Hydroxyurea-based treatment for sickle cell anemia previously available for pediatric patients now approved for use in adults

2/16, 1:00 PM (Source: GlobeNewswire)

ROSEMONT, PA, Feb. 16, 2022 (GLOBE NEWSWIRE) -- Medunik USA is pleased to announce that Siklos® (hydroxyurea), previously indicated to reduce the frequency of painful crises and to reduce the need for blood transfusions in pediatric patients, 2 years of age and older, with sickle cell anemia with recurrent moderate to severe painful crises4, has now been approved for use in adults for the same indication.

Siklos® has a Boxed Warning regarding low blood cell counts and cancer; please read Important Safety Information below.“

Siklos® has been a valuable and effective treatment option for children so it is very useful to now have it available for them to continue as they grow into adults. Besides being a new treatment option for adults, Siklos® has the advantage of being the only formulation of hydroxyurea available in breakable tablet form that can be dissolved in a small amount of water for those who have difficulty swallowing pills or capsules,” said Dr. Wally Smith, Director of the Virginia Commonwealth University Adult Sickle Cell Disease Program in Richmond, Virginia.

Sickle cell anemia is the most common inherited blood disorder, resulting in the production of abnormal hemoglobin, known as hemoglobin-S, responsible for the sickling of red blood cells. This disease affects nearly 100,000 Americans, decreases life expectancy by 25 to 30 years, induces significant morbidity and, may therefore, reduce quality of life1,2. Most of those affected are of African ancestry; a minority are of Hispanic or southern European, Middle Eastern or Asian Indian descent3.

“Medunik USA is very proud to expand the availability of Siklos® as a new treatment option for adults with sickle cell anemia as part of our commitment to help Americans suffering from rare diseases. They deserve to have effective treatment options as much as those with more common conditions,” said Tanya Carro, Executive Vice-President of Medunik USA.

The approval of the new adult indication was based on data from the ESCORT-HU study which evaluated the efficacy and safety of Siklos® in 1,077 adults with sickle cell disease, of which 436 were naïve to hydroxyurea treatment. There were 370 evaluable patients who had at least 12 months follow-up.4

The most common side effects to Siklos® include infections and low white blood cells in children and infections, headache and dry skin in adults.

Siklos® is available in convenient 100 mg scored tablets and triple-scored 1000 mg tablets to permit flexibility in dosing for patients based on their weight and other factors. For more information about Siklos® tablets, please visit siklosusa.com

Medunik is committed to providing Siklos® at the lowest possible cost to all patients. That is why the company offers cost savings and free home delivery through the Siklos At Home™ program for eligible patients.

Medunik USA is part of the Duchesnay Pharmaceutical Group, which has recently come under new ownership by its Executive Team. “This new indication for Siklos® is part of our plan and commitment to help those with rare diseases and many others with our growing portfolio of important therapies,” said Eric Gervais, President of the Duchesnay Pharmaceutical Group. These significant milestones were made possible with the valued participation of BMO Bank of Montreal.


SIKLOS is a prescription medicine that is used to reduce the frequency of painful crises and reduce the need for blood transfusions in adults and children, 2 years of age and older, with sickle cell anemia with recurrent moderate to severe painful crises. It is not known if SIKLOS is safe and effective in children less than 2 years of age.


See Full Prescribing Information for complete Boxed Warning.

Low blood cell counts are common with SIKLOS, including low red blood cells, white blood cells, and platelets, and can be severe and life threatening. If your white blood cell count becomes very low, you are at increased risk for infection. Your healthcare provider will check your blood cell counts before and every 2 weeks during treatment with SIKLOS. Your healthcare provider may change your dose or tell you to stop taking SIKLOS if you have low blood cell counts. Tell your healthcare provider right away if you get any of the following symptoms: fever or chills; shortness of breath; body aches; unusual headache; feeling very tired; bleeding or unexplained bruising.

Cancer. Some people have developed cancer, such as leukemia and skin cancer, after taking SIKLOS for a long time. Your healthcare provider will check you for cancer. You should protect your skin from the sun using sunblock, hats, and sun-protective clothing.


  • SIKLOS can harm your unborn baby.
  • For females taking SIKLOS who can become pregnant:
    • You should talk with your healthcare provider about the risks of SIKLOS to your unborn baby.
    • You should use effective birth control during treatment with SIKLOS and for at least 6 months after treatment with SIKLOS.
    • Your healthcare provider will perform a pregnancy test before you start treatment with SIKLOS. Tell your healthcare provider right away if you become pregnant or think you may be pregnant.
  • For males taking SIKLOS:  SIKLOS can affect your sperm. If you have a female sexual partner who can become pregnant, you should use effective birth control during treatment with SIKLOS and for at least 6 months after treatment.
  • SIKLOS may cause fertility problems in males. Talk to your healthcare provider if this is a concern for you.

Do not take SIKLOS if you are allergic to hydroxyurea or any of the ingredients in SIKLOS. See the Medication Guide for a list of the ingredients in SIKLOS.

