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Study on the Effects of Stopping Alendronic Acid in Patients with Osteoporosis

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial, known as ALEXIS, focuses on studying the effects of stopping the medication alendronic acid in individuals with osteoporosis. Osteoporosis is a condition where bones become weak and are more likely to break. Alendronic acid, also known as alendronate, is a medication commonly used to strengthen bones and reduce the risk of fractures. The purpose of this study is to investigate how discontinuing alendronic acid affects the risk of bone fractures.

Participants in the study will be randomly assigned to either continue or stop taking alendronic acid. The study will last for three years, during which time the occurrence of bone fractures will be monitored. Additionally, changes in bone density, which is a measure of bone strength, will be assessed at the spine and hip. Bone turnover markers, which are substances in the blood that indicate how quickly bone is being broken down and rebuilt, will also be measured. The study will track any side effects experienced by participants.

The study aims to provide valuable information on whether it is safe to stop taking alendronic acid after long-term use and how it impacts bone health. This information could help guide future treatment decisions for individuals with osteoporosis. Participants will be closely monitored throughout the study to ensure their safety and well-being.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on specific criteria: being a postmenopausal female currently treated with alendronate for more than three years without a fracture, or more than five years with the last low-energy fracture occurring over three years ago.

  2. Step 2

    Randomization

    Participants are randomly assigned to either continue or discontinue alendronate treatment. This process ensures that the study results are unbiased and reliable.

  3. Step 3

    Treatment phase

    If assigned to continue treatment, alendronate is taken orally as prescribed. The dosage and frequency are determined by the study protocol and the participant's current treatment plan.

    If assigned to discontinue treatment, no further alendronate is taken. Monitoring continues to assess the effects of discontinuation.

  4. Step 4

    Monitoring and assessments

    Throughout the study, regular assessments are conducted to monitor bone health. This includes measuring bone mineral density (BMD) at the spine and hip, and evaluating bone turnover markers such as CTX and P1NP.

    Participants are observed for any fragility fractures and adverse events during the study period.

  5. Step 5

    Study completion

    The study is expected to last for three years. At the end of the study, final assessments are conducted to evaluate the incidence of fractures and changes in bone health.

    The results will help determine the impact of discontinuing alendronate on fracture risk.

Who can join the trial?

5 criteria

  • Must be a female who has gone through menopause. Menopause is when a woman's periods stop permanently, usually around the age of 50.
  • Currently taking a medication called Alendronate. Alendronate is a medicine used to treat and prevent bone loss.
  • Have been on Alendronate treatment for more than 3 years and have not had any bone fractures during this time.
  • Alternatively, have been on Alendronate treatment for more than 5 years and the last bone fracture was more than 3 years ago. A fracture is a break in a bone, and a low energy fracture happens from a minor fall or injury.
  • Age should be between 55 and 80 years old.

Who cannot join the trial?

4 criteria

  • Men cannot participate in the study. Only women are eligible.
  • Individuals who do not have osteoporosis cannot participate. Osteoporosis is a condition where bones become weak and are more likely to break.
  • Participants must be within a specific age range, typically adults and older adults. Children and teenagers are not eligible.
  • People who are considered part of a vulnerable population, such as those who may not be able to give informed consent, are not eligible.
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Investigated drugs

Alendronate is a medication used to treat and prevent bone loss. It helps to strengthen bones and reduce the risk of fractures, especially in conditions like osteoporosis. In this clinical trial, the focus is on understanding what happens to fracture risk when patients stop taking alendronate.

What is already known about the treatment

Alendronate – Alendronate is typically administered orally in the form of tablets. It is a well-established medication in the treatment of osteoporosis, with extensive documentation in medical literature. The primary therapeutic use of alendronate is to strengthen bones and reduce the risk of fractures in individuals with osteoporosis. It works by inhibiting the activity of cells that break down bone tissue, known as osteoclasts, thereby slowing bone loss and increasing bone density. Alendronate belongs to the pharmacological class of bisphosphonates, which are commonly used to treat bone-related conditions.

Investigated diseases

Osteoporosis – Osteoporosis is a condition characterized by weakened bones, making them more fragile and prone to fractures. It occurs when the creation of new bone doesn't keep up with the removal of old bone, leading to decreased bone density. This disease often progresses silently over many years, with no symptoms until a fracture occurs. Common fracture sites include the hip, spine, and wrist. As the disease advances, even minor stresses like bending over or coughing can cause fractures. Bone density tests are typically used to assess the progression of bone loss.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-510042-24-01Estimated enrolment1 400 patientsSponsorOdense University Hospital

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