A Phase 1 interventional study of Azenosertib and Gemcitabine in Osteosarcoma, sponsored by K-Group, Beta, Inc., a wholly owned subsidiary of Zentalis Pharmaceuticals, Inc. Completed at 17 sites in 2 countries. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by K-Group, Beta, Inc., a wholly owned subsidiary of Zentalis Pharmaceuticals, Inc · Phase 1, Interventional, and Treatment
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Among 278 studies in Osteosarcoma with a site in United States — 55 open to participants now, 83 under way, 1 of them phase 3. Osteosarcoma · United States.
Among the 278 studies in Osteosarcoma with a site in United States, this one is the 111th largest by enrollment of the 229 interventional ones that give a count, is one of 13 that started in 2021, is one of 91 in phase 1, and was the 225th registered.
488 studies on the registry are indexed under Osteosarcoma; 123 are open to participants now.
Browse Osteosarcoma studies →55 of the 278 studies in Osteosarcoma with a site in United States are open now. Recruiting first, the newest first:
Wake Forest University Health Sciences · Sites in United States
Ages 7–22
Emory University · Sites in United States
Ages up to 50
St. Jude Children's Research Hospital · Sites in United States
Ages up to 21
St. Jude Children's Research Hospital · Sites in United States
Baylor College of Medicine · Sites in United States
Ages 1–24
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 100 Osteosarcoma studies recruiting now, 41 (41%) set no upper age limit and 55 (55%) stop at 75 or younger; 75 take children under 18; 3 take healthy volunteers.
This study: 12 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
278 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 124 · Phase 2 131 · Phase 3 8
First in 1986; this study’s year is marked. 13 started in 2021.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 31 is below the median of 40 across 354 interventional studies indexed under Osteosarcoma.
Median enrollment 30 across the 229 interventional studies, 155 across the 32 observational. Of the 179 that completed or were terminated, 66 (37%) have results posted.
This tab as a report to print or save as PDF → With an account.
36 of 278 have an industry lead sponsor. The 10 most frequent:
K-Group, Beta, Inc., a wholly owned subsidiary of Zentalis Pharmaceuticals, Inc is the lead sponsor of 8 studies on the registry; 3 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
K-Group, Beta, Inc., a wholly owned subsidiary of Zentalis Pharmaceuticals, Inc has 1 study filed under Osteosarcoma — fewer than ten, so there is no comparison to draw.
28 of the studies in Osteosarcoma with a site in United States that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07129226Case Comprehensive Cancer CenterMusculoskeletal Cancers Remote Monitoring and Care | 2026-11 |
| NCT02508038University of Wisconsin, MadisonAlpha/Beta CD19+ Depleted Haploidentical Transplantation + Zometa for Pediatric Hematologic Malignancies and Solid Tumors | 2026-12 |
| NCT02013336South Plains Oncology ConsortiumPhase 1 Dose-escalating Study of MM-398 (Irinotecan Sucrosofate Liposome Injection) Plus Intravenous Cyclophosphamide in Recurrent or Refractory Pediatric Solid Tumors | 2026-12 |
| NCT05400603Emory UniversityAllogeneic Expanded Gamma Delta T Cells With GD2 Chemoimmunotherapy in Relapsed /Refractory Neuroblastoma or Refractory/ Relapsed Osteosarcoma | 2026-12 |
| NCT04901702St. Jude Children's Research HospitalStudy of Onivyde With Talazoparib or Temozolomide in Children With Recurrent Solid Tumors and Ewing Sarcoma | 2026-12-31 |
Add all 28 to your calendar (.ics) → With an account.
Among the 278 studies in Osteosarcoma with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This is a phase 1/2 study of azenosertib (ZN-c3) in combination with gemcitabine in adult and pediatric subjects with relapsed or refractory osteosarcoma.
This is a phase 1/2 dose escalation and dose expansion study, evaluating the clinical activity and safety, pharmacodynamics, and pharmacokinetics of azenosertib (ZN-c3) in combination with gemcitabine in relapsed or refractory osteosarcoma.
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.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
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.
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.
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.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
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.
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.
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.
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.
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.
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.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Azenosertib (ZN-c3) in combination with Gemcitabine
Drug: Azenosertib · Drug: Gemcitabine
Azenosertib is an investigational drug.
Also known as: ZN-c3
Gemcitabine is an approved drug
Also known as: Gemzar
Incidence of dose-limiting toxicities (DLT) in DLT evaluable subjects and the incidence and severity of adverse events.
Time frame: Through Cycle 1 (21 days) Phase 1
Event-free survival (EFS) at 18 weeks per RECIST (Response Evaluation Criteria in Solid Tumors) Guideline version 1.1.
EFS at 18 weeks is defined as time from study enrollment until date of disease progression, or detection of disease at a previously uninvolved site, or date of death of the subjects at 18 weeks.
Time frame: During phase 2, at 18 weeks
Event-free survival (EFS) per RECIST Guideline version 1.1.
EFS is defined as time from study enrollment until date of last contact, date of disease progression, or detection of disease at a previously uninvolved site, or date of death.
Time frame: At 12 months
Median overall survival (OS) and OS at 12 months per RECIST Guideline version 1.1.
OS is defined as the time from date of first dosing until the date of death.
Time frame: At 12 months
The frequency and severity of adverse events (AEs) and laboratory abnormalities per the National Cancer Institute Common Terminology (NCI CTCAE) version 5.0.lities.
Time frame: Through completion, approximately 42 months
Plasma pharmacokinetics (PK) maximum concentration (Cmax).
Time frame: Through completion, approximately 42 months
Plasma PK time to maximum concentration (Tmax).
Time frame: Through completion, approximately 42 months
Area under the plasma concentration versus timepoint curve (AUC last).
Time frame: Through completion, approximately 42 months
Terminal half-life of the plasma PK concentration.
Time frame: Through completion, approximately 42 months
Ran from Aug 2021 to primary completion in Aug 2023, 24 months.
Of 49 phase 1 interventional studies under Osteosarcoma, half reached primary completion within 77 months of starting (the median), counting those still running; a quarter within 54 and three quarters within 134. This study's 24 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Azenosertib
K-Group, Beta, Inc., a wholly owned subsidiary of Zentalis Pharmaceuticals, Inc