Rituximab is considered standard therapy for treatment naïve patients, but optimal treatment methods for relapsed/refractory patients have not been established.<h4>Case presentation</h4>We demonstrate that tirabrutinib, a second-generation Burton kinase inhibitor, led to drastic improvements of polyneuropathy that were affirmed by nerve conduction studies in a rituximab-refractory anti-MAG neuropathy patient. This evidence concerns the gene MAG and polyneuropathy.