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Treatment Name: Fostamatinib (Tavalisse®)

Fostamatinib (Tavalisse®) is a Treatment Regimen for Immune Thrombocytopenic Purpura (ITP)

How does fostamatinib (Tavalisse™) work in ITP?
Fostamatinib binds to and inhibits a protein called Spleen tYrosine Kinase or “Syk” which helps stop the immune system from destroying platelets. 

Specifically, inhibiting Syk may prevent macrophages from engulfing and platelet-coated antibodies

Goals of fostamatinib (Tavalisse™) therapy:
Fostamatinib is taken to increase platelets in the blood stream when platelets are low. It is usually taken with a goal of increasing platelets to 50 k/μL or higher and is not taken with the goal of "normalizing" the platelet count. Fostamatinib may be used for patients with chronic ITP that have low platelet counts after receiving a previous treatment such as dexamethasone, prednisone, immune globulin, or for patients with low platelets after spleen removal.

Fostamatinib (Tavalisse™) is only available as a prescription drug.


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  • Usual fostamatinib (Tavalisse™) starting dose: 100 mg oral tablet by mouth twice daily with or without food

If the platelet count remains below 50 k/μL after 4 weeks of taking fostamatinib, the dose may be increased to a 150 mg oral tablet by mouth twice daily as needed to decrease the risk of bleeding

Fostamatinib is usually taken at home. It is usually taken until it no longer works or unacceptable side effects are experienced.

Note: Individual doses may vary based upon your Doctor's recommendation, or drug availability.

Side Effects

In clinical studies, the most commonly reported side effects of fostamatinib (Tavalisse™) are shown here:

  • Diarrhea (31%)
  • High blood pressure (28%)
  • Nausea (19%)
  • Dizziness (11%)
  • Increase in liver enzymes (9-11%)
  • Sinus infection or pneumonia (11%)
  • Skin rash (9%)
  • Stomach pain (6%)
  • Fatigue (6%)
  • Chest pain (6%)
  • Neutropenia [low white blood cells] (6%)

On average, roughly 10% of patients discontinue treatment with fostamatinib due to unacceptable side effects. The most common side effects leading to a temporary pause in taking fostamatinib included diarrhea and flu-like illness. The most common side effects leading to fostamatinib dose reduction were diarrhea, high blood pressure, and liver enzyme elevation.

Side effect videos Side Effect Videos
DiarrheaDiarrheaNausea and VomitingNausea and VomitingPainPainFatigue Fatigue


How often is monitoring needed?
Labs (blood tests) may be checked before fostamatinib treatment and then monthly until your platelets are stable. If you are actively bleeding or bruising, the platelet count may be checked more regularly, such as once daily, until the bleeding resolves. Labs often include: Complete Blood Count (CBC), Comprehensive Metabolic Panel (CMP), plus any others your doctor may order. Your blood pressure should be monitored every 2 to 4 weeks while on therapy.

How often is imaging needed?
Imaging is not typically needed to monitor response or side effects from this drug; however, imaging may be used if there are concerns for bleeding. Imaging may include: magnetic resonance imaging (MRI) or computerized tomography (CT) scans.

How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise to continue fostamatinib as planned, reduce the dose, delay treatment until the side effect goes away, or switch to an alternative therapy. Fostamatinib (Tavalisse™) treatment should be discontinued if platelet levels have not improved to a level which prevents bleeding after 12 weeks of therapy.

Questions to Ask Your...

A better understanding of your treatments will allow you to ask more questions of your healthcare team. We then hope that with the answers, you will get better results and have greater satisfaction with your care. Because we know it's not always easy to know what questions to ask, we've tried to make it easy for you!

Choose any healthcare provider below to see common questions that you may want to ask of this person. Then, either print each list to bring to your clinic visits, or copy the questions and send them as a message to your healthcare team through your electronic medical record.

