Does Kesimpta Affect IgG Levels?
Kesimpta (ofatumumab), a CD20-directed monoclonal antibody for relapsing multiple sclerosis, can lower immunoglobulin levels, including IgG. Clinical trials showed mean IgG reductions of 6-10% over 1-2 years, with about 5-10% of patients developing low IgG (<5.65 g/L). These changes were not always linked to higher infection rates, but monitoring is recommended.[1][2]
Is Kesimpta Safe for Patients Starting with Low IgG?
Safety data for patients with pre-existing low IgG is limited. The drug's label advises caution in those with low immunoglobulins due to infection risk from B-cell depletion. No specific trials enrolled patients with baseline IgG below normal ranges, and prescribers should assess infection history and consider prophylaxis like vaccinations or antibiotics before starting.[1][3]
What Infections Are Linked to Low IgG on Kesimpta?
Upper respiratory infections occurred in 44% of patients, with serious infections in 2.5% (e.g., pneumonia, COVID-19). Low IgG correlated with higher infection odds in some analyses, though causality is unclear. Hypogammaglobulinemia prompted discontinuation in rare cases (<1%).[2][4]
How Should Doctors Monitor IgG During Treatment?
Baseline IgG testing is advised, with periodic checks (e.g., every 6-12 months). Hold or stop Kesimpta if IgG drops severely or infections recur. Prophylaxis against shingles or pneumococcus may be needed.[1][3]
Alternatives for Patients with Low IgG Concerns?
Options like teriflunomide or dimethyl fumarate have less impact on IgG. Interferon beta or glatiramer acetate avoid B-cell depletion entirely. Switch if IgG falls critically.[2][5]
[1]: Kesimpta Prescribing Information (Novartis)
[2]: Phase 3 ASCLEPIOS Trials (NEJM, 2020)
[3]: EMA Kesimpta Summary of Product Characteristics
[4]: Pooled Safety Analysis (Multiple Sclerosis Journal, 2022)
[5]: AAN MS Treatment Guidelines (2021)