A Phase 1 interventional study of Biopsy Procedure and Biospecimen Collection in Advanced Kidney Carcinoma, Advanced Renal Cell Carcinoma and Hereditary Leiomyomatosis and Renal Cell Carcinoma, sponsored by Jonsson Comprehensive Cancer Center. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by Jonsson Comprehensive Cancer Center · Phase 1, Interventional, and Treatment
This phase I/II trial studies the side effects and best dose of mercaptopurine, and to see how well it works in treating patients with hereditary leiomyomatosis and renal cell carcinoma (HLRCC). HLRCC is a rare inherited disorder that increases the risk of developing benign (not cancer) tumors of the skin and the uterus (leiomyomas) and malignant (cancer) tumors of the uterus (leiomyosarcoma) and the kidney. Mercaptopurine is in a class of medications called purine antagonists. It works by stopping the growth of cancer cells.
PRIMARY OBJECTIVE:
I. To identify the safety, side effects, and best dose of mercaptopurine (6-MP).
SECONDARY OBJECTIVES:
I. To assess clinical activity in treating metastatic fumarate hydratase (FH) Deficient Kidney Cancer.
II. To assess how treatment impacts uterine fibroid clinical symptoms. III. To determine the change in menstrual bleeding. IV. To evaluate changes in pain due to leiomyomas. V. To evaluate the overall improvement in leiomyoma symptoms.
EXPLORATORY OBJECTIVES:
I. Associate changes in serum thiopurine metabolites (6-methylmercaptopurine [6-MMP] and 6-thioguanine [6-TG]) with efficacy endpoints for kidney cancer, cutaneous leiomyoma, and uterine fibroids.
II. Generate in vitro and in vivo models of cutaneous leiomyomas and kidney cancer that may be useful to predict clinical activity to treatment with 6-MP or purine restriction.
III. Bank clinical specimens (urine, tissue, blood) and tissue for future HLRCC research.
OUTLINE: This is a phase I dose-escalation study followed by a phase II study.
Patients receive 6-MP orally (PO) once daily (QD) on days 1-28 of each cycle. Cycles repeat every 28 days for up to 26 cycles/2 years (for kidney cohort) or up to 13 cycles/1 year (for skin or uterine cohorts) in the absence of disease progression or unacceptable toxicity. Patients may also undergo computed tomography (CT) or magnetic resonance imaging (MRI) throughout the study (kidney and uterine cohorts only), tumor biopsy on study (kidney cohort only), skin biopsy on study (skin cohort only), and blood sample collection throughout the study (all cohorts).
After completion of study treatment, patients are followed up within 45 days and then every 12 months for 2 years.
Disease-causing, germline FH mutation including variants considered either:
Thiopurine S-methyltransferase (TPMT) and NUDT15 homozygous, wild-type genotype
Inclusion into ≥ 1 of the following symptomatic, disease states listed below:
Exclusion Criteria:
An untreated non-renal malignancy with the following exceptions:
Any prior treated, non-renal malignancy except for those meeting the following characteristics:
Patients receive 6-MP PO QD on days 1-28 of each cycle. Cycles repeat every 28 days for up to 26 cycles/2 years (for kidney cohort) or up to 13 cycles/1 year (for skin or uterine cohorts) in the absence of disease progression or unacceptable toxicity. Patients may also undergo CT or MRI throughout the study (kidney and uterine cohorts only), tumor biopsy on study (kidney cohort only), skin biopsy on study (skin cohort only), and blood sample collection throughout the study (all cohorts).
