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.