Matching Your Strength
with Clinical Research

Because Managing
Sickle Cell Disease
Symptoms is Not Enough

The STRONG SCD study is evaluating an oral
investigational drug designed to lessen SCD complications.


The STRONG SCD study is being conducted to help advance research into an oral investigational drug for people with sickle cell disease (SCD). It is evaluating the investigational drug—compared to placebo (looks like the investigational drug but does not contain any active ingredient)—to understand how it affects people with SCD and whether it can lessen complications, including pain crises.

Study participation provides the opportunity to help advance knowledge and contribute to research that may help the SCD community.

Watch the video below to learn more about sickle cell disease and the STRONG SCD clinical study.

The Investigational Drug

Designed to target the underlying cause of symptoms.

Sickle cell disease is an inherited red blood cell disorder that causes red blood cells to deform into a sickle shape, impacting blood flow to organs and tissues. The investigational drug is designed to increase the production of cGMP, something the body produces naturally.

Researchers believe that increasing cGMP may help improve blood flow and reduce inflammation while boosting the number of healthy red blood cells in people with sickle cell disease. By doing so, they believe that more nutrients will be able to get to the critical organs that need them, lessening the risk for disease complications.

Study Participation


If you qualify and choose to participate, you will have a 3-in-4 (75%) chance of receiving the investigational drug and a 1-in-4 (25%) chance of receiving the placebo. The placebo looks like the investigational drug but does not contain its active ingredients(s). Both are taken once daily, by mouth. Participation lasts approximately 4-5 months and includes 8 visits to the study center and 6 telephone calls.

8 Visits to the Study Center
(over 4-5 Months)

6 Telephone Calls

It’s natural to have questions about participation. The study doctor and his or her staff can answer your questions so that you have all the information you need to make a decision.

1 visit

  • The study doctor and his / her staff will perform medical tests and assessments to determine if you are eligible to participate.
  • If you are eligible to participate, you will enter the Run-in Period.

1 visit

  • You will continue to have medical tests and assessments.
  • You will receive either the investigational drug or placebo. You will not know which one you are receiving.
  • You will be given an eDiary and asked to record in it daily.

5 visits; 6 telephone calls

  • You will continue to have medical tests and assessments.
  • You will be randomly assigned (like drawing straws) to receive either the investigational drug or placebo (inactive substance).
  • You will have a 3-in-4 (75%) chance of receiving the investigational drug and a 1-in-4 (25%) chance of receiving the placebo. You will not know which one you are receiving.
  • You will be asked to record in the eDiary daily.

1 visit

  • You will return to the study site for final medical tests and assessments.

Neither you nor your insurance provider will be charged for the costs of any tests or procedures performed as part of the clinical research study.

All study participants will receive the following at no cost:

Investigational drug or placebo

Study-related care, medical tests and assessments

Visits with a doctor experienced in treating SCD

Participants may be reimbursed for their time and travel.


A Consideration for Parents of Adolescents
with Sickle Cell Disease (SCD)

The STRONG SCD study is enrolling patients ages 16–70. If you are a parent or legal guardian of an adolescent 16–17 years of age diagnosed with sickle cell disease, you may want to consider discussing the STRONG SCD study as a potential option. To see if your child may be eligible to participate, please answer a few questions. You must be 18 years of age or older to complete the questionnaire.


If you and your child decide on participation, and your child meets the preliminary eligibility criteria, you will be given an opportunity to speak with the study doctor and / or the study staff to learn more and to ask questions. Both you, as the parent or legal guardian, and your child will be asked to provide your consent to participate.

About Clinical Studies

Clinical research studies play an important part in the development of medical treatments. They are conducted to test investigational drugs to determine if they may be safe and effective treatment options for use in the future. In some studies, the investigational drug is compared to a placebo.

Participation in a clinical research study is always voluntary. If you decide to participate, you may withdraw at any time and for any reason. If you decide not to participate, your decision will not affect the care you are receiving now or may receive in the future.

A Note on the Study Sponsor

The STRONG SCD study, which was previously sponsored by Ironwood Pharmaceuticals, is now sponsored by Cyclerion Therapeutics. Cyclerion was spun out of Ironwood as an independent, publicly traded company in April 2019 and is focused on developing therapies for patients with serious and orphan diseases.

The Importance of Clinical Research for Sickle Cell Disease (SCD)

With only two approved treatments, there is an urgent need for new, innovative treatments for patients with SCD—not only for treatments that prevent painful crises and other acute complications, but also for treatments that address the daily symptoms of the disease, including chronic pain. Without people volunteering to be part of clinical research studies (like STRONG SCD), the development and discovery of potential new treatment options would not be possible.

What Is a Placebo?

A placebo is something that looks exactly like the investigational drug, and is delivered in exactly the same way, but does not contain the investigational drug’s active ingredient(s). Placebos help scientists to see whether any changes are due to the investigational drug in question or some other factor.

Starting the Conversation

If you are interested in participating and meet the general eligibility criteria, you will be given an opportunity to speak with the study doctor or his / her staff and ask questions. You also will be provided with a document called an “Informed Consent Form” that explains the study in detail. You may take the document home with you to review and discuss with family and friends while you consider participation.