Successful treatment of type I cryoglobulinemia with a combination of carfilzomib, cyclophosphamide, and dexamethasone: a case report and literature review.

Type I cryoglobulinemia is typically associated with hematological malignancies such as B-cell lymphomas and plasma cell neoplasms. Its treatment basically targets underlying hematological malignancies, and the prognosis remains unsatisfactory. Despite several reports of type I cryoglobulinemia treated with bortezomib-based regimens, little is available on the treatment of bortezomib-resistant cases. We report a case of severe type I cryoglobulinemia associated with plasma cell neoplasm, refractory to bortezomib and daratumumab, which was successfully managed with a combination of carfilzomib, cyclophosphamide, and dexamethasone (KCd therapy). No sign of relapse has been seen for more than 3 years with maintenance therapy with ongoing carfilzomib. This case highlights the potential efficacy of carfilzomib-based regimens in bortezomib-resistant type I cryoglobulinemia, offering a promising option for cases refractory to conventional treatments.