Radium223 dichloride (223RaCl) with aromatase inhibitor drug combination for patients with symptomatic bone metastases from breast cancer

2 1 1 1

What is this study about?

The study focuses on patients with symptomatic bone metastases from breast cancer, a condition where cancer that started in the breast has spread to the bones and causes pain or other symptoms. The treatment being tested is an intravenous injection of Radium223 dichloride (223RaCl). In some participants the drug is given alone, while in others it is combined with oral medicines that belong to the class of aromatase inhibitors, such as letrozole, anastrozole and exemestane.

The purpose of the study is to evaluate the efficacy and safety of this approach. Participants receive a series of injections over several months and are followed with regular visits to monitor pain, overall health and blood tests. The main goals include measuring PFS, which is the time until the disease gets worse or the patient dies, assessing reduction of bone pain and changes in QOL. Additional observations look at OS, the length of overall survival, the occurrence of serious bone problems, and changes in ALP, an enzyme that can indicate bone activity.

1 signing informed consent and baseline assessment

after joining the study, you will sign an informed consent form that confirms your agreement to participate.

a baseline assessment will be performed, which includes medical history, physical examination, and imaging to document the extent of bone metastases.

2 initiation of oral aromatase inhibitor

you will begin taking one of the oral aromatase inhibitors assigned by the study protocol.

the possible medications are:

exemestane 25 mg taken by mouth,

letrozole 2.5 mg taken by mouth,

or anastrozole 1 mg taken by mouth.

the exact schedule and duration will be defined by the study protocol.

3 administration of radium223 dichloride

you will receive an intravenous injection of radium223 dichloride.

the dose is 55 kBq per kilogram of body weight, administered through a vein.

the timing of each injection follows the study schedule; each administration is recorded in your study record.

4 repeated treatment cycles

the combination of the oral aromatase inhibitor and the intravenous radium223 injection will be repeated according to the study protocol.

each cycle includes a new dose of radium223 and continuation of the oral medication.

the number of cycles and the interval between them are specified by the protocol and will be followed consistently.

5 regular monitoring visits

throughout the treatment period, you will attend scheduled visits for safety monitoring and efficacy assessment.

these visits may include blood tests, imaging studies, and questionnaires that evaluate pain, quality of life, and disease progression.

any side effects or changes in health will be documented by the study team.

6 end of treatment assessment

after the final scheduled dose of radium223 and completion of the oral medication course, a final assessment will be performed.

this assessment includes the same examinations as the baseline visit to evaluate overall response, pain reduction, and quality of life.

7 follow‑up period

following the end of treatment, you will continue to be followed for a defined period to record long‑term outcomes such as overall survival and any delayed side effects.

follow‑up visits are scheduled according to the study protocol and may include additional imaging and laboratory tests.

Who Can Join the Study?

You must be 18 years old or older.
Your breast cancer must be confirmed by looking at tissue under a microscope (this is called a histology test).
You need to have mainly cancer that has spread to the bones (bone metastases) with at least two bone spots seen on a bone scan.
It is allowed if the cancer has also spread to soft tissues such as skin, muscle, fat, or lymph nodes.
Your overall health level, measured by the ECOG Performance Status, must be 2 or lower (meaning you can care for yourself and are not bedridden).
Your absolute neutrophil count (a type of white blood cell that fights infection) must be at least 1.5 × 10⁹ per liter.
Your platelet count (cells that help blood clot) must be at least 100 × 10⁹ per liter, and you must not have received a platelet transfusion in the four weeks before starting the study.
Your hemoglobin level (the part of blood that carries oxygen) must be at least 9.0 g/dL (100 g/L), and you must not have had a blood transfusion or a drug called erythropoietin in the four weeks before the first dose.

Who Cannot Join the Study?

If you have cancer that has spread to internal organs (called visceral disease) or any other condition that requires strong chemotherapy drugs (known as cytotoxic chemotherapy), you cannot join the study.
If you have a condition called carcinomatous lymphangitis, which means cancer cells are spreading through the tiny lymph vessels in the lungs, you cannot join the study.
If you have ever had another type of cancer, except a treated skin cancer called basal cell carcinoma or a very early bladder cancer (called superficial bladder cancer, stages Ta or Tis), you cannot join the study.
If you have previously received whole‑body radiation treatment that used special radioactive substances such as strontium‑89, samarium‑153, rhenium‑186, or rhenium‑188, you cannot join the study.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

No sites found in this category

Other Sites

Site Name	City	Country	Status
Azienda Ospedaliera Universitaria Policlinico Paolo Giaccone	Palermo	Italy

Trial status

Country	Status	Recruitment Start
Italy	Not yet recruiting	02.04.2026

Trial locations

Investigated drugs:

Exemestane is a medicine taken by mouth that blocks an enzyme called aromatase. By stopping this enzyme, the drug lowers the amount of estrogen in the body, which can help slow the growth of certain breast cancers that need estrogen to grow. In this study it is used as a comparison treatment to see how well the new therapy works.

Radium-223 dichloride is a radioactive drug given by injection into a vein. It travels to the bones and delivers a small amount of radiation directly to cancer cells that have spread to bone, helping to relieve pain and control tumor growth. In the trial it is the main experimental treatment being tested, either alone or together with other medicines.

Letrozole is an oral medication that also blocks the aromatase enzyme, reducing estrogen levels in the body. Lower estrogen can slow the spread of breast cancers that rely on this hormone. In this trial it serves as another standard treatment for comparison with the experimental drug.

Anastrozole is taken by mouth and works in the same way as letrozole and exemestane by inhibiting aromatase and lowering estrogen. It is used as an additional standard treatment option in the study to compare its effects with those of the new therapy.

Investigated diseases:

Breast cancer

Symptomatic bone metastases from breast cancer – It is a condition where cancer that began in the breast spreads to the bones and causes symptoms such as pain. The cancer cells grow within the bone, weakening its structure. As the disease advances, the pain may become more constant and may be felt during movement or at rest. The affected bones can become fragile and may fracture more easily. It can also lead to swelling or reduced mobility in the area of the spine or other bones. Over time, the involvement of more bones may increase discomfort and limit daily activities.

Trial ID:

2025-524208-31-00

Protocol code:

PA IT23 2009

Trial Phase:

Therapeutic exploratory (Phase II)

Other Trials to Consider

#1 Clinical Trials Search in Europe

Radium223 dichloride (223RaCl) with aromatase inhibitor drug combination for patients with symptomatic bone metastases from breast cancer

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?