T&T trial: adding Testosterone to Tamoxifen in male breast cancer patients

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 6

Inclusion Criteria

1. Male
2. A history of proven ER+ (>10% of cells), AR+ (>10% of cells), and HER2-
metastatic BC
3. Tumor progression after at least one line of conventional endocrine therapy
(tamoxifen, AI, fulvestrant, CDK4/6, ±LHRH analogue).
4. Age >= 18 years
5. Adequate hematological, renal and liver function as follows:
• Absolute neutrophil count > 1.5 x 109/L
• Platelet count >100 x 109/L
• White blood cell count >3 x 109/L
• AST and ALT <2.5 or <5.0 in case of liver metastases x upper limit of normal
(ULN)
• Creatinine clearance >50mL/min
• Prothrombin time, partial thromboplastin time and INR <1.5 x ULN
6. Written informed consent

Exclusion Criteria

1. History of prostate, testicular or liver cancer
2. Patients already using testosterone supplements
3. Patients using medication with anti-androgenic effects (e.g. spironolactone)
4. Elevated PSA (>4µg/L) or severe urinary tract problems (as defined with a
Prostate Symptom Score >19). Patients with known BRCA mutation and PSA *3 µg/L
will be referred to the urologist for prostate cancer screening, and can
participate if they have no signs of prostate cancer.
5. Hematocrit >50%
6. Patients with uncontrolled hypertension, diabetes mellitus or other
significant cardiovascular morbidity.
7. Patients with recent history of coronary artery disease or trombo-embolic
events within 6 months prior to screening
8. Severe concurrent disease, infection, co morbid condition that, in the
judgment of the investigator would make the patient inappropriate for
enrollment
9. Visceral crisis and/or rapid progression necessitating chemotherapy
10. Previous allergic reaction to androgen agonists
11. Contra-indication for PET imaging
12. Tamoxifen or fulvestrant treatment <5 weeks prior to FES-PET.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Safety profile, defined as the number of AEs and SAEs that occur while on<br /><br>tamoxifen and testosterone treatment.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>• AR to ER ratio on baseline FES- and FDHT-PET imaging (assessed per lesion and<br /><br>per patient by quantitative analysis using standardized uptake values (SUV))<br /><br>and/or tumor tissue (assessed by percentage of ER and AR expression).<br /><br>• Treatment response on 8 weeks FDG-PET/CT (assessed per lesion and per patient<br /><br>by quantitative analysis using standardized uptake values (SUV).<br /><br>• Relation between baseline imaging and tumor characteristics to treatment<br /><br>response.<br /><br>• Difference in adverse events between the two testosterone dosages. </p><br>