ProlactinomaPhase 4ProBOLICNCT07045935
Metabolic Outcomes in Patients With Prolactinomas Under Dopamine Agonist Treatment
A Phase 4 study testing Cabergoline (Dopamine Agonist) in people with Prolactinoma, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
Trial summary
This randomized, active-controlled, parallel-arm, single-blind trial is to compare the effects of Dopamine agonists (DA) therapy targeting different established treatment strategies on glucose metabolism assessed by an oral glucose tolerance test. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Prolactinoma
- What is being tested?
- Cabergoline (Dopamine Agonist)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteSwitzerland
- Study dates
- 16 Sep 2025to 31 Dec 2029
- Phase
- Phase 4
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosed adult patients (at least 18 years of age) with prolactinoma-induced hyperprolactinemia, defined as a prolactin level ≥ two times the local laboratory maximum and radiographic criteria, based on current guidelines.
- Diagnosed adult patients (at least 18 years of age) with prolactinoma-induced hyperprolactinaemia based on current guidelines.
- Patients treated with cabergoline as DA therapy and prolactin levels within the normal range
Who cannot join
- alternative explanation for hyperprolactinaemia
- Active substance use disorder within the last six months
- Current or previous psychotic disorder
- Pregnancy or breastfeeding within the last 8 weeks
- Severe hepatic insufficiency or cholestasis
- Child Pugh C or
Show all 14Show fewer
- AST/ ALT > 3 x the upper limit of normal ULN or
- Cholestasis (total bilirubin > 2x ULN)
- Severe renal impairment (eGFR < 30 ml/min)
- History of pulmonary, pericardial, and/or retroperitoneal fibrotic disorders
- Concomitant treatment with strong or moderate CYP3A4 inhibitors
- Local complications on morphological imaging, related to signs or clinical symptoms which make surgical intervention necessary or a clear patient's preference for surgical treatment
- Gastrointestinal disease or previous surgery: chronic active inflammatory bowel disease, active gastrointestinal ulcer disease, or surgery on the gastrointestinal tract (e.g. sleeve stomach, gastric band)
- Patient incapable of giving informed consent due to cognitive impairment or other reasons (e.g., legal incapacity)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site, 1 recruiting
- Recruiting
University Hospital Basel, Dept. of Endocrinology, Metabolism & Diabetes
Basel, 4031
Cihan Atila, Dr., cihan.atila@usb.ch
Cihan Atila, Dr.
About this study
Official title: Metabolic Outcomes in Patients With Prolactinomas Under Dopamine Agonist Treatment - A Randomized, Single-Blind Active- Controlled Trial
This randomized, active-controlled, parallel-arm, single-blind trial is to compare the effects of Dopamine agonists (DA) therapy targeting different established treatment strategies on glucose metabolism assessed by an oral glucose tolerance test.
Read the detailed description
Prolactinomas are the most common pituitary tumors, leading to hyperprolactinemia, which causes hypogonadism, infertility, and is associated with adverse metabolic effects such as insulin resistance, dyslipidemia, and obesity. Dopamine agonists (DAs), especially cabergoline, are the first-line treatment. They reduce prolactin levels and tumor size effectively. Despite their widespread use, there are no evidence-based guidelines regarding target prolactin levels during DA therapy. Limited evidence suggests that different prolactin levels may have different effects on metabolic health. This trial aims to assess glucose tolerance, insulin sensitivity, and beta-cell function-using OGTT with insulin levels-after 12 months of DA treatment, to target treatment options.
In Switzerland, cabergoline is the preferred DAs for treating hyperprolactinemia.
Cabergoline is available in tablet form, with doses of 0.5 mg per tablet. The standard dosing for hyperprolactinemia typically starts at 0.25 mg to 0.5 mg per week, which can be gradually increased based on the patient's response, with a usual range of 0.25 mg to 2 mg per week.
