This comprehensive analysis of European safety reports reveals important differences in injection-related reactions between two multiple sclerosis treatments: subcutaneous ofatumumab and intravenous ocrelizumab. While both medications showed similar reporting rates for these reactions, ofatumumab was primarily associated with fever (68.9% of cases), while ocrelizumab more frequently caused infusion reactions (53.7% of cases) and anaphylactic responses. The study found that 74 out of 89 cases where timing was documented occurred on the same day as treatment administration, highlighting when patients should be most vigilant about potential reactions.
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Understanding Injection Reactions with Multiple Sclerosis Treatments: Ofatumumab vs Ocrelizumab
Table of Contents
- Introduction: MS Treatments and Injection Reactions
- How the Research Was Conducted
- Detailed Results: What the Data Showed
- Specific Reaction Patterns for Each Medication
- When Reactions Typically Occur
- What This Means for MS Patients
- Study Limitations
- Practical Advice for Patients
- Source Information
Introduction: MS Treatments and Injection Reactions
Multiple sclerosis (MS) treatment has advanced significantly with the development of disease-modifying therapies that target the immune system. Among the most effective are anti-CD20 monoclonal antibodies, which work by depleting specific immune cells (B cells and T cells) that contribute to MS progression. This class includes several medications, but this study focuses on two particularly important ones: ocrelizumab (administered intravenously) and ofatumumab (administered subcutaneously).
The key difference between these treatments lies in their administration method. Ocrelizumab requires intravenous infusion in a clinical setting with premedication to prevent reactions, while ofatumumab is self-administered subcutaneously without recommended premedication. Understanding the different reaction profiles between these administration methods is crucial for patients and healthcare providers when making treatment decisions.
Injection-related reactions (IRRs) are common side effects with these medications and can range from mild symptoms like fever and headache to more serious allergic responses. This study represents the first comprehensive comparison of these reactions between ofatumumab and ocrelizumab using real-world data from the European spontaneous reporting system.
How the Research Was Conducted
Researchers analyzed data from EudraVigilance, the European spontaneous reporting system for medication side effects, covering the period from 2021 to November 3rd, 2023. They identified all individual case safety reports (ICSRs) involving either ofatumumab or ocrelizumab that described injection-related reactions.
The team searched for specific reaction types using standardized medical terminology (MedDRA Preferred Terms), including:
- Infusion related hypersensitivity reaction
- Infusion related reaction
- Injection related reaction
- Immediate post-injection reaction
- Anaphylactic reaction and anaphylactic shock
- Anaphylactoid reaction and anaphylactoid shock
- Influenza like illness
- Pyrexia (fever)
For each case report, researchers collected detailed information including patient age, gender, reaction type, severity, outcome, whether premedication was used, and the timing of the reaction relative to treatment administration. They analyzed 860 total case reports, with 441 involving ofatumumab and 419 involving ocrelizumab as the suspected medication.
Detailed Results: What the Data Showed
The analysis revealed several important patterns in how these reactions present differently between the two medications. The majority of patients experiencing reactions were women (67.6% for ofatumumab, 69.0% for ocrelizumab), which aligns with the higher prevalence of MS in women.
Age distribution showed notable differences between the treatments. For ocrelizumab, 72.6% of reactions occurred in patients aged 18-64 years, while for ofatumumab, the age group was not specified in 55.1% of reports. This difference in data completeness is important context when interpreting the results.
Most reports came from healthcare professionals (76.6% for ofatumumab, 76.4% for ocrelizumab), indicating that these reactions were typically identified and documented by medical experts. In the majority of cases, the anti-CD20 medication was the only suspected drug, reducing the likelihood that other medications caused the reactions.
Specific Reaction Patterns for Each Medication
The study found distinct patterns in the types of reactions reported for each medication. For ofatumumab, the most commonly reported reaction was pyrexia (fever), occurring in 304 out of 441 cases (68.9%). Influenza-like illness was the second most common reaction at 26.5% (117 cases).
For ocrelizumab, the pattern was quite different. The most frequent reaction was "infusion related reaction," reported in 225 of 419 cases (53.7%). Pyrexia was still common but less frequent than with ofatumumab (32.5%, 136 cases). Anaphylactic reactions were more frequently reported with ocrelizumab (6.9%, 29 cases) compared to ofatumumab (1.1%, 5 cases).
