Zydelig (idelalisib) is used to treat a certain type of blood cancer called chronic lymphocytic leukemia (CLL) that has come back. It’s a type of targeted therapy that works as a PI3K inhibitor. Zydelig (idelalisib) is approved for adults and is a tablet that’s taken by mouth twice a day. It can cause side effects such as diarrhea and fever. It also has a risk of serious liver problems, gut issues, and infection. Zydelig (idelalisib) is usually given with another cancer medication called Rituxan (rituximab).
Zydelig (idelalisib) is a type of kinase inhibitor. More specifically, it works as a PI3K inhibitor. This means it blocks a kinase or protein called PI3K-delta.
In people with CLL, this protein is too active and sends too many signals for cells to grow. This causes the cancer cells to grow and spread fast.
By blocking PI3K-delta, Zydelig (idelalisib) stops it from sending growth signals to cancer cells. This prevents the leukemia cells from growing or spreading as well.
| Common Brands | Zydelig |
|---|---|
| Drug Class | PI3K inhibitor |
| Controlled Substance Classification | Not a controlled medication |
| Generic Status | No lower-cost generic available |
| Availability | Prescription only |
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Note: Side effects are from people taking Zydelig (idelalisib) with Rituxan (rituximab).
Contact your healthcare provider immediately if you experience any of the following.
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Zydelig (idelalisib) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Some people have had liver problems while taking Zydelig (idelalisib) with other treatments. Sometimes, it can be serious or life-threatening.
A sign of liver problems is having high liver enzyme levels on blood tests. People typically had these signs within the first few months of treatment. Sometimes, the levels go back to normal after pausing Zydelig (idelalisib). Some people could restart it at a lower dose without problems. But others had to stop the medication altogether.
Your oncologist will check your liver with regular blood tests while you’re taking Zydelig (idelalisib). They’ll check every 2 weeks during the first 3 months, every 4 weeks for the next 3 months, and then every 1 to 3 months after that. If your blood tests show a problem, your oncologist might pause your treatment.
Avoid taking other medications that can harm the liver while taking Zydelig (idelalisib). Tell your care team right away if you notice yellow skin or eyes, stomach pain, or a swollen belly. These can be symptoms of liver problems.
Diarrhea can happen at any time while you’re taking Zydelig (idelalisib). Sometimes, it can be severe. Severe inflammation in the gut (colitis) can also happen. If possible, avoid other medications that can cause diarrhea, if possible.
If you have diarrhea while taking Zydelig (idelalisib), drink plenty of fluids to stay hydrated. Tell your care team, especially if you have a lot more bowel movements than usual. They might recommend an over-the-counter medication like loperamide (Imodium A-D). If it's severe, you might need to pause Zydelig (idelalisib) or take steroids to manage this.
In rare cases, some people taking Zydelig (idelalisib) have had a serious lung problem called pneumonitis. This means the lungs have become inflamed. In studies, it’s happened weeks to months after starting the medication.
Tell your oncologist right away if you have a cough, trouble breathing, or a fever. They’ll have you get a chest X-ray or CT scan to look at your lungs. They’ll also probably have you stop Zydelig (idelalisib) while they check what’s going on. If you develop pneumonitis, you might need stop taking Zydelig (idelalisib) completely and take steroids to treat the problem.
Your risk of infection is high with Zydelig (idelalisib). These infections can be serious or even life-threatening. Common infections people had during treatment were pneumonia and sepsis. Some also had a serious fever along with a low white blood cell count, which can be dangerous. Rarely, some people have had a viral infection called cytomegalovirus (CMV).
Your oncologist will prescribe antibiotics for you to take with Zydelig (idelalisib). These antibiotics help prevent Pneumocystis jirovecii pneumonia (PJP), a type of serious pneumonia.
Your oncology care team will also monitor you closely for infection during treatment. This might include testing or examining you for infection. They’ll go over signs of infection to look for at home.
Go to urgent care right away if you have a temperature of 100.4ºF or higher. This means you have a fever. If you have other signs of infection, also call your oncology care team so they can help treat it.
