Pomalidomide Induced Hypothyroidism in a Multiple Myeloma Patient: A Case Report

Pomalidomide is a third generation immunomodulatory agent that is currently reserved for the treatment of patients with relapsed/refractory multiple myeloma (MM). Unlike thalidomide and lenalidomide, hypothyroidism has not previously been reported as a side effect of pomalidomide. Herein, we report a case of hypothyroidism that acutely developed while the patient was receiving the 4th cycle of pomalidomide for refractory MM. The main manifestations were bilateral swelling of all extremities, muscle pain, and fatigue with serum creatinine up to 1.4 mg/dL. These clinical issues made us suspect hypothyroidism. Indeed, upon examination, her TSH was up to 173mIU/L. Her pomalidomide was stopped and she was started on replacement thyroid hormonal therapy with quick improvement in her symptoms and acute kidney failure. In conclusion, we report here the first case of pomalidomide induced clinically significant hypothyroidism. Thus, like with thalidomide and lenalidomide, practitioners prescribing pomalidomide should be aware of this complication and screen for it.