to 10, where 0 is "no pain" and 10 is "pain as bad as you can imagine."
| Score on a scale | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Change From Baseline in Brief Pain Inventory (BPI) Worst Pain NRS Score at Week 25 | -2.32 (-2.73 to -1.91) | -0.23 (-0.80 to 0.34) |
All participants were asked 11 or 13 questions from the PROMIS-PF item bank. The questions used one of two 5-point verbal rating scales: either 1 = "unable to do", 2 = "with much difficulty", 3 = "with some difficulty", 4 = "with a little difficulty", and 5 = "without any difficulty"; or 1 = "cannot do", 2 = "quite a lot", 3 = "somewhat", 4 = "very little", and 5 = "not at all." The T-score rescales the total raw score into a standardized score with a mean of 50 and a standard deviation (SD) of 10. Therefore, a person with a T-score of 40 is one SD below the mean. The T-score ranges from 0 to 100, with a higher score indicating better physical function status.
| T-score | Part 1- Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Change From Baseline in the Patient-reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) Score at Week 25 | 5.63 (4.21 to 7.06) | 2.23 (0.23 to 4.24) |
Collected over Collection of adverse events started from the signing of informed consent through safety follow-up (up to 5.9 months). Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Part 1 Pimicotinib(ABSK021) | 0/63 (0%) | 3/63 (4.8%) | 62/63 (98.4%) |
| Part 1- Placebo | 0/31 (0%) | 1/31 (3.2%) | 27/31 (87.1%) |
| Event | Part 1 Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Prostate cancerNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 0/63 | 1/31 |
| Enterocolitis infectiousInfections and infestations | 1/63 | 0/31 |
| Blood pressure increasedInvestigations | 1/63 | 0/31 |
| Erythema nodosumSkin and subcutaneous tissue disorders | 1/63 | 0/31 |
| Event | Part 1 Pimicotinib(ABSK021) | Part 1- Placebo |
|---|---|---|
| Blood creatine phosphokinase increasedInvestigations | 45/63 | 5/31 |
| Blood lactate dehydrogenase increasedInvestigations | 36/63 | 0/31 |
| Aspartate aminotransferase increasedInvestigations | 34/63 | 3/31 |
| PruritusSkin and subcutaneous tissue disorders | 33/63 | 1/31 |
| Face oedemaGeneral disorders | 30/63 | 0/31 |
| Amylase increasedInvestigations | 22/63 | 0/31 |
| RashSkin and subcutaneous tissue disorders | 22/63 | 0/31 |
| Periorbital oedemaEye disorders | 20/63 | 3/31 |
| FatigueGeneral disorders | 18/63 | 7/31 |
| NauseaGastrointestinal disorders | 17/63 | 2/31 |
This is the baseline analysis population for Part 1 (Weeks 1 - 24)
| Age, Continuous(years) | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) | Total |
|---|---|---|---|
| Mean | 42.6 ± 14.30 | 38.3 ± 12.46 | 41.2 ± 13.79 |
| Sex: Female, Male(Participants) | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) | Total |
|---|---|---|---|
| Female | 45 | 19 | 64 |
| Male | 18 | 12 | 30 |
| Race (NIH/OMB)(Participants) | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 32 | 16 | 48 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 3 | 2 | 5 |
| White | 26 | 11 | 37 |
| More than one race | 1 | 0 | 1 |
| Unknown or Not Reported | 1 | 2 | 3 |
| Region of Enrollment(participants) | Part 1/Part 2/Part 3- Pimicotinib(ABSK021) | Part 1- Placebo, Part 2/Part 3- Pimicotinib(ABSK021) | Total |
|---|---|---|---|
| Canada | 6 | 4 | 10 |
| Netherlands | 5 | 5 | 10 |
| United States | 8 | 3 | 11 |
| China | 31 | 14 | 45 |
| Poland | 2 | 0 | 2 |
| Italy | 4 | 2 | 6 |
| Spain | 7 | 3 | 10 |
PDFs hosted by the registry, ClinicalTrials.gov.
Ran from Apr 2023 to primary completion in Sep 2024, 16 months.
Results were first posted in May 2026, 1 year 7 months after primary completion.
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Studies of the drug tested here: Pimicotinib
Synovitis, Pigmented Villonodular →
Abbisko Therapeutics Co, Ltd →