Procedure: Biopsy Procedure · Procedure: Biospecimen Collection · Procedure: Computed Tomography · Procedure: Magnetic Resonance Imaging · Drug: Mercaptopurine · Other: Questionnaire Administration · Procedure: Skin Biopsy
Undergo tumor biopsy
Also known as: Biopsy, BIOPSY_TYPE, Bx
Undergo collection of blood
Also known as: Biological Sample Collection, Biospecimen Collected, Sample Collection, Specimen Collection
Undergo CT
Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, Computerized Tomography (CT) scan, CT, CT Scan, Diagnostic CAT Scan, Diagnostic CAT Scan Service Type, tomography
Undergo MRI
Also known as: Magnetic Resonance, Magnetic Resonance Imaging (MRI), Magnetic resonance imaging (procedure), Magnetic Resonance Imaging Scan, Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance, MR, MR Imaging, MRI, MRI Scan, MRIs, NMR Imaging, NMRI, Nuclear Magnetic Resonance Imaging, sMRI, Structural MRI
Given PO
Also known as: 3H-Purine-6-thiol, 6 MP, 6 Thiohypoxanthine, 6 Thiopurine, 6-Mercaptopurine, 6-Mercaptopurine Monohydrate, 6-MP, 6-Purinethiol, 6-Thiopurine, 6-Thioxopurine, 6H-Purine-6-thione, 1,7-dihydro- (9CI), 7-Mercapto-1,3,4,6-tetrazaindene, Alti-Mercaptopurine, Azathiopurine, Bw 57-323H, Flocofil, Ismipur, Leukerin, Leupurin, Mercaleukim, Mercaleukin, Mercaptina, Mercaptopurinum, Mercapurin, Mern, NCI-C04886, Puri-Nethol, Purimethol, Purine, 6-mercapto-, Purine-6-thiol (8CI), Purine-6-thiol, monohydrate, Purinethiol, Purinethol, U-4748, WR-2785
Ancillary studies
Undergo skin biopsy
Also known as: Biopsy of Skin
Maximum tolerated dose (MTD)
Will be determined using Common Terminology Criteria for Adverse Events version 5.0 grading.
Time frame: Up to cycle 2 (Cycles = 28 days)
Best overall response (Kidney Cancer Cohort)
Will be assessed per Response Evaluation Criteria in Solid Tumors. A descriptive summary will report the proportion of patients with complete response, partial response, stable disease, or progressive disease. Patients who are unevaluable will be summarized separately.
Time frame: Up to 2 years after completion of study treatment
Progression-free survival (PFS) (Kidney Cancer Cohort)
Kaplan-Meier survival curves will be generated to estimate the distribution of PFS, including median survival and confidence intervals. Landmark analyses will be conducted at 1-year and 2-year time points to estimate the proportion of patients remaining progression-free at these intervals, providing both longitudinal and milestone-based insights into disease control.
Time frame: From study enrollment to documented disease progression or death from any cause, assessed up to 2 years after completion of study treatment
Tumor volume changes (Uterine Fibroids Cohort)
Will be assessed via pelvic magnetic resonance imaging. A descriptive summary will report maximal volume reduction from baseline, including the proportion of patients achieving partial or complete response, stable disease, or progression, based on predefined thresholds. Mean and median volume changes will be calculated, and overall response rates will be summarized.
Time frame: Up to 1 year
Changes in Pictorial Blood Loss Assessment Chart (PBAC) scores (Uterine Fibroids Cohort)
Will be summarized from baseline to follow-up. Response will be defined as a ≥ 50% reduction in PBAC score. The proportion of responders and non-responders will be reported, along with changes in mean and median scores.
Time frame: Baseline up to 1 year
Changes in symptom severity (SSS) and health-related quality of life (HRQoL) domains (Uterine Fibroids Cohort)
Will be assessed using the Uterine Fibroid Symptom and Health-Related Quality of Life (UFS-QOL) questionnaire. Response will be defined as a ≥ 10-point improvement in SSS and ≥ 20-point improvement in HRQoL scores. Descriptive statistics will summarize changes from baseline, and response rates will be reported.
Time frame: Baseline up to 1 year
Changes in leiomyoma pain with/without ice provocation (Cutaneous Leiomyomas Cohort)
A descriptive summary of the Visual Analogue Scale will be provided from baseline to follow-up scans both with and without ice provocation. The number of responders (improvement in 2 points or 30% reduction) and non-responders will be reported. Similarly, changes in the Brief Pain Inventory-Short Form (BPI-SF) pain severity (average of the 4 questions) will identify the number of responders (2-point reduction or 30% improvement) and non-responders.
Time frame: Baseline up to 1 year
Changes in leiomyoma-associated interference (Cutaneous Leiomyomas Cohort)
Will be evaluated using BPI-SF interference scores across all time points. Descriptive statistics will summarize changes from baseline to each follow-up, as well as from baseline to maximal improvement. Response rates will be calculated based on predefined thresholds (≥ 2-point or ≥ 30% improvement), and changes in mean and median scores will be reported.
Time frame: Baseline up to 1 year
Changes in Patient-Reported Global Change (Cutaneous Leiomyomas Cohort)
The Patient's Global Impression of Change (PGIC) will be analyzed descriptively to assess perceived improvement in overall skin symptoms. The maximal PGIC score change from baseline will be summarized, and PGIC scores will be visualized across visits using spider plots to illustrate individual and cohort-level trends over time.
Time frame: Baseline up to 1 year
This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Hereditary leiomyomatosis and renal cell cancer
Jonsson Comprehensive Cancer Center