Obinutuzumab Dosage

Medically reviewed by Drugs.com. Last updated on Jul 14, 2023.

Usual Adult Dose for Chronic Lymphocytic Leukemia

THERAPY CONSISTS OF SIX 28-DAY TREATMENT CYCLES IN COMBINATION WITH CHLORAMBUCIL:

• Cycle 1, Day 1: 100 mg IV at 25 mg/hr over 4 hours; do not increase the infusion rate
• Cycle 1, Day 2: 900 mg IV at 50 mg/hr if no infusion reaction occurred during the previous infusion and the rate can be escalated in increments of 50 mg/hr every 30 minutes to a maximum rate of 400 mg/hr; if an infusion reaction occurred during the previous infusion, administer at 25 mg/hr and the rate can be escalated in increments of up to 50 mg/hr every 30 minutes to a maximum rate of 400 mg/hr
• Cycle 1, Days 8 and 15 AND Cycles 2 through 6, Day 1: 1000 mg IV at 100 mg/hr if no infusion reaction occurred during the previous infusion and the final rate was 100 mg/hr or faster and the rate can be escalated in increments of 100 mg/hr every 30 minutes to a maximum rate of 400 mg/hr; if an infusion reaction occurred during the previous infusion, administer at 50 mg/hr and the rate can be escalated in increments of 50 mg/hr every 30 minutes to a maximum rate of 400 mg/hr

NOTE: If a dose is missed, administer it as soon as possible and adjust dosing schedule to maintain the time interval between doses. If appropriate, patients who do not complete the Cycle 1 Day 1 dose may proceed to the Cycle 1 Day 2 dose.

Comments:
PREMEDICATION TO PREVENT INFUSION RELATED REACTIONS (IRR):

• CLL Cycle 1, Day 1 and 2 AND FL Cycle 1, Day 1: All patients should receive dexamethasone 20 mg or methylprednisolone 80 mg at least 1 hour prior to the obinutuzumab infusion AND acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes before the obinutuzumab infusion.
• All Subsequent Infusions: All patients should receive acetaminophen 650 to 1000 mg at least 30 minutes prior to the obinutuzumab infusion.
• If patients experienced Grade 1 or 2 IRR with the previous infusion: Administer acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes prior to the obinutuzumab infusion.
• If patients experienced Grade 3 IRR with the previous infusion OR have a lymphocyte count greater than 25 X 10(9)/L prior to next treatment: Administer an IV glucocorticoid (dexamethasone 20 mg or methylprednisolone 80 mg) at least 1 hour prior to the obinutuzumab infusion AND acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes prior to the obinutuzumab infusion.
• Administration should be by a healthcare professional with medical support to manage severe infusion reactions.
• Premedicate before each infusion to reduce infusion related reactions.
• Administer only as an IV infusion through a dedicated line; do not administer as an IV push or bolus.
• Patients at high risk of tumor lysis syndrome (e.g., high tumor burden, high circulating absolute lymphocyte counts [greater than 25 x 10(9)/L] or renal impairment) should be premedicated with antihyperuricemics (e.g., allopurinol, rasburicase) and be adequately hydrated prior to each infusion.
• Hypotension may occur during the IV infusion. The clinician may consider withholding antihypertensive treatments for 12 hours prior to and throughout each infusion and for the first hour after administration.
• Monitor blood counts at regular intervals.
• Patients with Grade 3 to 4 neutropenia lasting more than one week should receive antimicrobial prophylaxis until resolution of neutropenia to Grade 1 or 2.
• Antiviral and antifungal prophylaxis should be considered.
• Consider therapy interruption if patients experience an infection, Grade 3 or 4 cytopenia, or Grade 2 or higher nonhematologic toxicity.

