Kasimpta (Ofatumumab) for Clinically Isolated Syndrome
Yes, Kasimpta (ofatumumab) is FDA-approved and can be given to patients with clinically isolated syndrome (CIS), as it is specifically indicated for relapsing forms of multiple sclerosis that explicitly include CIS. 1
FDA-Approved Indication
The FDA label for Kesimpta (ofatumumab subcutaneous) clearly states that it is indicated for the treatment of relapsing forms of multiple sclerosis, which specifically includes:
This approval applies to adult patients. 1
Clinical Context for CIS Treatment
Understanding CIS Risk Profile
CIS represents a critical treatment window where early intervention can prevent progression to clinically definite MS. The rationale for treating CIS patients is compelling:
- 38-68% of CIS patients will develop clinically definite MS after their initial presentation 2
- When brain MRI shows clinically silent lesions (present in 50-80% of CIS patients), the risk of conversion to MS increases to 56-88% 2
- Axonal damage—the substrate for permanent disability—begins during the CIS stage, making early treatment crucial 2
Evidence Supporting Early Treatment
Disease-modifying therapies initiated at the CIS stage significantly reduce the risk of progression to clinically definite MS by 35-50%. 2 While this evidence was established with interferon beta, the principle of early treatment applies to modern high-efficacy therapies like ofatumumab, which has demonstrated superior efficacy in relapsing MS. 3
Real-World Usage Patterns
Ofatumumab is increasingly being used as a first-line therapy in clinical practice, with 58.4% of patients being DMT-naïve at 9 months post-FDA approval. 4 This suggests growing clinician confidence in using ofatumumab early in the disease course, which would include CIS patients meeting MS diagnostic criteria. 4
Key Clinical Considerations
Patient Selection Criteria
Treatment with ofatumumab is most appropriate for CIS patients who meet McDonald diagnostic criteria for MS based on MRI findings showing dissemination in space and time. 2 These are the patients at highest risk for conversion to clinically definite MS and most likely to benefit from early intervention. 2
Safety Profile
The most common adverse events with ofatumumab include:
- Upper respiratory tract infections 5, 3
- Nasopharyngitis and headache 3
- Injection-related reactions (fever, chills, flushing) 5
- Urinary tract infections 3
Importantly, there is no apparent association between immunoglobulin level changes and serious infection risk after 3.5 years of treatment. 3 However, monitoring of IgM and IgG levels is recommended, as low IgM increases infection risk with encapsulated bacteria. 5
Common Pitfall to Avoid
Do not withhold ofatumumab from CIS patients simply because they have not yet experienced a second clinical attack. The modern McDonald criteria allow MS diagnosis at CIS presentation based on MRI evidence of dissemination in space and time, making these patients eligible for treatment. 2 Waiting for a second clinical event means missing the critical window to prevent irreversible axonal damage that begins during the CIS stage. 2