- Conditions
- Prolactinoma
- Being tested
- Cabergoline (Dopamine Agonist)
- Keywords
- hyperprolactinemia, cabergoline, prolactin level, Dopamine agonist, glucose level, Oral Glucose Tolerance Test, hypoprolactinemia
- Medical subject headings
- Prolactinoma, Hyperprolactinemia, Prolactin Deficiency, Isolated
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cabergoline (Dopamine Agonist)Drug
Cabergoline is available in tablet form, with doses of 0.5 mg per tablet. The standard dosing for hyperprolactinemia typically starts at 0.25 mg to 0.5 mg per week, which can be gradually increased based on the patient's response, with a usual range of 0.25 mg to 2 mg per week. The dose required to achieve the target prolactin levels (pre- defined for each intervention arm) may vary between patients, so a fixed dose is not specified. This allows for individualized treatment based on each patient's response.
| Study group | Role | What they receive |
|---|---|---|
| Experimental intervention arm (Cabergoline) | Active comparator | The experimental intervention arm aims to treat patients (with hyperprolactinemia) with Cabergoline (Dopamine Agonist) by targeting the suppression of prolactin levels (below the normal plasma prolactin range). Receives: Drug: Cabergoline (Dopamine Agonist) |
| Control intervention arm (Cabergoline) | Active comparator | The control intervention arm aims to treat patients (with hyperprolactinemia ) with Cabergoline (Dopamine Agonist) by targeting the normalisation of prolactin levels (within the normal plasma prolactin range). Receives: Drug: Cabergoline (Dopamine Agonist) |
What is being measured
The primary outcome is the main question the study is designed to answer.
2-hour post-oral glucose tolerance test (OGTT) plasma glucose levels
The OGTT is a test used to assess the ability to process glucose. It involves fasting overnight and then drinking a solution containing a measured amount of glucose (75g). Blood Samples are taken at 120 min after glucose intake.
Measured: assessed at 12 months after randomisation
Secondary outcomes (9)
Change in Insulin sensitivity by MATSUDA Index
The Matsuda Index is a measure used to assess insulin sensitivity from the data obtained during an OGTT. The Index is derived from OGTT data and reflects whole-body insulin sensitivity by incorporating both fasting and postprandial glucose and insulin levels. The formula uses (1) fasting glucose and insulin before the glucose load and (2) mean glucose and mean insulin.
Measured: measured at time points (0, 30, 60, 90, and 120 minutes) during the OGTT
Change in Insulin Sensitivity Index (ISI)
ISI is an OGTT-based measure that quantifies insulin sensitivity using fasting and post-load insulin and glucose values. It is similar to the Matsuda Index but has variations depending on specific formulas. Higher ISI values reflect better insulin action.
Measured: measured at time points (0, 30, 60, 90, and 120 minutes) during the OGTT
Change in Quantitative Insulin Sensitivity Check Index (QUICKI)
QUICKI is a simple, fasting- based index to estimate insulin sensitivity, calculated as 1 / (log(Fasting Insulin) + log(Fasting Glucose)). Higher values indicate greater insulin sensitivity.
Measured: measured at time points Screening, Month 6, Month 12, Month 24
Change in Glycated Haemoglobin (HbA1c)
HbA1c reflects average blood glucose levels over the past 2-3 months by measuring glucose-bound haemoglobin. It is used for diagnosing and monitoring diabetes, with values ≥6.5% indicating diabetes.
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Change in Fasting glucose (mmol/L)
Fasting glucose measures baseline blood sugar levels after at least 8 hours of fasting. It is a primary diagnostic criterion for diabetes, with ≥7.0 mmol/L indicating diabetes.
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Change in Fasting insulin (µU/mL)
Fasting insulin provides insight into pancreatic insulin secretion and insulin resistance. Elevated levels often indicate insulin resistance, while low levels may suggest beta-cell dysfunction.
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Change in C-peptide (nmol/l)
C-peptide is released in equal amounts to insulin and is used to assess endogenous insulin production
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Change in Disposition Index (DI)
The DI integrates beta-cell function and insulin sensitivity, calculated as insulin secretion × insulin sensitivity. It reflects how well beta-cells compensate for insulin resistance, with lower values indicating a higher risk of diabetes.
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Change in plasma prolactin levels (ng/mL)
Change in plasma prolactin levels (ng/mL)
Measured: measured at time points Screening, Month 3, Month 6, Month 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jul 2025
- Study start16 Sep 2025
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ProlactinomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, Single-Blind Active-Controlled Trial
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Basel, Switzerland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Cihan Atila, Dr., Principal investigator, University Hospital Basel, Dept. of Endocrinology, Metabolism & Diabetes
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07045935
- Sponsor's protocol ID
- 2025-00829; kt25Atila
- Other IDs
- 2025
- Acronym
- ProBOLIC
- Status last verified
- Sep 2025
- First submitted
- 12 Jun 2025
- Last updated
- 23 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No