Use: The treatment of patients with previously untreated chronic lymphocytic leukemia (CLL) in combination with chlorambucil

Usual Adult Dose for Follicular Lymphoma

THERAPY REGIMENS FOR FOLLICULAR LYMPHOMA (FL):
1) For patients with follicular lymphoma who did not respond or who progressed during or up to 6 months after treatment with rituximab or a rituximab-containing regimen, administer obinutuzumab in combination with bendamustine in six 28-day cycles. Patients who achieve stable disease, complete response, or partial response to the initial 6 cycles should continue obinutuzumab 1000 mg as monotherapy for up to 2 years.
2) For patients with previously untreated FL, administer obinutuzumab with one of the following chemotherapy regimens:

• Six 28-day cycles in combination with bendamustine.
• Six 21-day cycles in combination with cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP), followed by 2 additional 21-day cycles of obinutuzumab alone.
• Eight 21-day cycles in combination with cyclophosphamide, vincristine, and prednisone/prednisolone/methylprednisolone (CVP).

Patients with previously untreated FL who achieve a complete response or partial response to the initial 6 or 8 cycles should continue obinutuzumab 1000 mg as monotherapy for up to 2 years.

DOSE TO BE ADMINISTERED DURING 6 TO 8 TREATMENT CYCLES, FOLLOWED BY OBINUTUZUMAB AS MONOTHERAPY FOR PATIENTS WITH FL:

• Cycle 1, Day 1: 1000 mg IV at 50 mg/hr; the rate of infusion can be escalated in 50 mg/hr increments every 30 minutes to a maximum of 400 mg/hr
• Cycle 1, Day 8 and Day 15 AND Cycles 2 through 6 on Day 1 OR 2 through 8 on Day 1 AND as monotherapy every 2 months for up to 2 years: 1000 mg IV at 100 mg/hr if no infusion reaction or a Grade 1 reaction occurred during the previous infusion and the final rate was 100 mg/hr or faster and the rate can be escalated in increments of 100 mg/hr every 30 minutes to a maximum rate of 400 mg/hr; if an infusion reaction of Grade 2 or higher occurred during the previous infusion, administer at 50 mg/hr and the rate can be escalated in increments of 50 mg/hr every 30 minutes to a maximum rate of 400 mg/hr
• If a planned dose is missed, administer it as soon as possible. During obinutuzumab and chemotherapy treatment, adjust the dosing schedule accordingly to maintain the time interval between chemotherapy cycles. During monotherapy, maintain the original dosing schedule for subsequent doses. Monotherapy should be initiated approximately 2 months after the last dose of obinutuzumab administered during the induction phase.

Comments:
PREMEDICATION TO PREVENT INFUSION RELATED REACTIONS (IRR):

• CLL Cycle 1, Day 1 and 2 AND FL Cycle 1, Day 1: All patients should receive dexamethasone 20 mg or methylprednisolone 80 mg at least 1 hour prior to the obinutuzumab infusion AND acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes before the obinutuzumab infusion.
• All Subsequent Infusions: All patients should receive acetaminophen 650 to 1000 mg at least 30 minutes prior to the obinutuzumab infusion.
• If patients experienced Grade 1 or 2 IRR with the previous infusion: Administer acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes prior to the obinutuzumab infusion.
• If patients experienced Grade 3 IRR with the previous infusion OR have a lymphocyte count greater than 25 X 10(9)/L prior to next treatment: Administer an IV glucocorticoid (dexamethasone 20 mg or methylprednisolone 80 mg) at least 1 hour prior to the obinutuzumab infusion AND acetaminophen 650 to 1000 mg and an antihistamine (e.g., diphenhydramine 50 mg) at least 30 minutes prior to the obinutuzumab infusion.
• Administration should be by a healthcare professional with medical support to manage severe infusion reactions.
• Premedicate before each infusion to reduce infusion related reactions.
• Administer only as an IV infusion through a dedicated line; do not administer as an IV push or bolus.
• Patients at high risk of tumor lysis syndrome (e.g., high tumor burden, high circulating absolute lymphocyte counts [greater than 25 x 10(9)/L] or renal impairment) should be premedicated with antihyperuricemics (e.g., allopurinol, rasburicase) and be adequately hydrated prior to each infusion.
• Hypotension may occur during the IV infusion. The clinician may consider withholding antihypertensive treatments for 12 hours prior to and throughout each infusion and for the first hour after administration.
• Monitor blood counts at regular intervals.
• Patients with Grade 3 to 4 neutropenia lasting more than one week should receive antimicrobial prophylaxis until resolution of neutropenia to Grade 1 or 2.
• Antiviral and antifungal prophylaxis should be considered.
• Consider therapy interruption if patients experience an infection, Grade 3 or 4 cytopenia, or Grade 2 or higher nonhematologic toxicity.

