OCREVUS (ocrelizumab) is an intravenous infusion medication approved for treating multiple sclerosis (MS), including relapsing forms and primary progressive MS in adults. The treatment involves initial 300 mg doses two weeks apart, followed by 600 mg infusions every six months. While effective for MS, OCREVUS carries important risks including infusion reactions (occurring in 34-40% of patients), increased infection rates, potential malignancy risk, and rare but serious complications like PML. Patients require pre-infusion screening for hepatitis B and immunoglobulins, along with premedication to reduce infusion reaction risks.
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Understanding OCREVUS (Ocrelizumab) for Multiple Sclerosis Treatment
Table of Contents
- Introduction to OCREVUS
- Dosage and Administration
- Required Screening Before Treatment
- Potential Risks and Side Effects
- Infection Risks and Management
- Ongoing Monitoring Requirements
- Special Considerations for Specific Populations
- Source Information
Introduction to OCREVUS
OCREVUS (ocrelizumab) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) for treating multiple sclerosis in adults. This medication belongs to a class of drugs called CD20-directed cytolytic antibodies, which work by targeting specific immune cells that contribute to MS symptoms.
The medication is approved for two main types of multiple sclerosis: relapsing forms of MS (including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease) and primary progressive MS. OCREVUS is administered through intravenous infusion (IV) in a medical setting under healthcare professional supervision.
Dosage and Administration
OCREVUS follows a specific dosing schedule that requires careful medical supervision. The initial treatment consists of two 300 mg infusions given two weeks apart. After this starting phase, patients receive a single 600 mg infusion every six months to maintain treatment effectiveness.
Each infusion requires careful preparation and monitoring. The medication must be diluted before administration and given through a dedicated IV line with a special filter. Patients are monitored closely during the infusion and for at least one hour afterward to watch for any reactions.
The infusion rates are carefully controlled for safety. For the first 300 mg infusion, the rate starts at 30 mL per hour and gradually increases every 30 minutes up to a maximum of 180 mL per hour. The total infusion time typically takes 2.5 hours or longer. Subsequent 600 mg infusions can be administered over approximately 3.5 hours or, if patients have tolerated previous infusions well, over approximately 2 hours using an accelerated schedule.
Required Screening Before Treatment
Before starting OCREVUS, patients must undergo several important screening tests. Hepatitis B virus (HBV) screening is mandatory because OCREVUS is contraindicated in patients with active HBV infection. Patients who test positive for hepatitis B core antibodies or are carriers of HBV require consultation with liver specialists before and during treatment.
Quantitative serum immunoglobulin testing is also required before treatment begins. This test measures antibody levels in your blood. Patients with low immunoglobulin levels may need consultation with immunology specialists before starting OCREVUS.
Vaccination timing is crucial before beginning treatment. All live or live-attenuated vaccines should be administered at least 4 weeks before starting OCREVUS, while non-live vaccines should be given at least 2 weeks before initiation whenever possible. This timing is important because OCREVUS may affect vaccine effectiveness and live vaccines are not recommended during treatment.
Potential Risks and Side Effects
OCREVUS carries several important risks that patients must understand. The most common side effect is infusion reactions, which occurred in 34-40% of patients in clinical trials. These reactions can include itching, rash, hives, redness, breathing difficulties, throat irritation, flushing, low blood pressure, fever, fatigue, headache, dizziness, nausea, and rapid heartbeat.
To reduce infusion reaction risks, patients receive premedication before each infusion. This typically includes 100 mg of methylprednisolone (or equivalent corticosteroid) given intravenously approximately 30 minutes before the infusion, along with an antihistamine (such as diphenhydramine) given 30-60 minutes before. Healthcare providers may also consider adding a fever reducer like acetaminophen.
The management of infusion reactions depends on their severity. For life-threatening reactions, OCREVUS is immediately and permanently discontinued. For severe reactions, the infusion is temporarily stopped and restarted at a slower rate once symptoms resolve. For mild to moderate reactions, the infusion rate is reduced by half for at least 30 minutes before gradually increasing again.
Infection Risks and Management
OCREVUS treatment increases the risk of infections, some of which can be serious or life-threatening. In clinical trials, 58% of patients with relapsing MS experienced infections compared to 52% of patients taking REBIF (another MS medication). In primary progressive MS trials, 70% of OCREVUS-treated patients had infections compared to 68% on placebo.
The medication particularly increases risks for specific types of infections:
- Upper respiratory tract infections (40% of OCREVUS patients vs 33% on REBIF in RMS trials)
- Lower respiratory tract infections (8% vs 5% with REBIF)
- Skin infections
- Herpes-related infections including herpes zoster (2.1% vs 1.0% with REBIF) and herpes simplex (0.7% vs 0.1%)
Serious cases of herpes infections have been reported, including central nervous system infections (encephalitis and meningitis), eye infections, and widespread skin and soft tissue infections. Some cases were life-threatening. If serious herpes infections occur, OCREVUS should be discontinued or withheld until the infection resolves.
Before each infusion, healthcare providers assess whether patients have active infections. If an active infection is present, the OCREVUS infusion is delayed until the infection resolves completely.
Ongoing Monitoring Requirements
Patients receiving OCREVUS require regular monitoring for several potential complications. Progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection caused by the JC virus, has been reported in patients taking OCREVUS. PML typically occurs in immunocompromised patients and usually leads to death or severe disability.
Patients should watch for symptoms that might suggest PML, including progressive weakness on one side of the body, clumsiness in limbs, vision disturbances, and changes in thinking, memory, and orientation that lead to confusion and personality changes. At the first sign of these symptoms, OCREVUS should be withheld and appropriate diagnostic testing performed.
Immunoglobulin levels must be monitored during and after OCREVUS treatment until B-cells repopulate. decreased immunoglobulin G levels have been associated with increased rates of serious infections. Patients with recurrent serious infections or those requiring intravenous immunoglobulin treatment for low antibody levels may need to discontinue OCREVUS.
There may be an increased risk of malignancies, including breast cancer. In clinical trials, breast cancer occurred in 6 of 781 females treated with OCREVUS compared to none of 668 females treated with REBIF or placebo. Patients should follow standard breast cancer screening guidelines while on this medication.
Immune-mediated colitis has been reported in patients receiving OCREVUS, with some cases requiring hospitalization and surgical intervention. Patients should report new or persistent diarrhea or other gastrointestinal symptoms promptly to their healthcare provider.
Special Considerations for Specific Populations
Pregnancy requires special consideration with OCREVUS treatment. Based on animal data, the medication may cause fetal harm. Women of reproductive potential should discuss family planning with their healthcare providers before starting treatment.
For infants born to mothers treated with OCREVUS during pregnancy, special vaccination precautions are necessary. Live or live-attenuated vaccines should not be administered until the infant's B-cell counts recover to normal levels as measured by CD19+ B-cells. Non-live vaccines can be given but healthcare providers should consider assessing whether the infant mounted a protective immune response.
Elderly patients may be at increased risk of infections due to the natural aging of the immune system combined with OCREVUS's effects on immune function. These patients require careful monitoring for infections throughout treatment.
Source Information
Original Article Title: OCREVUS- ocrelizumab injection
Manufacturer: Genentech, Inc.
Initial U.S. Approval: 2017
Latest Revision: June 2024
This patient-friendly article is based on peer-reviewed research and the official prescribing information for OCREVUS. Always consult with your healthcare provider for personalized medical advice regarding your treatment options and management.