The GALLOP-11 Study
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT05178030 |
Recruitment Status :
Recruiting
First Posted : January 5, 2022
Last Update Posted : May 23, 2023
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment |
---|---|
Gastro-intestinal Stromal Tumors | Other: vena punction |
This is an observational, non-interventional, multicenter study. The study will be performed within the Dutch GIST consortium (NKI-AvL, Erasmus MC, Radboud UMC, LUMC and UMCG). Patients diagnosed with GIST with a KIT exon 11 mutations that can be detected by our ddPCR assay are eligible. In this way we will study a homogenous patient population with GIST that (usually) responds very well to initial TKI treatment. Therefore, the KIT mutation status must be known. Patients can enter the study at any time point of their disease trajectory. Patients included in GALLOP-11 will have follow-up as described in the European Society of Medical Oncology and Dutch guidelines but with blood draws for ctDNA assessment at similar time points.
The primary objective is the negative predictive value (NPV) of the ddPCR assay result in relation to the results of the CT-scan and/or MRI scan (according to RECIST 1.1) at the same time point. Concordance of these results will be determined, from which the negative predictive value (NPV) of our ddPCR assay will be calculated. This is considered the most important value, as the most harmful scenario would be to miss progressive disease because not seen on ctDNA while it could have been seen on CT (and/or MRI). That would mean that ctDNA analysis is not reliable enough to replace CT-scan (and/or MRI) follow-up in the future.
To determine the negative predictive value, at least 250 patients need to have an evaluable follow-up strategy. To pursue a solid follow-up period within an achievable timeline, patients with at least four ctDNA measurements, accompanied by a CT-scan (and/or MRI scan), will be considered evaluable for the NPV analysis. Patients who have progression within four scans are always evaluable, since a positive outcome outweighs negative outcomes because it is known that ctDNA should have had measured change once it is seen on CT-scans (and/or MRI scans).
Study Type : | Observational |
Estimated Enrollment : | 250 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | Validation of Mutation Analysis in Circulating Tumor DNA With a ddPCR Assay as Diagnostic and Follow-up Tool for Patients With a KIT Exon 11 Mutated GIST: GALLOP-11 |
Actual Study Start Date : | May 11, 2021 |
Estimated Primary Completion Date : | January 2024 |
Estimated Study Completion Date : | September 2024 |

Group/Cohort | Intervention/treatment |
---|---|
GALLOP-11
Patients with a proven KIT exon 11 mutated GIST covered by our in-house designed ddPCR assay.
|
Other: vena punction
Regular 3-12 monthly follow-up by CT-scan will be compared to results of ctDNA analysis. Blood for analysis of mutation in ctDNA will be collected at the same moment a CT-scan is performed |
- The negative predictive value of the ddPCR assay with regard to KIT exon 11 circulating tumour mutation [ Time Frame: 3 years ]The negative predictive value of the ddPCR assay with regard to KIT exon 11 circulating tumour mutation digital droplet PCR (ddPCR) assay in relation to CT-scans.
- The sensitivity and specificity of the designed KIT exon 11 mutation [ Time Frame: 3 years ]To establish the sensitivity and specificity of the designed KIT exon 11 mutation ddPCR assay
- Technical validity of the ddPCR assay [ Time Frame: 3 years ]The detection of ctDNA expressed in copies/mL and fractional abundance, assessed by the designed KIT exon 11 circulating tumour mutation digital droplet PCR (ddPCR) assay, in different laboratories, and by Agena Bioscience, will be assessed.
- Clinical validity of the ddPCR assay [ Time Frame: 3 years ]The first detection of increase in the level of the primary KIT exon 11 mutation in ctDNA determined in time to progression seen on standard radiological evaluation by CT-scan based on RECIST 1.1
- Development of new assays to detect secondary mutations [ Time Frame: 3 years ]Based on mutation analysis of tumor biopsies of patients with progressive disease, ctDNA assays will be designed and tested
- Determination of time between first detection of secondary mutations and progression [ Time Frame: 3 years ]Based on progression of disease on CT, we will analyze ctDNA of patients to determine wether secondary mutations could be found before radiologic progression
Biospecimen Retention: Samples Without DNA

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Patients with GIST with a biopsy confirmed primary KIT exon 11 mutation covered by our KIT exon 11 ddPCR assay (mutation/deletion within target sequence of c.1665_1736);
- Patients with an indication for at least 4 CT-scans concomitant with regular laboratory examination in a neoadjuvant, adjuvant and/or palliative care trajectory within the time frame of the study;
- Age ≥18 years;
- Written informed consent provided.
Exclusion Criteria:
1. Patients who are unable to comply with study procedures and follow up.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05178030
Contact: An KL Reyners, MD, PhD | +31 50 361 1543 | a.k.l.reyners@umcg.nl |
Netherlands | |
Netherlands Cancer Institute | Not yet recruiting |
Amsterdam, Netherlands | |
Contact: N. Steeghs, MD, PhD | |
Principal Investigator: N. Steeghs, MD, PhD | |
University Medical Center Groningen | Recruiting |
Groningen, Netherlands | |
Contact: A. K.L. Reyners, MD, PhD +31 50 361 6161 a.k.l.reyners@umcg.nl | |
Contact: R. Bleckman, MD +31 50 361 6161 | |
Principal Investigator: A. K.L. Reyners, MD, PhD | |
LUMC | Not yet recruiting |
Leiden, Netherlands | |
Contact: A. J Gelderblom, MD, PhD | |
Principal Investigator: A J Gelderblom, MD, PhD | |
Radboud UMC | Not yet recruiting |
Nijmegen, Netherlands | |
Contact: I. Desar, MD, PhD | |
Principal Investigator: I. Desar, MD, PhD | |
Erasmus MC | Not yet recruiting |
Rotterdam, Netherlands | |
Contact: R HJ Mathijssen, MD, PhD | |
Principal Investigator: R HJ Mathijssen, MD, PhD |
Principal Investigator: | An KL Reyners, MD, PhD | Principal Investigator |
Responsible Party: | A.K.L. Reyners, Coordinating investigator/project leader, University Medical Center Groningen |
ClinicalTrials.gov Identifier: | NCT05178030 |
Other Study ID Numbers: |
201900781 |
First Posted: | January 5, 2022 Key Record Dates |
Last Update Posted: | May 23, 2023 |
Last Verified: | May 2023 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Gastrointestinal Stromal Tumors Neoplasms, Connective Tissue Neoplasms, Connective and Soft Tissue Neoplasms by Histologic Type Neoplasms |
Gastrointestinal Neoplasms Digestive System Neoplasms Digestive System Diseases Gastrointestinal Diseases |