Trial · NCT03834961

Larotrectinib in Treating Patients With Previously Untreated TRK Fusion Solid Tumors and TRK Fusion Relapsed Acute Leukemia

NCT03834961, Phase 2, Active not recruiting, Children's Oncology Group; results first posted 2025-12-02

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Larotrectinib in Treating Patients With Previously Untreated TRK Fusion Solid Tumors and TRK Fusion Relapsed Acute Leukemia. Trials, record NCT03834961. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03834961

On this page

Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Larotrectinib in Treating Patients With Previously Untreated TRK Fusion Solid Tumors and TRK Fusion Relapsed Acute Leukemia
NCT number: NCT03834961
Status: Active not recruiting
Phases: Phase 2
Enrollment: 33 participants, actual
Lead sponsor: Children's Oncology Group
Conditions: Central Nervous System Neoplasm, Infantile Fibrosarcoma, Recurrent Acute Leukemia, Refractory Acute Leukemia, Solid Neoplasm
Interventions: Larotrectinib Sulfate
First posted: 2019-02-08
Last updated: 2025-12-02
Results first posted: 2025-12-02

Source ClinicalTrials.gov

Registered outcomes10

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Objective Response Rate (ORR) of Children With Infantile Fibrosarcoma (IFS) Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years	A responder is defined as a patient who achieves a best response of partial response (PR) or complete response (CR) on the study. Response rates will be calculated as the percent of evaluable patients who are responders, and confidence intervals will be constructed accounting for the two-stage design.
Secondary	Event-free Survival (EFS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year	The Kaplan-Meier method will be used to estimate 1-year EFS, defined as the time from study entry until last contact, relapse, secondary malignancy, or death.
Secondary	Overall Survival (OS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year	The Kaplan-Meier method will be used to estimate 1-year OS, defined as the time from study entry until last contact or death.
Secondary	Duration of Response (DoR) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years	Will be defined among patients with a confirmed best response of either PR and CR. Will be computed as the time from first observation of either PR or CR until either the first observation of progressive disease (PD) (event) or last known observation of the patient (censored observation).
Secondary	ORR of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years	A responder is defined as a patient who achieves a best response of PR or CR on the study. Response rates will be calculated as the percent of evaluable patients who are responders, and confidence intervals will be constructed accounting for the two-stage design.
Secondary	EFS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year	The Kaplan-Meier method will be used to estimate 1-year EFS, defined as the time from study entry until last contact, relapse, secondary malignancy, or death.
Secondary	OS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year	The Kaplan-Meier method will be used to estimate 1-year OS, defined as the time from study entry until last contact or death.
Secondary	DoR of Children With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years	Will be defined among patients with a confirmed best response of either PR and CR. Will be computed as the time from first observation of either PR or CR until either the first observation of PD (event) or last known observation of the patient (censored observation).
Secondary	Percentage of Participants With Adverse Events	Through 30 days after treatment, a mean of 12.6 months	Will report the percentage of patients within each disease stratum who experienced a grade 3 or higher toxicity with attribution of possible, probable, or definite while on protocol therapy or within 30 days of the last dose of therapy. Will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.
Secondary	Percentage of Patients With TRK Fusion Solid Tumors With Detectable Circulating Tumor Deoxyribonucleic Acid (ctDNA)	Up to 5 years	The percentage of ctDNA and frequency with which patients have detectable ctDNA prior to the start of therapy and at times during therapy when subsequent serial samples are obtained (2 weeks, 4 weeks, 24 weeks of treatment, at the time of discontinuation of larotrectinib therapy, and at progression) will be calculated.

Source ClinicalTrials.gov

Outcomes10

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Objective Response Rate (ORR) of Children With Infantile Fibrosarcoma (IFS) Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years		percentage of patients	NUMBER
SECONDARY	Event-free Survival (EFS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year		percentage of patients	NUMBER
SECONDARY	Overall Survival (OS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year		percentage of patients	NUMBER
SECONDARY	Duration of Response (DoR) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years		years	MEDIAN
SECONDARY	ORR of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years		percentage of patients	NUMBER
SECONDARY	EFS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year		percentage of participants	NUMBER
SECONDARY	OS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 1 year		percentage of patients	NUMBER
SECONDARY	DoR of Children With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Up to 5 years		years	MEDIAN
SECONDARY	Percentage of Participants With Adverse Events	Through 30 days after treatment, a mean of 12.6 months	Zero patients were assigned to Cohort C	percentage of patients	NUMBER
SECONDARY	Percentage of Patients With TRK Fusion Solid Tumors With Detectable Circulating Tumor Deoxyribonucleic Acid (ctDNA)	Up to 5 years

