This family protocol summary provides a general overview of the Children's Oncology Group (COG) study AOST1321. It tells who is eligible and gives basic information about the study. More details about the study are in the consent form. You can get this from your oncologist.

AOST1321 is a Phase II clinical trial. A trial is another word for a study. This study (clinical trial) is a therapeutic clinical trial. That means it is done to learn about a treatment - its safety and how well it works. The purpose of a Phase II trial is to learn if a new treatment works in treating a specific type of cancer and how it affects the body.

In a Phase II trial, patients with a specific type of cancer receive a new treatment using a dose that was found to be safe in a Phase 1 trial. Patients are checked for side effects of the treatment and to see whether the cancer shrinks or goes away.

Phase II trials are offered to patients whose disease has not responded to standard types of treatments or to patients whose disease doesn't have a standard treatment.

It is important to understand that participating in a clinical trial is entirely voluntary. The decision about whether or not to participate will not affect the care provided by the health care team in any way. You can find additional information about participation in clinical trials at Always discuss any questions that you may have with your health care team.

Study Number


Official Title

Phase 2 Study of Denosumab, a RANK Ligand Antibody, for Recurrent or Refractory Osteosarcoma

Study Opening and Closing Date

AOST1321 opened on November 9, 2015 and close to patient accrual on July 20th, 2018.

General Patient Eligibility

  • Age:11 - 50 years of age
  • Diagnosis: osteosarcoma that has returned or stops responding to conventional therapy

Please consult your doctor to determine whether you or your child may participate in this study.

General Background and Study Goal

Patients who have osteosarcoma that no longer responds to treatment or comes back after treatment is complete have a poor outcome with current treatments. Denosumab is a new agent that has shown activity in a variety of cancers including osteosarcoma in laboratory studies. Denosumab is a monoclonal antibody. It is an antibody that is made to attach to specific problem areas within a cancer cell.

The goal of this study is to determine whether denosumab will have an effect in controlling the disease rate or produce a response in patients with osteosarcoma.

Summary of the Treatment

  • Denosumab is given in 28 day cycles
    • Cycle 1: denosumab is injected under the skin (subcutaneous) with a small needle on day 1, day 8 and day 15
    • Cycles 2 through 26: denosumab is given by subcutaneous injection on day 1, every 4 weeks
    • The study may continue for a total of 24 months or 26 cycles
    • Patients will be evaluated for disease response after every 2 cycles of therapy
    • Calcium and vitamin D supplementation are required and will begin with the first dose of denosumab

Special Considerations

  • Denosumab may be harmful to a developing baby. Patients of reproductive age who are sexually active must agree to use a highly effective contraceptive method for the duration of their study participation and for 5 months after the end of study treatment
  • Denosumab can interfere with healing after dental procedures. Dental procedures should be avoided while on denosumab. A dental exam with any needed treatments should be completed prior to starting this therapy
  • The first 15 patients younger than age 18 will have additional blood samples drawn to measure denosumab levels. Most of these will occur at the time of regular follow-up. These are required to participate in the study.

Risks and Side Effects

Chemotherapy can cause side effects during and after treatment. All patients will be closely monitored for possible side effects of the medicines. All risks and side effects will be explained by your treatment team during the consent process. They can answer any questions that you may have about giving permission for your child to be in the clinical trial or other aspects of care. Please refer to the consent form for a detailed explanation of the side effects associated with the treatment on this study.

Contact Information

Your child's oncologist and nurses are the best sources for further information.

Study Chair

Katherine Janeway MD
Dana Farber Cancer Institute


Initial development Name Date
Written by Jill Lee APRN, MSN, CPNP-AC, CPON December 9, 2015
Reviewed/approved by (PI) Katherine A. Janeway, MD, MMSc April 4, 2016
Ongoing review
Reviewed and updated by Jill Lee APRN, MSMSN, CPNP-AC, CPON January 26, 2018
November 8, 2018