Rarely, some people taking Zydelig (idelalisib) had tears in the gut. This can sometimes be serious and fatal. Most of the time this gut damage happened in studies, people also had moderate or severe diarrhea.
Get medical help right away if you have new or worsening stomach pain, nausea, vomiting, chills, or a fever. They could be signs of gut damage. If it’s confirmed, you’ll need to stop taking Zydelig (idelalisib).
It’s rare, but Zydelig (idelalisib) can cause severe skin reactions that can be life-threatening. They can include Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Another is Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS).
Stop taking Zydelig (idelalisib) and get medical help right away if you notice anything strange with your skin. Watch out for painful blisters, skin wounds, peeling skin, any kind of new rash, or fever. Serious skin reactions need immediate medical care.
It’s possible for some people to have a serious allergic reaction to Zydelig (idelalisib). This can include anaphylaxis. Call 911 right away if you have hives, swelling of your face or lips, throat tightness, or trouble breathing.
Zydelig (idelalisib) taken with Rituxan (rituximab) can cause very low white blood cell counts. To keep you safe, your oncologist will check your blood cell counts with regular blood tests. Your blood cell counts are usually checked at least every 2 weeks for the first 6 months of treatment. They might be checked more often if your counts end up dropping quite low.
If your white blood cell count gets too low, your oncologist might pause Zydelig (idelalisib) until your blood cell counts get back up. You might be able to restart later at a lower dose.
Zydelig (idelalisib) might harm an unborn baby. Because of this, your oncologist might ask you to take a pregnancy test before starting treatment. The test must be negative for you to start taking the medication.
If you can get pregnant, use effective birth control while taking Zydelig (idelalisib) and for 1 month after your last dose. If you’re sexually active with someone who can become pregnant, also use birth control like condoms during treatment and for 3 months after stopping. Tell your oncologist if you or your partner gets pregnant during treatment.
The recommended dose is 150 mg by mouth twice a day.
Your dose might be lower if you have bothersome or serious side effects.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Zydelig (idelalisib) will not be safe for you to take.
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No, Zydelig isn’t a traditional chemotherapy medication. Instead of affecting all fast-growing cells in the body, it works in a more targeted way for CLL. It specifically blocks a protein called PI3K-delta in cancer cells. This stops cancer cells from growing and spreading.
It’s possible. Some people taking Zydelig have had high liver enzyme levels. This can be a sign of liver irritation. In some cases, it can become serious or even life-threatening. Your oncologist will check your liver with regular blood tests. Changes in your liver enzyme levels most often happen in the first 3 months. But your oncologist will keep checking during treatment. If your test results are too high, your oncologist might pause your treatment with Zydelig. Liver irritation often doesn’t cause symptoms. But call your care team if you notice yellow skin or eyes, stomach pain, or a swollen belly. These could be signs of liver problems.
Usually, people who take Zydelig don’t lose their hair. If you notice any hair loss or hair thinning during treatment, talk to your oncology care team. They can discuss possible other causes of hair loss.
Try to avoid medications that can interact with Zydelig. For example, some seizure medications can make Zydelig work less well. Other medications, like clarithromycin or diltiazem (Cardizem), can raise your risk of side effects from Zydelig. Give your oncology care team a full list of your medications. This includes prescription medications, over-the-counter products, and herbal supplements. Also tell them before starting any new medications. Your care team can check for drug interactions. If you can’t avoid a medication, your oncologist might monitor you more closely. They might also suggest changes to your medications to keep you safe.
You usually get Zydelig from a specialty pharmacy. These pharmacies provide medications that need careful monitoring and special handling. The manufacturer works with certain specialty pharmacies. Zydelig isn’t available at regular local pharmacies. Talk to your oncologist about where and how to get the medication.
Avoid breastfeeding while taking Zydelig and for 1 month after your last dose. We don’t know if the medication passes into breast milk. But there’s a risk of serious side effects in the baby if it does. Speak to your oncologist or a lactation expert about safer feeding options.