Read the Instructions for Use for step-by-step instructions on how to prepare a dose of SIKLOS.

  • Take SIKLOS exactly as your healthcare provider tells you to take it.
  • Take SIKLOS 1 time a day at the same time each day.
  • Swallow the tablets with a glass of water. If you are not able to swallow SIKLOS tablets, you can dissolve your prescribed dose in a small amount of water in a teaspoon and swallow right away.
  • SIKLOS tablets must be handled with care.

Tell your healthcare provider about all of your medical conditions, including if you:

  • have kidney problems or are receiving hemodialysis
  • have liver problems
  • have human immunodeficiency virus (HIV) or take HIV medicines. Taking SIKLOS with certain HIV medicines can cause serious reactions and may lead to death.
  • have increased levels of uric acid in your blood (hyperuricemia)
  • have a history of receiving interferon therapy or are currently receiving interferon therapy
  • have leg wounds or ulcers
  • plan to receive any vaccinations. You should not receive “live vaccines” during treatment with SIKLOS.
  • are pregnant or plan to become pregnant. See “What is the most important information I should know about SIKLOS?”
  • are breastfeeding or plan to breastfeed. It is not known if SIKLOS can pass into your breast milk. Do not breastfeed during treatment with SIKLOS.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

SIKLOS may cause serious side effects, including:
See “What is the most important information I should know about SIKLOS?”

  • Skin ulcers, including leg ulcers, and death of skin tissue (gangrene) have happened in people who take SIKLOS. This has happened most often in people who receive interferon therapy or have a history of interferon therapy. Your healthcare provider will decrease your dose or stop treatment with SIKLOS if you develop any skin ulcers.
  • Enlarged red blood cells (macrocytosis). Macrocytosis is common in people who take SIKLOS and can make it difficult to detect a decrease of folic acid. Your healthcare provider may prescribe a folic acid supplement for you.
  • Hemolytic Anemia, the fast breakdown of red blood cells, has happened in people who take SIKLOS. Tell your healthcare provider if you develop yellowing of your skin (jaundice) or blood in your urine. Your healthcare provider may do blood tests if you have persistent or worsening anemia not related to sickle cell anemia.

The most common side effects of SIKLOS in children include: infections and low white blood cells.

The most common side effects of SIKLOS in adults include: infections, headache, and dry skin.

These are not all the possible side effects of SIKLOS.

You are encouraged to report negative side effects of prescription drugs to the FDA at www.fda.gov/medwatch, or 1-800-FDA-1088.

Please read the Full Prescribing Information, including Boxed Warning, Medication Guide and Instructions for Use, at www.SIKLOSusa.com.

About Medunik USA
Based in Pennsylvania, Medunik USA is part of the Duchesnay Pharmaceutical Group and works to improve the health and quality of life of Americans living with rare diseases by making orphan drug therapies available in the United States. With strategic partnerships at the global level, the company has critical experience in approval and market access processes as well as the marketing of orphan drug therapies. Medunik USA makes critical medications to treat rare diseases available to American patients who might not otherwise have access to these medications. For more information, visit www.medunikusa.com.

About the Duchesnay Pharmaceutical Group
The Duchesnay Pharmaceutical Group, with its affiliated companies, is headquartered in Blainville, Quebec. The group consists of five pharmaceutical companies to meet the needs of patients in Canada, the U.S., and abroad. The companies are Duchesnay and Duchesnay USA, both dedicated to women's health; Médunik Canada and Medunik USA, which provide treatments for rare diseases; and Analog Pharma, an American generic drugs company, specializing in authorized generics and orphan drugs. From its state-of-the-art manufacturing plant, Duchesnay can export its innovative treatments to more than 50 countries.

Duchesnay and Medunik, through their proprietary research and development, and through partnerships, offer innovative treatments for a variety of medical conditions in women's health, urology, oncology as well as for rare diseases. The group of companies recognizes the dedication and professionalism of its employees and promotes a positive culture and flexible work environment. It is deeply committed to environmental responsibility and giving back to the community through the support of various charitable organizations. For more information, please visit duchesnay.com, medunik.com and analogpharma.com.


  1. Platt OS et al. Mortality in sickle cell disease. Life expectancy and risk factors for early death. The New England Journal of Medicine 330, 1639-1644, doi:10.1056/NEJM199406093302303 (1994).
  2. McGann PT and Ware RE, Hydroxyurea therapy for sickle cell anemia. Expert opinion on drug safety 14, 1749-1758, doi:10.1517/14740338.2015.1088827 (2015).
  3. National Heart, Lung, and Blood Institute, National Institutes of Health, Sickle Cell Disease, https://www.nhlbi.nih.gov/health-topics/sickle-cell-disease
  4. Siklos® (hydroxyurea) tablets, for oral use [Prescribing Information]. Addmedica, December 2021.

Sabrina Sévigny
Capital-Image Inc. for the Duchesnay Pharmaceutical Group
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