Treatment Name: Rituximab (Rituxan®)
How does rituximab (Rituxan®) work in ITP?
Rituximab is an antibody that is designed to target and bind to a protein on the surface of B-cells (also known as B-lymphocytes).
In ITP, B-cells are responsible for producing antibodies (similar to rituximab) that happen to destroy your platelets, instead of fighting infection.
When rituximab binds to B-cells, it helps your immune system destroy the B-cell. By decreasing these B-lymphocytes, the production of antibodies that attack platelets decreases or goes away altogether.
Goals of therapy:
When the platelet count is less than 30 k/μL, patients are at an increased risk for spontaneous (sudden) bleeding and excessive bleeding from an injury, such as a fall. For patients with ITP, rituximab can be given to increase the number of platelets in the blood when platelets are low.
By increasing the platelet count to a goal of usually 50 k/μL or higher, the risk of bruising and bleeding (both spontaneous and injury-induced) is decreased.
Note: to increase the likelihood of response, dexamethasone (Decadron®) may be given with rituximab therapy for ITP.
- Rituximab intravenous (I.V.) infusion once a week for four weeks (4 total doses). The time of infusion varies depending upon tolerability
- Pre-medication with acetaminophen (Tylenol®) and diphenhydramine (Benadryl®) are commonly given before each dose of rituximab to help prevent infusion-related reactions
Estimated total infusion time for this treatment:
- Up to eight hours for the first dose; as short as 90 minutes for subsequent doses
- Infusion times are based on clinical studies, but may vary depending on doctor preference or patient tolerability. Pre-medications and intravenous (I.V.) fluids, such as hydration, may add more time
Rituximab is usually given in an outpatient infusion center, allowing the person to go home afterwards. On occasion, it may be given in the hospital if platelets are very low.
Rituxmab is repeated every seven days (Days 1, 8, 15 and 22) for four total doses. In most cases, only one treatment course of rituximab is needed; however, additional treatments with rituximab may be given in some cases at the discretion of your doctor.
Click here for the common rituximab starting dose for ITP.
In clinical studies, the most commonly reported side effects of rituximab are shown here. Side effects sometimes have percentage ranges [example: 1 – 9%] because they differed between clinical studies:
- Infection (up to 40%)
- Bleeding (38%)
- Infusion reactions (15%)
- Influenza, "the flu" (15%)
- Headache (1 - 9%)
- Bronchitis (7%)
- Chills or fever (3 - 7%)
- Sinus infection (5%)
- Skin rash (4 - 5%)
- Throat discomfort (2 - 5%)
- Abdominal discomfort (4%)
- Anemia [low red blood cells] (4%)
- Blood clots (4%)
- Tingling or burning sensation of the skin (2%)
- Cough (2%)
- Pneumonia (2%)
- Back pain (2%)
- High blood pressure and heart rate (1%)
Note: it is likely that infection risk is in part due to steroid treatment commonly given with rituximab. Additionally, bleeding may be the result of ITP and having a low platelet count, rather than a true side effect of rituximab.
About 2% of patients discontinued rituximab due to unacceptable side effects.
How often is monitoring needed?
Labs (blood tests) may be checked before treatment and as often as every day until stable. Labs often include: Complete Blood Count (CBC), Comprehensive Metabolic Panel (CMP), plus any others your doctor may order.
How often is imaging needed?
Imaging is not typically needed to monitor response or side effects from this rituximab when use for ITP.
How might blood test results/imaging affect treatment?
Depending upon the platelet count and other results, your doctor may advise to continue rituximab as planned, delay the next dose until the side effect goes away, or switch to an alternative therapy if the goals of therapy are not met.
- Premedications such as diphenhydramine (Benadryl®), acetaminophen (Tylenol®), and hydrocortisone (Solu-Cortef®) may be given before rituximab to help avoid infusion related reactions
- The first dose of rituximab is often the most difficult to tolerate. It may lead to fever, shaking, and chills even if medications are given beforehand to help prevent these side effects. Side effects generally go away when the rituximab is stopped. It may then be restarted at a slower rate. Most patients are able to receive the entire dose, although it may take longer. In most cases, after the first dose is well tolerated, rituximab can be given over 90 minutes
- A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately. Additionally, some medications may decrease the platelet count or increase the risk of bleeding and may be unsafe while your platelet count is low.
- 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 Rituximab (Rituxan®), 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 Rituximab (Rituxan®). Depending upon your income, they may be able to help cover the cost of:
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 Rituximab (Rituxan®) 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.
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 Rituximab (Rituxan®)
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 an Antibody?
An antibody is a small protein shaped like a “Y” that can attach to specific things in the blood, such as bacteria or a B-lymphocyte.
- Once an antibody binds to something, your immune system may attempt to get rid of it
Common rituximab starting dose for ITP
Rituximab 375 mg/m2 intravenous (I.V.) infusion once a week for four weeks (4 total doses; Days 1, 8, 15, and 22)
If you are interested in reading the clinical trials results, please click on references below:
1) Ghanima W, Khelif A, Waage A, et al. Rituximab as second-line treatment for adult immune thrombocytopenia (the RITP trial): a multicentre, randomised, double-blind, placebo-controlled trial. Lancet 2015;385:1653-1661.
2) Khellaf M, Charles-Nelson A, Fain O, et al. Safety and efficacy of rituximab in adult immune thrombocytopenia: results from a prospective registry including 248 patients. Blood 2014;124:3228-3236.
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.
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 status, 2) 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
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein
13) Serum glucose
14) Serum calcium
What is k/μL?
It is an abbreviation for thousand per microLiter, which is a measurement of quantity per volume unit of blood.