ChemoExperts Tips

  • Increases in blood pressure may happen after starting fostamatinib therapy. If you currently are taking medications to control blood pressure, the doses of these medications may need to be adjusted or you may need to take additional medications to help control blood pressure while on therapy with fostamatinib. Only 1% of patients experience a medical emergency of severely high blood pressure and rarely is a dose reduction of fostamatinib needed.
  • Diarrhea can be common with fostamatinib. To help prevent complications from diarrhea, drink plenty of water or sports drinks as recommended by your doctor. If needed, over-the-counter medications such as loperamide (Imodium®) can be used to treat diarrhea. Seek medical attention if you are experiencing 3 bowel movements more than usual per day to avoid dehydration
  • Fostamatinib may increase blood levels of common medications used to treat high cholesterol such as simvastatin (Zocor®) and rosuvastatin (Crestor®). Talk to your doctor to see if any dose adjustments should be made to these medications
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions with fostamatinib are prevented or managed appropriately
  • In a pooled analysis of two studies using fostamatinib for patients with chronic ITP, roughly one out of every three patients (34%) received previous treatment with rituximab, nearly one out of every two patients (47%) received either romiplostim or eltrombopag, and roughly one out of every three patients (34%) had already had their spleen removed before trying fostamatinib. In these studies, the number of prior ITP treatments did not affect the chances of responding to fostamatinib. However, more patients with detectable antibodies to platelets responded to fostamatinib (36%) compared to those patients without detectable antibodies to platelets (9%)
  • Clinical trials may exist for ITP. Ask your doctor if any studies are currently enrolling in your area. If not, go to clinicaltrials.gov to search for other centers offering study medications

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Fostamatinib (Tavalisse®), we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Fostamatinib (Tavalisse®). Depending upon your income, they may be able to help cover the cost of:

  • Fostamatinib

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Fostamatinib (Tavalisse®) and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

Emotional Wellness

What is Emotional Wellness?
Emotional wellness is having a positive outlook balanced with a realistic understanding of current life events. This requires both an awareness and acceptance of your emotions. It is with this knowledge that you can develop a plan to take the necessary actions to positively impact your life.

Emotional wellness uses an ongoing process to continually reflect on the stressors of life in a constructive manner to move forward and create happiness.

Because emotional wellness is deeply connected with physical, social, and spiritual wellness, pursuing it often becomes particularly difficult in times of major illness. Despite this difficulty, working toward emotional wellness has been connected to improved treatment outcomes and a higher likelihood of achieving goals of therapy.

Learn more about pursuing emotional wellness while receiving treatment with Fostamatinib (Tavalisse®)

Individual Drug Label Information

Fostamatinib (Tavalisse®)

  • Is an oral tablet available in 100 mg and 150 mg
  • Can be taken with or without food
  • If you miss a dose, skip the missed dose and take your next dose at the regularly scheduled time
  • Store at room temperature, 68°F to 77°F 
  • Dosage adjustments may be required for high blood pressure, live injury, diarrhea, or low white blood cells
  • May interact with St. Johns Wort and certain antifungal and seizure medications. Ask your doctor or pharmacist to review your medications for any possible interactions
  • May interact with grapefruit and grapefruit juice, pomegranate, star fruit, or seville oranges (in marmalade) causing increased blood levels of fostamatinib. This could increase your risk of experiencing side effects. Avoid eating or drinking these foods during treatment 
  • May cause fetal harm if taken while pregnant. Females of reproductive potential should use effective birth control during treatment and for at least one month after stopping treatment
  • Do not breastfeed during treatment and for at least one month after stopping treatment
General side effects from fostamatinib
  • Diarrhea
  • High blood pressure
  • Nausea
  • Liver Injury
  • Sinus infection or pneumonia
  • Skin rash
  • Stomach pain
  • Fatigue
  • Chest pain 
  • Low white blood cells
  • Click on the fostamatinib (Tavalisse®) package insert below for reported side effects, possible drug interactions, and other fostamatinib prescribing information

Side Effect Videos
Nausea and VomitingNausea and VomitingDiarrheaDiarrheaFatigue Fatigue PainPain

See DailyMed package insert.

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1) Bussel J, Arnold DM, Grossbard E, et al. Fostamatinib for the treatment of adult persistent and chronic immune thrombocytopenia: Results of two phase 3, randomized, placebo-controlled trials. Am J Hematol. 2018;93:921-930.

Created: August 1, 2019 Updated: August 22, 2019

What is Immune Thrombocytopenic Purpura (ITP)?

A disorder where platelets decrease in number due to decreased production in the bone marrow and increased destruction in the blood. This can lead to an increased risk of spontaneous bruising or bleeding (without injury), especially when the platelet count drops below 30,000 cells per microliter of blood.

I  = Immune, ITP is caused by a disturbance in the immune system
T  = Thrombocytopenic, a medical term meaning low platelet count
P  = Purpura, a type of bleeding in the skin

ITP is NOT a cancer, but it is commonly managed by hematologists (blood doctors) who often treat blood cancers as well. ITP is an uncommon condition and may be caused by auto-immune disorders, infections, certain medications, or pregnancy. However, in many cases, a cause cannot be identified which gives rise to its other name-idiopathic (meaning “cause unknown”) thrombocytopenic purpura. Although ITP may spontaneously resolve, for some patients lifelong therapy may be needed.