The researchers also examined premedication use, finding it reported in 148 total cases. Significantly, premedication was much more common with ocrelizumab (131 cases) than with ofatumumab (17 cases), reflecting the different treatment protocols for these medications.
When Reactions Typically Occur
The timing of reactions provided crucial information for patients and clinicians. Researchers were able to calculate the time-to-event (how long after treatment the reaction occurred) for 89 cases where sufficient data was available.
The results showed that reactions typically occurred soon after treatment administration. Out of the 89 cases with calculable timing, 74 (83.1%) experienced reactions on the same day as drug administration. This highlights the importance of monitoring for reactions immediately after treatment.
The average time to reaction was similar between medications: 56.4 days for ofatumumab and 58 days for ocrelizumab. However, the substantial standard deviations (242.5 days for ofatumumab, 124.9 days for ocrelizumab) indicate significant variation in when reactions can occur, with some happening much later after treatment.
What This Means for MS Patients
This research provides valuable real-world evidence about what MS patients can expect regarding injection-related reactions with these two treatment options. The findings confirm that while both medications can cause reactions, the patterns differ significantly.
Ofatumumab appears more associated with systemic symptoms like fever and flu-like illness, which are generally manageable. Ocrelizumab shows a higher association with infusion reactions and anaphylactic responses, which may explain why premedication is standard protocol for this treatment but not recommended for ofatumumab.
The similar overall reporting rates (441 vs. 419 cases) suggest that neither medication is clearly superior in terms of reaction frequency, but the different reaction profiles may influence treatment choice based on individual patient factors and preferences. The subcutaneous administration of ofatumumab offers convenience, but patients should be aware of the likelihood of fever reactions, especially with initial doses.
Study Limitations
While this study provides valuable insights, several limitations should be considered. Spontaneous reporting systems inherently suffer from underreporting, meaning the actual number of reactions is likely higher than what appears in the database.
The significant missing data for age information (particularly for ofatumumab, where 55.1% of cases lacked age specification) limits our ability to draw firm conclusions about age-related patterns. Additionally, timing data was only available for a small subset of cases (89 out of 860), which restricts the certainty of conclusions about when reactions typically occur.
The researchers also noted that some case reports might not have been properly completed, particularly regarding whether premedication was used. This could affect the accuracy of comparisons between the two medications regarding premedication practices.
Practical Advice for Patients
Based on these findings, MS patients considering or currently using these treatments should:
- Understand the different reaction patterns - Ofatumumab users should anticipate possible fever and flu-like symptoms, especially with initial doses, while ocrelizumab users should be vigilant for infusion reactions
- Monitor closely after treatment - Since 83% of reactions occurred on the same day as administration, pay particular attention to how you feel immediately after treatment
- Follow premedication protocols - If prescribed ocrelizumab, ensure you receive the recommended premedication; for ofatumumab, follow your doctor's guidance even though premedication isn't routinely recommended
- Report all reactions - Regardless of severity, report any unexpected symptoms to your healthcare team to contribute to better understanding of these treatments
- Discuss options with your neurologist - Use this information to have informed conversations about which treatment approach aligns best with your lifestyle and tolerance for different types of potential reactions
Remember that while injection reactions can be uncomfortable, both medications have demonstrated significant benefits in managing multiple sclerosis. The manageable nature of most reactions should be weighed against the important disease-modifying benefits these treatments provide.
Source Information
Original Article Title: Comparison of injective related reactions following ofatumumab and ocrelizumab in patients with multiple sclerosis: data from the European spontaneous reporting system
Authors: Cristina Scavone, Antonietta Anatriello, Isabella Baccari, Andrea Cantone, Daniele Di Giulio Cesare, Francesca Futura Bernardi, Ornella Moreggia, Valerio Liguori, Vincenzo Andreone, Giorgia Teresa Maniscalco, Annalisa Capuano
Publication: Frontiers in Neurology, published 27 June 2024
DOI: 10.3389/fneur.2024.1383910
This patient-friendly article is based on peer-reviewed research originally published in Frontiers in Neurology. The information has been translated into accessible language while preserving all scientific findings, data points, and conclusions from the original study.