Immune thrombocytopenia, also known as ITP, is a condition that causes low platelet levels in your body. Platelets are created by your bone marrow and work to make your blood clot and to stop bleeding. ITP is an autoimmune condition that causes the immune system to attack and destroy platelets. This, in turn, can cause bleeding problems.
Nplate (“N-plate”) was approved in 2008 to help increase platelet count in people with ITP.
How Does It Work for ITP?
There is no cure for ITP. Its symptoms can vary from person to person, with some people not having any symptoms. Because ITP causes low platelets, the main side effects that you or your child may have are bleeding problems, which may show up in different ways as listed below.
- Small red dots on the skin called petechiae
- Purple spots in the skin called purpura
- Bruising easily from minor bumps, especially in your arms or legs (ecchymosis)
- Frequent or heavy nosebleeds
- In women, having periods with heavy bleeding (menorrhagia)
- Bleeding gums
- Blood in the urine (hematuria)
Nplate is known as a platelet booster. It is approved to be used in children 1 year of age and older and in adults who have tried other medicines or procedures that have not worked well enough for their ITP. These include trying corticosteroids (steroid medicines), trying immunoglobulin medicines (which are antibodies that help your immune system), or having your spleen removed (splenectomy). Your spleen is part of your immune system, and in ITP, the spleen can contribute to your platelets getting destroyed. Nplate may not be the first medicine your health care provider gives you or your child for your ITP.
A protein called thrombopoietin (TPO) helps your bone marrow make platelets. People who have ITP have low levels of TPO. Nplate works the same way as TPO, which tells the bone marrow to make platelets.
Nplate is used to keep your platelets above 50,000 per microliter to lower your risk of bleeding. The medicine does not work to increase your platelet count to normal levels, which can be anywhere from 150,000 to 450,000 platelets per microliter.
How Will I Receive Nplate?
Nplate is given as a shot under the skin. It will be given to you or your child by a health care provider once a week. Your dose will generally depend on your weight. Your health care provider may adjust your dose depending on how well the medicine is working to increase your platelet count. Try to keep all appointments with your health care provider. If you miss a dose of Nplate, call your health care provider right away to reschedule your next dose.
How Was It Studied for ITP?
Multiple clinical trials were done in adults and children to test the efficacy and safety of Nplate.
Adults
Studies 1 and 2 included people who had tried at least one medicine for their ITP and had a platelet count of 30 billion cells per liter or less. Study 1 included people who had not had their spleen removed, while Study 2 included people who had their spleen removed. People in the study either received Nplate or a placebo containing no medicine every week for 24 weeks. Researchers measured how well people responded to Nplate based on their platelet count. In this study, it was defined as the percentage of people who had a platelet count of 50 billion cells per liter or more for at least 6 of the last 8 weeks of treatment. The study included White people (82%), Black people (7%), Hispanic or Latino people (6%), and those classified as “Other” (5%), which included Asian people and Native Hawaiians or other Pacific Islanders. The average age of people in the study was 52 years old, and a higher number of people in the study were women (65%).
Study 3 included people who had tried at least one first-line medicine for their ITP and had a platelet count of 30 billion cells per liter or less. Researchers measured how well people responded to Nplate based on their platelet count. In this study, it was defined as the number of months in which people had a platelet count of 50 billion cells per liter or more while receiving Nplate over a 12-month period. The study included White people, Black people, and Asian people, with a majority of people in the study being White. The median age was 39 years old, and a higher number of people in the study were women (59%).
Children
Study 4 included children who were 1 to 17 years of age who had tried at least one medicine for their ITP and had a platelet count of 30 billion cells per liter or less. The children in the study received either Nplate or a placebo for 24 weeks. Researchers measured how well the children responded to Nplate based on their platelet count. In this study, it was defined as the percentage of children with a platelet count of 50 billion cells per liter or more for at least 6 of the last 8 weeks of treatment. The study included White people (75%), Black people (10%), Asian people (10%), and those classified as “Other” (5%). A higher number of children in the study were girls (56%), and the median age was around 10 years old.
Study 5 included children who were 1 to 17 years of age who had a platelet count of 30 billion cells per liter or less. The children in the study received either Nplate or a placebo for 12 weeks. Researchers measured how well the children responded to Nplate based on their platelet count. In this study, it was defined as the percentage of children who had a platelet count of 50 billion cells per liter or more for 2 consecutive weeks. The study included White people (59%), Black people (23%), Hispanic or Latino people (14%), and those classified as “Other” (5%). A higher number of children in the study were boys (73%), and the median age was 10 years old.
Study 6 included children who were 1 to 17 years of age who had tried at least one medicine for their ITP. The children in the study received Nplate. The study looked to see the time children had a platelet response, which was defined as 50 billion cells per liter or more, during the first 6 months of treatment. The study included White people (81%), Black people (5%), Asian people (6%), and those classified as “Other” (8%). The median age was 10 years old.
What Were the Benefits?
