Targeting RET

Consider ARROW - a clinical trial of BLU-667 for RET-altered non-small cell lung cancer (NSCLC), medullary thyroid cancer (MTC) and other RET-altered cancers.

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About the ARROW clinical trial

The ARROW clinical trial will test an investigational drug called BLU-667 in people who have RET-altered non-small cell lung cancer (NSCLC), medullary thyroid cancer (MTC) or another solid tumor that has a RET fusion or mutation. It is a phase 1 trial designed to test the safety and the initial clinical activity of BLU-667.

Information about RET-altered cancers

All cancers begin when one or more genes are mutated (altered) and the cell starts to divide and grow out of control. Identifying these genes is important, because drugs can be developed to target them.

RET fusions and mutations are specific alterations that are sometimes found in a gene called RET. This gene provides the instructions for making the RET protein that is involved in important cell functions. RET alterations have been shown to cause non-small cell lung cancer, medullary thyroid cancer and other solid tumors in some people. BLU-667 is an investigational drug that was specifically designed to inhibit (block) altered forms of RET.

Who is eligible
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Who is eligible to participate in the ARROW clinical trial?

You may be eligible to take part in the ARROW clinical trial if you:

Have non-small cell lung cancer (NSCLC) with a known RET fusion or mutation

Have medullary thyroid cancer (MTC). A known RET alteration is not required

Have another solid tumor with a known RET fusion or mutation

Are at least 18 years old

Are not eligible for surgery and have exhausted all standard therapy options

Other eligibility criteria apply and these will be assessed at screening

RET fusions and mutations may be identified by your doctor with a tumor biopsy or a blood test

About the investigational drug
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About the investigational drug

If you take part in the ARROW clinical trial, you would receive the investigational drug BLU-667. BLU-667 comes in a capsule or tablet form, and should be swallowed whole with water, once a day.

What does taking part involve?
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What does taking part in the ARROW clinical trial involve?

*There is no maximum duration for this trial. You will continue with your cycles of treatment until:

  • Your disease worsens
  • You can’t tolerate any side effects you may have
  • You decide to leave the trial
  • The trial doctor decides you should leave the trial
  • The trial sponsor decides to discontinue the trial

About ARROW clinic visits
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ARROW trial clinic visits

During the trial, a variety of health assessments will be conducted to see how you are responding to the investigational drug. In most cases, these assessments will be done at a clinical site.

Health assessments will vary between visits, but may include:

MRI or CT scan

Vital signs(temperature, blood pressure, heart rate and weight)

ECG(painless heart scan)

Blood tests

More information about health assessments and visit length will be found in the informed consent form, which you will need to read and sign if you want to take part in the ARROW clinical trial.

How often will these visits take place?*

Cycle 1

6 times

Cycle 2

2 times

Cycle 3 onwards

Once per cycle

*Please note that these numbers are approximate. One treatment cycle is 28 days.

Find a trial site

Where is the ARROW clinical trial taking place?


Centre Leon Berard, Lyon

Gustave Roussy, Villejuif

Insitut Claudius Regauld, Toulouse


Universitätsklinikum Heidelberg, Heidelberg

Universitätsklinikum Essen, Essen


Istituto Europeo di Oncologia (IEO), Milano

Grande Ospedale Metropolitano Niguarda, Milano

Republic of Korea

Asan Medical Center, Seoul

Seoul National University Hospital, Seoul


National Cancer Centre Singapore, Singapore


Hospital Universitari Vall d'Hebron, Barcelona


National Taiwan University Hospital, Teipei City

United Kingdom

NIHR UCLH Clinical Research Facility, University College of London NHS Foundation Trust, London

Guy's Hospital St. Thomas NHS Foundation Trust, London

United States

Mayo Clinic Cancer Center, Phoenix, AZ

UC Irvine Medical Center, Orange, CA

University of Colorado Cancer Center, Aurora, CO

Georgetown University, Washington, D.C.

Mayo Clinic Cancer Center, Jacksonville, FL

University of Miami Hospitals and Clinics, Sylvester Comprehensive Cancer Center, Miami, FL

Massachusetts General Hospital, Boston, MA

University of Michigan Health System, Ann Arbor, MI

Mayo Clinic Cancer Center, Rochester, MN

Washington University School of Medicine, Saint Louis, MO

Duke University Medical Center, Durham, NC

Cornell University, New York, NY

Oregon Health and Science University, Portland, OR

University of Pennsylvania, Philadelphia, PA

MD Anderson Cancer Center, Houston, TX

University of Washington, Seattle Cancer Care Alliance, Seattle, WA

More information about this clinical trial, including participating trial sites, is available on Last updated: 30 Jan 2019.

How can I learn more about the ARROW trial?

If you think you meet the criteria specified above and are interested in taking part in the ARROW trial, or you would simply like more information, please call: +1 617-714-6707 or email: A member of our team will talk you through the next steps and will connect you to a suitable trial doctor.

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