The H2 blocker famotidine suppresses progression of ossification of the posterior longitudinal ligament in a mouse model

BACKGROUND Ossification of the posterior longitudinal ligament (OPLL) of the spine is a common human myelopathy that leads to spinal cord compression. No disease-modifying drug for OPLL has been identified, whereas surgery and conservative management have been established. OBJECTIVES To evaluate the therapeutic potential of the H2 blocker famotidine for ectopic ossification in the cervical spine in an OPLL mouse model. METHODS The H2 blocker famotidine was orally administered to Enpp1 (ttw/ttw) mice, a model of OPLL, at either 4 or 15 weeks of age. Radiological and survival rate analyses were performed to assess the effects of famotidine on OPLL-like lesions and mortality in Enpp1 (ttw/ttw) mice. RESULTS Oral administration of famotidine suppressed the progression of OPLL-like ectopic ossification and reduced mortality in Enpp1 (ttw/ttw) mice when administration began at 4 weeks of age, early in the development of ossification. CONCLUSIONS This study points to the use of famotidine as a disease-modifying drug for ectopic ossification of spinal soft tissue, including OPLL.