Studies 1 and 2
- Among those who had their spleen removed, 38% of people receiving Nplate achieved a platelet count of 50 billion cells per liter or more, compared to 0% of people who took a placebo.
- Among those who did not have their spleen removed, 61% of people receiving Nplate achieved a platelet count of 50 billion cells per liter or more, compared to 5% of people who took a placebo.
Study 3
- On average, people had a platelet count of 50 billion cells per liter or more for 9 out of the 12 months of the study.
Study 4
- Fifty-two percent of children who received Nplate had a platelet count of 50 billion cells per liter or more, compared to 10% of children who received a placebo.
Study 5
- Eighty-eight percent of children who received Nplate had a platelet count of 50 billion cells per liter or more for 2 consecutive weeks, compared to 0% of children who received a placebo.
Study 6
- A platelet count of 50 billion cells per liter or more was achieved a median of 50% of the time during the first 6 months of treatment.
How Long Does It Take to Work?
According to clinical studies, Nplate worked to increase platelet levels in as little as 2 weeks after starting the medicine. You or your child may notice less bleeding or bruising as your platelet levels go up. Your health care provider may monitor your platelets through blood tests while you are receiving Nplate. Based on this, your health care provider can find out how Nplate is working for you, if more medicine needs to be added, or if you may need to switch to a new medicine altogether.
What Are the Possible Side Effects, and How Can I Manage Them?
The most common side effects seen with Nplate in adults are listed below.
- Joint and muscle pain
- Dizziness
- Trouble sleeping
- Pain in your arms and legs
- Stomach pain
- Shoulder pain
- Upset stomach (or indigestion)
- Numbness, tingling, or burning in your arms, feet, or face
- Headache
- Bronchitis
- Inflammation of the sinuses (sinusitis)
- Nausea, vomiting, or diarrhea
- Infection in the nose or throat, a sore throat, or common cold symptoms
- Coughing
- Mouth and throat pain
The most common side effects seen with Nplate in children are listed below.
- Bruising
- Infection in the nose or throat, a sore throat, or common cold symptoms
- Mouth and throat pain
Talk to your health care provider if you are having joint or muscle pain; pain in your arms and legs; shoulder pain; numbness, tingling, or burning in your arms, feet, or face; or a cough. Your health care provider can advise you on how to best manage these symptoms.
Talk to your health care provider if you feel congested in your face or chest; have trouble breathing; or have a blocked nose, runny nose, body aches, or a fever. These symptoms may be a sign of bronchitis or a sinus infection. Your health care provider may prescribe you prescription medicines to treat this or may ask you to keep over-the-counter medicines on hand such as pain medicines (acetaminophen, ibuprofen), cough and cold medicines, or decongestants. Drinking plenty of water or using a humidifier can also help. Always follow the instructions of your health care provider.
If you vomit or have nausea, make sure you are drinking plenty of water to prevent yourself from becoming dehydrated, and call your health care provider if your symptoms are not getting any better. You can also take these steps to lessen the symptoms:
- Avoid greasy food.
- Eat bland food such as toast and crackers.
- Avoid strong smells.
- Eat slowly.
You may get diarrhea while you are taking Nplate. To limit diarrhea, you can try simple steps such as eating bland foods like rice, bananas, and toast; drinking plenty of water; and lowering the amount of caffeine you are drinking. Call your health care provider if your diarrhea symptoms are not improving or are becoming worse.
Do not drive or operate heavy machinery until you know how the medicine affects you, as it can cause dizziness.
Nplate can cause sleeping problems. Following a sleeping schedule, avoiding screen time before bed, limiting caffeine, and techniques such as meditating can help.
You may get headaches while receiving Nplate. Taking over-the-counter medicines such as acetaminophen or ibuprofen can help, but call your health care provider if this gets worse.
Nplate can cause an upset stomach, also known as indigestion or dyspepsia. You may have discomfort or pain in your stomach; feel full too soon while eating; feel uncomfortable after eating; get bloated or nauseated; or have gas or heartburn. Taking over-the-counter medicines such as antacids, famotidine, or omeprazole can help with indigestion symptoms. Talk to your health care provider if your indigestion symptoms do not improve or get worse.
Talk to their health care provider if you or your child gets bruising, cold symptoms, or mouth and throat pain. Your child’s health care provider can advise you on how to best manage these symptoms.
What Type of Drug Interactions Can Happen?
There currently are no noted drug interactions with Nplate. But it is important to avoid taking medicines that can increase your risk of bleeding and to avoid situations where you may hurt yourself while you are receiving Nplate. Always tell your health care provider about all your or your child’s prescription and over-the-counter medicines, and supplements, including any changes to your or your child’s medicines. Your health care provider will decide if any of the medicines you or your child is taking can increase the risk of bleeding.
Is There a Cost Savings Program?
The drugmaker offers a program that may make you eligible to pay as little as $0 for you or your child’s Nplate prescription. Whether you are eligible depends on the type of health insurance you or your child has. You can find out more information by calling 866-264-2778 or by visiting www.nplate.com/support#financial-assistance-container.