The effectiveness of medications may depend upon the causes of ITP and the ability to remove these causes, or whether a splenectomy (removal of the spleen) has been performed, or is able to be performed.

Deciding on a treatment for ITP is in a way like buying, owning, and driving a car. Think about the following similarities to help you understand which treatment is right for you:

BUYING: "0 - 50 time" (0 to 50 k/µL platelets, instead of 0 - 60 m.p.h) is an important performance feature
Once the platelet count exceeds 50 k/µL, bleeding episodes are rare. Therefore, the time it takes to go from very few platelets to a platelet count over 50 k/µL matters. In general, steroids such as prednisone and dexamethasone have the fastest "0 - 50" time.

  • Although exceptions, the thrombopoeitin receptor agonists romiplostim and eltrombopag usually have a 0 - 50 k/µL platelet time of 1 - 2 weeks
  • Although exceptions, one-half of rituximab recipients have a 0 - 50 k/µL platelet time below 5.5 weeks, and the other half over 5.5 weeks. The response to rituximab is often unpredictable

OWNING: Warranty offered?
A 5-year bumper-to-bumper warranty helps us worry less about something breaking or going wrong with our vehicle after we buy it. Likewise, not all medications used for ITP have a long-lasting effect in keeping the platelet count above 50 k/µL.

  • When it works, rituximab can work for 1 - 2 years, but lasting responses beyond two years are rarer. The 5 year rituximab response rate is estimated at 20 - 25%. When the rituximab "warranty" runs out and platelets fall, patients with ITP that had a long lasting response to rituximab may respond to another course of therapy. Certain insurances require the platelet count to be less than 30 k/µL before it will be covered.
  • When they work, the thrombopoeitin receptor agonists romiplostim and eltrombopag generally have lasting effect beyond that of rituximab. The "warranty" period where the platelet count remains above 50 k/µL often lasts 2 years or longer

DRIVING: Cruise control optional?
The ability for a treatment to maintain the platelet count within the goal range is similar to setting the cruise control on a car.

  • Steroids are given in a pulse (example: dexamethasone daily for 4 consecutive days) or given daily for several weeks (example: prednisone), then decreased over several weeks and eventually discontinued a few months after it is started. As a result, when steroids are no longer taken there is a chance for ITP to relapse
  • Because eltrombopag and romiplostim are administered continuously, these medications have the highest likelihood of keeping the platelet count in the goal range for the long haul
  • Rituximab is typically given once weekly for 4 doses, and usually takes several weeks to determine if it is working (see above), therefore it is difficult to predict who will have a lasting response to this therapy
NOTE: Treatment Options listed below are not all-inclusive. Other treatments may be available. ChemoExperts provides drug information and does not recommend any one treatment over another. Only your Doctor can choose which therapy is appropriate for you.

What is a CBC?

A Complete Blood Count (CBC) is a frequently ordered blood test that tells clinicians the status of your: 1) White blood cell count, 2) Hemoglobin, and 3) Platelet count at the time the test was taken.

Common uses:
1) White blood cell count (WBC): is used to determine infection risk, or response to chemotherapy. Certain chemotherapy agents may harm our good infection-fighting cells. Sometimes chemotherapy may need to be delayed to allow these cells to recover.

2) Hemoglobin: is used to determine if someone is anemic. Anytime the hemoglobin is below 12 g/dL, the person is said to be anemic. Red blood cell transfusions, and sometimes iron can be given to restore the hemoglobin level, but anemia treatment should always aim at treating the underlying cause or condition.

3) Platelet count: is used to determine if the risk of bleeding is increased or if a platelet transfusion is required to prevent bleeding. Certain medications that increase bleeding risk, such as: aspirin, certain chemotherapy agents, and blood thinners, may need to be stopped temporarily until the platelet count is within a safe range.

What is a CMP?

A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.

Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride

Kidney Function:
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)

Liver Function:
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein

Blood sugar:
13) Serum glucose

14) Serum calcium

What is an antibody?

  • An antibody is a small protein shaped like a “Y” that can attach and stick to specific things in the blood, such as a platelet.
  • Once an antibody sticks to something, your immune system may attempt to get rid of it
    • When antibodies stick to platelets, or the cells tha make platelets, the platelet count may be low until the antibodies go away or treatments are given to stop the body from destroying platelets