Reviewed on 6/7/2022

What Is Obinutuzumab and How Does It Work?

Obinutuzumab is a prescription medication used for the treatment of chronic lymphocytic leukemia.

  • Obinutuzumab is available under the following different brand names: Gazyva

What Are Dosages of Obinutuzumab?

Adult dosage

IV solution

  • 25mg/mL (1000mg/40mL single-use vial)

Chronic Lymphocytic Leukemia

Adult dosage

Administer for 6 treatment cycles (28-day cycles)

  • Cycle 1
    • Day 1: 100 mg IV
    • Day 2: 900 mg IV
    • Days 8 and 15: 1000 mg IV
  • Cycles 2-6
    • Day 1: 1000 mg IV

Follicular Lymphoma

Adult dosage

Dosage regimen

  • Cycle 1: 1000 mg IV on Days 1, 8, and 15
  • Cycles 2-6 or 2-8: 1000 mg IV on Day 1
  • If a complete or partial response is achieved, continue with obinutuzumab 1000 mg every 2 months as monotherapy for up to 2 years


  • 1000 mg IV every 2 months for up to 2 years

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Are Side Effects Associated with Using Obinutuzumab?

Common side effects of the Obinutuzumab include:

  • reaction during or shortly after the injection,
  • tiredness,
  • low white blood cell counts,
  • diarrhea,
  • constipation,
  • muscle or joint pain,
  • stuffy nose,
  • sneezing,
  • cough, and
  • sore throat

Serious side effects of the Obinutuzumab include:

  • hives,
  • difficulty breathing,
  • swelling of the face, lips, tongue, or throat,
  • rash,
  • fever,
  • joint pain,
  • fast heartbeats,
  • chest pain,
  • wheezing,
  • problems with speech, thought, vision, or muscle movement,
  • sudden warmth,
  • redness,
  • tingly feeling,
  • chills,
  • lightheadedness,
  • nausea,
  • headache,
  • pounding in the neck or ears,
  • tiredness,
  • dizziness,
  • diarrhea,
  • vomiting,
  • chest discomfort,
  • easy bruising,
  • unusual bleeding,
  • purple or red spots under the skin,
  • confusion,
  • vision problems,
  • problems with speech or walking,
  • weakness,
  • cough,
  • burning while passing urine,
  • right-sided upper stomach pain,
  • loss of appetite,
  • yellowing of the skin or eyes,
  • loss of balance or coordination,
  • mouth sores,
  • skin sores,
  • sore throat,
  • cough,
  • tiredness,
  • muscle cramps,
  • fast or slow heart rate, and
  • tingling in the hands and feet or around the mouth

Rare side effects of the Obinutuzumab include:

  • none

This is not a complete list of side effects and other serious side effects or health problems that may occur due to the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Obinutuzumab?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Obinutuzumab has severe interactions with no other drugs.
  • Obinutuzumab has serious interactions with the following drugs:
    • axicabtagene ciloleucel
    • brexucabtagene autoleucel
    • ciltacabtagene autoleucel
    • deferiprone
    • idecabtagene vicleucel
    • lisocabtagene maraleucel
    • palifermin
    • ropeginterferon alfa 2b
    • tisagenlecleucel
  • Obinutuzumab has moderate interactions with at least 30 other drugs.
  • Obinutuzumab has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

What Are Warnings and Precautions for Obinutuzumab?


  • None

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Obinutuzumab?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Obinutuzumab?”


  • Anticipate tumor lysis syndrome; premedicate with anti-hyperuricemic and adequate hydration especially for patients with high tumor burden and/or high circulating lymphocyte count; correct electrolyte abnormalities, provide supportive care, and monitor renal function and fluid balance
  • May reactivate hepatitis B virus (see Black Box Warnings)
  • Progressive multifocal leukoencephalopathy (PML) was reported (see Black Box Warnings)
  • Acute renal failure, hyperkalemia, hypocalcemia, hyperuricemia, and/or hyperphosphatemia from tumor lysis syndrome (TLS) can occur within 12-24 hours after the first infusion (see Premedication)
  • Serious bacterial, fungal, and new or reactivated viral infections can occur; do not give obinutuzumab with an active infection
  • Neutropenia may occur (in combination with chlorambucil, Grade 3 or 4 neutropenia was reported in 34% of patients); patients with neutropenia are strongly recommended to receive antimicrobial prophylaxis throughout the treatment period; antiviral and antifungal prophylaxis should be considered
  • Thrombocytopenia may occur (in combination with chlorambucil, Grade 3 or 4 neutropenia reported in 12% of patients); monitor all patients frequently for thrombocytopenia and hemorrhagic events, especially during the first cycle; management of hemorrhage may require blood product support
  • The safety and efficacy of immunization with live or attenuated viral vaccines during or following obinutuzumab therapy have not been studied; immunization with live virus vaccines is not recommended during treatment and until B-cell recovery
  • Hypersensitivity reactions have been reported; signs of immediate onset hypersensitivity (eg, dyspnea, bronchospasm, hypotension, urticaria, and tachycardia); late-onset hypersensitivity diagnosed as serum sickness have also been reported, and symptoms (eg, chest pain, diffuse arthralgia, and fever)
  • Infusion-related reactions
    • May cause severe and life-threatening infusion reactions (see Dosage Modification and Premedication sections)
    • Patients with pre-existing cardiac or pulmonary conditions are at greater risk of severe reactions
    • Monitor closely throughout the infusion and the post-infusion period; interrupt or discontinue infusion for reactions
    • Due to the risk of infusion induced hypotension, consider withholding antihypertensive treatments for 12 hours prior to, during, and for the first hour after administration until blood pressure is stable
    • Consider the benefits versus the risks of withholding their antihypertensive medication in patients who are at increased of hypertensive crisis

Pregnancy and Lactation

  • There are no data on obinutuzumab use in pregnant women to inform a drug-associated risk
  • Based on findings from animal studies and the drug’s mechanism of action, obinutuzumab may cause fe
  • Avoid administering live vaccines to neonates and infants exposed to obinutuzumab in utero until B-cell recovery occurs
  • In animal reproduction studies, weekly IV administration of obinutuzumab to pregnant cynomolgus monkeys from day 20 of pregnancy until parturition which includes the period of organogenesis at doses with exposures up to 2.4 times the exposure at the clinical dose of 1000 mg monthly produced opportunistic infections and immune complex-mediated hypersensitivity reactions
  • The drug can cause fetal harm when administered to a pregnant woman; advise females of reproductive potential to use effective contraception during treatment and for 6 months after the last dose
  • Lactation
    • Unknown if distributed in human breast milk; because of the potential of serious adverse reactions in a breastfed child, advise women not to breastfeed during treatment and for 6 months after the last dose
    • Excreted in the milk of lactating cynomolgus monkeys and human IgG is known to be excreted in human milk; consider developmental and health benefits along with the mother’s clinical need for therapy and any potential adverse effects on the breastfed infant

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