Brukinsa (zanubrutinib) is a targeted treatment that may be used to treat adults with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and Waldenström's macroglobulinemia (WM).

It may also be given to treat Mantle cell lymphoma (MCL) in people who have received at least one prior treatment for their cancer, and marginal zone lymphoma (MZL) that has returned or did not respond to treatment and who have received at least one certain type of treatment. For both MCL and MZL, approval was given under the accelerated approval scheme and is based on response rate. Continued approval may be contingent upon clinical trial results.

Brukinsa directly inhibits an enzyme, called Bruton’s tyrosine kinase (BTK), by forming a covalent bond with a cysteine residue on the enzyme, preventing its activity. BTK works as a signaling molecule for the B-cell antigen receptor (BCR) and cytokine receptor pathways. Activation of these pathways causes the proliferation of B cells and other interactions, and inhibition has been shown to reduce the growth and spread of malignant B cells.

Brukinsa was first approved in 2019 for MCL, and subsequent approvals for other indications followed. 

Serious hemorrhage, including intracranial or gastrointestinal hemorrhage, hematuria, and hemothorax has occurred in people receiving Brukinsa, 0.3% have been fatal. 30% of people reported bleeding of any grade, excluding purpura and petechiae. Coadministration with antiplatelet or anticoagulants may increase the risk. Your doctor will monitor for signs and symptoms of bleeding and discontinue if intracranial hemorrhage occurs. They may consider withholding Brukinsa for 3 to 7 days pre and post surgery depending on the risk of bleeding. Report any signs of excessive bleeding to your doctor.

Brukinsa affects your immune system. Serious bacterial, viral, or fungal infections have been reported with Brukinsa; 2.9% were fatal and 24% were Grade 3 or higher. Reactivation of hepatitis B has also occurred. Consider prophylaxis for herpes simplex virus, pneumocystis jirovecii pneumonia, and other infections in patients who are at increased risk for infections. Monitor yourself for fever or other signs and symptoms of infection and report them to your doctor.

Blood count abnormalities, including neutropenia, thrombocytopenia, and anemia, have occurred in people receiving Brukinsa. Your doctor will perform regular blood counts and interrupt treatment, reduce the dose, or discontinue treatment as warranted.

Serious cardiac arrhythmias, including Atrial fibrillation and atrial flutter, have been reported in patients treated with Brukinsa. The risk is more likely in those with cardiac risk factors, high blood pressure, and acute infections.  Monitor yourself for signs and symptoms of cardiac arrhythmias (such as palpitations, dizziness, dizziness when standing, and shortness of breath) and report these to your doctor immediately.

Using Brukinsa may increase your risk of developing other cancers, such as non-melanoma skin cancer. Ask your doctor about this risk and what skin symptoms to watch for. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Brukinsa can cause fetal harm when administered to a pregnant woman, including malformations. Women should use effective contraception and avoid becoming pregnant while taking Brukinsa and for 1 week after the last dose. Men should avoid fathering a child during treatment and for 1 week after the last dose.

It is not known if Brukinsa is safe and effective in children.

Take Brukinsa exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take this medicine with a full glass of water.

You may take Brukinsa with or without food.

Swallow the capsule whole and do not crush, chew, break, or open it.

Brukinsa affects your immune system. You may get infections more easily, even serious or fatal infections. Your doctor will need to examine you on a regular basis.

Store at room temperature away from moisture and heat.

Take Brukinsa exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

The recommended dosage is 160 mg orally twice daily or 320 mg once daily until disease progression or unacceptable toxicity occurs.

• Capsules should be swallowed whole with a full glass of water.
• May be taken with or without food. Do not open, break, or chew the capsules.
• The dosage may need to be reduced in those with severe hepatic impairment.

Before you start treatment with Brukinsa, tell your healthcare provider about all of your medical conditions, including if you:

• have bleeding problems
• have had recent surgery or plan to have surgery. Your healthcare provider may stop Brukinsa for any planned medical, surgical, or dental procedure
• have an infection
• have or had heart rhythm problems
• have high blood pressure
• have liver problems, including a history of hepatitis B virus (HBV) infection
• take any other medicines, including prescription and over-the-counter medicines, vitamins, and herbal supplements
• are pregnant or plan to become pregnant. Zanubrutinib can harm your unborn baby. If you can become pregnant, your healthcare provider may do a pregnancy test before starting treatment with this medicine.

You may need to have a negative pregnancy test before you start using Brukinsa. Females should not become pregnant during treatment and for at least 1 week after the last dose. You should use effective birth control (contraception) during treatment and for at least 1 week after the last dose.

Males should avoid getting female partners pregnant during treatment and for at least 1 week after the last dose of Brukinsa. You should use effective birth control (contraception) during treatment and for at least 1 week after the last dose.

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if Brukinsa passes into your breast milk. Do not breastfeed during treatment and for at least 2 weeks after your last dose.

Take the missed dose on the same day you remember it. Take your next dose at the regular time and stay on your once-daily schedule. Do not use 2 doses in one day.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction to Brukinsa: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Brukinsa can cause serious or life-threatening side effects. Call your doctor at once if you have:

• pounding heartbeats or fluttering in your chest
• chest discomfort
• a light-headed feeling, like you might pass out
• liver problems - right-sided upper stomach pain, vomiting, loss of appetite, yellowing of your skin or eyes, and not feeling well
• low platelets in your blood - easy bruising, unusual bleeding, purple or red spots under your skin
• low red blood cells - pale skin, weakness, unusual tiredness, feeling light-headed or short of breath, cold hands and feet, fast or irregular heartbeat
• low white blood cell counts - fever, mouth sores, skin sores, sore throat, cough, trouble breathing
• signs of bleeding inside your body - red or pink urine, bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds, severe headache, vision problems, numbness or weakness on one side, trouble speaking or understanding what is said to you or
• signs of infection - fever, chills, redness or swelling, cough with mucus, feeling short of breath.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common Brukinsa side effects affecting more than 10% of people may include:

• diarrhea or constipation
• low platelet or other blood cell counts
• easy bruising or bleeding
• musculoskeletal pain
• high blood pressure
• rash or
• cold or flu symptoms such as stuffy nose, sneezing, sore throat, or cough.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective. Common medications that may interact with Brukinsa include:

• Moderate to strong CYP3A Inhibitors, such as clarithromycin, nefazodone, itraconazole, ketoconazole, atazanavir, ritonavir, grapefruit juice, erythromycin, or verapamil
• Moderate to strong CYP3A inducers, such as glucocorticoids, rifampin, carbamazepine, phenobarbital, and phenytoin. Avoid coadministration.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking Brukinsa with certain other medications may affect how zanubrutinib works and can cause side effects.