Source ClinicalTrials.gov

Results by group10

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Objective Response Rate (ORR) of Children With Infantile Fibrosarcoma (IFS) Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort A	94.4	95% Confidence Interval 80.1 to 97.0	percentage of patients
Event-free Survival (EFS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort A	94.4	95% Confidence Interval 66.6 to 99.2	percentage of patients
Overall Survival (OS) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort A	100	95% Confidence Interval 100.0 to 100.0	percentage of patients
Duration of Response (DoR) of Children With IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort A	2.1	Full Range 0.4 to 4.2	years
ORR of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort B	60	95% Confidence Interval 32.3 to 83.7	percentage of patients
EFS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort B	93.3	95% Confidence Interval 61.3 to 99.0	percentage of participants
OS of Children and Adults With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort B	93.3	95% Confidence Interval 61.3 to 99.0	percentage of patients
DoR of Children With Newly Diagnosed TRK Fusion Solid Tumors Other Than IFS Treated With Neoadjuvant Larotrectinib Prior to Local Control	Cohort B	2.9	Full Range 0.2 to 4.8	years
Percentage of Participants With Adverse Events	Cohort A	44.4	95% Confidence Interval 21.5 to 69.2	percentage of patients
Percentage of Participants With Adverse Events	Cohort B	20	95% Confidence Interval 4.3 to 48.1	percentage of patients

Source ClinicalTrials.gov

Participant flow9

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Cohort A	18
Overall Study	STARTED	Cohort B	15
Overall Study	STARTED	Cohort C	0
Overall Study	COMPLETED	Cohort A	17
Overall Study	COMPLETED	Cohort B	13
Overall Study	COMPLETED	Cohort C	0
Overall Study	NOT COMPLETED	Cohort A	1
Overall Study	NOT COMPLETED	Cohort B	2
Overall Study	NOT COMPLETED	Cohort C	0

Source ClinicalTrials.gov

Adverse events78

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	Anemia	Blood and lymphatic system disorders	Cohort A	2	18
other	Anemia	Blood and lymphatic system disorders	Cohort B	2	15
other	Anemia	Blood and lymphatic system disorders	Cohort C		0
other	Sinus tachycardia	Cardiac disorders	Cohort A	0	18
other	Sinus tachycardia	Cardiac disorders	Cohort B	1	15
other	Sinus tachycardia	Cardiac disorders	Cohort C		0
other	Abdominal pain	Gastrointestinal disorders	Cohort A	0	18
other	Abdominal pain	Gastrointestinal disorders	Cohort B	1	15
other	Abdominal pain	Gastrointestinal disorders	Cohort C		0
other	Constipation	Gastrointestinal disorders	Cohort A	1	18

1 to 10 of 78Source ClinicalTrials.gov

See all 78 adverse events

Adverse event totals9

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Cohort A	1	18
Total, all-cause mortality	Cohort B	1	15
Total, all-cause mortality	Cohort C	0	0
Total, other adverse events	Cohort A	9	18
Total, other adverse events	Cohort B	5	15
Total, other adverse events	Cohort C	0	0
Total, serious adverse events	Cohort A	3	18
Total, serious adverse events	Cohort B	1	15
Total, serious adverse events	Cohort C	0	0

Source ClinicalTrials.gov

Papers1

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as
39652801	DERIVED

Source PubMed

Grants1

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

Project	Title	Principal investigators	Organization	Funder	Fiscal years
U10CA180886	COG NCTN Network Group Operations Center	Hawkins, Douglas S.	COG RESEARCH FOUNDATION, LLC	NATIONAL CANCER INSTITUTE	2014 to 2026

Source NIH RePORTER

Trial comparisons0

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

None in this release.

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT03834961

GET https://conductscience.org/api/trials/v1/NCT03834961/events?page=2

API reference For AI assistants