A Study to Compare the Results of FGFR Testing by Either ctDNA Blood Testing or Standard Tumor Tissue Testing

Bernie Eigl

Status

Active, not recruiting

Conditions

Metastatic Bladder Cancer

Metastatic Urothelial Carcinoma

Treatments

Genetic: FGFR Testing

Study type

Observational

Funder types

Other

Identifiers

NCT06129084

ctDNA FGFR

Details and patient eligibility

About

A new drug, erdafitinib, became available for some patients with bladder cancer that has spread to other organs. To qualify, patients must have specific genetic changes in their tumors. Currently, doctors use tumor tissue samples to check for these genetic changes, but these samples might not accurately reflect the current state of the patient's cancer.

In this study, Investigators will test the patient's blood for these genetic changes in addition to the tumor tissue samples. It is thought that the blood test will give a more accurate result.

Investigators hope this study will help to find out if more patients can benefit from erdafitinib than the ones identified by tissue testing only.

Full description

Recently, the first targeted therapy for patients with metastatic urothelial cancer (mUC) received approval, i.e. erdafitinib. Erdafitinib is a pan-FGFR small molecule inhibitor. Approximately twenty percent of mUC patients' tumors harbor qualifying alterations in FGFR2 or FGFR3. Currently, standard testing uses archival tumor tissue. However, this type of testing may not be representative of a patient's clinically dominant tumor clone at the time of treatment initiation due to temporal and spatial biopsy bias of archival tissue testing.

In this study, patients will undergo circulating tumor DNA testing, in addition to conventional tissue testing, for treatment eligibility. Investigators hypothesize that blood-based ctDNA testing will provide a more accurate assessment of somatic FGFR status than same patient archival primary tissue.

This study's objectives are:

Objective 1 (Primary): To evaluate the diagnostic value of ctDNA testing against the "gold standard" of tissue testing.

Objective 2 (Secondary): To evaluate whether ctDNA may be a superior predictive marker by identifying actionable FGFR alterations that are currently missed on tissue assays.

Procedures:

Medical history will be reviewed, including all previous anti-cancer treatments.
A blood sample will be collected for ctDNA testing at the time of screening for FGFR alterations and at progression under erdafitinib therapy. Test results will be compared to archival tissue testing.

Enrollment

260 patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Patients with metastatic bladder cancer who are about to undergo tissue testing for FGFR mutations and who have blood samples drawn during the management of their disease are eligible to be included in this analysis.

Exclusion criteria