Uses:

• In combination with bendamustine followed by obinutuzumab as monotherapy for the treatment of patients with follicular lymphoma (FL) who relapsed after, or are refractory to, a rituximab containing regimen
• In combination with chemotherapy followed by obinutuzumab monotherapy in patients achieving at least a partial remission, is indicated for the treatment of adult patients with previously untreated stage II bulky, III or IV follicular lymphoma (FL)

Renal Dose Adjustments

Mild to moderate renal impairment (CrCl 30 mL/min or greater): No adjustment recommended
Severe renal impairment: Data not available

Liver Dose Adjustments

Data not available

Dose Adjustments

INFUSION REACTIONS IN CLL AND FL PATIENTS:
GRADE 1 to 2 (mild to moderate):

• Reduce infusion rate or interrupt infusion and treat symptoms.
• Upon resolution of symptoms, continue or resume infusion.
• If no further infusion reaction symptoms occur, infusion rate escalation may resume at the increments and intervals as appropriate for the treatment cycle dose.
• For CLL patients only: The Day 1 infusion rate may be increased back up to 25 mg/hr after 1 hour but not increased further.

GRADE 3 (severe):

• Interrupt infusion and manage symptoms.
• Upon resolution of symptoms, consider restarting the infusion at no more than half the previous rate (the rate used at the time the infusion reaction occurred).
• If no further infusion reaction symptoms occur, infusion rate escalation may resume at the increments and intervals as appropriate for the treatment cycle dose.
• Permanently discontinue therapy if patients experience a Grade 3 infusion related symptom at rechallenge.
• For CLL patients only: The Day 1 infusion rate may be increased back up to 25 mg/hr after 1 hour but not increased further.

GRADE 4 (life threatening):

• Stop infusion immediately and permanently discontinue therapy.

Precautions

US BOXED WARNINGS:

• Hepatitis B Virus (HBV) reactivation, in some cases resulting in fulminant hepatitis, hepatic failure, and death can occur in patients receiving CD-20-directed cytolytic antibodies, including this drug. Screen patients for HBV infection before initiating therapy. Monitor HBV-positive patients during and after therapy with this drug.
• Progressive Multifocal Leukoencephalopathy (PML) resulting in death.

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• If a planned dose is missed, administer the missed dose as soon as possible and adjust dosing schedule accordingly.
• Administer as an IV infusion only.
• Do not administer as an IV push or bolus.
• Do not mix this drug with other drugs.

Patient advice:

• Advise patients to seek immediate medical attention for signs of infusion reactions (e.g., dizziness, nausea, chills, fever, vomiting, diarrhea, breathing problems, chest pain).
• Advise patients to seek immediate medical attention for signs of tumor lysis syndrome (TLS) (e.g., nausea, vomiting, diarrhea, lethargy).
• Advise patients to seek immediate medical attention for signs of infection (e.g., fever, cough).
• Advise patients to seek immediate medical attention for signs of hepatitis (e.g., worsening of fatigue, yellow discoloration of the skin or eyes).
• Advise patients to seek immediate medical attention for new or changes in neurological symptoms (e.g., confusion, dizziness, loss of balance, difficulty talking or walking, vision problems).

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